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Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control o
From: |
Jan Beulich |
Subject: |
Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register |
Date: |
Mon, 20 Apr 2015 15:08:09 +0100 |
>>> On 20.04.15 at 15:43, <address@hidden> wrote:
> On Mon, Apr 13, 2015 at 01:51:06PM +0100, Jan Beulich wrote:
>> >>> On 13.04.15 at 14:47, <address@hidden> wrote:
>> > Can you check device capabilities register, offset 0x4 within
>> > pci express capability structure?
>> > Bit 15 is 15 Role-Based Error Reporting.
>> > Is it set?
>> >
>> > The spec says:
>> >
>> > 15
>> > On platforms where robust error handling and PC-compatible
>> > Configuration
>> > Space probing is
>> > required, it is suggested that software or firmware have the
>> > Unsupported
>> > Request Reporting Enable
>> > bit Set for Role-Based Error Reporting Functions, but clear for 1.0a
>> > Functions. Software or
>> > firmware can distinguish the two classes of Functions by examining the
>> > Role-Based Error Reporting
>> > bit in the Device Capabilities register.
>>
>> Yes, that bit is set.
>
> curiouser and curiouser.
>
> So with functions that do support Role-Based Error Reporting, we have
> this:
>
>
> With device Functions implementing Role-Based Error Reporting, setting
> the
> Unsupported Request
> Reporting Enable bit will not interfere with PC-compatible
> Configuration
> Space probing, assuming
> that the severity for UR is left at its default of non-fatal. However,
> setting the Unsupported Request
> Reporting Enable bit will enable the Function to report UR errors 97
> detected with posted Requests,
> helping avoid this case for potential silent data corruption.
I still don't see what the PC-compatible config space probing has to
do with our issue.
> did firmware reconfigure this device to report URs as fatal errors then?
No, the Unsupported Request Error Serverity flag is zero.
Jan
- Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register, (continued)
- Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register, Andrew Cooper, 2015/04/01
- Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register, Michael S. Tsirkin, 2015/04/01
- Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register, Jan Beulich, 2015/04/13
- Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register, Michael S. Tsirkin, 2015/04/13
- Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register, Jan Beulich, 2015/04/13
- Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register, Michael S. Tsirkin, 2015/04/13
- Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register, Jan Beulich, 2015/04/13
- Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register, Michael S. Tsirkin, 2015/04/13
- Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register, Jan Beulich, 2015/04/13
- Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register, Michael S. Tsirkin, 2015/04/20
- Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register,
Jan Beulich <=
- Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register, Michael S. Tsirkin, 2015/04/20
- Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register, Jan Beulich, 2015/04/20
Re: [Qemu-devel] [Xen-devel] [PATCH][XSA-126] xen: limit guest control of PCI command register, Ian Campbell, 2015/04/01