linux/arch/powerpc/kvm/book3s_64_mmu_hv.c
Alexander Graf d2a1b483a4 KVM: PPC: Add HPT preallocator
We're currently allocating 16MB of linear memory on demand when creating
a guest. That does work some times, but finding 16MB of linear memory
available in the system at runtime is definitely not a given.

So let's add another command line option similar to the RMA preallocator,
that we can use to keep a pool of page tables around. Now, when a guest
gets created it has a pretty low chance of receiving an OOM.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:57:28 +02:00

1024 lines
26 KiB
C

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
*/
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/hugetlb.h>
#include <linux/vmalloc.h>
#include <asm/tlbflush.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/mmu-hash64.h>
#include <asm/hvcall.h>
#include <asm/synch.h>
#include <asm/ppc-opcode.h>
#include <asm/cputable.h>
/* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */
#define MAX_LPID_970 63
#define NR_LPIDS (LPID_RSVD + 1)
unsigned long lpid_inuse[BITS_TO_LONGS(NR_LPIDS)];
long kvmppc_alloc_hpt(struct kvm *kvm)
{
unsigned long hpt;
unsigned long lpid;
struct revmap_entry *rev;
struct kvmppc_linear_info *li;
/* Allocate guest's hashed page table */
li = kvm_alloc_hpt();
if (li) {
/* using preallocated memory */
hpt = (ulong)li->base_virt;
kvm->arch.hpt_li = li;
} else {
/* using dynamic memory */
hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|
__GFP_NOWARN, HPT_ORDER - PAGE_SHIFT);
}
if (!hpt) {
pr_err("kvm_alloc_hpt: Couldn't alloc HPT\n");
return -ENOMEM;
}
kvm->arch.hpt_virt = hpt;
/* Allocate reverse map array */
rev = vmalloc(sizeof(struct revmap_entry) * HPT_NPTE);
if (!rev) {
pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n");
goto out_freehpt;
}
kvm->arch.revmap = rev;
/* Allocate the guest's logical partition ID */
do {
lpid = find_first_zero_bit(lpid_inuse, NR_LPIDS);
if (lpid >= NR_LPIDS) {
pr_err("kvm_alloc_hpt: No LPIDs free\n");
goto out_freeboth;
}
} while (test_and_set_bit(lpid, lpid_inuse));
kvm->arch.sdr1 = __pa(hpt) | (HPT_ORDER - 18);
kvm->arch.lpid = lpid;
pr_info("KVM guest htab at %lx, LPID %lx\n", hpt, lpid);
return 0;
out_freeboth:
vfree(rev);
out_freehpt:
free_pages(hpt, HPT_ORDER - PAGE_SHIFT);
return -ENOMEM;
}
void kvmppc_free_hpt(struct kvm *kvm)
{
clear_bit(kvm->arch.lpid, lpid_inuse);
vfree(kvm->arch.revmap);
if (kvm->arch.hpt_li)
kvm_release_hpt(kvm->arch.hpt_li);
else
free_pages(kvm->arch.hpt_virt, HPT_ORDER - PAGE_SHIFT);
}
/* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize)
{
return (pgsize > 0x1000) ? HPTE_V_LARGE : 0;
}
/* Bits in second HPTE dword for pagesize 4k, 64k or 16M */
static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize)
{
return (pgsize == 0x10000) ? 0x1000 : 0;
}
void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
unsigned long porder)
{
unsigned long i;
unsigned long npages;
unsigned long hp_v, hp_r;
unsigned long addr, hash;
unsigned long psize;
unsigned long hp0, hp1;
long ret;
psize = 1ul << porder;
npages = memslot->npages >> (porder - PAGE_SHIFT);
/* VRMA can't be > 1TB */
if (npages > 1ul << (40 - porder))
npages = 1ul << (40 - porder);
/* Can't use more than 1 HPTE per HPTEG */
if (npages > HPT_NPTEG)
npages = HPT_NPTEG;
hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
hp1 = hpte1_pgsize_encoding(psize) |
HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX;
for (i = 0; i < npages; ++i) {
addr = i << porder;
/* can't use hpt_hash since va > 64 bits */
hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & HPT_HASH_MASK;
/*
* We assume that the hash table is empty and no
* vcpus are using it at this stage. Since we create
* at most one HPTE per HPTEG, we just assume entry 7
* is available and use it.
*/
hash = (hash << 3) + 7;
hp_v = hp0 | ((addr >> 16) & ~0x7fUL);
hp_r = hp1 | addr;
ret = kvmppc_virtmode_h_enter(vcpu, H_EXACT, hash, hp_v, hp_r);
if (ret != H_SUCCESS) {
pr_err("KVM: map_vrma at %lx failed, ret=%ld\n",
addr, ret);
break;
}
}
}
int kvmppc_mmu_hv_init(void)
{
unsigned long host_lpid, rsvd_lpid;
if (!cpu_has_feature(CPU_FTR_HVMODE))
return -EINVAL;
memset(lpid_inuse, 0, sizeof(lpid_inuse));
if (cpu_has_feature(CPU_FTR_ARCH_206)) {
host_lpid = mfspr(SPRN_LPID); /* POWER7 */
rsvd_lpid = LPID_RSVD;
} else {
host_lpid = 0; /* PPC970 */
rsvd_lpid = MAX_LPID_970;
}
set_bit(host_lpid, lpid_inuse);
/* rsvd_lpid is reserved for use in partition switching */
set_bit(rsvd_lpid, lpid_inuse);
return 0;
}
void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
{
}
static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu)
{
kvmppc_set_msr(vcpu, MSR_SF | MSR_ME);
}
/*
* This is called to get a reference to a guest page if there isn't
* one already in the kvm->arch.slot_phys[][] arrays.
*/
static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn,
struct kvm_memory_slot *memslot,
unsigned long psize)
{
unsigned long start;
long np, err;
struct page *page, *hpage, *pages[1];
unsigned long s, pgsize;
unsigned long *physp;
unsigned int is_io, got, pgorder;
struct vm_area_struct *vma;
unsigned long pfn, i, npages;
physp = kvm->arch.slot_phys[memslot->id];
if (!physp)
return -EINVAL;
if (physp[gfn - memslot->base_gfn])
return 0;
is_io = 0;
got = 0;
page = NULL;
pgsize = psize;
err = -EINVAL;
start = gfn_to_hva_memslot(memslot, gfn);
/* Instantiate and get the page we want access to */
np = get_user_pages_fast(start, 1, 1, pages);
if (np != 1) {
/* Look up the vma for the page */
down_read(&current->mm->mmap_sem);
vma = find_vma(current->mm, start);
if (!vma || vma->vm_start > start ||
start + psize > vma->vm_end ||
!(vma->vm_flags & VM_PFNMAP))
goto up_err;
is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
pfn = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
/* check alignment of pfn vs. requested page size */
if (psize > PAGE_SIZE && (pfn & ((psize >> PAGE_SHIFT) - 1)))
goto up_err;
up_read(&current->mm->mmap_sem);
} else {
page = pages[0];
got = KVMPPC_GOT_PAGE;
/* See if this is a large page */
s = PAGE_SIZE;
if (PageHuge(page)) {
hpage = compound_head(page);
s <<= compound_order(hpage);
/* Get the whole large page if slot alignment is ok */
if (s > psize && slot_is_aligned(memslot, s) &&
!(memslot->userspace_addr & (s - 1))) {
start &= ~(s - 1);
pgsize = s;
page = hpage;
}
}
if (s < psize)
goto out;
pfn = page_to_pfn(page);
}
npages = pgsize >> PAGE_SHIFT;
pgorder = __ilog2(npages);
physp += (gfn - memslot->base_gfn) & ~(npages - 1);
spin_lock(&kvm->arch.slot_phys_lock);
for (i = 0; i < npages; ++i) {
if (!physp[i]) {
physp[i] = ((pfn + i) << PAGE_SHIFT) +
got + is_io + pgorder;
got = 0;
}
}
spin_unlock(&kvm->arch.slot_phys_lock);
err = 0;
out:
if (got) {
if (PageHuge(page))
page = compound_head(page);
put_page(page);
}
return err;
up_err:
up_read(&current->mm->mmap_sem);
return err;
}
/*
* We come here on a H_ENTER call from the guest when we are not
* using mmu notifiers and we don't have the requested page pinned
* already.
*/
long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
long pte_index, unsigned long pteh, unsigned long ptel)
{
struct kvm *kvm = vcpu->kvm;
unsigned long psize, gpa, gfn;
struct kvm_memory_slot *memslot;
long ret;
if (kvm->arch.using_mmu_notifiers)
goto do_insert;
psize = hpte_page_size(pteh, ptel);
if (!psize)
return H_PARAMETER;
pteh &= ~(HPTE_V_HVLOCK | HPTE_V_ABSENT | HPTE_V_VALID);
/* Find the memslot (if any) for this address */
gpa = (ptel & HPTE_R_RPN) & ~(psize - 1);
gfn = gpa >> PAGE_SHIFT;
memslot = gfn_to_memslot(kvm, gfn);
if (memslot && !(memslot->flags & KVM_MEMSLOT_INVALID)) {
if (!slot_is_aligned(memslot, psize))
return H_PARAMETER;
if (kvmppc_get_guest_page(kvm, gfn, memslot, psize) < 0)
return H_PARAMETER;
}
do_insert:
/* Protect linux PTE lookup from page table destruction */
rcu_read_lock_sched(); /* this disables preemption too */
vcpu->arch.pgdir = current->mm->pgd;
ret = kvmppc_h_enter(vcpu, flags, pte_index, pteh, ptel);
rcu_read_unlock_sched();
if (ret == H_TOO_HARD) {
/* this can't happen */
pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");
ret = H_RESOURCE; /* or something */
}
return ret;
}
static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu,
gva_t eaddr)
{
u64 mask;
int i;
for (i = 0; i < vcpu->arch.slb_nr; i++) {
if (!(vcpu->arch.slb[i].orige & SLB_ESID_V))
continue;
if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T)
mask = ESID_MASK_1T;
else
mask = ESID_MASK;
if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0)
return &vcpu->arch.slb[i];
}
return NULL;
}
static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r,
unsigned long ea)
{
unsigned long ra_mask;
ra_mask = hpte_page_size(v, r) - 1;
return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask);
}
static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
struct kvmppc_pte *gpte, bool data)
{
struct kvm *kvm = vcpu->kvm;
struct kvmppc_slb *slbe;
unsigned long slb_v;
unsigned long pp, key;
unsigned long v, gr;
unsigned long *hptep;
int index;
int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR);
/* Get SLB entry */
if (virtmode) {
slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr);
if (!slbe)
return -EINVAL;
slb_v = slbe->origv;
} else {
/* real mode access */
slb_v = vcpu->kvm->arch.vrma_slb_v;
}
/* Find the HPTE in the hash table */
index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v,
HPTE_V_VALID | HPTE_V_ABSENT);
if (index < 0)
return -ENOENT;
hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4));
v = hptep[0] & ~HPTE_V_HVLOCK;
gr = kvm->arch.revmap[index].guest_rpte;
/* Unlock the HPTE */
asm volatile("lwsync" : : : "memory");
hptep[0] = v;
gpte->eaddr = eaddr;
gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff);
/* Get PP bits and key for permission check */
pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
key &= slb_v;
/* Calculate permissions */
gpte->may_read = hpte_read_permission(pp, key);
gpte->may_write = hpte_write_permission(pp, key);
gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G));
/* Storage key permission check for POWER7 */
if (data && virtmode && cpu_has_feature(CPU_FTR_ARCH_206)) {
int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr);
if (amrfield & 1)
gpte->may_read = 0;
if (amrfield & 2)
gpte->may_write = 0;
}
/* Get the guest physical address */
gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr);
return 0;
}
/*
* Quick test for whether an instruction is a load or a store.
* If the instruction is a load or a store, then this will indicate
* which it is, at least on server processors. (Embedded processors
* have some external PID instructions that don't follow the rule
* embodied here.) If the instruction isn't a load or store, then
* this doesn't return anything useful.
*/
static int instruction_is_store(unsigned int instr)
{
unsigned int mask;
mask = 0x10000000;
if ((instr & 0xfc000000) == 0x7c000000)
mask = 0x100; /* major opcode 31 */
return (instr & mask) != 0;
}
static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned long gpa, int is_store)
{
int ret;
u32 last_inst;
unsigned long srr0 = kvmppc_get_pc(vcpu);
/* We try to load the last instruction. We don't let
* emulate_instruction do it as it doesn't check what
* kvmppc_ld returns.
* If we fail, we just return to the guest and try executing it again.
*/
if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) {
ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false);
if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED)
return RESUME_GUEST;
vcpu->arch.last_inst = last_inst;
}
/*
* WARNING: We do not know for sure whether the instruction we just
* read from memory is the same that caused the fault in the first
* place. If the instruction we read is neither an load or a store,
* then it can't access memory, so we don't need to worry about
* enforcing access permissions. So, assuming it is a load or
* store, we just check that its direction (load or store) is
* consistent with the original fault, since that's what we
* checked the access permissions against. If there is a mismatch
* we just return and retry the instruction.
*/
if (instruction_is_store(vcpu->arch.last_inst) != !!is_store)
return RESUME_GUEST;
/*
* Emulated accesses are emulated by looking at the hash for
* translation once, then performing the access later. The
* translation could be invalidated in the meantime in which
* point performing the subsequent memory access on the old
* physical address could possibly be a security hole for the
* guest (but not the host).
*
* This is less of an issue for MMIO stores since they aren't
* globally visible. It could be an issue for MMIO loads to
* a certain extent but we'll ignore it for now.
*/
vcpu->arch.paddr_accessed = gpa;
return kvmppc_emulate_mmio(run, vcpu);
}
int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned long ea, unsigned long dsisr)
{
struct kvm *kvm = vcpu->kvm;
unsigned long *hptep, hpte[3], r;
unsigned long mmu_seq, psize, pte_size;
unsigned long gfn, hva, pfn;
struct kvm_memory_slot *memslot;
unsigned long *rmap;
struct revmap_entry *rev;
struct page *page, *pages[1];
long index, ret, npages;
unsigned long is_io;
unsigned int writing, write_ok;
struct vm_area_struct *vma;
unsigned long rcbits;
/*
* Real-mode code has already searched the HPT and found the
* entry we're interested in. Lock the entry and check that
* it hasn't changed. If it has, just return and re-execute the
* instruction.
*/
if (ea != vcpu->arch.pgfault_addr)
return RESUME_GUEST;
index = vcpu->arch.pgfault_index;
hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4));
rev = &kvm->arch.revmap[index];
preempt_disable();
while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
cpu_relax();
hpte[0] = hptep[0] & ~HPTE_V_HVLOCK;
hpte[1] = hptep[1];
hpte[2] = r = rev->guest_rpte;
asm volatile("lwsync" : : : "memory");
hptep[0] = hpte[0];
preempt_enable();
if (hpte[0] != vcpu->arch.pgfault_hpte[0] ||
hpte[1] != vcpu->arch.pgfault_hpte[1])
return RESUME_GUEST;
/* Translate the logical address and get the page */
psize = hpte_page_size(hpte[0], r);
gfn = hpte_rpn(r, psize);
memslot = gfn_to_memslot(kvm, gfn);
/* No memslot means it's an emulated MMIO region */
if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
unsigned long gpa = (gfn << PAGE_SHIFT) | (ea & (psize - 1));
return kvmppc_hv_emulate_mmio(run, vcpu, gpa,
dsisr & DSISR_ISSTORE);
}
if (!kvm->arch.using_mmu_notifiers)
return -EFAULT; /* should never get here */
/* used to check for invalidations in progress */
mmu_seq = kvm->mmu_notifier_seq;
smp_rmb();
is_io = 0;
pfn = 0;
page = NULL;
pte_size = PAGE_SIZE;
writing = (dsisr & DSISR_ISSTORE) != 0;
/* If writing != 0, then the HPTE must allow writing, if we get here */
write_ok = writing;
hva = gfn_to_hva_memslot(memslot, gfn);
npages = get_user_pages_fast(hva, 1, writing, pages);
if (npages < 1) {
/* Check if it's an I/O mapping */
down_read(&current->mm->mmap_sem);
vma = find_vma(current->mm, hva);
if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end &&
(vma->vm_flags & VM_PFNMAP)) {
pfn = vma->vm_pgoff +
((hva - vma->vm_start) >> PAGE_SHIFT);
pte_size = psize;
is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
write_ok = vma->vm_flags & VM_WRITE;
}
up_read(&current->mm->mmap_sem);
if (!pfn)
return -EFAULT;
} else {
page = pages[0];
if (PageHuge(page)) {
page = compound_head(page);
pte_size <<= compound_order(page);
}
/* if the guest wants write access, see if that is OK */
if (!writing && hpte_is_writable(r)) {
pte_t *ptep, pte;
/*
* We need to protect against page table destruction
* while looking up and updating the pte.
*/
rcu_read_lock_sched();
ptep = find_linux_pte_or_hugepte(current->mm->pgd,
hva, NULL);
if (ptep && pte_present(*ptep)) {
pte = kvmppc_read_update_linux_pte(ptep, 1);
if (pte_write(pte))
write_ok = 1;
}
rcu_read_unlock_sched();
}
pfn = page_to_pfn(page);
}
ret = -EFAULT;
if (psize > pte_size)
goto out_put;
/* Check WIMG vs. the actual page we're accessing */
if (!hpte_cache_flags_ok(r, is_io)) {
if (is_io)
return -EFAULT;
/*
* Allow guest to map emulated device memory as
* uncacheable, but actually make it cacheable.
*/
r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M;
}
/* Set the HPTE to point to pfn */
r = (r & ~(HPTE_R_PP0 - pte_size)) | (pfn << PAGE_SHIFT);
if (hpte_is_writable(r) && !write_ok)
r = hpte_make_readonly(r);
ret = RESUME_GUEST;
preempt_disable();
while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
cpu_relax();
if ((hptep[0] & ~HPTE_V_HVLOCK) != hpte[0] || hptep[1] != hpte[1] ||
rev->guest_rpte != hpte[2])
/* HPTE has been changed under us; let the guest retry */
goto out_unlock;
hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
rmap = &memslot->rmap[gfn - memslot->base_gfn];
lock_rmap(rmap);
/* Check if we might have been invalidated; let the guest retry if so */
ret = RESUME_GUEST;
if (mmu_notifier_retry(vcpu, mmu_seq)) {
unlock_rmap(rmap);
goto out_unlock;
}
/* Only set R/C in real HPTE if set in both *rmap and guest_rpte */
rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
r &= rcbits | ~(HPTE_R_R | HPTE_R_C);
if (hptep[0] & HPTE_V_VALID) {
/* HPTE was previously valid, so we need to invalidate it */
unlock_rmap(rmap);
hptep[0] |= HPTE_V_ABSENT;
kvmppc_invalidate_hpte(kvm, hptep, index);
/* don't lose previous R and C bits */
r |= hptep[1] & (HPTE_R_R | HPTE_R_C);
} else {
kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0);
}
hptep[1] = r;
eieio();
hptep[0] = hpte[0];
asm volatile("ptesync" : : : "memory");
preempt_enable();
if (page && hpte_is_writable(r))
SetPageDirty(page);
out_put:
if (page)
put_page(page);
return ret;
out_unlock:
hptep[0] &= ~HPTE_V_HVLOCK;
preempt_enable();
goto out_put;
}
static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
int (*handler)(struct kvm *kvm, unsigned long *rmapp,
unsigned long gfn))
{
int ret;
int retval = 0;
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
slots = kvm_memslots(kvm);
kvm_for_each_memslot(memslot, slots) {
unsigned long start = memslot->userspace_addr;
unsigned long end;
end = start + (memslot->npages << PAGE_SHIFT);
if (hva >= start && hva < end) {
gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
ret = handler(kvm, &memslot->rmap[gfn_offset],
memslot->base_gfn + gfn_offset);
retval |= ret;
}
}
return retval;
}
static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
unsigned long gfn)
{
struct revmap_entry *rev = kvm->arch.revmap;
unsigned long h, i, j;
unsigned long *hptep;
unsigned long ptel, psize, rcbits;
for (;;) {
lock_rmap(rmapp);
if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
unlock_rmap(rmapp);
break;
}
/*
* To avoid an ABBA deadlock with the HPTE lock bit,
* we can't spin on the HPTE lock while holding the
* rmap chain lock.
*/
i = *rmapp & KVMPPC_RMAP_INDEX;
hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
/* unlock rmap before spinning on the HPTE lock */
unlock_rmap(rmapp);
while (hptep[0] & HPTE_V_HVLOCK)
cpu_relax();
continue;
}
j = rev[i].forw;
if (j == i) {
/* chain is now empty */
*rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
} else {
/* remove i from chain */
h = rev[i].back;
rev[h].forw = j;
rev[j].back = h;
rev[i].forw = rev[i].back = i;
*rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
}
/* Now check and modify the HPTE */
ptel = rev[i].guest_rpte;
psize = hpte_page_size(hptep[0], ptel);
if ((hptep[0] & HPTE_V_VALID) &&
hpte_rpn(ptel, psize) == gfn) {
hptep[0] |= HPTE_V_ABSENT;
kvmppc_invalidate_hpte(kvm, hptep, i);
/* Harvest R and C */
rcbits = hptep[1] & (HPTE_R_R | HPTE_R_C);
*rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
rev[i].guest_rpte = ptel | rcbits;
}
unlock_rmap(rmapp);
hptep[0] &= ~HPTE_V_HVLOCK;
}
return 0;
}
int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
{
if (kvm->arch.using_mmu_notifiers)
kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
return 0;
}
static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
unsigned long gfn)
{
struct revmap_entry *rev = kvm->arch.revmap;
unsigned long head, i, j;
unsigned long *hptep;
int ret = 0;
retry:
lock_rmap(rmapp);
if (*rmapp & KVMPPC_RMAP_REFERENCED) {
*rmapp &= ~KVMPPC_RMAP_REFERENCED;
ret = 1;
}
if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
unlock_rmap(rmapp);
return ret;
}
i = head = *rmapp & KVMPPC_RMAP_INDEX;
do {
hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
j = rev[i].forw;
/* If this HPTE isn't referenced, ignore it */
if (!(hptep[1] & HPTE_R_R))
continue;
if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
/* unlock rmap before spinning on the HPTE lock */
unlock_rmap(rmapp);
while (hptep[0] & HPTE_V_HVLOCK)
cpu_relax();
goto retry;
}
/* Now check and modify the HPTE */
if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_R)) {
kvmppc_clear_ref_hpte(kvm, hptep, i);
rev[i].guest_rpte |= HPTE_R_R;
ret = 1;
}
hptep[0] &= ~HPTE_V_HVLOCK;
} while ((i = j) != head);
unlock_rmap(rmapp);
return ret;
}
int kvm_age_hva(struct kvm *kvm, unsigned long hva)
{
if (!kvm->arch.using_mmu_notifiers)
return 0;
return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
}
static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
unsigned long gfn)
{
struct revmap_entry *rev = kvm->arch.revmap;
unsigned long head, i, j;
unsigned long *hp;
int ret = 1;
if (*rmapp & KVMPPC_RMAP_REFERENCED)
return 1;
lock_rmap(rmapp);
if (*rmapp & KVMPPC_RMAP_REFERENCED)
goto out;
if (*rmapp & KVMPPC_RMAP_PRESENT) {
i = head = *rmapp & KVMPPC_RMAP_INDEX;
do {
hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4));
j = rev[i].forw;
if (hp[1] & HPTE_R_R)
goto out;
} while ((i = j) != head);
}
ret = 0;
out:
unlock_rmap(rmapp);
return ret;
}
int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
{
if (!kvm->arch.using_mmu_notifiers)
return 0;
return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp);
}
void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
{
if (!kvm->arch.using_mmu_notifiers)
return;
kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
}
static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp)
{
struct revmap_entry *rev = kvm->arch.revmap;
unsigned long head, i, j;
unsigned long *hptep;
int ret = 0;
retry:
lock_rmap(rmapp);
if (*rmapp & KVMPPC_RMAP_CHANGED) {
*rmapp &= ~KVMPPC_RMAP_CHANGED;
ret = 1;
}
if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
unlock_rmap(rmapp);
return ret;
}
i = head = *rmapp & KVMPPC_RMAP_INDEX;
do {
hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
j = rev[i].forw;
if (!(hptep[1] & HPTE_R_C))
continue;
if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
/* unlock rmap before spinning on the HPTE lock */
unlock_rmap(rmapp);
while (hptep[0] & HPTE_V_HVLOCK)
cpu_relax();
goto retry;
}
/* Now check and modify the HPTE */
if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_C)) {
/* need to make it temporarily absent to clear C */
hptep[0] |= HPTE_V_ABSENT;
kvmppc_invalidate_hpte(kvm, hptep, i);
hptep[1] &= ~HPTE_R_C;
eieio();
hptep[0] = (hptep[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
rev[i].guest_rpte |= HPTE_R_C;
ret = 1;
}
hptep[0] &= ~HPTE_V_HVLOCK;
} while ((i = j) != head);
unlock_rmap(rmapp);
return ret;
}
long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
{
unsigned long i;
unsigned long *rmapp, *map;
preempt_disable();
rmapp = memslot->rmap;
map = memslot->dirty_bitmap;
for (i = 0; i < memslot->npages; ++i) {
if (kvm_test_clear_dirty(kvm, rmapp))
__set_bit_le(i, map);
++rmapp;
}
preempt_enable();
return 0;
}
void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa,
unsigned long *nb_ret)
{
struct kvm_memory_slot *memslot;
unsigned long gfn = gpa >> PAGE_SHIFT;
struct page *page, *pages[1];
int npages;
unsigned long hva, psize, offset;
unsigned long pa;
unsigned long *physp;
memslot = gfn_to_memslot(kvm, gfn);
if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
return NULL;
if (!kvm->arch.using_mmu_notifiers) {
physp = kvm->arch.slot_phys[memslot->id];
if (!physp)
return NULL;
physp += gfn - memslot->base_gfn;
pa = *physp;
if (!pa) {
if (kvmppc_get_guest_page(kvm, gfn, memslot,
PAGE_SIZE) < 0)
return NULL;
pa = *physp;
}
page = pfn_to_page(pa >> PAGE_SHIFT);
} else {
hva = gfn_to_hva_memslot(memslot, gfn);
npages = get_user_pages_fast(hva, 1, 1, pages);
if (npages < 1)
return NULL;
page = pages[0];
}
psize = PAGE_SIZE;
if (PageHuge(page)) {
page = compound_head(page);
psize <<= compound_order(page);
}
if (!kvm->arch.using_mmu_notifiers)
get_page(page);
offset = gpa & (psize - 1);
if (nb_ret)
*nb_ret = psize - offset;
return page_address(page) + offset;
}
void kvmppc_unpin_guest_page(struct kvm *kvm, void *va)
{
struct page *page = virt_to_page(va);
page = compound_head(page);
put_page(page);
}
void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
{
struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
if (cpu_has_feature(CPU_FTR_ARCH_206))
vcpu->arch.slb_nr = 32; /* POWER7 */
else
vcpu->arch.slb_nr = 64;
mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr;
vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
}