From: "Richard W.M. Jones" <rjones@redhat.com>
To: Michael Clark <mjc@sifive.com>
Cc: "Philippe Mathieu-Daudé" <f4bug@amsat.org>,
"QEMU Developers" <qemu-devel@nongnu.org>,
"Palmer Dabbelt" <palmer@sifive.com>,
"Peter Maydell" <peter.maydell@linaro.org>
Subject: Re: [Qemu-devel] [PATCH v3] RISC-V: Fix riscv_isa_string memory size bug
Date: Mon, 19 Mar 2018 19:42:42 +0000 [thread overview]
Message-ID: <20180319194242.GQ2787@redhat.com> (raw)
In-Reply-To: <CAHNT7Nuv9G+e3-m-356HZDoiLju=vPCucfWhXLJ0QHPGM7NSQw@mail.gmail.com>
On Mon, Mar 19, 2018 at 11:35:51AM -0700, Michael Clark wrote:
> The RISC-V post-merge spec conformance and cleanup series has had a lot of
> testing. I've been using it to compile QEMU inside of QEMU using the RISC-V
> Fedora Image and its native RISC-V GCC toolchain running inside SMP Linux
> 4.16-rc2. It appears to be pretty rock-solid. The rcu lock fix would likely
> only affect users who are ballooning memory while a guest is under load.
> The page walker changes have also been tested under load (including
> performance tests).
Did you see the problem with restoring floating point registers on
context switch? The test case is quite simple:
http://oirase.annexia.org/tmp/sched.c
Note you must compile it with gcc -O2 to manifest the bug. (We
originally thought it was a problem with gcc's optimization, but it
isn't.)
In Fedora's qemu tree are carrying the following patch which is just a
workaround:
https://github.com/rwmjones/fedora-riscv-bootstrap/blob/master/stage1-riscv-qemu/force-float-save.patch
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
libguestfs lets you edit virtual machines. Supports shell scripting,
bindings from many languages. http://libguestfs.org
next prev parent reply other threads:[~2018-03-19 19:42 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-16 17:26 [Qemu-devel] [PATCH v3] RISC-V: Fix riscv_isa_string memory size bug Michael Clark
2018-03-18 23:22 ` Philippe Mathieu-Daudé
2018-03-19 18:35 ` Michael Clark
2018-03-19 19:42 ` Richard W.M. Jones [this message]
2018-03-19 21:39 ` Michael Clark
2018-03-22 21:06 ` Michael Clark
2018-03-22 22:09 ` Richard W.M. Jones
2018-03-22 22:17 ` DJ Delorie
2018-03-22 22:21 ` Michael Clark
2018-03-23 20:01 ` Palmer Dabbelt
2018-03-20 4:43 ` Richard Henderson
2018-03-20 18:06 ` Michael Clark
2018-03-24 4:35 ` Richard Henderson
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