From: Paul Mackerras <paulus@ozlabs.org>
To: Thomas Huth <thuth@redhat.com>
Cc: kvm-ppc@vger.kernel.org, kvm@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org,
Michael Ellerman <mpe@ellerman.id.au>,
Alexander Graf <agraf@suse.com>,
stable@vger.kernel.org
Subject: Re: [PATCH] KVM: PPC: Book3s PR: Allow access to unprivileged MMCR2 register
Date: Tue, 27 Sep 2016 15:45:33 +1000 [thread overview]
Message-ID: <20160927054533.3azixxy77bh6v3om@oak.ozlabs.ibm.com> (raw)
In-Reply-To: <1474463205-5965-1-git-send-email-thuth@redhat.com>
On Wed, Sep 21, 2016 at 03:06:45PM +0200, Thomas Huth wrote:
> The MMCR2 register is available twice, one time with number 785
> (privileged access), and one time with number 769 (unprivileged,
> but it can be disabled completely). In former times, the Linux
> kernel was using the unprivileged register 769 only, but since
> commit 8dd75ccb571f3c92c ("powerpc: Use privileged SPR number
> for MMCR2"), it uses the privileged register 785 instead.
> The KVM-PR code then of course also switched to use the SPR 785,
> but this is causing older guest kernels to crash, since these
> kernels still access 769 instead. So to support older kernels
> with KVM-PR again, we have to support register 769 in KVM-PR, too.
>
> Fixes: 8dd75ccb571f3c92c48014b3dabd3d51a115ab41
> Cc: stable@vger.kernel.org # v3.10+
> Signed-off-by: Thomas Huth <thuth@redhat.com>
Thanks, applied to kvm-ppc-next.
Paul.
prev parent reply other threads:[~2016-09-27 5:47 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-21 13:06 [PATCH] KVM: PPC: Book3s PR: Allow access to unprivileged MMCR2 register Thomas Huth
2016-09-27 5:45 ` Paul Mackerras [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=20160927054533.3azixxy77bh6v3om@oak.ozlabs.ibm.com \
--to=paulus@ozlabs.org \
--cc=agraf@suse.com \
--cc=kvm-ppc@vger.kernel.org \
--cc=kvm@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mpe@ellerman.id.au \
--cc=stable@vger.kernel.org \
--cc=thuth@redhat.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).