From: Paolo Bonzini <pbonzini@redhat.com>
To: Li Wang <liwang@redhat.com>,
ricardo.neri-calderon@linux.intel.com, tglx@linutronix.de,
kernellwp@gmail.com, ricardo.neri@intel.com,
pengfei.xu@intel.com
Cc: LTP List <ltp@lists.linux.it>,
linux-kernel <linux-kernel@vger.kernel.org>,
Ping Fang <pifang@redhat.com>
Subject: Re: [Kernel BUG?] SMSW operation get success on UMIP KVM guest
Date: Mon, 1 Jul 2019 14:02:35 +0200 [thread overview]
Message-ID: <5622c0ac-236f-4e3e-a132-c8d3bd8fadc4@redhat.com> (raw)
In-Reply-To: <CAEemH2cg01cdz=amrCWU00Xof9+cxmfR_DqCBaQe36QoGsakmA@mail.gmail.com>
On 01/07/19 09:50, Li Wang wrote:
> Hello there,
>
> LTP/umip_basic_test get failed on KVM UMIP
> system(kernel-v5.2-rc4.x86_64). The test is only trying to do
> asm volatile("smsw %0\n" : "=m" (val));
> and expect to get SIGSEGV in this SMSW operation, but it exits with 0
> unexpectedly.
In addition to what Thomas said, perhaps you are using a host that does
*not* have UMIP, and configuring KVM to emulate it(*). In that case, it
is not possible to intercept SMSW, and therefore it will incorrectly
succeed.
Paolo
(*) before the x86 people jump at me, this won't happen unless you
explicitly pass an option to QEMU, such as "-cpu host,+umip". :) The
incorrect emulation of SMSW when CR4.UMIP=1 is why.
next prev parent reply other threads:[~2019-07-01 12:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAEemH2cg01cdz=amrCWU00Xof9+cxmfR_DqCBaQe36QoGsakmA@mail.gmail.com>
2019-07-01 8:03 ` Thomas Gleixner
2019-07-01 12:02 ` Paolo Bonzini [this message]
2019-07-01 14:53 ` Ricardo Neri
2019-07-01 17:30 ` Paolo Bonzini
[not found] ` <CAEemH2fqMpoiBo+asyawHsOWgdXy-ggV0mwQs9A9EJ1kh=uhAA@mail.gmail.com>
2019-07-01 16:03 ` Ricardo Neri
[not found] ` <CAEemH2fR98TBHaOM37aGmzbgdZ_XPokJeUNN6dU1r=1WhOSmEw@mail.gmail.com>
2019-07-02 8:40 ` Pengfei Xu
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=5622c0ac-236f-4e3e-a132-c8d3bd8fadc4@redhat.com \
--to=pbonzini@redhat.com \
--cc=kernellwp@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=liwang@redhat.com \
--cc=ltp@lists.linux.it \
--cc=pengfei.xu@intel.com \
--cc=pifang@redhat.com \
--cc=ricardo.neri-calderon@linux.intel.com \
--cc=ricardo.neri@intel.com \
--cc=tglx@linutronix.de \
/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
all inboxes | Powered by JetHome®