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authorSean Christopherson <seanjc@google.com>2023-01-06 04:12:37 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-03-10 11:34:12 +0300
commit1ccd12324abd25573bddba5d4dedb5ac88de4930 (patch)
tree1ab460d8618903228e251a50a0804890949687c5 /arch/x86
parentdbc2e94515597410841911114afb80f359ac8f98 (diff)
downloadlinux-1ccd12324abd25573bddba5d4dedb5ac88de4930.tar.xz
KVM: SVM: Process ICR on AVIC IPI delivery failure due to invalid target
commit 5aede752a839904059c2b5d68be0dc4501c6c15f upstream. Emulate ICR writes on AVIC IPI failures due to invalid targets using the same logic as failures due to invalid types. AVIC acceleration fails if _any_ of the targets are invalid, and crucially VM-Exits before sending IPIs to targets that _are_ valid. In logical mode, the destination is a bitmap, i.e. a single IPI can target multiple logical IDs. Doing nothing causes KVM to drop IPIs if at least one target is valid and at least one target is invalid. Fixes: 18f40c53e10f ("svm: Add VMEXIT handlers for AVIC") Cc: stable@vger.kernel.org Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20230106011306.85230-5-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/svm/avic.c16
1 files changed, 9 insertions, 7 deletions
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 712330b80891..3b2c88b168ba 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -502,14 +502,18 @@ int avic_incomplete_ipi_interception(struct kvm_vcpu *vcpu)
trace_kvm_avic_incomplete_ipi(vcpu->vcpu_id, icrh, icrl, id, index);
switch (id) {
+ case AVIC_IPI_FAILURE_INVALID_TARGET:
case AVIC_IPI_FAILURE_INVALID_INT_TYPE:
/*
* Emulate IPIs that are not handled by AVIC hardware, which
- * only virtualizes Fixed, Edge-Triggered INTRs. The exit is
- * a trap, e.g. ICR holds the correct value and RIP has been
- * advanced, KVM is responsible only for emulating the IPI.
- * Sadly, hardware may sometimes leave the BUSY flag set, in
- * which case KVM needs to emulate the ICR write as well in
+ * only virtualizes Fixed, Edge-Triggered INTRs, and falls over
+ * if _any_ targets are invalid, e.g. if the logical mode mask
+ * is a superset of running vCPUs.
+ *
+ * The exit is a trap, e.g. ICR holds the correct value and RIP
+ * has been advanced, KVM is responsible only for emulating the
+ * IPI. Sadly, hardware may sometimes leave the BUSY flag set,
+ * in which case KVM needs to emulate the ICR write as well in
* order to clear the BUSY flag.
*/
if (icrl & APIC_ICR_BUSY)
@@ -525,8 +529,6 @@ int avic_incomplete_ipi_interception(struct kvm_vcpu *vcpu)
*/
avic_kick_target_vcpus(vcpu->kvm, apic, icrl, icrh, index);
break;
- case AVIC_IPI_FAILURE_INVALID_TARGET:
- break;
case AVIC_IPI_FAILURE_INVALID_BACKING_PAGE:
WARN_ONCE(1, "Invalid backing page\n");
break;