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-rw-r--r--arch/x86/kvm/mmu.c15
-rw-r--r--arch/x86/kvm/paging_tmpl.h18
2 files changed, 26 insertions, 7 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 6c67b230e95..5cd8b4ec3a0 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -156,6 +156,8 @@ module_param(oos_shadow, bool, 0644);
#define CREATE_TRACE_POINTS
#include "mmutrace.h"
+#define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
+
#define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
struct kvm_rmap_desc {
@@ -1754,7 +1756,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
unsigned pte_access, int user_fault,
int write_fault, int dirty, int level,
gfn_t gfn, pfn_t pfn, bool speculative,
- bool can_unsync)
+ bool can_unsync, bool reset_host_protection)
{
u64 spte;
int ret = 0;
@@ -1781,6 +1783,9 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
spte |= kvm_x86_ops->get_mt_mask(vcpu, gfn,
kvm_is_mmio_pfn(pfn));
+ if (reset_host_protection)
+ spte |= SPTE_HOST_WRITEABLE;
+
spte |= (u64)pfn << PAGE_SHIFT;
if ((pte_access & ACC_WRITE_MASK)
@@ -1826,7 +1831,8 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
unsigned pt_access, unsigned pte_access,
int user_fault, int write_fault, int dirty,
int *ptwrite, int level, gfn_t gfn,
- pfn_t pfn, bool speculative)
+ pfn_t pfn, bool speculative,
+ bool reset_host_protection)
{
int was_rmapped = 0;
int was_writeble = is_writeble_pte(*sptep);
@@ -1858,7 +1864,8 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
}
if (set_spte(vcpu, sptep, pte_access, user_fault, write_fault,
- dirty, level, gfn, pfn, speculative, true)) {
+ dirty, level, gfn, pfn, speculative, true,
+ reset_host_protection)) {
if (write_fault)
*ptwrite = 1;
kvm_x86_ops->tlb_flush(vcpu);
@@ -1906,7 +1913,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
if (iterator.level == level) {
mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, ACC_ALL,
0, write, 1, &pt_write,
- level, gfn, pfn, false);
+ level, gfn, pfn, false, true);
++vcpu->stat.pf_fixed;
break;
}
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index d2fec9c12d2..72558f8ff3f 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -273,9 +273,13 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
if (mmu_notifier_retry(vcpu, vcpu->arch.update_pte.mmu_seq))
return;
kvm_get_pfn(pfn);
+ /*
+ * we call mmu_set_spte() with reset_host_protection = true beacuse that
+ * vcpu->arch.update_pte.pfn was fetched from get_user_pages(write = 1).
+ */
mmu_set_spte(vcpu, spte, page->role.access, pte_access, 0, 0,
gpte & PT_DIRTY_MASK, NULL, PT_PAGE_TABLE_LEVEL,
- gpte_to_gfn(gpte), pfn, true);
+ gpte_to_gfn(gpte), pfn, true, true);
}
/*
@@ -308,7 +312,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
user_fault, write_fault,
gw->ptes[gw->level-1] & PT_DIRTY_MASK,
ptwrite, level,
- gw->gfn, pfn, false);
+ gw->gfn, pfn, false, true);
break;
}
@@ -558,6 +562,7 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
{
int i, offset, nr_present;
+ bool reset_host_protection;
offset = nr_present = 0;
@@ -595,9 +600,16 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
nr_present++;
pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
+ if (!(sp->spt[i] & SPTE_HOST_WRITEABLE)) {
+ pte_access &= ~ACC_WRITE_MASK;
+ reset_host_protection = 0;
+ } else {
+ reset_host_protection = 1;
+ }
set_spte(vcpu, &sp->spt[i], pte_access, 0, 0,
is_dirty_gpte(gpte), PT_PAGE_TABLE_LEVEL, gfn,
- spte_to_pfn(sp->spt[i]), true, false);
+ spte_to_pfn(sp->spt[i]), true, false,
+ reset_host_protection);
}
return !nr_present;