Re: [Qemu-devel] [PATCH v2] Fix guest OS hang when 64bit PCI bar present

[Peter Maydell]

On 22 February 2013 03:58, Alexey Korolev <address@hidden> wrote:
> This patch addresses the issue fully described here:
> http://lists.nongnu.org/archive/html/qemu-devel/2013-02/msg01804.html
>
> Linux kernels prior to 2.6.36 do not disable the PCI device during
> enumeration process. Since lower and higher parts of a 64bit BAR
> are programmed separately this leads to qemu receiving a request to occupy
> a completely wrong address region for a short period of time.
> We have found that the boot process screws up completely if kvm-apic range
> is overlapped even for a short period of time (it is fine for other
> regions though).
>
> This patch raises the priority of the kvm-apic memory region, so it is
> never pushed out by PCI devices. The patch is quite safe as it does not
> touch memory manager.
>
> Signed-off-by: Alexey Korolev <address@hidden>
> Signed-off-by: Michael S. Tsirkin <address@hidden>

Reviewed-by: Peter Maydell <address@hidden>
as far as the sysbus changes go. I can't comment on whether the
change to the PC emulation is correct or not but it looks
vaguely plausible.

thanks
-- PMM