@@ -121,6 +121,7 @@ KVM_X86_OP_NULL(enable_direct_tlbflush)
KVM_X86_OP_NULL(migrate_timers)
KVM_X86_OP(msr_filter_changed)
KVM_X86_OP_NULL(complete_emulated_msr)
+KVM_X86_OP_NULL(apicv_check_inhibit);
#undef KVM_X86_OP
#undef KVM_X86_OP_NULL
@@ -1036,7 +1036,6 @@ struct kvm_x86_msr_filter {
#define APICV_INHIBIT_REASON_DISABLE 0
#define APICV_INHIBIT_REASON_HYPERV 1
-#define APICV_INHIBIT_REASON_NESTED 2
#define APICV_INHIBIT_REASON_IRQWIN 3
#define APICV_INHIBIT_REASON_PIT_REINJ 4
#define APICV_INHIBIT_REASON_X2APIC 5
@@ -1498,6 +1497,12 @@ struct kvm_x86_ops {
int (*complete_emulated_msr)(struct kvm_vcpu *vcpu, int err);
void (*vcpu_deliver_sipi_vector)(struct kvm_vcpu *vcpu, u8 vector);
+
+ /*
+ * Returns false if for some reason APICv (e.g guest mode)
+ * must be inhibited on this vCPU
+ */
+ bool (*apicv_check_inhibit)(struct kvm_vcpu *vcpu);
};
struct kvm_x86_nested_ops {
@@ -734,6 +734,11 @@ int svm_deliver_avic_intr(struct kvm_vcpu *vcpu, int vec)
return 0;
}
+bool avic_is_vcpu_inhibited(struct kvm_vcpu *vcpu)
+{
+ return is_guest_mode(vcpu);
+}
+
bool svm_dy_apicv_has_pending_interrupt(struct kvm_vcpu *vcpu)
{
return false;
@@ -950,7 +955,6 @@ bool svm_check_apicv_inhibit_reasons(ulong bit)
ulong supported = BIT(APICV_INHIBIT_REASON_DISABLE) |
BIT(APICV_INHIBIT_REASON_ABSENT) |
BIT(APICV_INHIBIT_REASON_HYPERV) |
- BIT(APICV_INHIBIT_REASON_NESTED) |
BIT(APICV_INHIBIT_REASON_IRQWIN) |
BIT(APICV_INHIBIT_REASON_PIT_REINJ) |
BIT(APICV_INHIBIT_REASON_X2APIC) |
@@ -551,12 +551,6 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm)
* exit_int_info, exit_int_info_err, next_rip, insn_len, insn_bytes.
*/
- /*
- * Also covers avic_vapic_bar, avic_backing_page, avic_logical_id,
- * avic_physical_id.
- */
- WARN_ON(kvm_apicv_activated(svm->vcpu.kvm));
-
/* Copied from vmcb01. msrpm_base can be overwritten later. */
svm->vmcb->control.nested_ctl = svm->vmcb01.ptr->control.nested_ctl;
svm->vmcb->control.iopm_base_pa = svm->vmcb01.ptr->control.iopm_base_pa;
@@ -659,6 +653,9 @@ int enter_svm_guest_mode(struct kvm_vcpu *vcpu, u64 vmcb12_gpa,
svm_set_gif(svm, true);
+ if (kvm_vcpu_apicv_active(vcpu))
+ kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu);
+
return 0;
}
@@ -697,6 +694,7 @@ int nested_svm_vmrun(struct kvm_vcpu *vcpu)
return -EINVAL;
nested_copy_vmcb_control_to_cache(svm, &vmcb12->control);
+
nested_copy_vmcb_save_to_cache(svm, &vmcb12->save);
if (!nested_vmcb_check_save(vcpu) ||
@@ -923,6 +921,9 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
if (unlikely(svm->vmcb->save.rflags & X86_EFLAGS_TF))
kvm_queue_exception(&(svm->vcpu), DB_VECTOR);
+ if (kvm_apicv_activated(vcpu->kvm))
+ kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu);
+
return 0;
}
@@ -1620,7 +1620,8 @@ static void svm_set_vintr(struct vcpu_svm *svm)
/*
* The following fields are ignored when AVIC is enabled
*/
- WARN_ON(kvm_apicv_activated(svm->vcpu.kvm));
+ if (!is_guest_mode(&svm->vcpu))
+ WARN_ON(kvm_apicv_activated(svm->vcpu.kvm));
svm_set_intercept(svm, INTERCEPT_VINTR);
@@ -3090,11 +3091,16 @@ static int interrupt_window_interception(struct kvm_vcpu *vcpu)
svm_clear_vintr(to_svm(vcpu));
/*
- * For AVIC, the only reason to end up here is ExtINTs.
+ * If not running nested, for AVIC, the only reason to end up here is ExtINTs.
* In this case AVIC was temporarily disabled for
* requesting the IRQ window and we have to re-enable it.
+ *
+ * If running nested, this vCPU has avic inhibited during the
+ * nested run, and can use the IRQ window
*/
- kvm_request_apicv_update(vcpu->kvm, true, APICV_INHIBIT_REASON_IRQWIN);
+
+ if (!is_guest_mode(vcpu))
+ kvm_request_apicv_update(vcpu->kvm, true, APICV_INHIBIT_REASON_IRQWIN);
++vcpu->stat.irq_window_exits;
return 1;
@@ -3644,7 +3650,10 @@ static void svm_enable_irq_window(struct kvm_vcpu *vcpu)
* via AVIC. In such case, we need to temporarily disable AVIC,
* and fallback to injecting IRQ via V_IRQ.
*/
- kvm_request_apicv_update(vcpu->kvm, false, APICV_INHIBIT_REASON_IRQWIN);
+
+ if (!is_guest_mode(vcpu))
+ kvm_request_apicv_update(vcpu->kvm, false, APICV_INHIBIT_REASON_IRQWIN);
+
svm_set_vintr(svm);
}
}
@@ -4114,14 +4123,6 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
if (guest_cpuid_has(vcpu, X86_FEATURE_X2APIC))
kvm_request_apicv_update(vcpu->kvm, false,
APICV_INHIBIT_REASON_X2APIC);
-
- /*
- * Currently, AVIC does not work with nested virtualization.
- * So, we disable AVIC when cpuid for SVM is set in the L1 guest.
- */
- if (nested && guest_cpuid_has(vcpu, X86_FEATURE_SVM))
- kvm_request_apicv_update(vcpu->kvm, false,
- APICV_INHIBIT_REASON_NESTED);
}
init_vmcb_after_set_cpuid(vcpu);
}
@@ -4719,6 +4720,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.complete_emulated_msr = svm_complete_emulated_msr,
.vcpu_deliver_sipi_vector = svm_vcpu_deliver_sipi_vector,
+ .apicv_check_inhibit = avic_is_vcpu_inhibited,
};
static struct kvm_x86_init_ops svm_init_ops __initdata = {
@@ -590,6 +590,7 @@ void svm_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap);
void svm_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr);
void svm_hwapic_isr_update(struct kvm_vcpu *vcpu, int max_isr);
int svm_deliver_avic_intr(struct kvm_vcpu *vcpu, int vec);
+bool avic_is_vcpu_inhibited(struct kvm_vcpu *vcpu);
bool svm_dy_apicv_has_pending_interrupt(struct kvm_vcpu *vcpu);
int svm_update_pi_irte(struct kvm *kvm, unsigned int host_irq,
uint32_t guest_irq, bool set);
@@ -9161,6 +9161,10 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool *req_immediate_exit)
r = kvm_check_nested_events(vcpu);
if (r < 0)
goto out;
+
+ /* Nested VM exit might need to update APICv status */
+ if (kvm_check_request(KVM_REQ_APICV_UPDATE, vcpu))
+ kvm_vcpu_update_apicv(vcpu);
}
/* try to inject new event if pending */
@@ -9538,6 +9542,10 @@ void kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu)
down_read(&vcpu->kvm->arch.apicv_update_lock);
activate = kvm_apicv_activated(vcpu->kvm);
+
+ if (kvm_x86_ops.apicv_check_inhibit)
+ activate = activate && !kvm_x86_ops.apicv_check_inhibit(vcpu);
+
if (vcpu->arch.apicv_active == activate)
goto out;
@@ -9578,6 +9586,7 @@ void __kvm_request_apicv_update(struct kvm *kvm, bool activate, ulong bit)
if (!!old != !!new) {
trace_kvm_apicv_update_request(activate, bit);
+
/*
* Kick all vCPUs before setting apicv_inhibit_reasons to avoid
* false positives in the sanity check WARN in svm_vcpu_run().
@@ -9932,7 +9941,10 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
* per-VM state, and responsing vCPUs must wait for the update
* to complete before servicing KVM_REQ_APICV_UPDATE.
*/
- WARN_ON_ONCE(kvm_apicv_activated(vcpu->kvm) != kvm_vcpu_apicv_active(vcpu));
+ if (!is_guest_mode(vcpu))
+ WARN_ON_ONCE(kvm_apicv_activated(vcpu->kvm) != kvm_vcpu_apicv_active(vcpu));
+ else
+ WARN_ON(kvm_vcpu_apicv_active(vcpu));
exit_fastpath = static_call(kvm_x86_run)(vcpu);
if (likely(exit_fastpath != EXIT_FASTPATH_REENTER_GUEST))
Inhibit the AVIC of the vCPU that is running nested for the duration of the nested run, so that all interrupts arriving from both its vCPU siblings and from KVM are delivered using normal IPIs and cause that vCPU to vmexit. Note that in the theory when a nested guest doesn't intercept physical interrupts, we could continue using AVIC to deliver them to it but don't bother doing so for now. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> --- arch/x86/include/asm/kvm-x86-ops.h | 1 + arch/x86/include/asm/kvm_host.h | 7 ++++++- arch/x86/kvm/svm/avic.c | 6 +++++- arch/x86/kvm/svm/nested.c | 13 +++++++------ arch/x86/kvm/svm/svm.c | 26 ++++++++++++++------------ arch/x86/kvm/svm/svm.h | 1 + arch/x86/kvm/x86.c | 14 +++++++++++++- 7 files changed, 47 insertions(+), 21 deletions(-)