[PATCH 3/6] KVM: SEV: Set sev_info.active after initial checks in sev_guest_init()

From: Sean Christopherson
Date: Tue Nov 09 2021 - 16:53:33 EST


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@xxxxxxxxxx>
---
arch/x86/kvm/svm/sev.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 6d14e2595c96..a869b11301df 100644
--- 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 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
sev->asid = 0;
e_no_asid:
sev->es_active = false;
+ sev->active = false;
return ret;
}

--
2.34.0.rc0.344.g81b53c2807-goog