KVM: SEV: Set sev_info.active after initial checks in sev_guest_init()

Set sev_info.active during SEV/SEV-ES activation before calling any code
that can potentially consume sev_info.es_active, e.g. set "active" and
"es_active" as a pair immediately after the initial sanity checks.  KVM
generally expects that es_active can be true if and only if active is
true, e.g. sev_asid_new() deliberately avoids sev_es_guest() so that it
doesn't get a false negative.  This will allow WARNing in sev_es_guest()
if the VM is tagged as SEV-ES but not SEV.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109215101.2211373-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index eeec499e437280ee97d4b7f11a65de9cb2829ac6..50b9d76e9137395b194b32987f38ae50c3d1a510 100644 (file)
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -229,7 +229,6 @@ static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
 static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
        struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
-       bool es_active = argp->id == KVM_SEV_ES_INIT;
        int asid, ret;
 
        if (kvm->created_vcpus)
@@ -239,7 +238,8 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
        if (unlikely(sev->active))
                return ret;
 
-       sev->es_active = es_active;
+       sev->active = true;
+       sev->es_active = argp->id == KVM_SEV_ES_INIT;
        asid = sev_asid_new(sev);
        if (asid < 0)
                goto e_no_asid;
@@ -249,7 +249,6 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
        if (ret)
                goto e_free;
 
-       sev->active = true;
        sev->asid = asid;
        INIT_LIST_HEAD(&sev->regions_list);
 
@@ -260,6 +259,7 @@ e_free:
        sev->asid = 0;
 e_no_asid:
        sev->es_active = false;
+       sev->active = false;
        return ret;
 }