linux/arch/powerpc/kvm/book3s_32_mmu_host.c
Alexander Graf 468a12c2b5 KVM: PPC: Use get/set for to_svcpu to help preemption
When running the 64-bit Book3s PR code without CONFIG_PREEMPT_NONE, we were
doing a few things wrong, most notably access to PACA fields without making
sure that the pointers stay stable accross the access (preempt_disable()).

This patch moves to_svcpu towards a get/put model which allows us to disable
preemption while accessing the shadow vcpu fields in the PACA. That way we
can run preemptible and everyone's happy!

Reported-by: Jörg Sommer <joerg@alea.gnuu.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:52:30 +02:00

394 lines
9.6 KiB
C

/*
* Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
*
* Authors:
* Alexander Graf <agraf@suse.de>
*
* 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.
*/
#include <linux/kvm_host.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/mmu-hash32.h>
#include <asm/machdep.h>
#include <asm/mmu_context.h>
#include <asm/hw_irq.h>
/* #define DEBUG_MMU */
/* #define DEBUG_SR */
#ifdef DEBUG_MMU
#define dprintk_mmu(a, ...) printk(KERN_INFO a, __VA_ARGS__)
#else
#define dprintk_mmu(a, ...) do { } while(0)
#endif
#ifdef DEBUG_SR
#define dprintk_sr(a, ...) printk(KERN_INFO a, __VA_ARGS__)
#else
#define dprintk_sr(a, ...) do { } while(0)
#endif
#if PAGE_SHIFT != 12
#error Unknown page size
#endif
#ifdef CONFIG_SMP
#error XXX need to grab mmu_hash_lock
#endif
#ifdef CONFIG_PTE_64BIT
#error Only 32 bit pages are supported for now
#endif
static ulong htab;
static u32 htabmask;
void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
{
volatile u32 *pteg;
/* Remove from host HTAB */
pteg = (u32*)pte->slot;
pteg[0] = 0;
/* And make sure it's gone from the TLB too */
asm volatile ("sync");
asm volatile ("tlbie %0" : : "r" (pte->pte.eaddr) : "memory");
asm volatile ("sync");
asm volatile ("tlbsync");
}
/* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
* a hash, so we don't waste cycles on looping */
static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
{
return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
}
static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
{
struct kvmppc_sid_map *map;
u16 sid_map_mask;
if (vcpu->arch.shared->msr & MSR_PR)
gvsid |= VSID_PR;
sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
map = &to_book3s(vcpu)->sid_map[sid_map_mask];
if (map->guest_vsid == gvsid) {
dprintk_sr("SR: Searching 0x%llx -> 0x%llx\n",
gvsid, map->host_vsid);
return map;
}
map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
if (map->guest_vsid == gvsid) {
dprintk_sr("SR: Searching 0x%llx -> 0x%llx\n",
gvsid, map->host_vsid);
return map;
}
dprintk_sr("SR: Searching 0x%llx -> not found\n", gvsid);
return NULL;
}
static u32 *kvmppc_mmu_get_pteg(struct kvm_vcpu *vcpu, u32 vsid, u32 eaddr,
bool primary)
{
u32 page, hash;
ulong pteg = htab;
page = (eaddr & ~ESID_MASK) >> 12;
hash = ((vsid ^ page) << 6);
if (!primary)
hash = ~hash;
hash &= htabmask;
pteg |= hash;
dprintk_mmu("htab: %lx | hash: %x | htabmask: %x | pteg: %lx\n",
htab, hash, htabmask, pteg);
return (u32*)pteg;
}
extern char etext[];
int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte)
{
pfn_t hpaddr;
u64 va;
u64 vsid;
struct kvmppc_sid_map *map;
volatile u32 *pteg;
u32 eaddr = orig_pte->eaddr;
u32 pteg0, pteg1;
register int rr = 0;
bool primary = false;
bool evict = false;
struct hpte_cache *pte;
int r = 0;
/* Get host physical address for gpa */
hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT);
if (is_error_pfn(hpaddr)) {
printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n",
orig_pte->eaddr);
r = -EINVAL;
goto out;
}
hpaddr <<= PAGE_SHIFT;
/* and write the mapping ea -> hpa into the pt */
vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
map = find_sid_vsid(vcpu, vsid);
if (!map) {
kvmppc_mmu_map_segment(vcpu, eaddr);
map = find_sid_vsid(vcpu, vsid);
}
BUG_ON(!map);
vsid = map->host_vsid;
va = (vsid << SID_SHIFT) | (eaddr & ~ESID_MASK);
next_pteg:
if (rr == 16) {
primary = !primary;
evict = true;
rr = 0;
}
pteg = kvmppc_mmu_get_pteg(vcpu, vsid, eaddr, primary);
/* not evicting yet */
if (!evict && (pteg[rr] & PTE_V)) {
rr += 2;
goto next_pteg;
}
dprintk_mmu("KVM: old PTEG: %p (%d)\n", pteg, rr);
dprintk_mmu("KVM: %08x - %08x\n", pteg[0], pteg[1]);
dprintk_mmu("KVM: %08x - %08x\n", pteg[2], pteg[3]);
dprintk_mmu("KVM: %08x - %08x\n", pteg[4], pteg[5]);
dprintk_mmu("KVM: %08x - %08x\n", pteg[6], pteg[7]);
dprintk_mmu("KVM: %08x - %08x\n", pteg[8], pteg[9]);
dprintk_mmu("KVM: %08x - %08x\n", pteg[10], pteg[11]);
dprintk_mmu("KVM: %08x - %08x\n", pteg[12], pteg[13]);
dprintk_mmu("KVM: %08x - %08x\n", pteg[14], pteg[15]);
pteg0 = ((eaddr & 0x0fffffff) >> 22) | (vsid << 7) | PTE_V |
(primary ? 0 : PTE_SEC);
pteg1 = hpaddr | PTE_M | PTE_R | PTE_C;
if (orig_pte->may_write) {
pteg1 |= PP_RWRW;
mark_page_dirty(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
} else {
pteg1 |= PP_RWRX;
}
local_irq_disable();
if (pteg[rr]) {
pteg[rr] = 0;
asm volatile ("sync");
}
pteg[rr + 1] = pteg1;
pteg[rr] = pteg0;
asm volatile ("sync");
local_irq_enable();
dprintk_mmu("KVM: new PTEG: %p\n", pteg);
dprintk_mmu("KVM: %08x - %08x\n", pteg[0], pteg[1]);
dprintk_mmu("KVM: %08x - %08x\n", pteg[2], pteg[3]);
dprintk_mmu("KVM: %08x - %08x\n", pteg[4], pteg[5]);
dprintk_mmu("KVM: %08x - %08x\n", pteg[6], pteg[7]);
dprintk_mmu("KVM: %08x - %08x\n", pteg[8], pteg[9]);
dprintk_mmu("KVM: %08x - %08x\n", pteg[10], pteg[11]);
dprintk_mmu("KVM: %08x - %08x\n", pteg[12], pteg[13]);
dprintk_mmu("KVM: %08x - %08x\n", pteg[14], pteg[15]);
/* Now tell our Shadow PTE code about the new page */
pte = kvmppc_mmu_hpte_cache_next(vcpu);
dprintk_mmu("KVM: %c%c Map 0x%llx: [%lx] 0x%llx (0x%llx) -> %lx\n",
orig_pte->may_write ? 'w' : '-',
orig_pte->may_execute ? 'x' : '-',
orig_pte->eaddr, (ulong)pteg, va,
orig_pte->vpage, hpaddr);
pte->slot = (ulong)&pteg[rr];
pte->host_va = va;
pte->pte = *orig_pte;
pte->pfn = hpaddr >> PAGE_SHIFT;
kvmppc_mmu_hpte_cache_map(vcpu, pte);
out:
return r;
}
static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
{
struct kvmppc_sid_map *map;
struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
u16 sid_map_mask;
static int backwards_map = 0;
if (vcpu->arch.shared->msr & MSR_PR)
gvsid |= VSID_PR;
/* We might get collisions that trap in preceding order, so let's
map them differently */
sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
if (backwards_map)
sid_map_mask = SID_MAP_MASK - sid_map_mask;
map = &to_book3s(vcpu)->sid_map[sid_map_mask];
/* Make sure we're taking the other map next time */
backwards_map = !backwards_map;
/* Uh-oh ... out of mappings. Let's flush! */
if (vcpu_book3s->vsid_next >= VSID_POOL_SIZE) {
vcpu_book3s->vsid_next = 0;
memset(vcpu_book3s->sid_map, 0,
sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
kvmppc_mmu_pte_flush(vcpu, 0, 0);
kvmppc_mmu_flush_segments(vcpu);
}
map->host_vsid = vcpu_book3s->vsid_pool[vcpu_book3s->vsid_next];
vcpu_book3s->vsid_next++;
map->guest_vsid = gvsid;
map->valid = true;
return map;
}
int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
{
u32 esid = eaddr >> SID_SHIFT;
u64 gvsid;
u32 sr;
struct kvmppc_sid_map *map;
struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
int r = 0;
if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
/* Invalidate an entry */
svcpu->sr[esid] = SR_INVALID;
r = -ENOENT;
goto out;
}
map = find_sid_vsid(vcpu, gvsid);
if (!map)
map = create_sid_map(vcpu, gvsid);
map->guest_esid = esid;
sr = map->host_vsid | SR_KP;
svcpu->sr[esid] = sr;
dprintk_sr("MMU: mtsr %d, 0x%x\n", esid, sr);
out:
svcpu_put(svcpu);
return r;
}
void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
{
int i;
struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
dprintk_sr("MMU: flushing all segments (%d)\n", ARRAY_SIZE(svcpu->sr));
for (i = 0; i < ARRAY_SIZE(svcpu->sr); i++)
svcpu->sr[i] = SR_INVALID;
svcpu_put(svcpu);
}
void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
{
int i;
kvmppc_mmu_hpte_destroy(vcpu);
preempt_disable();
for (i = 0; i < SID_CONTEXTS; i++)
__destroy_context(to_book3s(vcpu)->context_id[i]);
preempt_enable();
}
/* From mm/mmu_context_hash32.c */
#define CTX_TO_VSID(c, id) ((((c) * (897 * 16)) + (id * 0x111)) & 0xffffff)
int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
int err;
ulong sdr1;
int i;
int j;
for (i = 0; i < SID_CONTEXTS; i++) {
err = __init_new_context();
if (err < 0)
goto init_fail;
vcpu3s->context_id[i] = err;
/* Remember context id for this combination */
for (j = 0; j < 16; j++)
vcpu3s->vsid_pool[(i * 16) + j] = CTX_TO_VSID(err, j);
}
vcpu3s->vsid_next = 0;
/* Remember where the HTAB is */
asm ( "mfsdr1 %0" : "=r"(sdr1) );
htabmask = ((sdr1 & 0x1FF) << 16) | 0xFFC0;
htab = (ulong)__va(sdr1 & 0xffff0000);
kvmppc_mmu_hpte_init(vcpu);
return 0;
init_fail:
for (j = 0; j < i; j++) {
if (!vcpu3s->context_id[j])
continue;
__destroy_context(to_book3s(vcpu)->context_id[j]);
}
return -1;
}