qemu/softmmu/physmem.c
David Hildenbrand d94e0bc9ef util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE under Linux
Let's support RAM_NORESERVE via MAP_NORESERVE on Linux. The flag has no
effect on most shared mappings - except for hugetlbfs and anonymous memory.

Linux man page:
  "MAP_NORESERVE: Do not reserve swap space for this mapping. When swap
  space is reserved, one has the guarantee that it is possible to modify
  the mapping. When swap space is not reserved one might get SIGSEGV
  upon a write if no physical memory is available. See also the discussion
  of the file /proc/sys/vm/overcommit_memory in proc(5). In kernels before
  2.6, this flag had effect only for private writable mappings."

Note that the "guarantee" part is wrong with memory overcommit in Linux.

Also, in Linux hugetlbfs is treated differently - we configure reservation
of huge pages from the pool, not reservation of swap space (huge pages
cannot be swapped).

The rough behavior is [1]:
a) !Hugetlbfs:

  1) Without MAP_NORESERVE *or* with memory overcommit under Linux
     disabled ("/proc/sys/vm/overcommit_memory == 2"), the following
     accounting/reservation happens:
      For a file backed map
       SHARED or READ-only - 0 cost (the file is the map not swap)
       PRIVATE WRITABLE - size of mapping per instance

      For an anonymous or /dev/zero map
       SHARED   - size of mapping
       PRIVATE READ-only - 0 cost (but of little use)
       PRIVATE WRITABLE - size of mapping per instance

  2) With MAP_NORESERVE, no accounting/reservation happens.

b) Hugetlbfs:

  1) Without MAP_NORESERVE, huge pages are reserved.

  2) With MAP_NORESERVE, no huge pages are reserved.

Note: With "/proc/sys/vm/overcommit_memory == 0", we were already able
to configure it for !hugetlbfs globally; this toggle now allows
configuring it more fine-grained, not for the whole system.

The target use case is virtio-mem, which dynamically exposes memory
inside a large, sparse memory area to the VM.

[1] https://www.kernel.org/doc/Documentation/vm/overcommit-accounting

Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com> for memory backend and machine core
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210510114328.21835-10-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-15 20:27:38 +02:00

3740 lines
112 KiB
C

/*
* RAM allocation and memory access
*
* Copyright (c) 2003 Fabrice Bellard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "qapi/error.h"
#include "qemu/cutils.h"
#include "qemu/cacheflush.h"
#ifdef CONFIG_TCG
#include "hw/core/tcg-cpu-ops.h"
#endif /* CONFIG_TCG */
#include "exec/exec-all.h"
#include "exec/target_page.h"
#include "hw/qdev-core.h"
#include "hw/qdev-properties.h"
#include "hw/boards.h"
#include "hw/xen/xen.h"
#include "sysemu/kvm.h"
#include "sysemu/tcg.h"
#include "sysemu/qtest.h"
#include "qemu/timer.h"
#include "qemu/config-file.h"
#include "qemu/error-report.h"
#include "qemu/qemu-print.h"
#include "exec/memory.h"
#include "exec/ioport.h"
#include "sysemu/dma.h"
#include "sysemu/hostmem.h"
#include "sysemu/hw_accel.h"
#include "sysemu/xen-mapcache.h"
#include "trace/trace-root.h"
#ifdef CONFIG_FALLOCATE_PUNCH_HOLE
#include <linux/falloc.h>
#endif
#include "qemu/rcu_queue.h"
#include "qemu/main-loop.h"
#include "exec/translate-all.h"
#include "sysemu/replay.h"
#include "exec/memory-internal.h"
#include "exec/ram_addr.h"
#include "exec/log.h"
#include "qemu/pmem.h"
#include "migration/vmstate.h"
#include "qemu/range.h"
#ifndef _WIN32
#include "qemu/mmap-alloc.h"
#endif
#include "monitor/monitor.h"
#ifdef CONFIG_LIBDAXCTL
#include <daxctl/libdaxctl.h>
#endif
//#define DEBUG_SUBPAGE
/* ram_list is read under rcu_read_lock()/rcu_read_unlock(). Writes
* are protected by the ramlist lock.
*/
RAMList ram_list = { .blocks = QLIST_HEAD_INITIALIZER(ram_list.blocks) };
static MemoryRegion *system_memory;
static MemoryRegion *system_io;
AddressSpace address_space_io;
AddressSpace address_space_memory;
static MemoryRegion io_mem_unassigned;
typedef struct PhysPageEntry PhysPageEntry;
struct PhysPageEntry {
/* How many bits skip to next level (in units of L2_SIZE). 0 for a leaf. */
uint32_t skip : 6;
/* index into phys_sections (!skip) or phys_map_nodes (skip) */
uint32_t ptr : 26;
};
#define PHYS_MAP_NODE_NIL (((uint32_t)~0) >> 6)
/* Size of the L2 (and L3, etc) page tables. */
#define ADDR_SPACE_BITS 64
#define P_L2_BITS 9
#define P_L2_SIZE (1 << P_L2_BITS)
#define P_L2_LEVELS (((ADDR_SPACE_BITS - TARGET_PAGE_BITS - 1) / P_L2_BITS) + 1)
typedef PhysPageEntry Node[P_L2_SIZE];
typedef struct PhysPageMap {
struct rcu_head rcu;
unsigned sections_nb;
unsigned sections_nb_alloc;
unsigned nodes_nb;
unsigned nodes_nb_alloc;
Node *nodes;
MemoryRegionSection *sections;
} PhysPageMap;
struct AddressSpaceDispatch {
MemoryRegionSection *mru_section;
/* This is a multi-level map on the physical address space.
* The bottom level has pointers to MemoryRegionSections.
*/
PhysPageEntry phys_map;
PhysPageMap map;
};
#define SUBPAGE_IDX(addr) ((addr) & ~TARGET_PAGE_MASK)
typedef struct subpage_t {
MemoryRegion iomem;
FlatView *fv;
hwaddr base;
uint16_t sub_section[];
} subpage_t;
#define PHYS_SECTION_UNASSIGNED 0
static void io_mem_init(void);
static void memory_map_init(void);
static void tcg_log_global_after_sync(MemoryListener *listener);
static void tcg_commit(MemoryListener *listener);
/**
* CPUAddressSpace: all the information a CPU needs about an AddressSpace
* @cpu: the CPU whose AddressSpace this is
* @as: the AddressSpace itself
* @memory_dispatch: its dispatch pointer (cached, RCU protected)
* @tcg_as_listener: listener for tracking changes to the AddressSpace
*/
struct CPUAddressSpace {
CPUState *cpu;
AddressSpace *as;
struct AddressSpaceDispatch *memory_dispatch;
MemoryListener tcg_as_listener;
};
struct DirtyBitmapSnapshot {
ram_addr_t start;
ram_addr_t end;
unsigned long dirty[];
};
static void phys_map_node_reserve(PhysPageMap *map, unsigned nodes)
{
static unsigned alloc_hint = 16;
if (map->nodes_nb + nodes > map->nodes_nb_alloc) {
map->nodes_nb_alloc = MAX(alloc_hint, map->nodes_nb + nodes);
map->nodes = g_renew(Node, map->nodes, map->nodes_nb_alloc);
alloc_hint = map->nodes_nb_alloc;
}
}
static uint32_t phys_map_node_alloc(PhysPageMap *map, bool leaf)
{
unsigned i;
uint32_t ret;
PhysPageEntry e;
PhysPageEntry *p;
ret = map->nodes_nb++;
p = map->nodes[ret];
assert(ret != PHYS_MAP_NODE_NIL);
assert(ret != map->nodes_nb_alloc);
e.skip = leaf ? 0 : 1;
e.ptr = leaf ? PHYS_SECTION_UNASSIGNED : PHYS_MAP_NODE_NIL;
for (i = 0; i < P_L2_SIZE; ++i) {
memcpy(&p[i], &e, sizeof(e));
}
return ret;
}
static void phys_page_set_level(PhysPageMap *map, PhysPageEntry *lp,
hwaddr *index, uint64_t *nb, uint16_t leaf,
int level)
{
PhysPageEntry *p;
hwaddr step = (hwaddr)1 << (level * P_L2_BITS);
if (lp->skip && lp->ptr == PHYS_MAP_NODE_NIL) {
lp->ptr = phys_map_node_alloc(map, level == 0);
}
p = map->nodes[lp->ptr];
lp = &p[(*index >> (level * P_L2_BITS)) & (P_L2_SIZE - 1)];
while (*nb && lp < &p[P_L2_SIZE]) {
if ((*index & (step - 1)) == 0 && *nb >= step) {
lp->skip = 0;
lp->ptr = leaf;
*index += step;
*nb -= step;
} else {
phys_page_set_level(map, lp, index, nb, leaf, level - 1);
}
++lp;
}
}
static void phys_page_set(AddressSpaceDispatch *d,
hwaddr index, uint64_t nb,
uint16_t leaf)
{
/* Wildly overreserve - it doesn't matter much. */
phys_map_node_reserve(&d->map, 3 * P_L2_LEVELS);
phys_page_set_level(&d->map, &d->phys_map, &index, &nb, leaf, P_L2_LEVELS - 1);
}
/* Compact a non leaf page entry. Simply detect that the entry has a single child,
* and update our entry so we can skip it and go directly to the destination.
*/
static void phys_page_compact(PhysPageEntry *lp, Node *nodes)
{
unsigned valid_ptr = P_L2_SIZE;
int valid = 0;
PhysPageEntry *p;
int i;
if (lp->ptr == PHYS_MAP_NODE_NIL) {
return;
}
p = nodes[lp->ptr];
for (i = 0; i < P_L2_SIZE; i++) {
if (p[i].ptr == PHYS_MAP_NODE_NIL) {
continue;
}
valid_ptr = i;
valid++;
if (p[i].skip) {
phys_page_compact(&p[i], nodes);
}
}
/* We can only compress if there's only one child. */
if (valid != 1) {
return;
}
assert(valid_ptr < P_L2_SIZE);
/* Don't compress if it won't fit in the # of bits we have. */
if (P_L2_LEVELS >= (1 << 6) &&
lp->skip + p[valid_ptr].skip >= (1 << 6)) {
return;
}
lp->ptr = p[valid_ptr].ptr;
if (!p[valid_ptr].skip) {
/* If our only child is a leaf, make this a leaf. */
/* By design, we should have made this node a leaf to begin with so we
* should never reach here.
* But since it's so simple to handle this, let's do it just in case we
* change this rule.
*/
lp->skip = 0;
} else {
lp->skip += p[valid_ptr].skip;
}
}
void address_space_dispatch_compact(AddressSpaceDispatch *d)
{
if (d->phys_map.skip) {
phys_page_compact(&d->phys_map, d->map.nodes);
}
}
static inline bool section_covers_addr(const MemoryRegionSection *section,
hwaddr addr)
{
/* Memory topology clips a memory region to [0, 2^64); size.hi > 0 means
* the section must cover the entire address space.
*/
return int128_gethi(section->size) ||
range_covers_byte(section->offset_within_address_space,
int128_getlo(section->size), addr);
}
static MemoryRegionSection *phys_page_find(AddressSpaceDispatch *d, hwaddr addr)
{
PhysPageEntry lp = d->phys_map, *p;
Node *nodes = d->map.nodes;
MemoryRegionSection *sections = d->map.sections;
hwaddr index = addr >> TARGET_PAGE_BITS;
int i;
for (i = P_L2_LEVELS; lp.skip && (i -= lp.skip) >= 0;) {
if (lp.ptr == PHYS_MAP_NODE_NIL) {
return &sections[PHYS_SECTION_UNASSIGNED];
}
p = nodes[lp.ptr];
lp = p[(index >> (i * P_L2_BITS)) & (P_L2_SIZE - 1)];
}
if (section_covers_addr(&sections[lp.ptr], addr)) {
return &sections[lp.ptr];
} else {
return &sections[PHYS_SECTION_UNASSIGNED];
}
}
/* Called from RCU critical section */
static MemoryRegionSection *address_space_lookup_region(AddressSpaceDispatch *d,
hwaddr addr,
bool resolve_subpage)
{
MemoryRegionSection *section = qatomic_read(&d->mru_section);
subpage_t *subpage;
if (!section || section == &d->map.sections[PHYS_SECTION_UNASSIGNED] ||
!section_covers_addr(section, addr)) {
section = phys_page_find(d, addr);
qatomic_set(&d->mru_section, section);
}
if (resolve_subpage && section->mr->subpage) {
subpage = container_of(section->mr, subpage_t, iomem);
section = &d->map.sections[subpage->sub_section[SUBPAGE_IDX(addr)]];
}
return section;
}
/* Called from RCU critical section */
static MemoryRegionSection *
address_space_translate_internal(AddressSpaceDispatch *d, hwaddr addr, hwaddr *xlat,
hwaddr *plen, bool resolve_subpage)
{
MemoryRegionSection *section;
MemoryRegion *mr;
Int128 diff;
section = address_space_lookup_region(d, addr, resolve_subpage);
/* Compute offset within MemoryRegionSection */
addr -= section->offset_within_address_space;
/* Compute offset within MemoryRegion */
*xlat = addr + section->offset_within_region;
mr = section->mr;
/* MMIO registers can be expected to perform full-width accesses based only
* on their address, without considering adjacent registers that could
* decode to completely different MemoryRegions. When such registers
* exist (e.g. I/O ports 0xcf8 and 0xcf9 on most PC chipsets), MMIO
* regions overlap wildly. For this reason we cannot clamp the accesses
* here.
*
* If the length is small (as is the case for address_space_ldl/stl),
* everything works fine. If the incoming length is large, however,
* the caller really has to do the clamping through memory_access_size.
*/
if (memory_region_is_ram(mr)) {
diff = int128_sub(section->size, int128_make64(addr));
*plen = int128_get64(int128_min(diff, int128_make64(*plen)));
}
return section;
}
/**
* address_space_translate_iommu - translate an address through an IOMMU
* memory region and then through the target address space.
*
* @iommu_mr: the IOMMU memory region that we start the translation from
* @addr: the address to be translated through the MMU
* @xlat: the translated address offset within the destination memory region.
* It cannot be %NULL.
* @plen_out: valid read/write length of the translated address. It
* cannot be %NULL.
* @page_mask_out: page mask for the translated address. This
* should only be meaningful for IOMMU translated
* addresses, since there may be huge pages that this bit
* would tell. It can be %NULL if we don't care about it.
* @is_write: whether the translation operation is for write
* @is_mmio: whether this can be MMIO, set true if it can
* @target_as: the address space targeted by the IOMMU
* @attrs: transaction attributes
*
* This function is called from RCU critical section. It is the common
* part of flatview_do_translate and address_space_translate_cached.
*/
static MemoryRegionSection address_space_translate_iommu(IOMMUMemoryRegion *iommu_mr,
hwaddr *xlat,
hwaddr *plen_out,
hwaddr *page_mask_out,
bool is_write,
bool is_mmio,
AddressSpace **target_as,
MemTxAttrs attrs)
{
MemoryRegionSection *section;
hwaddr page_mask = (hwaddr)-1;
do {
hwaddr addr = *xlat;
IOMMUMemoryRegionClass *imrc = memory_region_get_iommu_class_nocheck(iommu_mr);
int iommu_idx = 0;
IOMMUTLBEntry iotlb;
if (imrc->attrs_to_index) {
iommu_idx = imrc->attrs_to_index(iommu_mr, attrs);
}
iotlb = imrc->translate(iommu_mr, addr, is_write ?
IOMMU_WO : IOMMU_RO, iommu_idx);
if (!(iotlb.perm & (1 << is_write))) {
goto unassigned;
}
addr = ((iotlb.translated_addr & ~iotlb.addr_mask)
| (addr & iotlb.addr_mask));
page_mask &= iotlb.addr_mask;
*plen_out = MIN(*plen_out, (addr | iotlb.addr_mask) - addr + 1);
*target_as = iotlb.target_as;
section = address_space_translate_internal(
address_space_to_dispatch(iotlb.target_as), addr, xlat,
plen_out, is_mmio);
iommu_mr = memory_region_get_iommu(section->mr);
} while (unlikely(iommu_mr));
if (page_mask_out) {
*page_mask_out = page_mask;
}
return *section;
unassigned:
return (MemoryRegionSection) { .mr = &io_mem_unassigned };
}
/**
* flatview_do_translate - translate an address in FlatView
*
* @fv: the flat view that we want to translate on
* @addr: the address to be translated in above address space
* @xlat: the translated address offset within memory region. It
* cannot be @NULL.
* @plen_out: valid read/write length of the translated address. It
* can be @NULL when we don't care about it.
* @page_mask_out: page mask for the translated address. This
* should only be meaningful for IOMMU translated
* addresses, since there may be huge pages that this bit
* would tell. It can be @NULL if we don't care about it.
* @is_write: whether the translation operation is for write
* @is_mmio: whether this can be MMIO, set true if it can
* @target_as: the address space targeted by the IOMMU
* @attrs: memory transaction attributes
*
* This function is called from RCU critical section
*/
static MemoryRegionSection flatview_do_translate(FlatView *fv,
hwaddr addr,
hwaddr *xlat,
hwaddr *plen_out,
hwaddr *page_mask_out,
bool is_write,
bool is_mmio,
AddressSpace **target_as,
MemTxAttrs attrs)
{
MemoryRegionSection *section;
IOMMUMemoryRegion *iommu_mr;
hwaddr plen = (hwaddr)(-1);
if (!plen_out) {
plen_out = &plen;
}
section = address_space_translate_internal(
flatview_to_dispatch(fv), addr, xlat,
plen_out, is_mmio);
iommu_mr = memory_region_get_iommu(section->mr);
if (unlikely(iommu_mr)) {
return address_space_translate_iommu(iommu_mr, xlat,
plen_out, page_mask_out,
is_write, is_mmio,
target_as, attrs);
}
if (page_mask_out) {
/* Not behind an IOMMU, use default page size. */
*page_mask_out = ~TARGET_PAGE_MASK;
}
return *section;
}
/* Called from RCU critical section */
IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
bool is_write, MemTxAttrs attrs)
{
MemoryRegionSection section;
hwaddr xlat, page_mask;
/*
* This can never be MMIO, and we don't really care about plen,
* but page mask.
*/
section = flatview_do_translate(address_space_to_flatview(as), addr, &xlat,
NULL, &page_mask, is_write, false, &as,
attrs);
/* Illegal translation */
if (section.mr == &io_mem_unassigned) {
goto iotlb_fail;
}
/* Convert memory region offset into address space offset */
xlat += section.offset_within_address_space -
section.offset_within_region;
return (IOMMUTLBEntry) {
.target_as = as,
.iova = addr & ~page_mask,
.translated_addr = xlat & ~page_mask,
.addr_mask = page_mask,
/* IOTLBs are for DMAs, and DMA only allows on RAMs. */
.perm = IOMMU_RW,
};
iotlb_fail:
return (IOMMUTLBEntry) {0};
}
/* Called from RCU critical section */
MemoryRegion *flatview_translate(FlatView *fv, hwaddr addr, hwaddr *xlat,
hwaddr *plen, bool is_write,
MemTxAttrs attrs)
{
MemoryRegion *mr;
MemoryRegionSection section;
AddressSpace *as = NULL;
/* This can be MMIO, so setup MMIO bit. */
section = flatview_do_translate(fv, addr, xlat, plen, NULL,
is_write, true, &as, attrs);
mr = section.mr;
if (xen_enabled() && memory_access_is_direct(mr, is_write)) {
hwaddr page = ((addr & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE) - addr;
*plen = MIN(page, *plen);
}
return mr;
}
typedef struct TCGIOMMUNotifier {
IOMMUNotifier n;
MemoryRegion *mr;
CPUState *cpu;
int iommu_idx;
bool active;
} TCGIOMMUNotifier;
static void tcg_iommu_unmap_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
{
TCGIOMMUNotifier *notifier = container_of(n, TCGIOMMUNotifier, n);
if (!notifier->active) {
return;
}
tlb_flush(notifier->cpu);
notifier->active = false;
/* We leave the notifier struct on the list to avoid reallocating it later.
* Generally the number of IOMMUs a CPU deals with will be small.
* In any case we can't unregister the iommu notifier from a notify
* callback.
*/
}
static void tcg_register_iommu_notifier(CPUState *cpu,
IOMMUMemoryRegion *iommu_mr,
int iommu_idx)
{
/* Make sure this CPU has an IOMMU notifier registered for this
* IOMMU/IOMMU index combination, so that we can flush its TLB
* when the IOMMU tells us the mappings we've cached have changed.
*/
MemoryRegion *mr = MEMORY_REGION(iommu_mr);
TCGIOMMUNotifier *notifier = NULL;
int i;
for (i = 0; i < cpu->iommu_notifiers->len; i++) {
notifier = g_array_index(cpu->iommu_notifiers, TCGIOMMUNotifier *, i);
if (notifier->mr == mr && notifier->iommu_idx == iommu_idx) {
break;
}
}
if (i == cpu->iommu_notifiers->len) {
/* Not found, add a new entry at the end of the array */
cpu->iommu_notifiers = g_array_set_size(cpu->iommu_notifiers, i + 1);
notifier = g_new0(TCGIOMMUNotifier, 1);
g_array_index(cpu->iommu_notifiers, TCGIOMMUNotifier *, i) = notifier;
notifier->mr = mr;
notifier->iommu_idx = iommu_idx;
notifier->cpu = cpu;
/* Rather than trying to register interest in the specific part
* of the iommu's address space that we've accessed and then
* expand it later as subsequent accesses touch more of it, we
* just register interest in the whole thing, on the assumption
* that iommu reconfiguration will be rare.
*/
iommu_notifier_init(&notifier->n,
tcg_iommu_unmap_notify,
IOMMU_NOTIFIER_UNMAP,
0,
HWADDR_MAX,
iommu_idx);
memory_region_register_iommu_notifier(notifier->mr, &notifier->n,
&error_fatal);
}
if (!notifier->active) {
notifier->active = true;
}
}
void tcg_iommu_free_notifier_list(CPUState *cpu)
{
/* Destroy the CPU's notifier list */
int i;
TCGIOMMUNotifier *notifier;
for (i = 0; i < cpu->iommu_notifiers->len; i++) {
notifier = g_array_index(cpu->iommu_notifiers, TCGIOMMUNotifier *, i);
memory_region_unregister_iommu_notifier(notifier->mr, &notifier->n);
g_free(notifier);
}
g_array_free(cpu->iommu_notifiers, true);
}
void tcg_iommu_init_notifier_list(CPUState *cpu)
{
cpu->iommu_notifiers = g_array_new(false, true, sizeof(TCGIOMMUNotifier *));
}
/* Called from RCU critical section */
MemoryRegionSection *
address_space_translate_for_iotlb(CPUState *cpu, int asidx, hwaddr addr,
hwaddr *xlat, hwaddr *plen,
MemTxAttrs attrs, int *prot)
{
MemoryRegionSection *section;
IOMMUMemoryRegion *iommu_mr;
IOMMUMemoryRegionClass *imrc;
IOMMUTLBEntry iotlb;
int iommu_idx;
AddressSpaceDispatch *d =
qatomic_rcu_read(&cpu->cpu_ases[asidx].memory_dispatch);
for (;;) {
section = address_space_translate_internal(d, addr, &addr, plen, false);
iommu_mr = memory_region_get_iommu(section->mr);
if (!iommu_mr) {
break;
}
imrc = memory_region_get_iommu_class_nocheck(iommu_mr);
iommu_idx = imrc->attrs_to_index(iommu_mr, attrs);
tcg_register_iommu_notifier(cpu, iommu_mr, iommu_idx);
/* We need all the permissions, so pass IOMMU_NONE so the IOMMU
* doesn't short-cut its translation table walk.
*/
iotlb = imrc->translate(iommu_mr, addr, IOMMU_NONE, iommu_idx);
addr = ((iotlb.translated_addr & ~iotlb.addr_mask)
| (addr & iotlb.addr_mask));
/* Update the caller's prot bits to remove permissions the IOMMU
* is giving us a failure response for. If we get down to no
* permissions left at all we can give up now.
*/
if (!(iotlb.perm & IOMMU_RO)) {
*prot &= ~(PAGE_READ | PAGE_EXEC);
}
if (!(iotlb.perm & IOMMU_WO)) {
*prot &= ~PAGE_WRITE;
}
if (!*prot) {
goto translate_fail;
}
d = flatview_to_dispatch(address_space_to_flatview(iotlb.target_as));
}
assert(!memory_region_is_iommu(section->mr));
*xlat = addr;
return section;
translate_fail:
return &d->map.sections[PHYS_SECTION_UNASSIGNED];
}
void cpu_address_space_init(CPUState *cpu, int asidx,
const char *prefix, MemoryRegion *mr)
{
CPUAddressSpace *newas;
AddressSpace *as = g_new0(AddressSpace, 1);
char *as_name;
assert(mr);
as_name = g_strdup_printf("%s-%d", prefix, cpu->cpu_index);
address_space_init(as, mr, as_name);
g_free(as_name);
/* Target code should have set num_ases before calling us */
assert(asidx < cpu->num_ases);
if (asidx == 0) {
/* address space 0 gets the convenience alias */
cpu->as = as;
}
/* KVM cannot currently support multiple address spaces. */
assert(asidx == 0 || !kvm_enabled());
if (!cpu->cpu_ases) {
cpu->cpu_ases = g_new0(CPUAddressSpace, cpu->num_ases);
}
newas = &cpu->cpu_ases[asidx];
newas->cpu = cpu;
newas->as = as;
if (tcg_enabled()) {
newas->tcg_as_listener.log_global_after_sync = tcg_log_global_after_sync;
newas->tcg_as_listener.commit = tcg_commit;
memory_listener_register(&newas->tcg_as_listener, as);
}
}
AddressSpace *cpu_get_address_space(CPUState *cpu, int asidx)
{
/* Return the AddressSpace corresponding to the specified index */
return cpu->cpu_ases[asidx].as;
}
/* Add a watchpoint. */
int cpu_watchpoint_insert(CPUState *cpu, vaddr addr, vaddr len,
int flags, CPUWatchpoint **watchpoint)
{
CPUWatchpoint *wp;
vaddr in_page;
/* forbid ranges which are empty or run off the end of the address space */
if (len == 0 || (addr + len - 1) < addr) {
error_report("tried to set invalid watchpoint at %"
VADDR_PRIx ", len=%" VADDR_PRIu, addr, len);
return -EINVAL;
}
wp = g_malloc(sizeof(*wp));
wp->vaddr = addr;
wp->len = len;
wp->flags = flags;
/* keep all GDB-injected watchpoints in front */
if (flags & BP_GDB) {
QTAILQ_INSERT_HEAD(&cpu->watchpoints, wp, entry);
} else {
QTAILQ_INSERT_TAIL(&cpu->watchpoints, wp, entry);
}
in_page = -(addr | TARGET_PAGE_MASK);
if (len <= in_page) {
tlb_flush_page(cpu, addr);
} else {
tlb_flush(cpu);
}
if (watchpoint)
*watchpoint = wp;
return 0;
}
/* Remove a specific watchpoint. */
int cpu_watchpoint_remove(CPUState *cpu, vaddr addr, vaddr len,
int flags)
{
CPUWatchpoint *wp;
QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
if (addr == wp->vaddr && len == wp->len
&& flags == (wp->flags & ~BP_WATCHPOINT_HIT)) {
cpu_watchpoint_remove_by_ref(cpu, wp);
return 0;
}
}
return -ENOENT;
}
/* Remove a specific watchpoint by reference. */
void cpu_watchpoint_remove_by_ref(CPUState *cpu, CPUWatchpoint *watchpoint)
{
QTAILQ_REMOVE(&cpu->watchpoints, watchpoint, entry);
tlb_flush_page(cpu, watchpoint->vaddr);
g_free(watchpoint);
}
/* Remove all matching watchpoints. */
void cpu_watchpoint_remove_all(CPUState *cpu, int mask)
{
CPUWatchpoint *wp, *next;
QTAILQ_FOREACH_SAFE(wp, &cpu->watchpoints, entry, next) {
if (wp->flags & mask) {
cpu_watchpoint_remove_by_ref(cpu, wp);
}
}
}
#ifdef CONFIG_TCG
/* Return true if this watchpoint address matches the specified
* access (ie the address range covered by the watchpoint overlaps
* partially or completely with the address range covered by the
* access).
*/
static inline bool watchpoint_address_matches(CPUWatchpoint *wp,
vaddr addr, vaddr len)
{
/* We know the lengths are non-zero, but a little caution is
* required to avoid errors in the case where the range ends
* exactly at the top of the address space and so addr + len
* wraps round to zero.
*/
vaddr wpend = wp->vaddr + wp->len - 1;
vaddr addrend = addr + len - 1;
return !(addr > wpend || wp->vaddr > addrend);
}
/* Return flags for watchpoints that match addr + prot. */
int cpu_watchpoint_address_matches(CPUState *cpu, vaddr addr, vaddr len)
{
CPUWatchpoint *wp;
int ret = 0;
QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
if (watchpoint_address_matches(wp, addr, len)) {
ret |= wp->flags;
}
}
return ret;
}
/* Generate a debug exception if a watchpoint has been hit. */
void cpu_check_watchpoint(CPUState *cpu, vaddr addr, vaddr len,
MemTxAttrs attrs, int flags, uintptr_t ra)
{
CPUClass *cc = CPU_GET_CLASS(cpu);
CPUWatchpoint *wp;
assert(tcg_enabled());
if (cpu->watchpoint_hit) {
/*
* We re-entered the check after replacing the TB.
* Now raise the debug interrupt so that it will
* trigger after the current instruction.
*/
qemu_mutex_lock_iothread();
cpu_interrupt(cpu, CPU_INTERRUPT_DEBUG);
qemu_mutex_unlock_iothread();
return;
}
if (cc->tcg_ops->adjust_watchpoint_address) {
/* this is currently used only by ARM BE32 */
addr = cc->tcg_ops->adjust_watchpoint_address(cpu, addr, len);
}
QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
if (watchpoint_address_matches(wp, addr, len)
&& (wp->flags & flags)) {
if (replay_running_debug()) {
/*
* replay_breakpoint reads icount.
* Force recompile to succeed, because icount may
* be read only at the end of the block.
*/
if (!cpu->can_do_io) {
/* Force execution of one insn next time. */
cpu->cflags_next_tb = 1 | CF_LAST_IO | curr_cflags(cpu);
cpu_loop_exit_restore(cpu, ra);
}
/*
* Don't process the watchpoints when we are
* in a reverse debugging operation.
*/
replay_breakpoint();
return;
}
if (flags == BP_MEM_READ) {
wp->flags |= BP_WATCHPOINT_HIT_READ;
} else {
wp->flags |= BP_WATCHPOINT_HIT_WRITE;
}
wp->hitaddr = MAX(addr, wp->vaddr);
wp->hitattrs = attrs;
if (!cpu->watchpoint_hit) {
if (wp->flags & BP_CPU && cc->tcg_ops->debug_check_watchpoint &&
!cc->tcg_ops->debug_check_watchpoint(cpu, wp)) {
wp->flags &= ~BP_WATCHPOINT_HIT;
continue;
}
cpu->watchpoint_hit = wp;
mmap_lock();
tb_check_watchpoint(cpu, ra);
if (wp->flags & BP_STOP_BEFORE_ACCESS) {
cpu->exception_index = EXCP_DEBUG;
mmap_unlock();
cpu_loop_exit_restore(cpu, ra);
} else {
/* Force execution of one insn next time. */
cpu->cflags_next_tb = 1 | curr_cflags(cpu);
mmap_unlock();
if (ra) {
cpu_restore_state(cpu, ra, true);
}
cpu_loop_exit_noexc(cpu);
}
}
} else {
wp->flags &= ~BP_WATCHPOINT_HIT;
}
}
}
#endif /* CONFIG_TCG */
/* Called from RCU critical section */
static RAMBlock *qemu_get_ram_block(ram_addr_t addr)
{
RAMBlock *block;
block = qatomic_rcu_read(&ram_list.mru_block);
if (block && addr - block->offset < block->max_length) {
return block;
}
RAMBLOCK_FOREACH(block) {
if (addr - block->offset < block->max_length) {
goto found;
}
}
fprintf(stderr, "Bad ram offset %" PRIx64 "\n", (uint64_t)addr);
abort();
found:
/* It is safe to write mru_block outside the iothread lock. This
* is what happens:
*
* mru_block = xxx
* rcu_read_unlock()
* xxx removed from list
* rcu_read_lock()
* read mru_block
* mru_block = NULL;
* call_rcu(reclaim_ramblock, xxx);
* rcu_read_unlock()
*
* qatomic_rcu_set is not needed here. The block was already published
* when it was placed into the list. Here we're just making an extra
* copy of the pointer.
*/
ram_list.mru_block = block;
return block;
}
static void tlb_reset_dirty_range_all(ram_addr_t start, ram_addr_t length)
{
CPUState *cpu;
ram_addr_t start1;
RAMBlock *block;
ram_addr_t end;
assert(tcg_enabled());
end = TARGET_PAGE_ALIGN(start + length);
start &= TARGET_PAGE_MASK;
RCU_READ_LOCK_GUARD();
block = qemu_get_ram_block(start);
assert(block == qemu_get_ram_block(end - 1));
start1 = (uintptr_t)ramblock_ptr(block, start - block->offset);
CPU_FOREACH(cpu) {
tlb_reset_dirty(cpu, start1, length);
}
}
/* Note: start and end must be within the same ram block. */
bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
ram_addr_t length,
unsigned client)
{
DirtyMemoryBlocks *blocks;
unsigned long end, page, start_page;
bool dirty = false;
RAMBlock *ramblock;
uint64_t mr_offset, mr_size;
if (length == 0) {
return false;
}
end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
start_page = start >> TARGET_PAGE_BITS;
page = start_page;
WITH_RCU_READ_LOCK_GUARD() {
blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
ramblock = qemu_get_ram_block(start);
/* Range sanity check on the ramblock */
assert(start >= ramblock->offset &&
start + length <= ramblock->offset + ramblock->used_length);
while (page < end) {
unsigned long idx = page / DIRTY_MEMORY_BLOCK_SIZE;
unsigned long offset = page % DIRTY_MEMORY_BLOCK_SIZE;
unsigned long num = MIN(end - page,
DIRTY_MEMORY_BLOCK_SIZE - offset);
dirty |= bitmap_test_and_clear_atomic(blocks->blocks[idx],
offset, num);
page += num;
}
mr_offset = (ram_addr_t)(start_page << TARGET_PAGE_BITS) - ramblock->offset;
mr_size = (end - start_page) << TARGET_PAGE_BITS;
memory_region_clear_dirty_bitmap(ramblock->mr, mr_offset, mr_size);
}
if (dirty && tcg_enabled()) {
tlb_reset_dirty_range_all(start, length);
}
return dirty;
}
DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty
(MemoryRegion *mr, hwaddr offset, hwaddr length, unsigned client)
{
DirtyMemoryBlocks *blocks;
ram_addr_t start = memory_region_get_ram_addr(mr) + offset;
unsigned long align = 1UL << (TARGET_PAGE_BITS + BITS_PER_LEVEL);
ram_addr_t first = QEMU_ALIGN_DOWN(start, align);
ram_addr_t last = QEMU_ALIGN_UP(start + length, align);
DirtyBitmapSnapshot *snap;
unsigned long page, end, dest;
snap = g_malloc0(sizeof(*snap) +
((last - first) >> (TARGET_PAGE_BITS + 3)));
snap->start = first;
snap->end = last;
page = first >> TARGET_PAGE_BITS;
end = last >> TARGET_PAGE_BITS;
dest = 0;
WITH_RCU_READ_LOCK_GUARD() {
blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
while (page < end) {
unsigned long idx = page / DIRTY_MEMORY_BLOCK_SIZE;
unsigned long offset = page % DIRTY_MEMORY_BLOCK_SIZE;
unsigned long num = MIN(end - page,
DIRTY_MEMORY_BLOCK_SIZE - offset);
assert(QEMU_IS_ALIGNED(offset, (1 << BITS_PER_LEVEL)));
assert(QEMU_IS_ALIGNED(num, (1 << BITS_PER_LEVEL)));
offset >>= BITS_PER_LEVEL;
bitmap_copy_and_clear_atomic(snap->dirty + dest,
blocks->blocks[idx] + offset,
num);
page += num;
dest += num >> BITS_PER_LEVEL;
}
}
if (tcg_enabled()) {
tlb_reset_dirty_range_all(start, length);
}
memory_region_clear_dirty_bitmap(mr, offset, length);
return snap;
}
bool cpu_physical_memory_snapshot_get_dirty(DirtyBitmapSnapshot *snap,
ram_addr_t start,
ram_addr_t length)
{
unsigned long page, end;
assert(start >= snap->start);
assert(start + length <= snap->end);
end = TARGET_PAGE_ALIGN(start + length - snap->start) >> TARGET_PAGE_BITS;
page = (start - snap->start) >> TARGET_PAGE_BITS;
while (page < end) {
if (test_bit(page, snap->dirty)) {
return true;
}
page++;
}
return false;
}
/* Called from RCU critical section */
hwaddr memory_region_section_get_iotlb(CPUState *cpu,
MemoryRegionSection *section)
{
AddressSpaceDispatch *d = flatview_to_dispatch(section->fv);
return section - d->map.sections;
}
static int subpage_register(subpage_t *mmio, uint32_t start, uint32_t end,
uint16_t section);
static subpage_t *subpage_init(FlatView *fv, hwaddr base);
static uint16_t phys_section_add(PhysPageMap *map,
MemoryRegionSection *section)
{
/* The physical section number is ORed with a page-aligned
* pointer to produce the iotlb entries. Thus it should
* never overflow into the page-aligned value.
*/
assert(map->sections_nb < TARGET_PAGE_SIZE);
if (map->sections_nb == map->sections_nb_alloc) {
map->sections_nb_alloc = MAX(map->sections_nb_alloc * 2, 16);
map->sections = g_renew(MemoryRegionSection, map->sections,
map->sections_nb_alloc);
}
map->sections[map->sections_nb] = *section;
memory_region_ref(section->mr);
return map->sections_nb++;
}
static void phys_section_destroy(MemoryRegion *mr)
{
bool have_sub_page = mr->subpage;
memory_region_unref(mr);
if (have_sub_page) {
subpage_t *subpage = container_of(mr, subpage_t, iomem);
object_unref(OBJECT(&subpage->iomem));
g_free(subpage);
}
}
static void phys_sections_free(PhysPageMap *map)
{
while (map->sections_nb > 0) {
MemoryRegionSection *section = &map->sections[--map->sections_nb];
phys_section_destroy(section->mr);
}
g_free(map->sections);
g_free(map->nodes);
}
static void register_subpage(FlatView *fv, MemoryRegionSection *section)
{
AddressSpaceDispatch *d = flatview_to_dispatch(fv);
subpage_t *subpage;
hwaddr base = section->offset_within_address_space
& TARGET_PAGE_MASK;
MemoryRegionSection *existing = phys_page_find(d, base);
MemoryRegionSection subsection = {
.offset_within_address_space = base,
.size = int128_make64(TARGET_PAGE_SIZE),
};
hwaddr start, end;
assert(existing->mr->subpage || existing->mr == &io_mem_unassigned);
if (!(existing->mr->subpage)) {
subpage = subpage_init(fv, base);
subsection.fv = fv;
subsection.mr = &subpage->iomem;
phys_page_set(d, base >> TARGET_PAGE_BITS, 1,
phys_section_add(&d->map, &subsection));
} else {
subpage = container_of(existing->mr, subpage_t, iomem);
}
start = section->offset_within_address_space & ~TARGET_PAGE_MASK;
end = start + int128_get64(section->size) - 1;
subpage_register(subpage, start, end,
phys_section_add(&d->map, section));
}
static void register_multipage(FlatView *fv,
MemoryRegionSection *section)
{
AddressSpaceDispatch *d = flatview_to_dispatch(fv);
hwaddr start_addr = section->offset_within_address_space;
uint16_t section_index = phys_section_add(&d->map, section);
uint64_t num_pages = int128_get64(int128_rshift(section->size,
TARGET_PAGE_BITS));
assert(num_pages);
phys_page_set(d, start_addr >> TARGET_PAGE_BITS, num_pages, section_index);
}
/*
* The range in *section* may look like this:
*
* |s|PPPPPPP|s|
*
* where s stands for subpage and P for page.
*/
void flatview_add_to_dispatch(FlatView *fv, MemoryRegionSection *section)
{
MemoryRegionSection remain = *section;
Int128 page_size = int128_make64(TARGET_PAGE_SIZE);
/* register first subpage */
if (remain.offset_within_address_space & ~TARGET_PAGE_MASK) {
uint64_t left = TARGET_PAGE_ALIGN(remain.offset_within_address_space)
- remain.offset_within_address_space;
MemoryRegionSection now = remain;
now.size = int128_min(int128_make64(left), now.size);
register_subpage(fv, &now);
if (int128_eq(remain.size, now.size)) {
return;
}
remain.size = int128_sub(remain.size, now.size);
remain.offset_within_address_space += int128_get64(now.size);
remain.offset_within_region += int128_get64(now.size);
}
/* register whole pages */
if (int128_ge(remain.size, page_size)) {
MemoryRegionSection now = remain;
now.size = int128_and(now.size, int128_neg(page_size));
register_multipage(fv, &now);
if (int128_eq(remain.size, now.size)) {
return;
}
remain.size = int128_sub(remain.size, now.size);
remain.offset_within_address_space += int128_get64(now.size);
remain.offset_within_region += int128_get64(now.size);
}
/* register last subpage */
register_subpage(fv, &remain);
}
void qemu_flush_coalesced_mmio_buffer(void)
{
if (kvm_enabled())
kvm_flush_coalesced_mmio_buffer();
}
void qemu_mutex_lock_ramlist(void)
{
qemu_mutex_lock(&ram_list.mutex);
}
void qemu_mutex_unlock_ramlist(void)
{
qemu_mutex_unlock(&ram_list.mutex);
}
void ram_block_dump(Monitor *mon)
{
RAMBlock *block;
char *psize;
RCU_READ_LOCK_GUARD();
monitor_printf(mon, "%24s %8s %18s %18s %18s\n",
"Block Name", "PSize", "Offset", "Used", "Total");
RAMBLOCK_FOREACH(block) {
psize = size_to_str(block->page_size);
monitor_printf(mon, "%24s %8s 0x%016" PRIx64 " 0x%016" PRIx64
" 0x%016" PRIx64 "\n", block->idstr, psize,
(uint64_t)block->offset,
(uint64_t)block->used_length,
(uint64_t)block->max_length);
g_free(psize);
}
}
#ifdef __linux__
/*
* FIXME TOCTTOU: this iterates over memory backends' mem-path, which
* may or may not name the same files / on the same filesystem now as
* when we actually open and map them. Iterate over the file
* descriptors instead, and use qemu_fd_getpagesize().
*/
static int find_min_backend_pagesize(Object *obj, void *opaque)
{
long *hpsize_min = opaque;
if (object_dynamic_cast(obj, TYPE_MEMORY_BACKEND)) {
HostMemoryBackend *backend = MEMORY_BACKEND(obj);
long hpsize = host_memory_backend_pagesize(backend);
if (host_memory_backend_is_mapped(backend) && (hpsize < *hpsize_min)) {
*hpsize_min = hpsize;
}
}
return 0;
}
static int find_max_backend_pagesize(Object *obj, void *opaque)
{
long *hpsize_max = opaque;
if (object_dynamic_cast(obj, TYPE_MEMORY_BACKEND)) {
HostMemoryBackend *backend = MEMORY_BACKEND(obj);
long hpsize = host_memory_backend_pagesize(backend);
if (host_memory_backend_is_mapped(backend) && (hpsize > *hpsize_max)) {
*hpsize_max = hpsize;
}
}
return 0;
}
/*
* TODO: We assume right now that all mapped host memory backends are
* used as RAM, however some might be used for different purposes.
*/
long qemu_minrampagesize(void)
{
long hpsize = LONG_MAX;
Object *memdev_root = object_resolve_path("/objects", NULL);
object_child_foreach(memdev_root, find_min_backend_pagesize, &hpsize);
return hpsize;
}
long qemu_maxrampagesize(void)
{
long pagesize = 0;
Object *memdev_root = object_resolve_path("/objects", NULL);
object_child_foreach(memdev_root, find_max_backend_pagesize, &pagesize);
return pagesize;
}
#else
long qemu_minrampagesize(void)
{
return qemu_real_host_page_size;
}
long qemu_maxrampagesize(void)
{
return qemu_real_host_page_size;
}
#endif
#ifdef CONFIG_POSIX
static int64_t get_file_size(int fd)
{
int64_t size;
#if defined(__linux__)
struct stat st;
if (fstat(fd, &st) < 0) {
return -errno;
}
/* Special handling for devdax character devices */
if (S_ISCHR(st.st_mode)) {
g_autofree char *subsystem_path = NULL;
g_autofree char *subsystem = NULL;
subsystem_path = g_strdup_printf("/sys/dev/char/%d:%d/subsystem",
major(st.st_rdev), minor(st.st_rdev));
subsystem = g_file_read_link(subsystem_path, NULL);
if (subsystem && g_str_has_suffix(subsystem, "/dax")) {
g_autofree char *size_path = NULL;
g_autofree char *size_str = NULL;
size_path = g_strdup_printf("/sys/dev/char/%d:%d/size",
major(st.st_rdev), minor(st.st_rdev));
if (g_file_get_contents(size_path, &size_str, NULL, NULL)) {
return g_ascii_strtoll(size_str, NULL, 0);
}
}
}
#endif /* defined(__linux__) */
/* st.st_size may be zero for special files yet lseek(2) works */
size = lseek(fd, 0, SEEK_END);
if (size < 0) {
return -errno;
}
return size;
}
static int64_t get_file_align(int fd)
{
int64_t align = -1;
#if defined(__linux__) && defined(CONFIG_LIBDAXCTL)
struct stat st;
if (fstat(fd, &st) < 0) {
return -errno;
}
/* Special handling for devdax character devices */
if (S_ISCHR(st.st_mode)) {
g_autofree char *path = NULL;
g_autofree char *rpath = NULL;
struct daxctl_ctx *ctx;
struct daxctl_region *region;
int rc = 0;
path = g_strdup_printf("/sys/dev/char/%d:%d",
major(st.st_rdev), minor(st.st_rdev));
rpath = realpath(path, NULL);
rc = daxctl_new(&ctx);
if (rc) {
return -1;
}
daxctl_region_foreach(ctx, region) {
if (strstr(rpath, daxctl_region_get_path(region))) {
align = daxctl_region_get_align(region);
break;
}
}
daxctl_unref(ctx);
}
#endif /* defined(__linux__) && defined(CONFIG_LIBDAXCTL) */
return align;
}
static int file_ram_open(const char *path,
const char *region_name,
bool readonly,
bool *created,
Error **errp)
{
char *filename;
char *sanitized_name;
char *c;
int fd = -1;
*created = false;
for (;;) {
fd = open(path, readonly ? O_RDONLY : O_RDWR);
if (fd >= 0) {
/* @path names an existing file, use it */
break;
}
if (errno == ENOENT) {
/* @path names a file that doesn't exist, create it */
fd = open(path, O_RDWR | O_CREAT | O_EXCL, 0644);
if (fd >= 0) {
*created = true;
break;
}
} else if (errno == EISDIR) {
/* @path names a directory, create a file there */
/* Make name safe to use with mkstemp by replacing '/' with '_'. */
sanitized_name = g_strdup(region_name);
for (c = sanitized_name; *c != '\0'; c++) {
if (*c == '/') {
*c = '_';
}
}
filename = g_strdup_printf("%s/qemu_back_mem.%s.XXXXXX", path,
sanitized_name);
g_free(sanitized_name);
fd = mkstemp(filename);
if (fd >= 0) {
unlink(filename);
g_free(filename);
break;
}
g_free(filename);
}
if (errno != EEXIST && errno != EINTR) {
error_setg_errno(errp, errno,
"can't open backing store %s for guest RAM",
path);
return -1;
}
/*
* Try again on EINTR and EEXIST. The latter happens when
* something else creates the file between our two open().
*/
}
return fd;
}
static void *file_ram_alloc(RAMBlock *block,
ram_addr_t memory,
int fd,
bool readonly,
bool truncate,
off_t offset,
Error **errp)
{
uint32_t qemu_map_flags;
void *area;
block->page_size = qemu_fd_getpagesize(fd);
if (block->mr->align % block->page_size) {
error_setg(errp, "alignment 0x%" PRIx64
" must be multiples of page size 0x%zx",
block->mr->align, block->page_size);
return NULL;
} else if (block->mr->align && !is_power_of_2(block->mr->align)) {
error_setg(errp, "alignment 0x%" PRIx64
" must be a power of two", block->mr->align);
return NULL;
}
block->mr->align = MAX(block->page_size, block->mr->align);
#if defined(__s390x__)
if (kvm_enabled()) {
block->mr->align = MAX(block->mr->align, QEMU_VMALLOC_ALIGN);
}
#endif
if (memory < block->page_size) {
error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be equal to "
"or larger than page size 0x%zx",
memory, block->page_size);
return NULL;
}
memory = ROUND_UP(memory, block->page_size);
/*
* ftruncate is not supported by hugetlbfs in older
* hosts, so don't bother bailing out on errors.
* If anything goes wrong with it under other filesystems,
* mmap will fail.
*
* Do not truncate the non-empty backend file to avoid corrupting
* the existing data in the file. Disabling shrinking is not
* enough. For example, the current vNVDIMM implementation stores
* the guest NVDIMM labels at the end of the backend file. If the
* backend file is later extended, QEMU will not be able to find
* those labels. Therefore, extending the non-empty backend file
* is disabled as well.
*/
if (truncate && ftruncate(fd, memory)) {
perror("ftruncate");
}
qemu_map_flags = readonly ? QEMU_MAP_READONLY : 0;
qemu_map_flags |= (block->flags & RAM_SHARED) ? QEMU_MAP_SHARED : 0;
qemu_map_flags |= (block->flags & RAM_PMEM) ? QEMU_MAP_SYNC : 0;
qemu_map_flags |= (block->flags & RAM_NORESERVE) ? QEMU_MAP_NORESERVE : 0;
area = qemu_ram_mmap(fd, memory, block->mr->align, qemu_map_flags, offset);
if (area == MAP_FAILED) {
error_setg_errno(errp, errno,
"unable to map backing store for guest RAM");
return NULL;
}
block->fd = fd;
return area;
}
#endif
/* Allocate space within the ram_addr_t space that governs the
* dirty bitmaps.
* Called with the ramlist lock held.
*/
static ram_addr_t find_ram_offset(ram_addr_t size)
{
RAMBlock *block, *next_block;
ram_addr_t offset = RAM_ADDR_MAX, mingap = RAM_ADDR_MAX;
assert(size != 0); /* it would hand out same offset multiple times */
if (QLIST_EMPTY_RCU(&ram_list.blocks)) {
return 0;
}
RAMBLOCK_FOREACH(block) {
ram_addr_t candidate, next = RAM_ADDR_MAX;
/* Align blocks to start on a 'long' in the bitmap
* which makes the bitmap sync'ing take the fast path.
*/
candidate = block->offset + block->max_length;
candidate = ROUND_UP(candidate, BITS_PER_LONG << TARGET_PAGE_BITS);
/* Search for the closest following block
* and find the gap.
*/
RAMBLOCK_FOREACH(next_block) {
if (next_block->offset >= candidate) {
next = MIN(next, next_block->offset);
}
}
/* If it fits remember our place and remember the size
* of gap, but keep going so that we might find a smaller
* gap to fill so avoiding fragmentation.
*/
if (next - candidate >= size && next - candidate < mingap) {
offset = candidate;
mingap = next - candidate;
}
trace_find_ram_offset_loop(size, candidate, offset, next, mingap);
}
if (offset == RAM_ADDR_MAX) {
fprintf(stderr, "Failed to find gap of requested size: %" PRIu64 "\n",
(uint64_t)size);
abort();
}
trace_find_ram_offset(size, offset);
return offset;
}
static unsigned long last_ram_page(void)
{
RAMBlock *block;
ram_addr_t last = 0;
RCU_READ_LOCK_GUARD();
RAMBLOCK_FOREACH(block) {
last = MAX(last, block->offset + block->max_length);
}
return last >> TARGET_PAGE_BITS;
}
static void qemu_ram_setup_dump(void *addr, ram_addr_t size)
{
int ret;
/* Use MADV_DONTDUMP, if user doesn't want the guest memory in the core */
if (!machine_dump_guest_core(current_machine)) {
ret = qemu_madvise(addr, size, QEMU_MADV_DONTDUMP);
if (ret) {
perror("qemu_madvise");
fprintf(stderr, "madvise doesn't support MADV_DONTDUMP, "
"but dump_guest_core=off specified\n");
}
}
}
const char *qemu_ram_get_idstr(RAMBlock *rb)
{
return rb->idstr;
}
void *qemu_ram_get_host_addr(RAMBlock *rb)
{
return rb->host;
}
ram_addr_t qemu_ram_get_offset(RAMBlock *rb)
{
return rb->offset;
}
ram_addr_t qemu_ram_get_used_length(RAMBlock *rb)
{
return rb->used_length;
}
ram_addr_t qemu_ram_get_max_length(RAMBlock *rb)
{
return rb->max_length;
}
bool qemu_ram_is_shared(RAMBlock *rb)
{
return rb->flags & RAM_SHARED;
}
bool qemu_ram_is_noreserve(RAMBlock *rb)
{
return rb->flags & RAM_NORESERVE;
}
/* Note: Only set at the start of postcopy */
bool qemu_ram_is_uf_zeroable(RAMBlock *rb)
{
return rb->flags & RAM_UF_ZEROPAGE;
}
void qemu_ram_set_uf_zeroable(RAMBlock *rb)
{
rb->flags |= RAM_UF_ZEROPAGE;
}
bool qemu_ram_is_migratable(RAMBlock *rb)
{
return rb->flags & RAM_MIGRATABLE;
}
void qemu_ram_set_migratable(RAMBlock *rb)
{
rb->flags |= RAM_MIGRATABLE;
}
void qemu_ram_unset_migratable(RAMBlock *rb)
{
rb->flags &= ~RAM_MIGRATABLE;
}
/* Called with iothread lock held. */
void qemu_ram_set_idstr(RAMBlock *new_block, const char *name, DeviceState *dev)
{
RAMBlock *block;
assert(new_block);
assert(!new_block->idstr[0]);
if (dev) {
char *id = qdev_get_dev_path(dev);
if (id) {
snprintf(new_block->idstr, sizeof(new_block->idstr), "%s/", id);
g_free(id);
}
}
pstrcat(new_block->idstr, sizeof(new_block->idstr), name);
RCU_READ_LOCK_GUARD();
RAMBLOCK_FOREACH(block) {
if (block != new_block &&
!strcmp(block->idstr, new_block->idstr)) {
fprintf(stderr, "RAMBlock \"%s\" already registered, abort!\n",
new_block->idstr);
abort();
}
}
}
/* Called with iothread lock held. */
void qemu_ram_unset_idstr(RAMBlock *block)
{
/* FIXME: arch_init.c assumes that this is not called throughout
* migration. Ignore the problem since hot-unplug during migration
* does not work anyway.
*/
if (block) {
memset(block->idstr, 0, sizeof(block->idstr));
}
}
size_t qemu_ram_pagesize(RAMBlock *rb)
{
return rb->page_size;
}
/* Returns the largest size of page in use */
size_t qemu_ram_pagesize_largest(void)
{
RAMBlock *block;
size_t largest = 0;
RAMBLOCK_FOREACH(block) {
largest = MAX(largest, qemu_ram_pagesize(block));
}
return largest;
}
static int memory_try_enable_merging(void *addr, size_t len)
{
if (!machine_mem_merge(current_machine)) {
/* disabled by the user */
return 0;
}
return qemu_madvise(addr, len, QEMU_MADV_MERGEABLE);
}
/*
* Resizing RAM while migrating can result in the migration being canceled.
* Care has to be taken if the guest might have already detected the memory.
*
* As memory core doesn't know how is memory accessed, it is up to
* resize callback to update device state and/or add assertions to detect
* misuse, if necessary.
*/
int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp)
{
const ram_addr_t oldsize = block->used_length;
const ram_addr_t unaligned_size = newsize;
assert(block);
newsize = HOST_PAGE_ALIGN(newsize);
if (block->used_length == newsize) {
/*
* We don't have to resize the ram block (which only knows aligned
* sizes), however, we have to notify if the unaligned size changed.
*/
if (unaligned_size != memory_region_size(block->mr)) {
memory_region_set_size(block->mr, unaligned_size);
if (block->resized) {
block->resized(block->idstr, unaligned_size, block->host);
}
}
return 0;
}
if (!(block->flags & RAM_RESIZEABLE)) {
error_setg_errno(errp, EINVAL,
"Size mismatch: %s: 0x" RAM_ADDR_FMT
" != 0x" RAM_ADDR_FMT, block->idstr,
newsize, block->used_length);
return -EINVAL;
}
if (block->max_length < newsize) {
error_setg_errno(errp, EINVAL,
"Size too large: %s: 0x" RAM_ADDR_FMT
" > 0x" RAM_ADDR_FMT, block->idstr,
newsize, block->max_length);
return -EINVAL;
}
/* Notify before modifying the ram block and touching the bitmaps. */
if (block->host) {
ram_block_notify_resize(block->host, oldsize, newsize);
}
cpu_physical_memory_clear_dirty_range(block->offset, block->used_length);
block->used_length = newsize;
cpu_physical_memory_set_dirty_range(block->offset, block->used_length,
DIRTY_CLIENTS_ALL);
memory_region_set_size(block->mr, unaligned_size);
if (block->resized) {
block->resized(block->idstr, unaligned_size, block->host);
}
return 0;
}
/*
* Trigger sync on the given ram block for range [start, start + length]
* with the backing store if one is available.
* Otherwise no-op.
* @Note: this is supposed to be a synchronous op.
*/
void qemu_ram_msync(RAMBlock *block, ram_addr_t start, ram_addr_t length)
{
/* The requested range should fit in within the block range */
g_assert((start + length) <= block->used_length);
#ifdef CONFIG_LIBPMEM
/* The lack of support for pmem should not block the sync */
if (ramblock_is_pmem(block)) {
void *addr = ramblock_ptr(block, start);
pmem_persist(addr, length);
return;
}
#endif
if (block->fd >= 0) {
/**
* Case there is no support for PMEM or the memory has not been
* specified as persistent (or is not one) - use the msync.
* Less optimal but still achieves the same goal
*/
void *addr = ramblock_ptr(block, start);
if (qemu_msync(addr, length, block->fd)) {
warn_report("%s: failed to sync memory range: start: "
RAM_ADDR_FMT " length: " RAM_ADDR_FMT,
__func__, start, length);
}
}
}
/* Called with ram_list.mutex held */
static void dirty_memory_extend(ram_addr_t old_ram_size,
ram_addr_t new_ram_size)
{
ram_addr_t old_num_blocks = DIV_ROUND_UP(old_ram_size,
DIRTY_MEMORY_BLOCK_SIZE);
ram_addr_t new_num_blocks = DIV_ROUND_UP(new_ram_size,
DIRTY_MEMORY_BLOCK_SIZE);
int i;
/* Only need to extend if block count increased */
if (new_num_blocks <= old_num_blocks) {
return;
}
for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
DirtyMemoryBlocks *old_blocks;
DirtyMemoryBlocks *new_blocks;
int j;
old_blocks = qatomic_rcu_read(&ram_list.dirty_memory[i]);
new_blocks = g_malloc(sizeof(*new_blocks) +
sizeof(new_blocks->blocks[0]) * new_num_blocks);
if (old_num_blocks) {
memcpy(new_blocks->blocks, old_blocks->blocks,
old_num_blocks * sizeof(old_blocks->blocks[0]));
}
for (j = old_num_blocks; j < new_num_blocks; j++) {
new_blocks->blocks[j] = bitmap_new(DIRTY_MEMORY_BLOCK_SIZE);
}
qatomic_rcu_set(&ram_list.dirty_memory[i], new_blocks);
if (old_blocks) {
g_free_rcu(old_blocks, rcu);
}
}
}
static void ram_block_add(RAMBlock *new_block, Error **errp)
{
const bool noreserve = qemu_ram_is_noreserve(new_block);
const bool shared = qemu_ram_is_shared(new_block);
RAMBlock *block;
RAMBlock *last_block = NULL;
ram_addr_t old_ram_size, new_ram_size;
Error *err = NULL;
old_ram_size = last_ram_page();
qemu_mutex_lock_ramlist();
new_block->offset = find_ram_offset(new_block->max_length);
if (!new_block->host) {
if (xen_enabled()) {
xen_ram_alloc(new_block->offset, new_block->max_length,
new_block->mr, &err);
if (err) {
error_propagate(errp, err);
qemu_mutex_unlock_ramlist();
return;
}
} else {
new_block->host = qemu_anon_ram_alloc(new_block->max_length,
&new_block->mr->align,
shared, noreserve);
if (!new_block->host) {
error_setg_errno(errp, errno,
"cannot set up guest memory '%s'",
memory_region_name(new_block->mr));
qemu_mutex_unlock_ramlist();
return;
}
memory_try_enable_merging(new_block->host, new_block->max_length);
}
}
new_ram_size = MAX(old_ram_size,
(new_block->offset + new_block->max_length) >> TARGET_PAGE_BITS);
if (new_ram_size > old_ram_size) {
dirty_memory_extend(old_ram_size, new_ram_size);
}
/* Keep the list sorted from biggest to smallest block. Unlike QTAILQ,
* QLIST (which has an RCU-friendly variant) does not have insertion at
* tail, so save the last element in last_block.
*/
RAMBLOCK_FOREACH(block) {
last_block = block;
if (block->max_length < new_block->max_length) {
break;
}
}
if (block) {
QLIST_INSERT_BEFORE_RCU(block, new_block, next);
} else if (last_block) {
QLIST_INSERT_AFTER_RCU(last_block, new_block, next);
} else { /* list is empty */
QLIST_INSERT_HEAD_RCU(&ram_list.blocks, new_block, next);
}
ram_list.mru_block = NULL;
/* Write list before version */
smp_wmb();
ram_list.version++;
qemu_mutex_unlock_ramlist();
cpu_physical_memory_set_dirty_range(new_block->offset,
new_block->used_length,
DIRTY_CLIENTS_ALL);
if (new_block->host) {
qemu_ram_setup_dump(new_block->host, new_block->max_length);
qemu_madvise(new_block->host, new_block->max_length, QEMU_MADV_HUGEPAGE);
/*
* MADV_DONTFORK is also needed by KVM in absence of synchronous MMU
* Configure it unless the machine is a qtest server, in which case
* KVM is not used and it may be forked (eg for fuzzing purposes).
*/
if (!qtest_enabled()) {
qemu_madvise(new_block->host, new_block->max_length,
QEMU_MADV_DONTFORK);
}
ram_block_notify_add(new_block->host, new_block->used_length,
new_block->max_length);
}
}
#ifdef CONFIG_POSIX
RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
uint32_t ram_flags, int fd, off_t offset,
bool readonly, Error **errp)
{
RAMBlock *new_block;
Error *local_err = NULL;
int64_t file_size, file_align;
/* Just support these ram flags by now. */
assert((ram_flags & ~(RAM_SHARED | RAM_PMEM | RAM_NORESERVE)) == 0);
if (xen_enabled()) {
error_setg(errp, "-mem-path not supported with Xen");
return NULL;
}
if (kvm_enabled() && !kvm_has_sync_mmu()) {
error_setg(errp,
"host lacks kvm mmu notifiers, -mem-path unsupported");
return NULL;
}
size = HOST_PAGE_ALIGN(size);
file_size = get_file_size(fd);
if (file_size > 0 && file_size < size) {
error_setg(errp, "backing store size 0x%" PRIx64
" does not match 'size' option 0x" RAM_ADDR_FMT,
file_size, size);
return NULL;
}
file_align = get_file_align(fd);
if (file_align > 0 && mr && file_align > mr->align) {
error_setg(errp, "backing store align 0x%" PRIx64
" is larger than 'align' option 0x%" PRIx64,
file_align, mr->align);
return NULL;
}
new_block = g_malloc0(sizeof(*new_block));
new_block->mr = mr;
new_block->used_length = size;
new_block->max_length = size;
new_block->flags = ram_flags;
new_block->host = file_ram_alloc(new_block, size, fd, readonly,
!file_size, offset, errp);
if (!new_block->host) {
g_free(new_block);
return NULL;
}
ram_block_add(new_block, &local_err);
if (local_err) {
g_free(new_block);
error_propagate(errp, local_err);
return NULL;
}
return new_block;
}
RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
uint32_t ram_flags, const char *mem_path,
bool readonly, Error **errp)
{
int fd;
bool created;
RAMBlock *block;
fd = file_ram_open(mem_path, memory_region_name(mr), readonly, &created,
errp);
if (fd < 0) {
return NULL;
}
block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, 0, readonly, errp);
if (!block) {
if (created) {
unlink(mem_path);
}
close(fd);
return NULL;
}
return block;
}
#endif
static
RAMBlock *qemu_ram_alloc_internal(ram_addr_t size, ram_addr_t max_size,
void (*resized)(const char*,
uint64_t length,
void *host),
void *host, uint32_t ram_flags,
MemoryRegion *mr, Error **errp)
{
RAMBlock *new_block;
Error *local_err = NULL;
assert((ram_flags & ~(RAM_SHARED | RAM_RESIZEABLE | RAM_PREALLOC)) == 0);
assert((ram_flags & ~(RAM_SHARED | RAM_RESIZEABLE | RAM_PREALLOC |
RAM_NORESERVE)) == 0);
assert(!host ^ (ram_flags & RAM_PREALLOC));
size = HOST_PAGE_ALIGN(size);
max_size = HOST_PAGE_ALIGN(max_size);
new_block = g_malloc0(sizeof(*new_block));
new_block->mr = mr;
new_block->resized = resized;
new_block->used_length = size;
new_block->max_length = max_size;
assert(max_size >= size);
new_block->fd = -1;
new_block->page_size = qemu_real_host_page_size;
new_block->host = host;
new_block->flags = ram_flags;
ram_block_add(new_block, &local_err);
if (local_err) {
g_free(new_block);
error_propagate(errp, local_err);
return NULL;
}
return new_block;
}
RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
MemoryRegion *mr, Error **errp)
{
return qemu_ram_alloc_internal(size, size, NULL, host, RAM_PREALLOC, mr,
errp);
}
RAMBlock *qemu_ram_alloc(ram_addr_t size, uint32_t ram_flags,
MemoryRegion *mr, Error **errp)
{
assert((ram_flags & ~(RAM_SHARED | RAM_NORESERVE)) == 0);
return qemu_ram_alloc_internal(size, size, NULL, NULL, ram_flags, mr, errp);
}
RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t maxsz,
void (*resized)(const char*,
uint64_t length,
void *host),
MemoryRegion *mr, Error **errp)
{
return qemu_ram_alloc_internal(size, maxsz, resized, NULL,
RAM_RESIZEABLE, mr, errp);
}
static void reclaim_ramblock(RAMBlock *block)
{
if (block->flags & RAM_PREALLOC) {
;
} else if (xen_enabled()) {
xen_invalidate_map_cache_entry(block->host);
#ifndef _WIN32
} else if (block->fd >= 0) {
qemu_ram_munmap(block->fd, block->host, block->max_length);
close(block->fd);
#endif
} else {
qemu_anon_ram_free(block->host, block->max_length);
}
g_free(block);
}
void qemu_ram_free(RAMBlock *block)
{
if (!block) {
return;
}
if (block->host) {
ram_block_notify_remove(block->host, block->used_length,
block->max_length);
}
qemu_mutex_lock_ramlist();
QLIST_REMOVE_RCU(block, next);
ram_list.mru_block = NULL;
/* Write list before version */
smp_wmb();
ram_list.version++;
call_rcu(block, reclaim_ramblock, rcu);
qemu_mutex_unlock_ramlist();
}
#ifndef _WIN32
void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
{
RAMBlock *block;
ram_addr_t offset;
int flags;
void *area, *vaddr;
RAMBLOCK_FOREACH(block) {
offset = addr - block->offset;
if (offset < block->max_length) {
vaddr = ramblock_ptr(block, offset);
if (block->flags & RAM_PREALLOC) {
;
} else if (xen_enabled()) {
abort();
} else {
flags = MAP_FIXED;
flags |= block->flags & RAM_SHARED ?
MAP_SHARED : MAP_PRIVATE;
flags |= block->flags & RAM_NORESERVE ? MAP_NORESERVE : 0;
if (block->fd >= 0) {
area = mmap(vaddr, length, PROT_READ | PROT_WRITE,
flags, block->fd, offset);
} else {
flags |= MAP_ANONYMOUS;
area = mmap(vaddr, length, PROT_READ | PROT_WRITE,
flags, -1, 0);
}
if (area != vaddr) {
error_report("Could not remap addr: "
RAM_ADDR_FMT "@" RAM_ADDR_FMT "",
length, addr);
exit(1);
}
memory_try_enable_merging(vaddr, length);
qemu_ram_setup_dump(vaddr, length);
}
}
}
}
#endif /* !_WIN32 */
/* Return a host pointer to ram allocated with qemu_ram_alloc.
* This should not be used for general purpose DMA. Use address_space_map
* or address_space_rw instead. For local memory (e.g. video ram) that the
* device owns, use memory_region_get_ram_ptr.
*
* Called within RCU critical section.
*/
void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr)
{
RAMBlock *block = ram_block;
if (block == NULL) {
block = qemu_get_ram_block(addr);
addr -= block->offset;
}
if (xen_enabled() && block->host == NULL) {
/* We need to check if the requested address is in the RAM
* because we don't want to map the entire memory in QEMU.
* In that case just map until the end of the page.
*/
if (block->offset == 0) {
return xen_map_cache(addr, 0, 0, false);
}
block->host = xen_map_cache(block->offset, block->max_length, 1, false);
}
return ramblock_ptr(block, addr);
}
/* Return a host pointer to guest's ram. Similar to qemu_map_ram_ptr
* but takes a size argument.
*
* Called within RCU critical section.
*/
static void *qemu_ram_ptr_length(RAMBlock *ram_block, ram_addr_t addr,
hwaddr *size, bool lock)
{
RAMBlock *block = ram_block;
if (*size == 0) {
return NULL;
}
if (block == NULL) {
block = qemu_get_ram_block(addr);
addr -= block->offset;
}
*size = MIN(*size, block->max_length - addr);
if (xen_enabled() && block->host == NULL) {
/* We need to check if the requested address is in the RAM
* because we don't want to map the entire memory in QEMU.
* In that case just map the requested area.
*/
if (block->offset == 0) {
return xen_map_cache(addr, *size, lock, lock);
}
block->host = xen_map_cache(block->offset, block->max_length, 1, lock);
}
return ramblock_ptr(block, addr);
}
/* Return the offset of a hostpointer within a ramblock */
ram_addr_t qemu_ram_block_host_offset(RAMBlock *rb, void *host)
{
ram_addr_t res = (uint8_t *)host - (uint8_t *)rb->host;
assert((uintptr_t)host >= (uintptr_t)rb->host);
assert(res < rb->max_length);
return res;
}
/*
* Translates a host ptr back to a RAMBlock, a ram_addr and an offset
* in that RAMBlock.
*
* ptr: Host pointer to look up
* round_offset: If true round the result offset down to a page boundary
* *ram_addr: set to result ram_addr
* *offset: set to result offset within the RAMBlock
*
* Returns: RAMBlock (or NULL if not found)
*
* By the time this function returns, the returned pointer is not protected
* by RCU anymore. If the caller is not within an RCU critical section and
* does not hold the iothread lock, it must have other means of protecting the
* pointer, such as a reference to the region that includes the incoming
* ram_addr_t.
*/
RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
ram_addr_t *offset)
{
RAMBlock *block;
uint8_t *host = ptr;
if (xen_enabled()) {
ram_addr_t ram_addr;
RCU_READ_LOCK_GUARD();
ram_addr = xen_ram_addr_from_mapcache(ptr);
block = qemu_get_ram_block(ram_addr);
if (block) {
*offset = ram_addr - block->offset;
}
return block;
}
RCU_READ_LOCK_GUARD();
block = qatomic_rcu_read(&ram_list.mru_block);
if (block && block->host && host - block->host < block->max_length) {
goto found;
}
RAMBLOCK_FOREACH(block) {
/* This case append when the block is not mapped. */
if (block->host == NULL) {
continue;
}
if (host - block->host < block->max_length) {
goto found;
}
}
return NULL;
found:
*offset = (host - block->host);
if (round_offset) {
*offset &= TARGET_PAGE_MASK;
}
return block;
}
/*
* Finds the named RAMBlock
*
* name: The name of RAMBlock to find
*
* Returns: RAMBlock (or NULL if not found)
*/
RAMBlock *qemu_ram_block_by_name(const char *name)
{
RAMBlock *block;
RAMBLOCK_FOREACH(block) {
if (!strcmp(name, block->idstr)) {
return block;
}
}
return NULL;
}
/* Some of the softmmu routines need to translate from a host pointer
(typically a TLB entry) back to a ram offset. */
ram_addr_t qemu_ram_addr_from_host(void *ptr)
{
RAMBlock *block;
ram_addr_t offset;
block = qemu_ram_block_from_host(ptr, false, &offset);
if (!block) {
return RAM_ADDR_INVALID;
}
return block->offset + offset;
}
static MemTxResult flatview_read(FlatView *fv, hwaddr addr,
MemTxAttrs attrs, void *buf, hwaddr len);
static MemTxResult flatview_write(FlatView *fv, hwaddr addr, MemTxAttrs attrs,
const void *buf, hwaddr len);
static bool flatview_access_valid(FlatView *fv, hwaddr addr, hwaddr len,
bool is_write, MemTxAttrs attrs);
static MemTxResult subpage_read(void *opaque, hwaddr addr, uint64_t *data,
unsigned len, MemTxAttrs attrs)
{
subpage_t *subpage = opaque;
uint8_t buf[8];
MemTxResult res;
#if defined(DEBUG_SUBPAGE)
printf("%s: subpage %p len %u addr " TARGET_FMT_plx "\n", __func__,
subpage, len, addr);
#endif
res = flatview_read(subpage->fv, addr + subpage->base, attrs, buf, len);
if (res) {
return res;
}
*data = ldn_p(buf, len);
return MEMTX_OK;
}
static MemTxResult subpage_write(void *opaque, hwaddr addr,
uint64_t value, unsigned len, MemTxAttrs attrs)
{
subpage_t *subpage = opaque;
uint8_t buf[8];
#if defined(DEBUG_SUBPAGE)
printf("%s: subpage %p len %u addr " TARGET_FMT_plx
" value %"PRIx64"\n",
__func__, subpage, len, addr, value);
#endif
stn_p(buf, len, value);
return flatview_write(subpage->fv, addr + subpage->base, attrs, buf, len);
}
static bool subpage_accepts(void *opaque, hwaddr addr,
unsigned len, bool is_write,
MemTxAttrs attrs)
{
subpage_t *subpage = opaque;
#if defined(DEBUG_SUBPAGE)
printf("%s: subpage %p %c len %u addr " TARGET_FMT_plx "\n",
__func__, subpage, is_write ? 'w' : 'r', len, addr);
#endif
return flatview_access_valid(subpage->fv, addr + subpage->base,
len, is_write, attrs);
}
static const MemoryRegionOps subpage_ops = {
.read_with_attrs = subpage_read,
.write_with_attrs = subpage_write,
.impl.min_access_size = 1,
.impl.max_access_size = 8,
.valid.min_access_size = 1,
.valid.max_access_size = 8,
.valid.accepts = subpage_accepts,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static int subpage_register(subpage_t *mmio, uint32_t start, uint32_t end,
uint16_t section)
{
int idx, eidx;
if (start >= TARGET_PAGE_SIZE || end >= TARGET_PAGE_SIZE)
return -1;
idx = SUBPAGE_IDX(start);
eidx = SUBPAGE_IDX(end);
#if defined(DEBUG_SUBPAGE)
printf("%s: %p start %08x end %08x idx %08x eidx %08x section %d\n",
__func__, mmio, start, end, idx, eidx, section);
#endif
for (; idx <= eidx; idx++) {
mmio->sub_section[idx] = section;
}
return 0;
}
static subpage_t *subpage_init(FlatView *fv, hwaddr base)
{
subpage_t *mmio;
/* mmio->sub_section is set to PHYS_SECTION_UNASSIGNED with g_malloc0 */
mmio = g_malloc0(sizeof(subpage_t) + TARGET_PAGE_SIZE * sizeof(uint16_t));
mmio->fv = fv;
mmio->base = base;
memory_region_init_io(&mmio->iomem, NULL, &subpage_ops, mmio,
NULL, TARGET_PAGE_SIZE);
mmio->iomem.subpage = true;
#if defined(DEBUG_SUBPAGE)
printf("%s: %p base " TARGET_FMT_plx " len %08x\n", __func__,
mmio, base, TARGET_PAGE_SIZE);
#endif
return mmio;
}
static uint16_t dummy_section(PhysPageMap *map, FlatView *fv, MemoryRegion *mr)
{
assert(fv);
MemoryRegionSection section = {
.fv = fv,
.mr = mr,
.offset_within_address_space = 0,
.offset_within_region = 0,
.size = int128_2_64(),
};
return phys_section_add(map, &section);
}
MemoryRegionSection *iotlb_to_section(CPUState *cpu,
hwaddr index, MemTxAttrs attrs)
{
int asidx = cpu_asidx_from_attrs(cpu, attrs);
CPUAddressSpace *cpuas = &cpu->cpu_ases[asidx];
AddressSpaceDispatch *d = qatomic_rcu_read(&cpuas->memory_dispatch);
MemoryRegionSection *sections = d->map.sections;
return &sections[index & ~TARGET_PAGE_MASK];
}
static void io_mem_init(void)
{
memory_region_init_io(&io_mem_unassigned, NULL, &unassigned_mem_ops, NULL,
NULL, UINT64_MAX);
}
AddressSpaceDispatch *address_space_dispatch_new(FlatView *fv)
{
AddressSpaceDispatch *d = g_new0(AddressSpaceDispatch, 1);
uint16_t n;
n = dummy_section(&d->map, fv, &io_mem_unassigned);
assert(n == PHYS_SECTION_UNASSIGNED);
d->phys_map = (PhysPageEntry) { .ptr = PHYS_MAP_NODE_NIL, .skip = 1 };
return d;
}
void address_space_dispatch_free(AddressSpaceDispatch *d)
{
phys_sections_free(&d->map);
g_free(d);
}
static void do_nothing(CPUState *cpu, run_on_cpu_data d)
{
}
static void tcg_log_global_after_sync(MemoryListener *listener)
{
CPUAddressSpace *cpuas;
/* Wait for the CPU to end the current TB. This avoids the following
* incorrect race:
*
* vCPU migration
* ---------------------- -------------------------
* TLB check -> slow path
* notdirty_mem_write
* write to RAM
* mark dirty
* clear dirty flag
* TLB check -> fast path
* read memory
* write to RAM
*
* by pushing the migration thread's memory read after the vCPU thread has
* written the memory.
*/
if (replay_mode == REPLAY_MODE_NONE) {
/*
* VGA can make calls to this function while updating the screen.
* In record/replay mode this causes a deadlock, because
* run_on_cpu waits for rr mutex. Therefore no races are possible
* in this case and no need for making run_on_cpu when
* record/replay is not enabled.
*/
cpuas = container_of(listener, CPUAddressSpace, tcg_as_listener);
run_on_cpu(cpuas->cpu, do_nothing, RUN_ON_CPU_NULL);
}
}
static void tcg_commit(MemoryListener *listener)
{
CPUAddressSpace *cpuas;
AddressSpaceDispatch *d;
assert(tcg_enabled());
/* since each CPU stores ram addresses in its TLB cache, we must
reset the modified entries */
cpuas = container_of(listener, CPUAddressSpace, tcg_as_listener);
cpu_reloading_memory_map();
/* The CPU and TLB are protected by the iothread lock.
* We reload the dispatch pointer now because cpu_reloading_memory_map()
* may have split the RCU critical section.
*/
d = address_space_to_dispatch(cpuas->as);
qatomic_rcu_set(&cpuas->memory_dispatch, d);
tlb_flush(cpuas->cpu);
}
static void memory_map_init(void)
{
system_memory = g_malloc(sizeof(*system_memory));
memory_region_init(system_memory, NULL, "system", UINT64_MAX);
address_space_init(&address_space_memory, system_memory, "memory");
system_io = g_malloc(sizeof(*system_io));
memory_region_init_io(system_io, NULL, &unassigned_io_ops, NULL, "io",
65536);
address_space_init(&address_space_io, system_io, "I/O");
}
MemoryRegion *get_system_memory(void)
{
return system_memory;
}
MemoryRegion *get_system_io(void)
{
return system_io;
}
static void invalidate_and_set_dirty(MemoryRegion *mr, hwaddr addr,
hwaddr length)
{
uint8_t dirty_log_mask = memory_region_get_dirty_log_mask(mr);
addr += memory_region_get_ram_addr(mr);
/* No early return if dirty_log_mask is or becomes 0, because
* cpu_physical_memory_set_dirty_range will still call
* xen_modified_memory.
*/
if (dirty_log_mask) {
dirty_log_mask =
cpu_physical_memory_range_includes_clean(addr, length, dirty_log_mask);
}
if (dirty_log_mask & (1 << DIRTY_MEMORY_CODE)) {
assert(tcg_enabled());
tb_invalidate_phys_range(addr, addr + length);
dirty_log_mask &= ~(1 << DIRTY_MEMORY_CODE);
}
cpu_physical_memory_set_dirty_range(addr, length, dirty_log_mask);
}
void memory_region_flush_rom_device(MemoryRegion *mr, hwaddr addr, hwaddr size)
{
/*
* In principle this function would work on other memory region types too,
* but the ROM device use case is the only one where this operation is
* necessary. Other memory regions should use the
* address_space_read/write() APIs.
*/
assert(memory_region_is_romd(mr));
invalidate_and_set_dirty(mr, addr, size);
}
static int memory_access_size(MemoryRegion *mr, unsigned l, hwaddr addr)
{
unsigned access_size_max = mr->ops->valid.max_access_size;
/* Regions are assumed to support 1-4 byte accesses unless
otherwise specified. */
if (access_size_max == 0) {
access_size_max = 4;
}
/* Bound the maximum access by the alignment of the address. */
if (!mr->ops->impl.unaligned) {
unsigned align_size_max = addr & -addr;
if (align_size_max != 0 && align_size_max < access_size_max) {
access_size_max = align_size_max;
}
}
/* Don't attempt accesses larger than the maximum. */
if (l > access_size_max) {
l = access_size_max;
}
l = pow2floor(l);
return l;
}
static bool prepare_mmio_access(MemoryRegion *mr)
{
bool release_lock = false;
if (!qemu_mutex_iothread_locked()) {
qemu_mutex_lock_iothread();
release_lock = true;
}
if (mr->flush_coalesced_mmio) {
qemu_flush_coalesced_mmio_buffer();
}
return release_lock;
}
/* Called within RCU critical section. */
static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr,
MemTxAttrs attrs,
const void *ptr,
hwaddr len, hwaddr addr1,
hwaddr l, MemoryRegion *mr)
{
uint8_t *ram_ptr;
uint64_t val;
MemTxResult result = MEMTX_OK;
bool release_lock = false;
const uint8_t *buf = ptr;
for (;;) {
if (!memory_access_is_direct(mr, true)) {
release_lock |= prepare_mmio_access(mr);
l = memory_access_size(mr, l, addr1);
/* XXX: could force current_cpu to NULL to avoid
potential bugs */
val = ldn_he_p(buf, l);
result |= memory_region_dispatch_write(mr, addr1, val,
size_memop(l), attrs);
} else {
/* RAM case */
ram_ptr = qemu_ram_ptr_length(mr->ram_block, addr1, &l, false);
memcpy(ram_ptr, buf, l);
invalidate_and_set_dirty(mr, addr1, l);
}
if (release_lock) {
qemu_mutex_unlock_iothread();
release_lock = false;
}
len -= l;
buf += l;
addr += l;
if (!len) {
break;
}
l = len;
mr = flatview_translate(fv, addr, &addr1, &l, true, attrs);
}
return result;
}
/* Called from RCU critical section. */
static MemTxResult flatview_write(FlatView *fv, hwaddr addr, MemTxAttrs attrs,
const void *buf, hwaddr len)
{
hwaddr l;
hwaddr addr1;
MemoryRegion *mr;
MemTxResult result = MEMTX_OK;
l = len;
mr = flatview_translate(fv, addr, &addr1, &l, true, attrs);
result = flatview_write_continue(fv, addr, attrs, buf, len,
addr1, l, mr);
return result;
}
/* Called within RCU critical section. */
MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr,
MemTxAttrs attrs, void *ptr,
hwaddr len, hwaddr addr1, hwaddr l,
MemoryRegion *mr)
{
uint8_t *ram_ptr;
uint64_t val;
MemTxResult result = MEMTX_OK;
bool release_lock = false;
uint8_t *buf = ptr;
fuzz_dma_read_cb(addr, len, mr);
for (;;) {
if (!memory_access_is_direct(mr, false)) {
/* I/O case */
release_lock |= prepare_mmio_access(mr);
l = memory_access_size(mr, l, addr1);
result |= memory_region_dispatch_read(mr, addr1, &val,
size_memop(l), attrs);
stn_he_p(buf, l, val);
} else {
/* RAM case */
ram_ptr = qemu_ram_ptr_length(mr->ram_block, addr1, &l, false);
memcpy(buf, ram_ptr, l);
}
if (release_lock) {
qemu_mutex_unlock_iothread();
release_lock = false;
}
len -= l;
buf += l;
addr += l;
if (!len) {
break;
}
l = len;
mr = flatview_translate(fv, addr, &addr1, &l, false, attrs);
}
return result;
}
/* Called from RCU critical section. */
static MemTxResult flatview_read(FlatView *fv, hwaddr addr,
MemTxAttrs attrs, void *buf, hwaddr len)
{
hwaddr l;
hwaddr addr1;
MemoryRegion *mr;
l = len;
mr = flatview_translate(fv, addr, &addr1, &l, false, attrs);
return flatview_read_continue(fv, addr, attrs, buf, len,
addr1, l, mr);
}
MemTxResult address_space_read_full(AddressSpace *as, hwaddr addr,
MemTxAttrs attrs, void *buf, hwaddr len)
{
MemTxResult result = MEMTX_OK;
FlatView *fv;
if (len > 0) {
RCU_READ_LOCK_GUARD();
fv = address_space_to_flatview(as);
result = flatview_read(fv, addr, attrs, buf, len);
}
return result;
}
MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
MemTxAttrs attrs,
const void *buf, hwaddr len)
{
MemTxResult result = MEMTX_OK;
FlatView *fv;
if (len > 0) {
RCU_READ_LOCK_GUARD();
fv = address_space_to_flatview(as);
result = flatview_write(fv, addr, attrs, buf, len);
}
return result;
}
MemTxResult address_space_rw(AddressSpace *as, hwaddr addr, MemTxAttrs attrs,
void *buf, hwaddr len, bool is_write)
{
if (is_write) {
return address_space_write(as, addr, attrs, buf, len);
} else {
return address_space_read_full(as, addr, attrs, buf, len);
}
}
void cpu_physical_memory_rw(hwaddr addr, void *buf,
hwaddr len, bool is_write)
{
address_space_rw(&address_space_memory, addr, MEMTXATTRS_UNSPECIFIED,
buf, len, is_write);
}
enum write_rom_type {
WRITE_DATA,
FLUSH_CACHE,
};
static inline MemTxResult address_space_write_rom_internal(AddressSpace *as,
hwaddr addr,
MemTxAttrs attrs,
const void *ptr,
hwaddr len,
enum write_rom_type type)
{
hwaddr l;
uint8_t *ram_ptr;
hwaddr addr1;
MemoryRegion *mr;
const uint8_t *buf = ptr;
RCU_READ_LOCK_GUARD();
while (len > 0) {
l = len;
mr = address_space_translate(as, addr, &addr1, &l, true, attrs);
if (!(memory_region_is_ram(mr) ||
memory_region_is_romd(mr))) {
l = memory_access_size(mr, l, addr1);
} else {
/* ROM/RAM case */
ram_ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
switch (type) {
case WRITE_DATA:
memcpy(ram_ptr, buf, l);
invalidate_and_set_dirty(mr, addr1, l);
break;
case FLUSH_CACHE:
flush_idcache_range((uintptr_t)ram_ptr, (uintptr_t)ram_ptr, l);
break;
}
}
len -= l;
buf += l;
addr += l;
}
return MEMTX_OK;
}
/* used for ROM loading : can write in RAM and ROM */
MemTxResult address_space_write_rom(AddressSpace *as, hwaddr addr,
MemTxAttrs attrs,
const void *buf, hwaddr len)
{
return address_space_write_rom_internal(as, addr, attrs,
buf, len, WRITE_DATA);
}
void cpu_flush_icache_range(hwaddr start, hwaddr len)
{
/*
* This function should do the same thing as an icache flush that was
* triggered from within the guest. For TCG we are always cache coherent,
* so there is no need to flush anything. For KVM / Xen we need to flush
* the host's instruction cache at least.
*/
if (tcg_enabled()) {
return;
}
address_space_write_rom_internal(&address_space_memory,
start, MEMTXATTRS_UNSPECIFIED,
NULL, len, FLUSH_CACHE);
}
typedef struct {
MemoryRegion *mr;
void *buffer;
hwaddr addr;
hwaddr len;
bool in_use;
} BounceBuffer;
static BounceBuffer bounce;
typedef struct MapClient {
QEMUBH *bh;
QLIST_ENTRY(MapClient) link;
} MapClient;
QemuMutex map_client_list_lock;
static QLIST_HEAD(, MapClient) map_client_list
= QLIST_HEAD_INITIALIZER(map_client_list);
static void cpu_unregister_map_client_do(MapClient *client)
{
QLIST_REMOVE(client, link);
g_free(client);
}
static void cpu_notify_map_clients_locked(void)
{
MapClient *client;
while (!QLIST_EMPTY(&map_client_list)) {
client = QLIST_FIRST(&map_client_list);
qemu_bh_schedule(client->bh);
cpu_unregister_map_client_do(client);
}
}
void cpu_register_map_client(QEMUBH *bh)
{
MapClient *client = g_malloc(sizeof(*client));
qemu_mutex_lock(&map_client_list_lock);
client->bh = bh;
QLIST_INSERT_HEAD(&map_client_list, client, link);
if (!qatomic_read(&bounce.in_use)) {
cpu_notify_map_clients_locked();
}
qemu_mutex_unlock(&map_client_list_lock);
}
void cpu_exec_init_all(void)
{
qemu_mutex_init(&ram_list.mutex);
/* The data structures we set up here depend on knowing the page size,
* so no more changes can be made after this point.
* In an ideal world, nothing we did before we had finished the
* machine setup would care about the target page size, and we could
* do this much later, rather than requiring board models to state
* up front what their requirements are.
*/
finalize_target_page_bits();
io_mem_init();
memory_map_init();
qemu_mutex_init(&map_client_list_lock);
}
void cpu_unregister_map_client(QEMUBH *bh)
{
MapClient *client;
qemu_mutex_lock(&map_client_list_lock);
QLIST_FOREACH(client, &map_client_list, link) {
if (client->bh == bh) {
cpu_unregister_map_client_do(client);
break;
}
}
qemu_mutex_unlock(&map_client_list_lock);
}
static void cpu_notify_map_clients(void)
{
qemu_mutex_lock(&map_client_list_lock);
cpu_notify_map_clients_locked();
qemu_mutex_unlock(&map_client_list_lock);
}
static bool flatview_access_valid(FlatView *fv, hwaddr addr, hwaddr len,
bool is_write, MemTxAttrs attrs)
{
MemoryRegion *mr;
hwaddr l, xlat;
while (len > 0) {
l = len;
mr = flatview_translate(fv, addr, &xlat, &l, is_write, attrs);
if (!memory_access_is_direct(mr, is_write)) {
l = memory_access_size(mr, l, addr);
if (!memory_region_access_valid(mr, xlat, l, is_write, attrs)) {
return false;
}
}
len -= l;
addr += l;
}
return true;
}
bool address_space_access_valid(AddressSpace *as, hwaddr addr,
hwaddr len, bool is_write,
MemTxAttrs attrs)
{
FlatView *fv;
bool result;
RCU_READ_LOCK_GUARD();
fv = address_space_to_flatview(as);
result = flatview_access_valid(fv, addr, len, is_write, attrs);
return result;
}
static hwaddr
flatview_extend_translation(FlatView *fv, hwaddr addr,
hwaddr target_len,
MemoryRegion *mr, hwaddr base, hwaddr len,
bool is_write, MemTxAttrs attrs)
{
hwaddr done = 0;
hwaddr xlat;
MemoryRegion *this_mr;
for (;;) {
target_len -= len;
addr += len;
done += len;
if (target_len == 0) {
return done;
}
len = target_len;
this_mr = flatview_translate(fv, addr, &xlat,
&len, is_write, attrs);
if (this_mr != mr || xlat != base + done) {
return done;
}
}
}
/* Map a physical memory region into a host virtual address.
* May map a subset of the requested range, given by and returned in *plen.
* May return NULL if resources needed to perform the mapping are exhausted.
* Use only for reads OR writes - not for read-modify-write operations.
* Use cpu_register_map_client() to know when retrying the map operation is
* likely to succeed.
*/
void *address_space_map(AddressSpace *as,
hwaddr addr,
hwaddr *plen,
bool is_write,
MemTxAttrs attrs)
{
hwaddr len = *plen;
hwaddr l, xlat;
MemoryRegion *mr;
void *ptr;
FlatView *fv;
if (len == 0) {
return NULL;
}
l = len;
RCU_READ_LOCK_GUARD();
fv = address_space_to_flatview(as);
mr = flatview_translate(fv, addr, &xlat, &l, is_write, attrs);
if (!memory_access_is_direct(mr, is_write)) {
if (qatomic_xchg(&bounce.in_use, true)) {
*plen = 0;
return NULL;
}
/* Avoid unbounded allocations */
l = MIN(l, TARGET_PAGE_SIZE);
bounce.buffer = qemu_memalign(TARGET_PAGE_SIZE, l);
bounce.addr = addr;
bounce.len = l;
memory_region_ref(mr);
bounce.mr = mr;
if (!is_write) {
flatview_read(fv, addr, MEMTXATTRS_UNSPECIFIED,
bounce.buffer, l);
}
*plen = l;
return bounce.buffer;
}
memory_region_ref(mr);
*plen = flatview_extend_translation(fv, addr, len, mr, xlat,
l, is_write, attrs);
fuzz_dma_read_cb(addr, *plen, mr);
ptr = qemu_ram_ptr_length(mr->ram_block, xlat, plen, true);
return ptr;
}
/* Unmaps a memory region previously mapped by address_space_map().
* Will also mark the memory as dirty if is_write is true. access_len gives
* the amount of memory that was actually read or written by the caller.
*/
void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
bool is_write, hwaddr access_len)
{
if (buffer != bounce.buffer) {
MemoryRegion *mr;
ram_addr_t addr1;
mr = memory_region_from_host(buffer, &addr1);
assert(mr != NULL);
if (is_write) {
invalidate_and_set_dirty(mr, addr1, access_len);
}
if (xen_enabled()) {
xen_invalidate_map_cache_entry(buffer);
}
memory_region_unref(mr);
return;
}
if (is_write) {
address_space_write(as, bounce.addr, MEMTXATTRS_UNSPECIFIED,
bounce.buffer, access_len);
}
qemu_vfree(bounce.buffer);
bounce.buffer = NULL;
memory_region_unref(bounce.mr);
qatomic_mb_set(&bounce.in_use, false);
cpu_notify_map_clients();
}
void *cpu_physical_memory_map(hwaddr addr,
hwaddr *plen,
bool is_write)
{
return address_space_map(&address_space_memory, addr, plen, is_write,
MEMTXATTRS_UNSPECIFIED);
}
void cpu_physical_memory_unmap(void *buffer, hwaddr len,
bool is_write, hwaddr access_len)
{
return address_space_unmap(&address_space_memory, buffer, len, is_write, access_len);
}
#define ARG1_DECL AddressSpace *as
#define ARG1 as
#define SUFFIX
#define TRANSLATE(...) address_space_translate(as, __VA_ARGS__)
#define RCU_READ_LOCK(...) rcu_read_lock()
#define RCU_READ_UNLOCK(...) rcu_read_unlock()
#include "memory_ldst.c.inc"
int64_t address_space_cache_init(MemoryRegionCache *cache,
AddressSpace *as,
hwaddr addr,
hwaddr len,
bool is_write)
{
AddressSpaceDispatch *d;
hwaddr l;
MemoryRegion *mr;
Int128 diff;
assert(len > 0);
l = len;
cache->fv = address_space_get_flatview(as);
d = flatview_to_dispatch(cache->fv);
cache->mrs = *address_space_translate_internal(d, addr, &cache->xlat, &l, true);
/*
* cache->xlat is now relative to cache->mrs.mr, not to the section itself.
* Take that into account to compute how many bytes are there between
* cache->xlat and the end of the section.
*/
diff = int128_sub(cache->mrs.size,
int128_make64(cache->xlat - cache->mrs.offset_within_region));
l = int128_get64(int128_min(diff, int128_make64(l)));
mr = cache->mrs.mr;
memory_region_ref(mr);
if (memory_access_is_direct(mr, is_write)) {
/* We don't care about the memory attributes here as we're only
* doing this if we found actual RAM, which behaves the same
* regardless of attributes; so UNSPECIFIED is fine.
*/
l = flatview_extend_translation(cache->fv, addr, len, mr,
cache->xlat, l, is_write,
MEMTXATTRS_UNSPECIFIED);
cache->ptr = qemu_ram_ptr_length(mr->ram_block, cache->xlat, &l, true);
} else {
cache->ptr = NULL;
}
cache->len = l;
cache->is_write = is_write;
return l;
}
void address_space_cache_invalidate(MemoryRegionCache *cache,
hwaddr addr,
hwaddr access_len)
{
assert(cache->is_write);
if (likely(cache->ptr)) {
invalidate_and_set_dirty(cache->mrs.mr, addr + cache->xlat, access_len);
}
}
void address_space_cache_destroy(MemoryRegionCache *cache)
{
if (!cache->mrs.mr) {
return;
}
if (xen_enabled()) {
xen_invalidate_map_cache_entry(cache->ptr);
}
memory_region_unref(cache->mrs.mr);
flatview_unref(cache->fv);
cache->mrs.mr = NULL;
cache->fv = NULL;
}
/* Called from RCU critical section. This function has the same
* semantics as address_space_translate, but it only works on a
* predefined range of a MemoryRegion that was mapped with
* address_space_cache_init.
*/
static inline MemoryRegion *address_space_translate_cached(
MemoryRegionCache *cache, hwaddr addr, hwaddr *xlat,
hwaddr *plen, bool is_write, MemTxAttrs attrs)
{
MemoryRegionSection section;
MemoryRegion *mr;
IOMMUMemoryRegion *iommu_mr;
AddressSpace *target_as;
assert(!cache->ptr);
*xlat = addr + cache->xlat;
mr = cache->mrs.mr;
iommu_mr = memory_region_get_iommu(mr);
if (!iommu_mr) {
/* MMIO region. */
return mr;
}
section = address_space_translate_iommu(iommu_mr, xlat, plen,
NULL, is_write, true,
&target_as, attrs);
return section.mr;
}
/* Called from RCU critical section. address_space_read_cached uses this
* out of line function when the target is an MMIO or IOMMU region.
*/
MemTxResult
address_space_read_cached_slow(MemoryRegionCache *cache, hwaddr addr,
void *buf, hwaddr len)
{
hwaddr addr1, l;
MemoryRegion *mr;
l = len;
mr = address_space_translate_cached(cache, addr, &addr1, &l, false,
MEMTXATTRS_UNSPECIFIED);
return flatview_read_continue(cache->fv,
addr, MEMTXATTRS_UNSPECIFIED, buf, len,
addr1, l, mr);
}
/* Called from RCU critical section. address_space_write_cached uses this
* out of line function when the target is an MMIO or IOMMU region.
*/
MemTxResult
address_space_write_cached_slow(MemoryRegionCache *cache, hwaddr addr,
const void *buf, hwaddr len)
{
hwaddr addr1, l;
MemoryRegion *mr;
l = len;
mr = address_space_translate_cached(cache, addr, &addr1, &l, true,
MEMTXATTRS_UNSPECIFIED);
return flatview_write_continue(cache->fv,
addr, MEMTXATTRS_UNSPECIFIED, buf, len,
addr1, l, mr);
}
#define ARG1_DECL MemoryRegionCache *cache
#define ARG1 cache
#define SUFFIX _cached_slow
#define TRANSLATE(...) address_space_translate_cached(cache, __VA_ARGS__)
#define RCU_READ_LOCK() ((void)0)
#define RCU_READ_UNLOCK() ((void)0)
#include "memory_ldst.c.inc"
/* virtual memory access for debug (includes writing to ROM) */
int cpu_memory_rw_debug(CPUState *cpu, target_ulong addr,
void *ptr, target_ulong len, bool is_write)
{
hwaddr phys_addr;
target_ulong l, page;
uint8_t *buf = ptr;
cpu_synchronize_state(cpu);
while (len > 0) {
int asidx;
MemTxAttrs attrs;
MemTxResult res;
page = addr & TARGET_PAGE_MASK;
phys_addr = cpu_get_phys_page_attrs_debug(cpu, page, &attrs);
asidx = cpu_asidx_from_attrs(cpu, attrs);
/* if no physical page mapped, return an error */
if (phys_addr == -1)
return -1;
l = (page + TARGET_PAGE_SIZE) - addr;
if (l > len)
l = len;
phys_addr += (addr & ~TARGET_PAGE_MASK);
if (is_write) {
res = address_space_write_rom(cpu->cpu_ases[asidx].as, phys_addr,
attrs, buf, l);
} else {
res = address_space_read(cpu->cpu_ases[asidx].as, phys_addr,
attrs, buf, l);
}
if (res != MEMTX_OK) {
return -1;
}
len -= l;
buf += l;
addr += l;
}
return 0;
}
/*
* Allows code that needs to deal with migration bitmaps etc to still be built
* target independent.
*/
size_t qemu_target_page_size(void)
{
return TARGET_PAGE_SIZE;
}
int qemu_target_page_bits(void)
{
return TARGET_PAGE_BITS;
}
int qemu_target_page_bits_min(void)
{
return TARGET_PAGE_BITS_MIN;
}
bool cpu_physical_memory_is_io(hwaddr phys_addr)
{
MemoryRegion*mr;
hwaddr l = 1;
bool res;
RCU_READ_LOCK_GUARD();
mr = address_space_translate(&address_space_memory,
phys_addr, &phys_addr, &l, false,
MEMTXATTRS_UNSPECIFIED);
res = !(memory_region_is_ram(mr) || memory_region_is_romd(mr));
return res;
}
int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque)
{
RAMBlock *block;
int ret = 0;
RCU_READ_LOCK_GUARD();
RAMBLOCK_FOREACH(block) {
ret = func(block, opaque);
if (ret) {
break;
}
}
return ret;
}
/*
* Unmap pages of memory from start to start+length such that
* they a) read as 0, b) Trigger whatever fault mechanism
* the OS provides for postcopy.
* The pages must be unmapped by the end of the function.
* Returns: 0 on success, none-0 on failure
*
*/
int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length)
{
int ret = -1;
uint8_t *host_startaddr = rb->host + start;
if (!QEMU_PTR_IS_ALIGNED(host_startaddr, rb->page_size)) {
error_report("ram_block_discard_range: Unaligned start address: %p",
host_startaddr);
goto err;
}
if ((start + length) <= rb->max_length) {
bool need_madvise, need_fallocate;
if (!QEMU_IS_ALIGNED(length, rb->page_size)) {
error_report("ram_block_discard_range: Unaligned length: %zx",
length);
goto err;
}
errno = ENOTSUP; /* If we are missing MADVISE etc */
/* The logic here is messy;
* madvise DONTNEED fails for hugepages
* fallocate works on hugepages and shmem
* shared anonymous memory requires madvise REMOVE
*/
need_madvise = (rb->page_size == qemu_host_page_size);
need_fallocate = rb->fd != -1;
if (need_fallocate) {
/* For a file, this causes the area of the file to be zero'd
* if read, and for hugetlbfs also causes it to be unmapped
* so a userfault will trigger.
*/
#ifdef CONFIG_FALLOCATE_PUNCH_HOLE
ret = fallocate(rb->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
start, length);
if (ret) {
ret = -errno;
error_report("ram_block_discard_range: Failed to fallocate "
"%s:%" PRIx64 " +%zx (%d)",
rb->idstr, start, length, ret);
goto err;
}
#else
ret = -ENOSYS;
error_report("ram_block_discard_range: fallocate not available/file"
"%s:%" PRIx64 " +%zx (%d)",
rb->idstr, start, length, ret);
goto err;
#endif
}
if (need_madvise) {
/* For normal RAM this causes it to be unmapped,
* for shared memory it causes the local mapping to disappear
* and to fall back on the file contents (which we just
* fallocate'd away).
*/
#if defined(CONFIG_MADVISE)
if (qemu_ram_is_shared(rb) && rb->fd < 0) {
ret = madvise(host_startaddr, length, QEMU_MADV_REMOVE);
} else {
ret = madvise(host_startaddr, length, QEMU_MADV_DONTNEED);
}
if (ret) {
ret = -errno;
error_report("ram_block_discard_range: Failed to discard range "
"%s:%" PRIx64 " +%zx (%d)",
rb->idstr, start, length, ret);
goto err;
}
#else
ret = -ENOSYS;
error_report("ram_block_discard_range: MADVISE not available"
"%s:%" PRIx64 " +%zx (%d)",
rb->idstr, start, length, ret);
goto err;
#endif
}
trace_ram_block_discard_range(rb->idstr, host_startaddr, length,
need_madvise, need_fallocate, ret);
} else {
error_report("ram_block_discard_range: Overrun block '%s' (%" PRIu64
"/%zx/" RAM_ADDR_FMT")",
rb->idstr, start, length, rb->max_length);
}
err:
return ret;
}
bool ramblock_is_pmem(RAMBlock *rb)
{
return rb->flags & RAM_PMEM;
}
static void mtree_print_phys_entries(int start, int end, int skip, int ptr)
{
if (start == end - 1) {
qemu_printf("\t%3d ", start);
} else {
qemu_printf("\t%3d..%-3d ", start, end - 1);
}
qemu_printf(" skip=%d ", skip);
if (ptr == PHYS_MAP_NODE_NIL) {
qemu_printf(" ptr=NIL");
} else if (!skip) {
qemu_printf(" ptr=#%d", ptr);
} else {
qemu_printf(" ptr=[%d]", ptr);
}
qemu_printf("\n");
}
#define MR_SIZE(size) (int128_nz(size) ? (hwaddr)int128_get64( \
int128_sub((size), int128_one())) : 0)
void mtree_print_dispatch(AddressSpaceDispatch *d, MemoryRegion *root)
{
int i;
qemu_printf(" Dispatch\n");
qemu_printf(" Physical sections\n");
for (i = 0; i < d->map.sections_nb; ++i) {
MemoryRegionSection *s = d->map.sections + i;
const char *names[] = { " [unassigned]", " [not dirty]",
" [ROM]", " [watch]" };
qemu_printf(" #%d @" TARGET_FMT_plx ".." TARGET_FMT_plx
" %s%s%s%s%s",
i,
s->offset_within_address_space,
s->offset_within_address_space + MR_SIZE(s->mr->size),
s->mr->name ? s->mr->name : "(noname)",
i < ARRAY_SIZE(names) ? names[i] : "",
s->mr == root ? " [ROOT]" : "",
s == d->mru_section ? " [MRU]" : "",
s->mr->is_iommu ? " [iommu]" : "");
if (s->mr->alias) {
qemu_printf(" alias=%s", s->mr->alias->name ?
s->mr->alias->name : "noname");
}
qemu_printf("\n");
}
qemu_printf(" Nodes (%d bits per level, %d levels) ptr=[%d] skip=%d\n",
P_L2_BITS, P_L2_LEVELS, d->phys_map.ptr, d->phys_map.skip);
for (i = 0; i < d->map.nodes_nb; ++i) {
int j, jprev;
PhysPageEntry prev;
Node *n = d->map.nodes + i;
qemu_printf(" [%d]\n", i);
for (j = 0, jprev = 0, prev = *n[0]; j < ARRAY_SIZE(*n); ++j) {
PhysPageEntry *pe = *n + j;
if (pe->ptr == prev.ptr && pe->skip == prev.skip) {
continue;
}
mtree_print_phys_entries(jprev, j, prev.skip, prev.ptr);
jprev = j;
prev = *pe;
}
if (jprev != ARRAY_SIZE(*n)) {
mtree_print_phys_entries(jprev, j, prev.skip, prev.ptr);
}
}
}
/*
* If positive, discarding RAM is disabled. If negative, discarding RAM is
* required to work and cannot be disabled.
*/
static int ram_block_discard_disabled;
int ram_block_discard_disable(bool state)
{
int old;
if (!state) {
qatomic_dec(&ram_block_discard_disabled);
return 0;
}
do {
old = qatomic_read(&ram_block_discard_disabled);
if (old < 0) {
return -EBUSY;
}
} while (qatomic_cmpxchg(&ram_block_discard_disabled,
old, old + 1) != old);
return 0;
}
int ram_block_discard_require(bool state)
{
int old;
if (!state) {
qatomic_inc(&ram_block_discard_disabled);
return 0;
}
do {
old = qatomic_read(&ram_block_discard_disabled);
if (old > 0) {
return -EBUSY;
}
} while (qatomic_cmpxchg(&ram_block_discard_disabled,
old, old - 1) != old);
return 0;
}
bool ram_block_discard_is_disabled(void)
{
return qatomic_read(&ram_block_discard_disabled) > 0;
}
bool ram_block_discard_is_required(void)
{
return qatomic_read(&ram_block_discard_disabled) < 0;
}