This is a note to let you know that I've just added the patch titled
KVM: SEV: Disallow COPY_ENC_CONTEXT_FROM if target has created vCPUs
to the 5.15-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-sev-disallow-copy_enc_context_from-if-target-has-created-vcpus.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 79b11142763791bdead8b6460052cbdde8e08e2f Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@xxxxxxxxxx>
Date: Tue, 9 Nov 2021 21:50:56 +0000
Subject: KVM: SEV: Disallow COPY_ENC_CONTEXT_FROM if target has created vCPUs
From: Sean Christopherson <seanjc@xxxxxxxxxx>
commit 79b11142763791bdead8b6460052cbdde8e08e2f upstream.
Reject COPY_ENC_CONTEXT_FROM if the destination VM has created vCPUs.
KVM relies on SEV activation to occur before vCPUs are created, e.g. to
set VMCB flags and intercepts correctly.
Fixes: 54526d1fd593 ("KVM: x86: Support KVM VMs sharing SEV context")
Cc: stable@xxxxxxxxxxxxxxx
Cc: Peter Gonda <pgonda@xxxxxxxxxx>
Cc: Marc Orr <marcorr@xxxxxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Nathan Tempelman <natet@xxxxxxxxxx>
Cc: Brijesh Singh <brijesh.singh@xxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Message-Id: <20211109215101.2211373-2-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/svm/sev.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1787,7 +1787,12 @@ int svm_vm_copy_asid_from(struct kvm *kv
mutex_unlock(&source_kvm->lock);
mutex_lock(&kvm->lock);
- if (sev_guest(kvm)) {
+ /*
+ * Disallow out-of-band SEV/SEV-ES init if the target is already an
+ * SEV guest, or if vCPUs have been created. KVM relies on vCPUs being
+ * created after SEV/SEV-ES initialization, e.g. to init intercepts.
+ */
+ if (sev_guest(kvm) || kvm->created_vcpus) {
ret = -EINVAL;
goto e_mirror_unlock;
}
Patches currently in stable-queue which might be from seanjc@xxxxxxxxxx are
queue-5.15/kvm-sev-disallow-copy_enc_context_from-if-target-has-created-vcpus.patch
queue-5.15/kvm-x86-mmu-include-efer.lma-in-extended-mmu-role.patch
queue-5.15/x86-hyperv-fix-null-deref-in-set_hv_tscchange_cb-if-hyper-v-setup-fails.patch
queue-5.15/kvm-x86-assume-a-64-bit-hypercall-for-guests-with-protected-state.patch
