From: Vasileios Almpanis <vasileios.almpanis@virtuozzo.com>
To: Konstantin Khorenko <khorenko@virtuozzo.com>
Cc: "Denis V. Lunev" <den@virtuozzo.com>, devel@openvz.org
Subject: Re: [Devel] [PATCH hci-8.1] x86/traps: emulate CPUID faults for user tasks in exc_general_protection()
Date: Tue, 06 Oct 2026 09:30:43 +0000 [thread overview]
Message-ID: <179127904348.743581.1830873974508885831.b4-review@b4> (raw)
In-Reply-To: <20261006-b4-prep-khorenko-vstor-148656-just-cpuid-v1-1-6f2a2a6deef3@virtuozzo.com>
On Tue, 06 Oct 2026 10:30:19 +0200, Konstantin Khorenko <khorenko@virtuozzo.com> wrote:
> A non-empty /proc/vz/cpuid_override table makes ve_setup_task() set
> TIF_CPUID_OVERRIDE on every task entering a VE, so the CPU raises #GP
> on each CPUID the task executes and check_cpuid_fault() is supposed
> to emulate the instruction with the table values.
>
> The call sits after the user-mode branch of exc_general_protection(),
> which ends in gp_user_force_sig_segv() and goto exit, so it is reached
> only for a kernel-mode #GP, where CPUID never faults. Every Container
> task dies with SIGSEGV on the first CPUID of glibc init_cpu_features()
> instead of getting the override:
>
> [...]
Reviewed-by: Vasileios Almpanis <vasileios.almpanis@virtuozzo.com>
--
Vasileios Almpanis <vasileios.almpanis@virtuozzo.com>
_______________________________________________
Devel mailing list
Devel@openvz.org
https://lists.openvz.org/mailman/listinfo/devel
next prev parent reply other threads:[~2026-10-06 9:32 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-06 8:30 Konstantin Khorenko
2026-10-06 8:32 ` no-reply
2026-10-06 9:30 ` Vasileios Almpanis [this message]
2026-10-06 9:36 ` Konstantin Khorenko
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=179127904348.743581.1830873974508885831.b4-review@b4 \
--to=vasileios.almpanis@virtuozzo.com \
--cc=den@virtuozzo.com \
--cc=devel@openvz.org \
--cc=khorenko@virtuozzo.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