KVM: PPC: Book3S HV: Relax check on H_SVM_INIT_ABORT
authorLaurent Dufour <ldufour@linux.ibm.com>
Wed, 20 May 2020 17:43:08 +0000 (19:43 +0200)
committerPaul Mackerras <paulus@ozlabs.org>
Wed, 27 May 2020 01:39:31 +0000 (11:39 +1000)
The commit 8c47b6ff29e3 ("KVM: PPC: Book3S HV: Check caller of H_SVM_*
Hcalls") added checks of secure bit of SRR1 to filter out the Hcall
reserved to the Ultravisor.

However, the Hcall H_SVM_INIT_ABORT is made by the Ultravisor passing the
context of the VM calling UV_ESM. This allows the Hypervisor to return to
the guest without going through the Ultravisor. Thus the Secure bit of SRR1
is not set in that particular case.

In the case a regular VM is calling H_SVM_INIT_ABORT, this hcall will be
filtered out in kvmppc_h_svm_init_abort() because kvm->arch.secure_guest is
not set in that case.

Fixes: 8c47b6ff29e3 ("KVM: PPC: Book3S HV: Check caller of H_SVM_* Hcalls")
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
arch/powerpc/kvm/book3s_hv.c

index e9aa5555d690199062bb8d4145ab8e31ed61db71..1b84806abef68b1a5e7117c77afa1ba78a93467e 100644 (file)
@@ -1097,9 +1097,14 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
                        ret = kvmppc_h_svm_init_done(vcpu->kvm);
                break;
        case H_SVM_INIT_ABORT:
-               ret = H_UNSUPPORTED;
-               if (kvmppc_get_srr1(vcpu) & MSR_S)
-                       ret = kvmppc_h_svm_init_abort(vcpu->kvm);
+               /*
+                * Even if that call is made by the Ultravisor, the SSR1 value
+                * is the guest context one, with the secure bit clear as it has
+                * not yet been secured. So we can't check it here.
+                * Instead the kvm->arch.secure_guest flag is checked inside
+                * kvmppc_h_svm_init_abort().
+                */
+               ret = kvmppc_h_svm_init_abort(vcpu->kvm);
                break;
 
        default: