From: Dionna Amalie Glaze <dionnaglaze@google.com>
To: Tom Lendacky <thomas.lendacky@amd.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-coco@lists.linux.dev, Paolo Bonzini <pbonzini@redhat.com>,
Joerg Roedel <jroedel@suse.de>, Peter Gonda <pgonda@google.com>,
Borislav Petkov <bp@alien8.de>,
Sean Christopherson <seanjc@google.com>
Subject: Re: [PATCH v6 2/2] kvm: sev: If ccp is busy, report busy to guest
Date: Thu, 5 Jun 2025 13:45:42 -0700 [thread overview]
Message-ID: <CAAH4kHaeMgzdNP6Y7zdkdODransNkP4UiQ8ROpCVgenpiveJ_Q@mail.gmail.com> (raw)
In-Reply-To: <b6b9b935-c5fa-dec6-ec82-56015b5dc733@amd.com>
On Thu, Jun 5, 2025 at 12:15 PM Tom Lendacky <thomas.lendacky@amd.com> wrote:
>
> On 6/5/25 10:02, Dionna Glaze wrote:
> > The ccp driver can be overloaded even with guest request rate limits.
> > The return value of -EBUSY means that there is no firmware error to
> > report back to user space, so the guest VM would see this as
> > exitinfo2 = 0. The false success can trick the guest to update its
> > message sequence number when it shouldn't have.
>
> -EBUSY from the CCP driver is an error, not a throttling condition. Either
Ah, okay thanks Tom. I'll drop it for v6. I'll see how the first patch
is received before cutting a new email.
--
-Dionna Glaze, PhD, CISSP, CCSP (she/her)
prev parent reply other threads:[~2025-06-05 20:45 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-05 15:02 [PATCH v6 0/2] kvm: sev: Add SNP guest request throttling Dionna Glaze
2025-06-05 15:02 ` [PATCH v6 1/2] kvm: sev: Add SEV-SNP " Dionna Glaze
2025-06-06 9:58 ` kernel test robot
2025-06-05 15:02 ` [PATCH v6 2/2] kvm: sev: If ccp is busy, report busy to guest Dionna Glaze
2025-06-05 19:15 ` Tom Lendacky
2025-06-05 20:45 ` Dionna Amalie Glaze [this message]
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=CAAH4kHaeMgzdNP6Y7zdkdODransNkP4UiQ8ROpCVgenpiveJ_Q@mail.gmail.com \
--to=dionnaglaze@google.com \
--cc=bp@alien8.de \
--cc=jroedel@suse.de \
--cc=kvm@vger.kernel.org \
--cc=linux-coco@lists.linux.dev \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=pgonda@google.com \
--cc=seanjc@google.com \
--cc=thomas.lendacky@amd.com \
/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).