From: Sean Christopherson <seanjc@google.com>
To: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Joerg Roedel <joro@8bytes.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>,
x86@kernel.org, Brijesh Singh <brijesh.singh@amd.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Joerg Roedel <jroedel@suse.de>
Subject: Re: [PATCH v5 4/6] KVM: SVM: Add support to handle AP reset MSR protocol
Date: Wed, 20 Oct 2021 18:38:06 +0000 [thread overview]
Message-ID: <YXBiDr5mgtkgwBDR@google.com> (raw)
In-Reply-To: <95d99b9a-8600-619b-9b83-63597d937bc6@amd.com>
On Wed, Oct 20, 2021, Tom Lendacky wrote:
> On 10/20/21 12:40 PM, Sean Christopherson wrote:
> > On Wed, Oct 20, 2021, Joerg Roedel wrote:
> > This can race with the SIPI and effectively corrupt svm->vmcb->control.ghcb_gpa.
> >
> > vCPU0 vCPU1
> > #VMGEXIT(RESET_HOLD)
> > __kvm_vcpu_halt()
> > INIT
> > SIPI
> > sev_vcpu_deliver_sipi_vector()
> > ghcb_msr_ap_rst_resp(1);
>
> This isn't possible. vCPU0 doesn't set vCPU1's GHCB value. vCPU1's GHCB
> value is set when vCPU1 handles events in vcpu_enter_guest().
Argh, I was thinking of injecting regular IPIs across vCPUs. In hindsight it
makes sense that INIT and SIPI are handled on the current vCPU, stuffing all that
state from a different vCPU would be needlessly complex.
next prev parent reply other threads:[~2021-10-20 18:38 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-20 12:44 [PATCH v5 0/6] KVM: SVM: Add initial GHCB protocol version 2 support Joerg Roedel
2021-10-20 12:44 ` [PATCH v5 1/6] KVM: SVM: Get rid of set_ghcb_msr() and *ghcb_msr_bits() functions Joerg Roedel
2021-10-20 12:44 ` [PATCH v5 2/6] KVM: SVM: Add helper to generate GHCB MSR verson info, and drop macro Joerg Roedel
2021-10-20 12:44 ` [PATCH v5 3/6] KVM: SVM: Move kvm_emulate_ap_reset_hold() to AMD specific code Joerg Roedel
2021-10-20 14:29 ` Sean Christopherson
2021-10-20 12:44 ` [PATCH v5 4/6] KVM: SVM: Add support to handle AP reset MSR protocol Joerg Roedel
2021-10-20 17:40 ` Sean Christopherson
2021-10-20 18:13 ` Tom Lendacky
2021-10-20 18:38 ` Sean Christopherson [this message]
2021-10-20 18:36 ` Tom Lendacky
2021-10-20 12:44 ` [PATCH v5 5/6] KVM: SVM: Add support for Hypervisor Feature support " Joerg Roedel
2021-10-20 12:44 ` [PATCH v5 6/6] KVM: SVM: Increase supported GHCB protocol version Joerg Roedel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YXBiDr5mgtkgwBDR@google.com \
--to=seanjc@google.com \
--cc=brijesh.singh@amd.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=jroedel@suse.de \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=thomas.lendacky@amd.com \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).