FAILED: patch "[PATCH] KVM: nSVM: Clear EVENTINJ fields in vmcb12 on nested #VMEXIT" failed to apply to 5.10-stable tree

gregkh
2026-05-03T12:18:17Z

The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 69b721a86d0dcb026f6db7d111dcde7550442d2e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026050304-strangely-plural-77e6@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 69b721a86d0dcb026f6db7d111dcde7550442d2e Mon Sep 17 00:00:00 2001
From: Yosry Ahmed <yosry@kernel.org>
Date: Tue, 3 Mar 2026 00:34:05 +0000
Subject: [PATCH] KVM: nSVM: Clear EVENTINJ fields in vmcb12 on nested #VMEXIT

According to the APM, from the reference of the VMRUN instruction:

Upon #VMEXIT, the processor performs the following actions in order to
return to the host execution context:

...

clear EVENTINJ field in VMCB

KVM already syncs EVENTINJ fields from vmcb02 to cached vmcb12 on every
L2->L0 #VMEXIT. Since these fields are zeroed by the CPU on #VMEXIT, they
will mostly be zeroed in vmcb12 on nested #VMEXIT by nested_svm_vmexit().

However, this is not the case when:

1. Consistency checks fail, as nested_svm_vmexit() is not called.
2. Entering guest mode fails before L2 runs (e.g. due to failed load of
CR3).

(2) was broken by commit 2d8a42be0e2b ("KVM: nSVM: synchronize VMCB
controls updated by the processor on every vmexit"), as prior to that
nested_svm_vmexit() always zeroed EVENTINJ fields.

Explicitly clear the fields in all nested #VMEXIT code paths.

Fixes: 3d6368ef580a ("KVM: SVM: Add VMRUN handler")
Fixes: 2d8a42be0e2b ("KVM: nSVM: synchronize VMCB controls updated by the processor on every vmexit")
Cc: stable@vger.kernel.org
Signed-off-by: Yosry Ahmed <yosry@kernel.org>
Link: https://patch.msgid.link/20260303003421.2185681-12-yosry@kernel.org
[sean: massage changelog formatting]
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index ac7d7f82c82b..90c8bc641bf3 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -1035,6 +1035,8 @@ int nested_svm_vmrun(struct kvm_vcpu *vcpu)
vmcb12->control.exit_code = SVM_EXIT_ERR;
vmcb12->control.exit_info_1 = 0;
vmcb12->control.exit_info_2 = 0;
+ vmcb12->control.event_inj = 0;
+ vmcb12->control.event_inj_err = 0;
svm_set_gif(svm, false);
goto out;
}
@@ -1178,9 +1180,9 @@ static int nested_svm_vmexit_update_vmcb12(struct kvm_vcpu *vcpu)
if (nested_vmcb12_has_lbrv(vcpu))
svm_copy_lbrs(&vmcb12->save, &vmcb02->save);

+ vmcb12->control.event_inj = 0;
+ vmcb12->control.event_inj_err = 0;
vmcb12->control.int_ctl = svm->nested.ctl.int_ctl;
- vmcb12->control.event_inj = svm->nested.ctl.event_inj;
- vmcb12->control.event_inj_err = svm->nested.ctl.event_inj_err;

trace_kvm_nested_vmexit_inject(vmcb12->control.exit_code,
vmcb12->control.exit_info_1,