KVM: Disable vapic support on Intel machines with FlexPriority

FlexPriority accelerates the tpr without any patching.

Signed-off-by: Avi Kivity <avi@qumranet.com>

4 files changed, 12 insertions, 2 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 3d4b71a94440..33f77b044c52 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1653,6 +1653,11 @@ static void svm_check_processor_compat(void *rtn)
         *(int *)rtn = 0;
 }
 
+static bool svm_cpu_has_accelerated_tpr(void)
+{
+        return false;
+}
+
 static struct kvm_x86_ops svm_x86_ops = {
         .cpu_has_kvm_support = has_svm,
         .disabled_by_bios = is_disabled,
@@ -1661,6 +1666,7 @@ static struct kvm_x86_ops svm_x86_ops = {
         .check_processor_compatibility = svm_check_processor_compat,
         .hardware_enable = svm_hardware_enable,
         .hardware_disable = svm_hardware_disable,
+        .cpu_has_accelerated_tpr = svm_cpu_has_accelerated_tpr,
 
         .vcpu_create = svm_create_vcpu,
         .vcpu_free = svm_free_vcpu,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index fc494aff5d8b..d1167fc303d6 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -192,7 +192,7 @@ static inline int cpu_has_secondary_exec_ctrls(void)
                 CPU_BASED_ACTIVATE_SECONDARY_CONTROLS);
 }
 
-static inline int cpu_has_vmx_virtualize_apic_accesses(void)
+static inline bool cpu_has_vmx_virtualize_apic_accesses(void)
 {
         return (vmcs_config.cpu_based_2nd_exec_ctrl &
                 SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES);
@@ -2565,6 +2565,7 @@ static struct kvm_x86_ops vmx_x86_ops = {
         .check_processor_compatibility = vmx_check_processor_compat,
         .hardware_enable = hardware_enable,
         .hardware_disable = hardware_disable,
+        .cpu_has_accelerated_tpr = cpu_has_vmx_virtualize_apic_accesses,
 
         .vcpu_create = vmx_create_vcpu,
         .vcpu_free = vmx_free_vcpu,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e7eac27adb7f..1f48ec871035 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -684,9 +684,11 @@ int kvm_dev_ioctl_check_extension(long ext)
         case KVM_CAP_USER_MEMORY:
         case KVM_CAP_SET_TSS_ADDR:
         case KVM_CAP_EXT_CPUID:
-        case KVM_CAP_VAPIC:
                 r = 1;
                 break;
+        case KVM_CAP_VAPIC:
+                r = !kvm_x86_ops->cpu_has_accelerated_tpr();
+                break;
         default:
                 r = 0;
                 break;
diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h
index 6e649af08d19..44b89259f6c4 100644
--- a/include/asm-x86/kvm_host.h
+++ b/include/asm-x86/kvm_host.h
@@ -329,6 +329,7 @@ struct kvm_x86_ops {
         void (*check_processor_compatibility)(void *rtn);
         int (*hardware_setup)(void);               /* __init */
         void (*hardware_unsetup)(void);            /* __exit */
+        bool (*cpu_has_accelerated_tpr)(void);
 
         /* Create, but do not attach this VCPU */
         struct kvm_vcpu *(*vcpu_create)(struct kvm *kvm, unsigned id);