Inhibit SVM's AVIC if multiple vCPUs are aliased to the same logical ID.
Architecturally, all CPUs whose logical ID matches the MDA are supposed
to receive the interrupt; overwriting existing entries in AVIC's
logical=>physical map can result in missed IPIs.
Fixes:
18f40c53e10f ("svm: Add VMEXIT handlers for AVIC")
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20230106011306.85230-25-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* AVIC is disabled because SEV doesn't support it.
*/
APICV_INHIBIT_REASON_SEV,
+
+ /*
+ * AVIC is disabled because not all vCPUs with a valid LDR have a 1:1
+ * mapping between logical ID and vCPU.
+ */
+ APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED,
};
struct kvm_arch {
else
kvm_clear_apicv_inhibit(kvm, APICV_INHIBIT_REASON_PHYSICAL_ID_ALIASED);
+ if (!new || new->logical_mode == KVM_APIC_MODE_MAP_DISABLED)
+ kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED);
+ else
+ kvm_clear_apicv_inhibit(kvm, APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED);
+
old = rcu_dereference_protected(kvm->arch.apic_map,
lockdep_is_held(&kvm->arch.apic_map_lock));
rcu_assign_pointer(kvm->arch.apic_map, new);
BIT(APICV_INHIBIT_REASON_SEV) |
BIT(APICV_INHIBIT_REASON_PHYSICAL_ID_ALIASED) |
BIT(APICV_INHIBIT_REASON_APIC_ID_MODIFIED) |
- BIT(APICV_INHIBIT_REASON_APIC_BASE_MODIFIED);
+ BIT(APICV_INHIBIT_REASON_APIC_BASE_MODIFIED) |
+ BIT(APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED);
return supported & BIT(reason);
}