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Commit 2843099f authored by Izik Eidus's avatar Izik Eidus Committed by Avi Kivity
Browse files

KVM: MMU: Fix aliased gfns treated as unaliased 



Some areas of kvm x86 mmu are using gfn offset inside a slot without
unaliasing the gfn first.  This patch makes sure that the gfn will be
unaliased and add gfn_to_memslot_unaliased() to save the calculating
of the gfn unaliasing in case we have it unaliased already.

Signed-off-by: default avatarIzik Eidus <ieidus@redhat.com>
Acked-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 6eb55818

arch/x86/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -617,6 +617,8 @@ void kvm_disable_tdp(void); 
int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3);

int complete_pio(struct kvm_vcpu *vcpu);



struct kvm_memory_slot *gfn_to_memslot_unaliased(struct kvm *kvm, gfn_t gfn);



static inline struct kvm_mmu_page *page_header(hpa_t shadow_page)

{

	struct page *page = pfn_to_page(shadow_page >> PAGE_SHIFT);

arch/x86/kvm/mmu.c

+10 −4
Original line number Diff line number Diff line
@@ -386,7 +386,9 @@ static void account_shadowed(struct kvm *kvm, gfn_t gfn) 
{

	int *write_count;



	write_count = slot_largepage_idx(gfn, gfn_to_memslot(kvm, gfn));

	gfn = unalias_gfn(kvm, gfn);

	write_count = slot_largepage_idx(gfn,

					 gfn_to_memslot_unaliased(kvm, gfn));

	*write_count += 1;

}
@@ -394,16 +396,20 @@ static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn) 
{

	int *write_count;



	write_count = slot_largepage_idx(gfn, gfn_to_memslot(kvm, gfn));

	gfn = unalias_gfn(kvm, gfn);

	write_count = slot_largepage_idx(gfn,

					 gfn_to_memslot_unaliased(kvm, gfn));

	*write_count -= 1;

	WARN_ON(*write_count < 0);

}



static int has_wrprotected_page(struct kvm *kvm, gfn_t gfn)

{

	struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);

	struct kvm_memory_slot *slot;

	int *largepage_idx;



	gfn = unalias_gfn(kvm, gfn);

	slot = gfn_to_memslot_unaliased(kvm, gfn);

	if (slot) {

		largepage_idx = slot_largepage_idx(gfn, slot);

		return *largepage_idx;
@@ -2973,8 +2979,8 @@ static void audit_write_protection(struct kvm_vcpu *vcpu) 
		if (sp->role.metaphysical)

			continue;



		slot = gfn_to_memslot(vcpu->kvm, sp->gfn);

		gfn = unalias_gfn(vcpu->kvm, sp->gfn);

		slot = gfn_to_memslot_unaliased(vcpu->kvm, sp->gfn);

		rmapp = &slot->rmap[gfn - slot->base_gfn];

		if (*rmapp)

			printk(KERN_ERR "%s: (%s) shadow page has writable"

virt/kvm/kvm_main.c

+5 −4
Original line number Diff line number Diff line
@@ -923,7 +923,7 @@ int kvm_is_error_hva(unsigned long addr) 
}

EXPORT_SYMBOL_GPL(kvm_is_error_hva);



static struct kvm_memory_slot *__gfn_to_memslot(struct kvm *kvm, gfn_t gfn)

struct kvm_memory_slot *gfn_to_memslot_unaliased(struct kvm *kvm, gfn_t gfn)

{

	int i;
@@ -936,11 +936,12 @@ static struct kvm_memory_slot *__gfn_to_memslot(struct kvm *kvm, gfn_t gfn) 
	}

	return NULL;

}

EXPORT_SYMBOL_GPL(gfn_to_memslot_unaliased);



struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)

{

	gfn = unalias_gfn(kvm, gfn);

	return __gfn_to_memslot(kvm, gfn);

	return gfn_to_memslot_unaliased(kvm, gfn);

}



int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
@@ -964,7 +965,7 @@ unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn) 
	struct kvm_memory_slot *slot;



	gfn = unalias_gfn(kvm, gfn);

	slot = __gfn_to_memslot(kvm, gfn);

	slot = gfn_to_memslot_unaliased(kvm, gfn);

	if (!slot)

		return bad_hva();

	return (slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE);
@@ -1215,7 +1216,7 @@ void mark_page_dirty(struct kvm *kvm, gfn_t gfn) 
	struct kvm_memory_slot *memslot;



	gfn = unalias_gfn(kvm, gfn);

	memslot = __gfn_to_memslot(kvm, gfn);

	memslot = gfn_to_memslot_unaliased(kvm, gfn);

	if (memslot && memslot->dirty_bitmap) {

		unsigned long rel_gfn = gfn - memslot->base_gfn;