x86: KVM: SVM: add support for Invalid IPI Vector interception

In later revisions of AMD's APM, there is a new 'incomplete IPI' exit code:

"Invalid IPI Vector - The vector for the specified IPI was set to an
illegal value (VEC < 16)"

Note that tests on Zen2 machine show that this VM exit doesn't happen and
instead AVIC just does nothing.

Add support for this exit code by doing nothing, instead of filling
the kernel log with errors.

Also replace an unthrottled 'pr_err()' if another unknown incomplete
IPI exit happens with vcpu_unimpl()

(e.g in case AMD adds yet another 'Invalid IPI' exit reason)

Cc: <stable@vger.kernel.org>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230928173354.217464-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 19bf955b67e0da097aa7e4187c0feecbf10268e4..3ac0ffc4f3e202b18fab10ee6ecacb6b1ea11a91 100644 (file)
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -268,6 +268,7 @@ enum avic_ipi_failure_cause {
        AVIC_IPI_FAILURE_TARGET_NOT_RUNNING,
        AVIC_IPI_FAILURE_INVALID_TARGET,
        AVIC_IPI_FAILURE_INVALID_BACKING_PAGE,
+       AVIC_IPI_FAILURE_INVALID_IPI_VECTOR,
 };
 
 #define AVIC_PHYSICAL_MAX_INDEX_MASK   GENMASK_ULL(8, 0)

diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 2092db892d7d052a6301396ca753de694c20d8a8..4b74ea91f4e6bb6ea3cea52be67eaeed049c506e 100644 (file)
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -529,8 +529,11 @@ int avic_incomplete_ipi_interception(struct kvm_vcpu *vcpu)
        case AVIC_IPI_FAILURE_INVALID_BACKING_PAGE:
                WARN_ONCE(1, "Invalid backing page\n");
                break;
+       case AVIC_IPI_FAILURE_INVALID_IPI_VECTOR:
+               /* Invalid IPI with vector < 16 */
+               break;
        default:
-               pr_err("Unknown IPI interception\n");
+               vcpu_unimpl(vcpu, "Unknown avic incomplete IPI interception\n");
        }
 
        return 1;