From: Dan Williams <dan.j.williams@intel.com>
To: Cedric Xing <cedric.xing@intel.com>,
Dan Williams <dan.j.williams@intel.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
<x86@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-kernel@vger.kernel.org>, <linux-coco@lists.linux.dev>,
"Dionna Amalie Glaze" <dionnaglaze@google.com>,
Guorui Yu <guorui.yu@linux.alibaba.com>,
James Bottomley <James.Bottomley@hansenpartnership.com>,
Dan Middleton <dan.middleton@linux.intel.com>,
Mikko Ylinen <mikko.ylinen@linux.intel.com>,
Sathyanarayanan Kuppuswamy
<sathyanarayanan.kuppuswamy@linux.intel.com>
Subject: Re: [PATCH v3 4/5] x86/tdx: tdx_mcall_get_report0: Return -EBUSY on TDCALL_OPERAND_BUSY error
Date: Tue, 8 Apr 2025 22:13:07 -0700 [thread overview]
Message-ID: <67f601e35845f_720529475@dwillia2-xfh.jf.intel.com.notmuch> (raw)
In-Reply-To: <20250407-tdx-rtmr-v3-4-54f17bc65228@intel.com>
Cedric Xing wrote:
> Return `-EBUSY` from tdx_mcall_get_report0() when `TDG.MR.REPORT` returns
> `TDCALL_OPERAND_BUSY`. This enables the caller to retry obtaining a
> TDREPORT later if another VCPU is extending an RTMR concurrently.
Can this not be prevented by proper locking? Otherwise this type of
collision sounds like a kernel bug, not something that should escape to
userspace.
I.e. userspace can not reasonably know when it is safe to retry, so take
locks to ensure forward progress.
next prev parent reply other threads:[~2025-04-09 5:13 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-07 18:59 [PATCH v3 0/5] tsm-mr: Unified Measurement Register ABI for TVMs Cedric Xing
2025-04-07 18:59 ` [PATCH v3 1/5] tsm-mr: Add TVM Measurement Register support Cedric Xing
2025-04-09 0:27 ` Dan Williams
2025-04-11 4:01 ` Xing, Cedric
2025-04-07 18:59 ` [PATCH v3 2/5] tsm-mr: Add tsm-mr sample code Cedric Xing
2025-04-09 2:11 ` kernel test robot
2025-04-09 4:26 ` Dan Williams
2025-04-07 18:59 ` [PATCH v3 3/5] x86/tdx: Add tdx_mcall_extend_rtmr() interface Cedric Xing
2025-04-09 5:10 ` Dan Williams
2025-04-11 17:49 ` Xing, Cedric
2025-04-07 18:59 ` [PATCH v3 4/5] x86/tdx: tdx_mcall_get_report0: Return -EBUSY on TDCALL_OPERAND_BUSY error Cedric Xing
2025-04-09 5:13 ` Dan Williams [this message]
2025-04-11 17:37 ` Xing, Cedric
2025-04-07 18:59 ` [PATCH v3 5/5] virt: tdx-guest: Expose TDX MRs as sysfs attributes Cedric Xing
2025-04-08 20:21 ` [PATCH v3 0/5] tsm-mr: Unified Measurement Register ABI for TVMs Dan Williams
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=67f601e35845f_720529475@dwillia2-xfh.jf.intel.com.notmuch \
--to=dan.j.williams@intel.com \
--cc=James.Bottomley@hansenpartnership.com \
--cc=bp@alien8.de \
--cc=cedric.xing@intel.com \
--cc=dan.middleton@linux.intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=dionnaglaze@google.com \
--cc=guorui.yu@linux.alibaba.com \
--cc=hpa@zytor.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-coco@lists.linux.dev \
--cc=linux-kernel@vger.kernel.org \
--cc=mikko.ylinen@linux.intel.com \
--cc=mingo@redhat.com \
--cc=sathyanarayanan.kuppuswamy@linux.intel.com \
--cc=tglx@linutronix.de \
--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