[PATCH v3 1/6] KVM: x86: return 1 unconditionally for availability of KVM_CAP_VAPIC

Paolo Bonzini
2022-02-17T18:08:40Z

The two ioctl used to implement userspace-accelerated TPR,
KVM_TPR_ACCESS_REPORTING and KVM_SET_VAPIC_ADDR, are available
even if hardware-accelerated TPR can be used. So there is
no reason not to report KVM_CAP_VAPIC.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/include/asm/kvm-x86-ops.h | 1 -
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/svm/svm.c | 6 ------
arch/x86/kvm/vmx/vmx.c | 6 ------
arch/x86/kvm/x86.c | 4 +---
5 files changed, 1 insertion(+), 17 deletions(-)

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 9e37dc3d8863..695ed7feef7e 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -15,7 +15,6 @@ BUILD_BUG_ON(1)
KVM_X86_OP_NULL(hardware_enable)
KVM_X86_OP_NULL(hardware_disable)
KVM_X86_OP_NULL(hardware_unsetup)
-KVM_X86_OP_NULL(cpu_has_accelerated_tpr)
KVM_X86_OP(has_emulated_msr)
KVM_X86_OP(vcpu_after_set_cpuid)
KVM_X86_OP(vm_init)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 10815b672a26..e0d2cdfe54ab 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1318,7 +1318,6 @@ struct kvm_x86_ops {
int (*hardware_enable)(void);
void (*hardware_disable)(void);
void (*hardware_unsetup)(void);
- bool (*cpu_has_accelerated_tpr)(void);
bool (*has_emulated_msr)(struct kvm *kvm, u32 index);
void (*vcpu_after_set_cpuid)(struct kvm_vcpu *vcpu);

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 4243bb355db0..abced3fe2013 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3912,11 +3912,6 @@ static int __init svm_check_processor_compat(void)
return 0;
}

-static bool svm_cpu_has_accelerated_tpr(void)
-{
- return false;
-}
-
/*
* The kvm parameter can be NULL (module initialization, or invocation before
* VM creation). Be sure to check the kvm parameter before using it.
@@ -4529,7 +4524,6 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.hardware_unsetup = svm_hardware_unsetup,
.hardware_enable = svm_hardware_enable,
.hardware_disable = svm_hardware_disable,
- .cpu_has_accelerated_tpr = svm_cpu_has_accelerated_tpr,
.has_emulated_msr = svm_has_emulated_msr,

.vcpu_create = svm_vcpu_create,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 70e7f00362bc..d8547144d3b7 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -541,11 +541,6 @@ static inline bool cpu_need_virtualize_apic_accesses(struct kvm_vcpu *vcpu)
return flexpriority_enabled && lapic_in_kernel(vcpu);
}

-static inline bool vmx_cpu_has_accelerated_tpr(void)
-{
- return flexpriority_enabled;
-}
-
static int possible_passthrough_msr_slot(u32 msr)
{
u32 i;
@@ -7714,7 +7709,6 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {

.hardware_enable = vmx_hardware_enable,
.hardware_disable = vmx_hardware_disable,
- .cpu_has_accelerated_tpr = vmx_cpu_has_accelerated_tpr,
.has_emulated_msr = vmx_has_emulated_msr,

.vm_size = sizeof(struct kvm_vmx),
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index eaa3b5b89c5e..746f72ae2c95 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4234,6 +4234,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_EXIT_ON_EMULATION_FAILURE:
case KVM_CAP_VCPU_ATTRIBUTES:
case KVM_CAP_SYS_ATTRIBUTES:
+ case KVM_CAP_VAPIC:
r = 1;
break;
case KVM_CAP_EXIT_HYPERCALL:
@@ -4274,9 +4275,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
*/
r = static_call(kvm_x86_has_emulated_msr)(kvm, MSR_IA32_SMBASE);
break;
- case KVM_CAP_VAPIC:
- r = !static_call(kvm_x86_cpu_has_accelerated_tpr)();
- break;
case KVM_CAP_NR_VCPUS:
r = min_t(unsigned int, num_online_cpus(), KVM_MAX_VCPUS);
break;
--
2.31.1