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path: root/arch/x86/kvm/paging_tmpl.h
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Diffstat (limited to 'arch/x86/kvm/paging_tmpl.h')
-rw-r--r--arch/x86/kvm/paging_tmpl.h29
1 files changed, 23 insertions, 6 deletions
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 7d5cdb3af594..97b21e7fd013 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -614,13 +614,14 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
struct guest_walker *gw,
int write_fault, int hlevel,
- kvm_pfn_t pfn, bool map_writable, bool prefault)
+ kvm_pfn_t pfn, bool map_writable, bool prefault,
+ bool lpage_disallowed)
{
struct kvm_mmu_page *sp = NULL;
struct kvm_shadow_walk_iterator it;
unsigned direct_access, access = gw->pt_access;
int top_level, ret;
- gfn_t base_gfn;
+ gfn_t gfn, base_gfn;
direct_access = gw->pte_access;
@@ -665,13 +666,25 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
link_shadow_page(vcpu, it.sptep, sp);
}
- base_gfn = gw->gfn;
+ /*
+ * FNAME(page_fault) might have clobbered the bottom bits of
+ * gw->gfn, restore them from the virtual address.
+ */
+ gfn = gw->gfn | ((addr & PT_LVL_OFFSET_MASK(gw->level)) >> PAGE_SHIFT);
+ base_gfn = gfn;
trace_kvm_mmu_spte_requested(addr, gw->level, pfn);
for (; shadow_walk_okay(&it); shadow_walk_next(&it)) {
clear_sp_write_flooding_count(it.sptep);
- base_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
+
+ /*
+ * We cannot overwrite existing page tables with an NX
+ * large page, as the leaf could be executable.
+ */
+ disallowed_hugepage_adjust(it, gfn, &pfn, &hlevel);
+
+ base_gfn = gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
if (it.level == hlevel)
break;
@@ -683,6 +696,8 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
sp = kvm_mmu_get_page(vcpu, base_gfn, addr,
it.level - 1, true, direct_access);
link_shadow_page(vcpu, it.sptep, sp);
+ if (lpage_disallowed)
+ account_huge_nx_page(vcpu->kvm, sp);
}
}
@@ -759,9 +774,11 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
int r;
kvm_pfn_t pfn;
int level = PT_PAGE_TABLE_LEVEL;
- bool force_pt_level = false;
unsigned long mmu_seq;
bool map_writable, is_self_change_mapping;
+ bool lpage_disallowed = (error_code & PFERR_FETCH_MASK) &&
+ is_nx_huge_page_enabled();
+ bool force_pt_level = lpage_disallowed;
pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code);
@@ -851,7 +868,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
if (!force_pt_level)
transparent_hugepage_adjust(vcpu, walker.gfn, &pfn, &level);
r = FNAME(fetch)(vcpu, addr, &walker, write_fault,
- level, pfn, map_writable, prefault);
+ level, pfn, map_writable, prefault, lpage_disallowed);
kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT);
out_unlock: