This is a note to let you know that I've just added the patch titled
KVM: SVM: Process ICR on AVIC IPI delivery failure due to invalid target
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-svm-process-icr-on-avic-ipi-delivery-failure-due-to-invalid-target.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 5aede752a839904059c2b5d68be0dc4501c6c15f Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@xxxxxxxxxx>
Date: Fri, 6 Jan 2023 01:12:37 +0000
Subject: KVM: SVM: Process ICR on AVIC IPI delivery failure due to invalid target
From: Sean Christopherson <seanjc@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Message-Id: <20230106011306.85230-5-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/svm/avic.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -502,14 +502,18 @@ int avic_incomplete_ipi_interception(str
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(str
*/
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;
Patches currently in stable-queue which might be from seanjc@xxxxxxxxxx are
queue-6.2/kvm-svm-hyper-v-placate-modpost-section-mismatch-error.patch
queue-6.2/kvm-svm-flush-the-current-tlb-when-activating-avic.patch
queue-6.2/x86-virt-force-gif-1-prior-to-disabling-svm-for-reboot-flows.patch
queue-6.2/kvm-x86-inject-gp-if-wrmsr-sets-reserved-bits-in-apic-self-ipi.patch
queue-6.2/x86-reboot-disable-svm-not-just-vmx-when-stopping-cpus.patch
queue-6.2/kvm-svm-process-icr-on-avic-ipi-delivery-failure-due-to-invalid-target.patch
queue-6.2/kvm-x86-don-t-inhibit-apicv-avic-if-xapic-id-mismatch-is-due-to-32-bit-id.patch
queue-6.2/x86-reboot-disable-virtualization-in-an-emergency-if-svm-is-supported.patch
queue-6.2/kvm-svm-don-t-put-load-avic-when-setting-virtual-apic-mode.patch
queue-6.2/x86-crash-disable-virt-in-core-nmi-crash-handler-to-avoid-double-shootdown.patch
queue-6.2/kvm-register-dev-kvm-as-the-_very_-last-thing-during-initialization.patch
queue-6.2/kvm-x86-don-t-inhibit-apicv-avic-on-xapic-id-change-if-apic-is-disabled.patch
queue-6.2/kvm-destroy-target-device-if-coalesced-mmio-unregistration-fails.patch
queue-6.2/kvm-svm-fix-potential-overflow-in-sev-s-send-receive_update_data.patch
queue-6.2/kvm-x86-blindly-get-current-x2apic-reg-value-on-nodecode-write-traps.patch
queue-6.2/kvm-x86-purge-highest-isr-cache-when-updating-apicv-state.patch
queue-6.2/kvm-x86-inject-gp-on-x2apic-wrmsr-that-sets-reserved-bits-63-32.patch
queue-6.2/kvm-vmx-fix-crash-due-to-uninitialized-current_vmcs.patch
