From: Sean Christopherson Date: Wed, 31 Mar 2021 03:19:36 +0000 (-0700) Subject: KVM: SVM: Do not allow SEV/SEV-ES initialization after vCPUs are created X-Git-Tag: accepted/tizen/unified/20230118.172025~7317^2~138 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8727906fde6ea665b52e68ddc58833772537f40a;p=platform%2Fkernel%2Flinux-rpi.git KVM: SVM: Do not allow SEV/SEV-ES initialization after vCPUs are created Reject KVM_SEV_INIT and KVM_SEV_ES_INIT if they are attempted after one or more vCPUs have been created. KVM assumes a VM is tagged SEV/SEV-ES prior to vCPU creation, e.g. init_vmcb() needs to mark the VMCB as SEV enabled, and svm_create_vcpu() needs to allocate the VMSA. At best, creating vCPUs before SEV/SEV-ES init will lead to unexpected errors and/or behavior, and at worst it will crash the host, e.g. sev_launch_update_vmsa() will dereference a null svm->vmsa pointer. Fixes: 1654efcbc431 ("KVM: SVM: Add KVM_SEV_INIT command") Fixes: ad73109ae7ec ("KVM: SVM: Provide support to launch and run an SEV-ES guest") Cc: stable@vger.kernel.org Cc: Brijesh Singh Cc: Tom Lendacky Signed-off-by: Sean Christopherson Message-Id: <20210331031936.2495277-4-seanjc@google.com> Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 97d42a00..824bc7d 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -182,6 +182,9 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) bool es_active = argp->id == KVM_SEV_ES_INIT; int asid, ret; + if (kvm->created_vcpus) + return -EINVAL; + ret = -EBUSY; if (unlikely(sev->active)) return ret;