[PATCH v2 08/26] KVM: VMX: Limit iterations with emulator_invalid_guest_state

Avi Kivity
2012-06-27T15:19:52Z

Otherwise, if the guest ends up looping, we never exit the srcu critical
section, which causes synchronize_srcu() to hang.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/vmx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index a9c0e40..8c4c336 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4977,11 +4977,12 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu)
int ret = 1;
u32 cpu_exec_ctrl;
bool intr_window_requested;
+ unsigned count = 130;

cpu_exec_ctrl = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
intr_window_requested = cpu_exec_ctrl & CPU_BASED_VIRTUAL_INTR_PENDING;

- while (!guest_state_valid(vcpu)) {
+ while (!guest_state_valid(vcpu) && count-- != 0) {
if (intr_window_requested
&& (kvm_get_rflags(&vmx->vcpu) & X86_EFLAGS_IF))
return handle_interrupt_window(&vmx->vcpu);
--
1.7.11