Re: [Xen-devel] [xen-unstable] [qemu-xen] pci passthrough msi-x returns same pirq

[Sander Eikelenboom <linux@xxxxxxxxxxxxxx>]

Friday, December 7, 2012, 6:24:10 PM, you wrote:

> On Thu, 6 Dec 2012, Sander Eikelenboom wrote:
>> Hi Stefano / Anthony,
>> 
>> With the debug output turned on i see some difference between 
>> qemu-traditional and qemu-upstream:
>> 
>> With the pci passthroughed device that fails with msi-x, in qemu-xen it 
>> seems to get the same pirq back for every entry
>> 
>> in qemu-traditional:
>> 
>> pt_msix_update_one: pt_msix_update_one requested pirq = 87
>> pt_msix_update_one: Update msix entry 0 with pirq 57 gvec 0
>> pt_msix_update_one: pt_msix_update_one requested pirq = 86
>> pt_msix_update_one: Update msix entry 1 with pirq 56 gvec 0
>> pt_msix_update_one: pt_msix_update_one requested pirq = 85
>> pt_msix_update_one: Update msix entry 2 with pirq 55 gvec 0
>> pt_msix_update_one: pt_msix_update_one requested pirq = 84
>> pt_msix_update_one: Update msix entry 3 with pirq 54 gvec 0
>> 
>> 
>> in qemu-xen (upstream):
>> 
>> [00:05.0] msi_msix_setup: requested pirq 4 for MSI-X (vec: 0, entry: 0)
>> [00:05.0] msi_msix_update: Updating MSI-X with pirq 4 gvec 0 gflags 0x3057 
>> (entry: 0)
>> [00:05.0] msi_msix_setup: requested pirq 4 for MSI-X (vec: 0, entry: 0x1)
>> [00:05.0] msi_msix_update: Updating MSI-X with pirq 4 gvec 0 gflags 0x3056 
>> (entry: 0x1)
>> [00:05.0] msi_msix_setup: requested pirq 4 for MSI-X (vec: 0, entry: 0x2)
>> [00:05.0] msi_msix_update: Updating MSI-X with pirq 4 gvec 0 gflags 0x3055 
>> (entry: 0x2)
>> [00:05.0] msi_msix_setup: requested pirq 4 for MSI-X (vec: 0, entry: 0x3)
>> [00:05.0] msi_msix_update: Updating MSI-X with pirq 4 gvec 0 gflags 0x3054 
>> (entry: 0x3)

> That is a good pointer, but unfortunately the code that parses those
> entries look exactly alike in both QEMU trees:

> qemu-xen-traditional/hw/pt-msi.c:pt_msix_update_one

> if (!gvec) {
>         /* if gvec is 0, the guest is asking for a particular pirq that
>          * is passed as dest_id */
>         pirq = ((gaddr >> 32) & 0xffffff00) |
>                (((gaddr & 0xffffffff) >> MSI_TARGET_CPU_SHIFT) & 0xff);



> qemu-xen/hw/xen_pt_msi.c:msi_msix_setup

> if (gvec == 0) {
>         /* if gvec is 0, the guest is asking for a particular pirq that
>          * is passed as dest_id */
>         *ppirq = msi_ext_dest_id(addr >> 32) | msi_dest_id(addr);

> given how msi_ext_dest_id and msi_dest_id are defined, they should
> behave the same way.

> Maybe adding a printk in msi_msix_setup to show addr would help
> nonetheless...

Hi Stefano,

I have added some printk's attached i have:

- qemu-upstream.log           boot of the guest with qemu upstream, device not 
working
- qemu-traditional.log        boot of the same guest with qemu traditional, 
device is working

- xl-dmesg-upstream.txt       part of xl-dmesg related to boot of guest with 
qemu-upstream
- xl-dmesg-traditional.txt    part of xl-dmesg related to boot of sameguest 
with qemu-traditional
- xl-dmesg.txt                complete xl-dmesg

- interrupts-dom0.txt         /proc/interrupts of dom0
- interrupts-upstream.txt     /proc/interrupts of guest with qemu-upstream

--
Sander

Attachment: interrupts-dom0.txt
Description: Text document

Attachment: interrupts-upstream.txt
Description: Text document

Attachment: qemu-traditional.log
Description: Binary data

Attachment: qemu-upstream.log
Description: Binary data

Attachment: xl-dmesg.txt
Description: Text document

Attachment: xl-dmesg-traditional.txt
Description: Text document

Attachment: xl-dmesg-upstream.txt
Description: Text document

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