KVM: x86 emulator: fix memory access during x86 emulation
Currently when x86 emulator needs to access memory, page walk is done with
broadest permission possible, so if emulated instruction was executed
by userspace process it can still access kernel memory. Fix that by
providing correct memory access to page walker during emulation.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index df15a53..81eab9a 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -490,18 +490,23 @@
spin_unlock(&vcpu->kvm->mmu_lock);
}
-static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)
+static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr, u32 access,
+ u32 *error)
{
struct guest_walker walker;
gpa_t gpa = UNMAPPED_GVA;
int r;
- r = FNAME(walk_addr)(&walker, vcpu, vaddr, 0, 0, 0);
+ r = FNAME(walk_addr)(&walker, vcpu, vaddr,
+ !!(access & PFERR_WRITE_MASK),
+ !!(access & PFERR_USER_MASK),
+ !!(access & PFERR_FETCH_MASK));
if (r) {
gpa = gfn_to_gpa(walker.gfn);
gpa |= vaddr & ~PAGE_MASK;
- }
+ } else if (error)
+ *error = walker.error_code;
return gpa;
}