[PATCH 2/2] KVM: VMX: report internal error for MMIO #PF due to deliveryevent

From: Xiao Guangrong
Date: Wed Oct 17 2012 - 01:48:12 EST


The #PF with PFEC.RSV = 1 indicates that the guest is accessing MMIO, we
can not fix it if it is caused by delivery event. Reporting internal error
for this case

Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 26 ++++++++++++++++----------
1 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index b8a0841..6599e45 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4287,16 +4287,6 @@ static int handle_exception(struct kvm_vcpu *vcpu)
if (is_machine_check(intr_info))
return handle_machine_check(vcpu);

- if ((vect_info & VECTORING_INFO_VALID_MASK) &&
- !is_page_fault(intr_info)) {
- vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
- vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_SIMUL_EX;
- vcpu->run->internal.ndata = 2;
- vcpu->run->internal.data[0] = vect_info;
- vcpu->run->internal.data[1] = intr_info;
- return 0;
- }
-
if ((intr_info & INTR_INFO_INTR_TYPE_MASK) == INTR_TYPE_NMI_INTR)
return 1; /* already handled by vmx_vcpu_run() */

@@ -4315,6 +4305,22 @@ static int handle_exception(struct kvm_vcpu *vcpu)
error_code = 0;
if (intr_info & INTR_INFO_DELIVER_CODE_MASK)
error_code = vmcs_read32(VM_EXIT_INTR_ERROR_CODE);
+
+ /*
+ * The #PF with PFEC.RSVD = 1 indicates the guest is accessing
+ * MMIO, it is better to report an internal error.
+ * See the comments in vmx_handle_exit.
+ */
+ if ((vect_info & VECTORING_INFO_VALID_MASK) &&
+ !(is_page_fault(intr_info) && !(error_code & PFERR_RSVD_MASK))) {
+ vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_SIMUL_EX;
+ vcpu->run->internal.ndata = 2;
+ vcpu->run->internal.data[0] = vect_info;
+ vcpu->run->internal.data[1] = intr_info;
+ return 0;
+ }
+
if (is_page_fault(intr_info)) {
/* EPT won't cause page fault directly */
BUG_ON(enable_ept);
--
1.7.7.6

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