VM exits during Event Delivery is really unexpected if it is not caused
by Exceptions/EPT-VIOLATION/TASK_SWITCH, we'd better to report an internal
and freeze the guest, the VMM has the chance to check the guest
Signed-off-by: Xiao Guangrong <[email protected]>
---
arch/x86/kvm/vmx.c | 19 +++++++++++++++----
include/linux/kvm.h | 8 ++++++--
2 files changed, 21 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ad6b1dd..b8a0841 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5979,13 +5979,24 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu)
return 0;
}
+ /*
+ * Note:
+ * Do not try to fix EXIT_REASON_EPT_MISCONFIG if it caused by
+ * delivery event since it indicates guest is accessing MMIO.
+ * The vm-exit can be triggered again after return to guest that
+ * will cause infinite loop.
+ */
if ((vectoring_info & VECTORING_INFO_VALID_MASK) &&
(exit_reason != EXIT_REASON_EXCEPTION_NMI &&
exit_reason != EXIT_REASON_EPT_VIOLATION &&
- exit_reason != EXIT_REASON_TASK_SWITCH))
- printk(KERN_WARNING "%s: unexpected, valid vectoring info "
- "(0x%x) and exit reason is 0x%x\n",
- __func__, vectoring_info, exit_reason);
+ exit_reason != EXIT_REASON_TASK_SWITCH)) {
+ vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_DELIVERY_EV;
+ vcpu->run->internal.ndata = 2;
+ vcpu->run->internal.data[0] = vectoring_info;
+ vcpu->run->internal.data[1] = exit_reason;
+ return 0;
+ }
if (unlikely(!cpu_has_virtual_nmis() && vmx->soft_vnmi_blocked &&
!(is_guest_mode(vcpu) && nested_cpu_has_virtual_nmis(
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 65ad5c6..494a84c 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -170,8 +170,12 @@ struct kvm_pit_config {
#define KVM_EXIT_WATCHDOG 21
/* For KVM_EXIT_INTERNAL_ERROR */
-#define KVM_INTERNAL_ERROR_EMULATION 1
-#define KVM_INTERNAL_ERROR_SIMUL_EX 2
+/* Emulate instruction failed. */
+#define KVM_INTERNAL_ERROR_EMULATION 1
+/* Encounter unexpected simultaneous exceptions. */
+#define KVM_INTERNAL_ERROR_SIMUL_EX 2
+/* Encounter unexpected vm-exit due to delivery event. */
+#define KVM_INTERNAL_ERROR_DELIVERY_EV 3
/* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */
struct kvm_run {
--
1.7.7.6
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 <[email protected]>
---
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
On 10/17/2012 07:48 AM, Xiao Guangrong wrote:
> 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
Applied, thanks.
--
error compiling committee.c: too many arguments to function