[patch 144/164] KVM: SVM: Fix wrong interrupt injection in enable_irq_windows

Greg KH
2010-07-01T21:01:25Z

2.6.33-stable review patch. If anyone has any objections, please let me know.

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

From: Joerg Roedel <joerg.roedel@amd.com>

The nested_svm_intr() function does not execute the vmexit
anymore. Therefore we may still be in the nested state after
that function ran. This patch changes the nested_svm_intr()
function to return wether the irq window could be enabled.

Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
(cherry picked from commit 8fe546547cf6857a9d984bfe2f2194910f3fc5d0)
---
arch/x86/kvm/svm.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)

--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1377,16 +1377,17 @@ static int nested_svm_check_exception(st
return vmexit;
}

-static inline int nested_svm_intr(struct vcpu_svm *svm)
+/* This function returns true if it is save to enable the irq window */
+static inline bool nested_svm_intr(struct vcpu_svm *svm)
{
if (!is_nested(svm))
- return 0;
+ return true;

if (!(svm->vcpu.arch.hflags & HF_VINTR_MASK))
- return 0;
+ return true;

if (!(svm->vcpu.arch.hflags & HF_HIF_MASK))
- return 0;
+ return false;

svm->vmcb->control.exit_code = SVM_EXIT_INTR;

@@ -1399,10 +1400,10 @@ static inline int nested_svm_intr(struct
*/
svm->nested.exit_required = true;
trace_kvm_nested_intr_vmexit(svm->vmcb->save.rip);
- return 1;
+ return false;
}

- return 0;
+ return true;
}

static void *nested_svm_map(struct vcpu_svm *svm, u64 gpa, struct page **_page)
@@ -2567,13 +2568,11 @@ static void enable_irq_window(struct kvm
{
struct vcpu_svm *svm = to_svm(vcpu);

- nested_svm_intr(svm);
-
/* In case GIF=0 we can't rely on the CPU to tell us when
* GIF becomes 1, because that's a separate STGI/VMRUN intercept.
* The next time we get that intercept, this function will be
* called again though and we'll get the vintr intercept. */
- if (gif_set(svm)) {
+ if (gif_set(svm) && nested_svm_intr(svm)) {
svm_set_vintr(svm);
svm_inject_irq(svm, 0x0);
}