KVM: VMX: Limit iterations with emulator_invalid_guest_state

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>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 82ab1fb..debac49 100644 (file)
--- 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);