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

commit 2dcf37abf9d3aab7f975002d29fc7c17272def38 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 02aac78cb21d4329968e99ba0d698fffb777c5e4..184fd776cd39f1e3f88e69392e2c3c95b664bfc1 100644 (file)
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -259,6 +259,7 @@ 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 d3e66740c7c682e387bb02106d09d6ed2d692ceb..fb125b54ee680103762e040d241b6db732133bbb 100644 (file)
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -542,8 +542,11 @@ 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;