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authorSean Christopherson <seanjc@google.com>2023-08-25 05:23:57 +0300
committerSean Christopherson <seanjc@google.com>2023-08-25 19:00:16 +0300
commit1952e74da96fb3e48b72a2d0ece78c688a5848c1 (patch)
tree8a0849a84a10a81f96bf5507bdcb464b23d29754 /arch/x86/kvm/svm
parentf1187ef24eb8f36e8ad8106d22615ceddeea6097 (diff)
downloadlinux-1952e74da96fb3e48b72a2d0ece78c688a5848c1.tar.xz
KVM: SVM: Skip VMSA init in sev_es_init_vmcb() if pointer is NULL
Skip initializing the VMSA physical address in the VMCB if the VMSA is NULL, which occurs during intrahost migration as KVM initializes the VMCB before copying over state from the source to the destination (including the VMSA and its physical address). In normal builds, __pa() is just math, so the bug isn't fatal, but with CONFIG_DEBUG_VIRTUAL=y, the validity of the virtual address is verified and passing in NULL will make the kernel unhappy. Fixes: 6defa24d3b12 ("KVM: SEV: Init target VMCBs in sev_migrate_from") Cc: stable@vger.kernel.org Cc: Peter Gonda <pgonda@google.com> Reviewed-by: Peter Gonda <pgonda@google.com> Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com> Link: https://lore.kernel.org/r/20230825022357.2852133-3-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kvm/svm')
-rw-r--r--arch/x86/kvm/svm/sev.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index acc700bcb299..5585a3556179 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2975,9 +2975,12 @@ static void sev_es_init_vmcb(struct vcpu_svm *svm)
/*
* An SEV-ES guest requires a VMSA area that is a separate from the
* VMCB page. Do not include the encryption mask on the VMSA physical
- * address since hardware will access it using the guest key.
+ * address since hardware will access it using the guest key. Note,
+ * the VMSA will be NULL if this vCPU is the destination for intrahost
+ * migration, and will be copied later.
*/
- svm->vmcb->control.vmsa_pa = __pa(svm->sev_es.vmsa);
+ if (svm->sev_es.vmsa)
+ svm->vmcb->control.vmsa_pa = __pa(svm->sev_es.vmsa);
/* Can't intercept CR register access, HV can't modify CR registers */
svm_clr_intercept(svm, INTERCEPT_CR0_READ);