From: Avi Kivity <avi@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alexey Korolev <alexey.korolev@endace.com>,
sfd@endace.com, Alex Williamson <alex.williamson@redhat.com>,
Kevin O'Connor <kevin@koconnor.net>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [RFC/PATCH] Fix guest OS panic when 64bit BAR is present
Date: Thu, 26 Jan 2012 16:33:00 +0200 [thread overview]
Message-ID: <4F21641C.9010600@redhat.com> (raw)
In-Reply-To: <20120126140543.GC17198@redhat.com>
On 01/26/2012 04:05 PM, Michael S. Tsirkin wrote:
> >
> > Let me see if I get this right: during BAR sizing, the guest sets the
> > BAR to ~1, which means 4GB-32MB -> 4GB, which overlaps the HPET. If so,
> > that's expected behaviour.
>
> Yes BAR sizing temporarily sets the BAR to an invalid value then
> restores it. What I don't understand is how come something accesses the
> HPET range in between.
Interrupt -> read time.
> > If the guest doesn't want this memory there,
> > it should disable mmio.
>
> Recent kernels do this for most devices, but not for
> platform devices.
Then they are vulnerable to this issue.
The i440fx spec states that the entire top-of-memory range to 4GB if
forwarded to PCI, so qemu appears to be correct here.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2012-01-26 14:34 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-25 5:46 [Qemu-devel] [RFC/PATCH] Fix guest OS panic when 64bit BAR is present Alexey Korolev
2012-01-25 12:51 ` Michael S. Tsirkin
2012-01-26 3:20 ` Alexey Korolev
2012-01-25 15:38 ` Michael S. Tsirkin
2012-01-25 18:59 ` Alex Williamson
2012-01-26 3:19 ` Alexey Korolev
2012-01-26 13:51 ` Avi Kivity
2012-01-26 14:05 ` Michael S. Tsirkin
2012-01-26 14:33 ` Avi Kivity [this message]
2012-01-26 9:14 ` Michael S. Tsirkin
2012-01-26 13:52 ` Avi Kivity
2012-01-26 14:36 ` Michael S. Tsirkin
2012-01-26 15:12 ` Avi Kivity
2012-01-27 4:42 ` Alexey Korolev
2012-01-31 9:40 ` Avi Kivity
2012-01-31 9:43 ` Avi Kivity
2012-02-01 5:44 ` Alexey Korolev
2012-02-01 7:04 ` Michael S. Tsirkin
2012-02-02 2:22 ` Alexey Korolev
2012-01-31 10:51 ` Avi Kivity
2012-01-27 4:40 ` Alexey Korolev
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