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Date: Wed, 20 May 2020 19:32:59 +0200 From: Greg Kurz <groug@...d.org> To: Laurent Dufour <ldufour@...ux.ibm.com> Cc: kvm-ppc@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org, linux-kernel@...r.kernel.org, paulus@...ba.org, mpe@...erman.id.au, sukadev@...ux.ibm.com, linuxram@...ibm.com Subject: Re: [PATCH] KVM: PPC: Book3S HV: relax check on H_SVM_INIT_ABORT On Wed, 20 May 2020 18:51:10 +0200 Laurent Dufour <ldufour@...ux.ibm.com> wrote: > 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. > Why not checking vcpu->kvm->arch.secure_guest then ? > Fixes: 8c47b6ff29e3 ("KVM: PPC: Book3S HV: Check caller of H_SVM_* Hcalls") > Signed-off-by: Laurent Dufour <ldufour@...ux.ibm.com> > --- > arch/powerpc/kvm/book3s_hv.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > index 93493f0cbfe8..eb1f96cb7b72 100644 > --- a/arch/powerpc/kvm/book3s_hv.c > +++ b/arch/powerpc/kvm/book3s_hv.c > @@ -1099,9 +1099,7 @@ 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); or at least put a comment to explain why H_SVM_INIT_ABORT doesn't have the same sanity check as the other SVM hcalls. > + ret = kvmppc_h_svm_init_abort(vcpu->kvm); > break; > > default:
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