[PATCH v3 09/28] KVM: SVM: Replace "avic_mode" enum with "x2avic_enabled" boolean

Sean Christopherson
2022-09-20T23:32:27Z

Replace the "avic_mode" enum with a single bool to track whether or not
x2AVIC is enabled. KVM already has "apicv_enabled" that tracks if any
flavor of AVIC is enabled, i.e. AVIC_MODE_NONE and AVIC_MODE_X1 are
redundant and unnecessary noise.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
---
arch/x86/kvm/svm/avic.c | 46 +++++++++++++++++++----------------------
arch/x86/kvm/svm/svm.c | 2 +-
arch/x86/kvm/svm/svm.h | 9 +-------
3 files changed, 23 insertions(+), 34 deletions(-)

diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 535e35edce1d..84beef0edae3 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -53,7 +53,7 @@ static DEFINE_HASHTABLE(svm_vm_data_hash, SVM_VM_DATA_HASH_BITS);
static u32 next_vm_id = 0;
static bool next_vm_id_wrapped = 0;
static DEFINE_SPINLOCK(svm_vm_data_hash_lock);
-enum avic_modes avic_mode;
+bool x2avic_enabled;

/*
* This is a wrapper of struct amd_iommu_ir_data.
@@ -79,8 +79,7 @@ static void avic_activate_vmcb(struct vcpu_svm *svm)
* (deletes the memslot) if any vCPU has x2APIC enabled, thus enabling
* AVIC in hybrid mode activates only the doorbell mechanism.
*/
- if (apic_x2apic_mode(svm->vcpu.arch.apic) &&
- avic_mode == AVIC_MODE_X2) {
+ if (x2avic_enabled && apic_x2apic_mode(svm->vcpu.arch.apic)) {
vmcb->control.int_ctl |= X2APIC_MODE_MASK;
vmcb->control.avic_physical_id |= X2AVIC_MAX_PHYSICAL_ID;
/* Disabling MSR intercept for x2APIC registers */
@@ -247,8 +246,8 @@ static u64 *avic_get_physical_id_entry(struct kvm_vcpu *vcpu,
u64 *avic_physical_id_table;
struct kvm_svm *kvm_svm = to_kvm_svm(vcpu->kvm);

- if ((avic_mode == AVIC_MODE_X1 && index > AVIC_MAX_PHYSICAL_ID) ||
- (avic_mode == AVIC_MODE_X2 && index > X2AVIC_MAX_PHYSICAL_ID))
+ if ((!x2avic_enabled && index > AVIC_MAX_PHYSICAL_ID) ||
+ (index > X2AVIC_MAX_PHYSICAL_ID))
return NULL;

avic_physical_id_table = page_address(kvm_svm->avic_physical_id_table_page);
@@ -262,8 +261,8 @@ static int avic_init_backing_page(struct kvm_vcpu *vcpu)
int id = vcpu->vcpu_id;
struct vcpu_svm *svm = to_svm(vcpu);

- if ((avic_mode == AVIC_MODE_X1 && id > AVIC_MAX_PHYSICAL_ID) ||
- (avic_mode == AVIC_MODE_X2 && id > X2AVIC_MAX_PHYSICAL_ID))
+ if ((!x2avic_enabled && id > AVIC_MAX_PHYSICAL_ID) ||
+ (id > X2AVIC_MAX_PHYSICAL_ID))
return -EINVAL;

if (!vcpu->arch.apic->regs)
@@ -1067,10 +1066,7 @@ void avic_refresh_virtual_apic_mode(struct kvm_vcpu *vcpu)
struct vcpu_svm *svm = to_svm(vcpu);
struct vmcb *vmcb = svm->vmcb01.ptr;

- if (!lapic_in_kernel(vcpu) || avic_mode == AVIC_MODE_NONE)
- return;
-
- if (!enable_apicv)
+ if (!lapic_in_kernel(vcpu) || !enable_apicv)
return;

if (kvm_vcpu_apicv_active(vcpu)) {
@@ -1146,32 +1142,32 @@ bool avic_hardware_setup(struct kvm_x86_ops *x86_ops)
if (!npt_enabled)
return false;

+ /* AVIC is a prerequisite for x2AVIC. */
+ if (!boot_cpu_has(X86_FEATURE_AVIC) && !force_avic) {
+ if (boot_cpu_has(X86_FEATURE_X2AVIC)) {
+ pr_warn(FW_BUG "Cannot support x2AVIC due to AVIC is disabled");
+ pr_warn(FW_BUG "Try enable AVIC using force_avic option");
+ }
+ return false;
+ }
+
if (boot_cpu_has(X86_FEATURE_AVIC)) {
- avic_mode = AVIC_MODE_X1;
pr_info("AVIC enabled\n");
} else if (force_avic) {
/*
* Some older systems does not advertise AVIC support.
* See Revision Guide for specific AMD processor for more detail.
*/
- avic_mode = AVIC_MODE_X1;
pr_warn("AVIC is not supported in CPUID but force enabled");
pr_warn("Your system might crash and burn");
}

/* AVIC is a prerequisite for x2AVIC. */
- if (boot_cpu_has(X86_FEATURE_X2AVIC)) {
- if (avic_mode == AVIC_MODE_X1) {
- avic_mode = AVIC_MODE_X2;
- pr_info("x2AVIC enabled\n");
- } else {
- pr_warn(FW_BUG "Cannot support x2AVIC due to AVIC is disabled");
- pr_warn(FW_BUG "Try enable AVIC using force_avic option");
- }
- }
+ x2avic_enabled = boot_cpu_has(X86_FEATURE_X2AVIC);
+ if (x2avic_enabled)
+ pr_info("x2AVIC enabled\n");

- if (avic_mode != AVIC_MODE_NONE)
- amd_iommu_register_ga_log_notifier(&avic_ga_log_notifier);
+ amd_iommu_register_ga_log_notifier(&avic_ga_log_notifier);

- return !!avic_mode;
+ return true;
}
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 2aa5069bafb2..709f0b3e7a48 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -821,7 +821,7 @@ void svm_set_x2apic_msr_interception(struct vcpu_svm *svm, bool intercept)
if (intercept == svm->x2avic_msrs_intercepted)
return;

- if (avic_mode != AVIC_MODE_X2 ||
+ if (!x2avic_enabled ||
!apic_x2apic_mode(svm->vcpu.arch.apic))
return;

diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 7a95f50e80e7..29c334a932c3 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -35,14 +35,7 @@ extern u32 msrpm_offsets[MSRPM_OFFSETS] __read_mostly;
extern bool npt_enabled;
extern int vgif;
extern bool intercept_smi;
-
-enum avic_modes {
- AVIC_MODE_NONE = 0,
- AVIC_MODE_X1,
- AVIC_MODE_X2,
-};
-
-extern enum avic_modes avic_mode;
+extern bool x2avic_enabled;

/*
* Clean bits in VMCB.
--
2.37.3.968.ga6b4b080e4-goog