From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
Commit c016004494b0 (KVM: x86: Avoid guest page table walk when gpa_available
is set) avoids the page table walk when cr2 has already contained a valid GPA.
However, that is not the truth if ept == 0 and shadow page table is used. In
this scenario cr2 can just contains a valid GVA. The commit results in guest
stuck during boot due to read/write emulation against GVA instead of GPA of
the guest.
This patch fixes it by setting the gpa_available flag under direct mode.
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Cc: Brijesh Singh <brijesh.singh@xxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
---
arch/x86/kvm/mmu.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 849312d..4780348 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3791,8 +3791,11 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
if (need_unprotect && kvm_event_needs_reinjection(vcpu))
kvm_mmu_unprotect_page_virt(vcpu, fault_address);
- vcpu->arch.gpa_available = true;
- vcpu->arch.gpa_val = fault_address;
+ /* With shadow page tables, cr2 could contain a GVA, not a GPA */
+ if (vcpu->arch.mmu.direct_map) {
+ vcpu->arch.gpa_available = true;
+ vcpu->arch.gpa_val = fault_address;
+ }
r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn,
insn_len);
break;
--
2.7.4
