From: Sean Christopherson <seanjc@google.com>
To: Ashish Kalra <ashish.kalra@amd.com>
Cc: Steve Rutherford <srutherford@google.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Joerg Roedel <joro@8bytes.org>, Borislav Petkov <bp@suse.de>,
Tom Lendacky <thomas.lendacky@amd.com>, X86 ML <x86@kernel.org>,
KVM list <kvm@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Venu Busireddy <venu.busireddy@oracle.com>,
Brijesh Singh <brijesh.singh@amd.com>,
Will Deacon <will@kernel.org>,
maz@kernel.org, Quentin Perret <qperret@google.com>
Subject: Re: [PATCH v11 08/13] KVM: X86: Introduce KVM_HC_PAGE_ENC_STATUS hypercall
Date: Tue, 6 Apr 2021 15:20:21 +0000 [thread overview]
Message-ID: <YGx8NbG6TGm7LnQh@google.com> (raw)
In-Reply-To: <YGx6JqTVO97GUzn7@google.com>
On Tue, Apr 06, 2021, Sean Christopherson wrote:
> On Tue, Apr 06, 2021, Ashish Kalra wrote:
> > On Mon, Apr 05, 2021 at 01:42:42PM -0700, Steve Rutherford wrote:
> > > On Mon, Apr 5, 2021 at 7:28 AM Ashish Kalra <Ashish.Kalra@amd.com> wrote:
> > > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > > > index f7d12fca397b..ef5c77d59651 100644
> > > > --- a/arch/x86/kvm/x86.c
> > > > +++ b/arch/x86/kvm/x86.c
> > > > @@ -8273,6 +8273,18 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
> > > > kvm_sched_yield(vcpu->kvm, a0);
> > > > ret = 0;
> > > > break;
> > > > + case KVM_HC_PAGE_ENC_STATUS: {
> > > > + int r;
> > > > +
> > > > + ret = -KVM_ENOSYS;
> > > > + if (kvm_x86_ops.page_enc_status_hc) {
> > > > + r = kvm_x86_ops.page_enc_status_hc(vcpu, a0, a1, a2);
> > > > + if (r >= 0)
> > > > + return r;
> > > > + ret = r;
> > > Style nit: Why not just set ret, and return ret if ret >=0?
> > >
> >
> > But ret is "unsigned long", if i set ret and return, then i will return to guest
> > even in case of error above ?
>
> As proposed, svm_page_enc_status_hc() already hooks complete_userspace_io(), so
> this could be hoisted out of the switch statement.
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 16fb39503296..794dde3adfab 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -8261,6 +8261,10 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
> goto out;
> }
>
> + /* comment goes here */
> + if (nr == KVM_HC_PAGE_ENC_STATUS && kvm_x86_ops.page_enc_status_hc)
> + return static_call(kvm_x86_page_enc_status_hc(vcpu, a0, a1, a2));
Gah, the SEV implementation can also return -EINVAL, and that should fail the
hypercall, not kill the guest. Normally we try to avoid output params, but
in this case it might be less ugly to do:
case KVM_HC_PAGE_ENC_STATUS: {
if (!kvm_x86_ops.page_enc_status_hc)
break;
if (!static_call(kvm_x86_page_enc_status_hc(vcpu, a0, a1,
a2, &ret));
return 0;
break;
> +
> ret = -KVM_ENOSYS;
>
> switch (nr) {
>
next prev parent reply other threads:[~2021-04-06 15:20 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-05 14:20 [PATCH v11 00/13] Add AMD SEV guest live migration support Ashish Kalra
2021-04-05 14:21 ` [PATCH v11 01/13] KVM: SVM: Add KVM_SEV SEND_START command Ashish Kalra
2021-04-05 14:23 ` [PATCH v11 02/13] KVM: SVM: Add KVM_SEND_UPDATE_DATA command Ashish Kalra
2021-04-05 14:23 ` [PATCH v11 03/13] KVM: SVM: Add KVM_SEV_SEND_FINISH command Ashish Kalra
2021-04-05 14:24 ` [PATCH v11 04/13] KVM: SVM: Add support for KVM_SEV_RECEIVE_START command Ashish Kalra
2021-04-05 14:24 ` [PATCH v11 05/13] KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command Ashish Kalra
2021-04-05 14:25 ` [PATCH v11 06/13] KVM: SVM: Add KVM_SEV_RECEIVE_FINISH command Ashish Kalra
2021-04-05 14:26 ` [PATCH v11 07/13] KVM: x86: Add AMD SEV specific Hypercall3 Ashish Kalra
2021-04-05 14:28 ` [PATCH v11 08/13] KVM: X86: Introduce KVM_HC_PAGE_ENC_STATUS hypercall Ashish Kalra
2021-04-05 20:42 ` Steve Rutherford
2021-04-06 6:22 ` Ashish Kalra
2021-04-06 15:11 ` Sean Christopherson
2021-04-06 15:20 ` Sean Christopherson [this message]
2021-04-06 18:14 ` Ashish Kalra
2021-04-06 15:48 ` Sean Christopherson
2021-04-06 16:07 ` Ashish Kalra
2021-04-06 20:14 ` Steve Rutherford
2021-04-06 20:27 ` Sean Christopherson
2021-04-07 14:01 ` Ashish Kalra
2021-04-05 14:29 ` [PATCH v11 09/13] mm: x86: Invoke hypercall when page encryption status is changed Ashish Kalra
2021-04-05 14:30 ` [PATCH v11 10/13] KVM: x86: Introduce new KVM_FEATURE_SEV_LIVE_MIGRATION feature & Custom MSR Ashish Kalra
2021-04-06 1:39 ` Steve Rutherford
2021-04-06 13:26 ` Ashish Kalra
2021-04-06 13:47 ` Paolo Bonzini
2021-04-06 13:59 ` Ashish Kalra
2021-04-06 19:41 ` Steve Rutherford
2021-04-05 14:30 ` [PATCH v11 11/13] EFI: Introduce the new AMD Memory Encryption GUID Ashish Kalra
2021-04-05 14:31 ` [PATCH v11 12/13] x86/kvm: Add guest support for detecting and enabling SEV Live Migration feature Ashish Kalra
2021-04-05 14:35 ` [PATCH v11 13/13] x86/kvm: Add kexec support for SEV Live Migration Ashish Kalra
2021-04-05 15:17 ` [PATCH v11 00/13] Add AMD SEV guest live migration support Peter Gonda
2021-04-05 18:27 ` Steve Rutherford
2021-04-06 13:48 ` Paolo Bonzini
2021-04-06 1:43 ` Steve Rutherford
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