[patch 004/108] KVM: VMX: Fix handling of a fault during NMI unblocked due to IRET

Greg KH
2009-07-01T00:48:07Z

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2.6.30-stable review patch. If anyone has any objections, please let us know.

------------------

From: Gleb Natapov <gleb@redhat.com>

commit 7b4a25cb296e2a73d2e87a4af65361d45d450a27 upstream.

Bit 12 is undefined in any of the following cases:
If the VM exit sets the valid bit in the IDT-vectoring information field.
If the VM exit is due to a double fault.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/x86/kvm/vmx.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3248,36 +3248,41 @@ static void update_tpr_threshold(struct
static void vmx_complete_interrupts(struct vcpu_vmx *vmx)
{
u32 exit_intr_info;
- u32 idt_vectoring_info;
+ u32 idt_vectoring_info = vmx->idt_vectoring_info;
bool unblock_nmi;
u8 vector;
int type;
bool idtv_info_valid;
u32 error;

+ idtv_info_valid = idt_vectoring_info & VECTORING_INFO_VALID_MASK;
exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
if (cpu_has_virtual_nmis()) {
unblock_nmi = (exit_intr_info & INTR_INFO_UNBLOCK_NMI) != 0;
vector = exit_intr_info & INTR_INFO_VECTOR_MASK;
/*
- * SDM 3: 25.7.1.2
+ * SDM 3: 27.7.1.2 (September 2008)
* Re-set bit "block by NMI" before VM entry if vmexit caused by
* a guest IRET fault.
+ * SDM 3: 23.2.2 (September 2008)
+ * Bit 12 is undefined in any of the following cases:
+ * If the VM exit sets the valid bit in the IDT-vectoring
+ * information field.
+ * If the VM exit is due to a double fault.
*/
- if (unblock_nmi && vector != DF_VECTOR)
+ if ((exit_intr_info & INTR_INFO_VALID_MASK) && unblock_nmi &&
+ vector != DF_VECTOR && !idtv_info_valid)
vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO,
GUEST_INTR_STATE_NMI);
} else if (unlikely(vmx->soft_vnmi_blocked))
vmx->vnmi_blocked_time +=
ktime_to_ns(ktime_sub(ktime_get(), vmx->entry_time));

- idt_vectoring_info = vmx->idt_vectoring_info;
- idtv_info_valid = idt_vectoring_info & VECTORING_INFO_VALID_MASK;
vector = idt_vectoring_info & VECTORING_INFO_VECTOR_MASK;
type = idt_vectoring_info & VECTORING_INFO_TYPE_MASK;
if (vmx->vcpu.arch.nmi_injected) {
/*
- * SDM 3: 25.7.1.2
+ * SDM 3: 27.7.1.2 (September 2008)
* Clear bit "block by NMI" before VM entry if a NMI delivery
* faulted.
*/