diff mbox series

[v2,2/4] x86: KVM: SVM: add support for Invalid IPI Vector interception

Message ID 20230928173354.217464-3-mlevitsk@redhat.com
State New
Headers
Series AVIC bugfixes and workarounds |

Commit Message

Maxim Levitsky Sept. 28, 2023, 5:33 p.m. UTC 
  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>
---
 arch/x86/include/asm/svm.h | 1 +
 arch/x86/kvm/svm/avic.c    | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

Comments

Sean Christopherson Sept. 29, 2023, 12:42 a.m. UTC | #1 
On Thu, Sep 28, 2023, Maxim Levitsky wrote:
> 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>
diff mbox series

Patch

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 19bf955b67e0da0..3ac0ffc4f3e202b 100644
--- 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 2092db892d7d052..4b74ea91f4e6bb6 100644
--- 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;