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From: John Snow <jsnow@redhat.com>
To: qemu-block@nongnu.org
Cc: peter.maydell@linaro.org, pjp@fedoraproject.org,
	qemu-devel@nongnu.org, zuozhi.fzz@alibaba-inc.com,
	pbonzini@redhat.com, John Snow <jsnow@redhat.com>
Subject: [Qemu-devel] [PATCH 0/4] ahci: unmap fixes
Date: Fri, 29 Jan 2016 16:41:25 -0500	[thread overview]
Message-ID: <1454103689-13042-1-git-send-email-jsnow@redhat.com> (raw)

As reported by Zuozhi fzz <zuozhi.fzz@alibaba-inc.com>, there's a problem
you can expose in AHCI by rewriting the command list buffer and/or FIS
receive buffer addresses, then re-starting the AHCI device before bringing
it to a stop. Depending on the success of the remap operations, you may
be able to transition the device to a state where it thinks it is "running"
but no longer has a guest memory mapping.

When you try to transition it to the stopped state, QEMU crashes.

Tighten up the start/stop conditions, and pepper in a paranoia check inside
of the unmap function.

________________________________________________________________________________

For convenience, this branch is available at:
https://github.com/jnsnow/qemu.git branch ahci-unmap-fixes
https://github.com/jnsnow/qemu/tree/ahci-unmap-fixes

This version is tagged ahci-unmap-fixes-v1:
https://github.com/jnsnow/qemu/releases/tag/ahci-unmap-fixes-v1

John Snow (4):
  ahci: Do not unmap NULL addresses
  ahci: handle LIST_ON and FIS_ON in map helpers
  ahci: explicitly reject bad engine states on post_load
  ahci: prohibit "restarting" the FIS or CLB engines

 hw/ide/ahci.c | 96 ++++++++++++++++++++++++++++++++++++-----------------------
 1 file changed, 59 insertions(+), 37 deletions(-)

-- 
2.4.3

             reply	other threads:[~2016-01-29 21:41 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-29 21:41 John Snow [this message]
2016-01-29 21:41 ` [Qemu-devel] [PATCH 1/4] ahci: Do not unmap NULL addresses John Snow
2016-01-29 21:41 ` [Qemu-devel] [PATCH 2/4] ahci: handle LIST_ON and FIS_ON in map helpers John Snow
2016-01-29 21:41 ` [Qemu-devel] [PATCH 3/4] ahci: explicitly reject bad engine states on post_load John Snow
2016-01-29 21:41 ` [Qemu-devel] [PATCH 4/4] ahci: prohibit "restarting" the FIS or CLB engines John Snow
2016-02-08 16:53 ` [Qemu-devel] [PATCH 0/4] ahci: unmap fixes John Snow
2016-02-09 17:38   ` P J P

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