LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Juergen Gross <jgross@suse.com>
To: xen-devel@lists.xenproject.org, linux-pm@vger.kernel.org,
	linux-kernel@vger.kernel.org, x86@kernel.org
Cc: Juergen Gross <jgross@suse.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	stable@vger.kernel.org,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	Stefano Stabellini <sstabellini@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH 0/2] xen: fix illegal rtc device usage of pv guests
Date: Fri,  3 Sep 2021 10:49:35 +0200	[thread overview]
Message-ID: <20210903084937.19392-1-jgross@suse.com> (raw)

A recent change in mc146818_get_time() resulted in WARN splats when
booting a Xen PV guest.

The main reason is that there is a code path resulting in accessing a
RTC device which is not present, which has been made obvious by a
call of WARN() in this case.

This small series is fixing this issue by:

- avoiding the RTC device access from drivers/base/power/trace.c in
  cast there is no legacy RTC device available
- resetting the availability flag of a legacy RTC device for Xen PV
  guests

Juergen Gross (2):
  PM: base: power: don't try to use non-existing RTC for storing data
  xen: reset legacy rtc flag for PV domU

 arch/x86/xen/enlighten_pv.c |  7 +++++++
 drivers/base/power/trace.c  | 10 ++++++++++
 2 files changed, 17 insertions(+)

-- 
2.26.2


             reply	other threads:[~2021-09-03  8:49 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-03  8:49 Juergen Gross [this message]
2021-09-03  8:49 ` [PATCH 1/2] PM: base: power: don't try to use non-existing RTC for storing data Juergen Gross
2021-09-03  8:56   ` Greg Kroah-Hartman
2021-09-03  9:01     ` Juergen Gross
2021-09-03  9:08       ` Greg Kroah-Hartman
2021-09-06 17:07       ` Rafael J. Wysocki
2021-09-07  4:18         ` Juergen Gross
2021-09-03  8:49 ` [PATCH 2/2] xen: reset legacy rtc flag for PV domU Juergen Gross
2021-09-08 14:54   ` Boris Ostrovsky
2021-09-10  7:27     ` Juergen Gross

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=20210903084937.19392-1-jgross@suse.com \
    --to=jgross@suse.com \
    --cc=boris.ostrovsky@oracle.com \
    --cc=bp@alien8.de \
    --cc=gregkh@linuxfoundation.org \
    --cc=hpa@zytor.com \
    --cc=len.brown@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=pavel@ucw.cz \
    --cc=rafael@kernel.org \
    --cc=rjw@rjwysocki.net \
    --cc=sstabellini@kernel.org \
    --cc=stable@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    --cc=xen-devel@lists.xenproject.org \
    --subject='Re: [PATCH 0/2] xen: fix illegal rtc device usage of pv guests' \
    /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

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).