[Qemu-devel] Question about unbind MSI in xen_pt_msi.c

[Qemu-devel] Question about unbind MSI in xen_pt_msi.c

[Julien Grall]

Hi,

I'm looking to replace any call to xc_domain_bind_pt_irq and
xc_domain_unbind_pt_irq by specific IRQ type helpers.

I found one strange call which will always fail in xen_pt_msix_update_remap.
The function xc_domain_unbind_pt_irq is called with PT_IRQ_TYPE_MSI
which is not supported by the function.

I'm not familiar with x86 passthrough but this looks wrong to me. Am I
right? Shouldn't we replace this call by xc_domain_unbind_msi_irq?

Regards,

-- 
Julien Grall

Re: [Qemu-devel] Question about unbind MSI in xen_pt_msi.c

[Stefano Stabellini]

On Wed, 1 Apr 2015, Julien Grall wrote:
> Hi,
> 
> I'm looking to replace any call to xc_domain_bind_pt_irq and
> xc_domain_unbind_pt_irq by specific IRQ type helpers.
> 
> I found one strange call which will always fail in xen_pt_msix_update_remap.
> The function xc_domain_unbind_pt_irq is called with PT_IRQ_TYPE_MSI
> which is not supported by the function.
> 
> I'm not familiar with x86 passthrough but this looks wrong to me. Am I
> right? Shouldn't we replace this call by xc_domain_unbind_msi_irq?

I think that nobody noticed because xen_pt_msix_update_remap is only
called by xen_pt_region_add at assignement time, when pirq is
XEN_PT_UNASSIGNED_PIRQ, therefore xc_domain_unbind_pt_irq is not
actually called.

Yes, I think it should be xc_domain_unbind_msi_irq.

Re: Question about unbind MSI in xen_pt_msi.c

[Stefano Stabellini]

On Wed, 1 Apr 2015, Julien Grall wrote:
> Hi,
> 
> I'm looking to replace any call to xc_domain_bind_pt_irq and
> xc_domain_unbind_pt_irq by specific IRQ type helpers.
> 
> I found one strange call which will always fail in xen_pt_msix_update_remap.
> The function xc_domain_unbind_pt_irq is called with PT_IRQ_TYPE_MSI
> which is not supported by the function.
> 
> I'm not familiar with x86 passthrough but this looks wrong to me. Am I
> right? Shouldn't we replace this call by xc_domain_unbind_msi_irq?

I think that nobody noticed because xen_pt_msix_update_remap is only
called by xen_pt_region_add at assignement time, when pirq is
XEN_PT_UNASSIGNED_PIRQ, therefore xc_domain_unbind_pt_irq is not
actually called.

Yes, I think it should be xc_domain_unbind_msi_irq.

Re: [Qemu-devel] Question about unbind MSI in xen_pt_msi.c

[Julien Grall]

Hi,

On 01/04/2015 16:32, Stefano Stabellini wrote:
> On Wed, 1 Apr 2015, Julien Grall wrote:
>> Hi,
>>
>> I'm looking to replace any call to xc_domain_bind_pt_irq and
>> xc_domain_unbind_pt_irq by specific IRQ type helpers.
>>
>> I found one strange call which will always fail in xen_pt_msix_update_remap.
>> The function xc_domain_unbind_pt_irq is called with PT_IRQ_TYPE_MSI
>> which is not supported by the function.
>>
>> I'm not familiar with x86 passthrough but this looks wrong to me. Am I
>> right? Shouldn't we replace this call by xc_domain_unbind_msi_irq?
>
> I think that nobody noticed because xen_pt_msix_update_remap is only
> called by xen_pt_region_add at assignement time, when pirq is
> XEN_PT_UNASSIGNED_PIRQ, therefore xc_domain_unbind_pt_irq is not
> actually called.

Right. I think it would be possible to hit the problem if the guest 
decide to relocate the BAR.

> Yes, I think it should be xc_domain_unbind_msi_irq.

I don't have any x86 platform. Can someone take this item?

Otherwise I will do a blind port.

Regards,

-- 
Julien Grall

Re: Question about unbind MSI in xen_pt_msi.c

[Julien Grall]

Hi,

On 01/04/2015 16:32, Stefano Stabellini wrote:
> On Wed, 1 Apr 2015, Julien Grall wrote:
>> Hi,
>>
>> I'm looking to replace any call to xc_domain_bind_pt_irq and
>> xc_domain_unbind_pt_irq by specific IRQ type helpers.
>>
>> I found one strange call which will always fail in xen_pt_msix_update_remap.
>> The function xc_domain_unbind_pt_irq is called with PT_IRQ_TYPE_MSI
>> which is not supported by the function.
>>
>> I'm not familiar with x86 passthrough but this looks wrong to me. Am I
>> right? Shouldn't we replace this call by xc_domain_unbind_msi_irq?
>
> I think that nobody noticed because xen_pt_msix_update_remap is only
> called by xen_pt_region_add at assignement time, when pirq is
> XEN_PT_UNASSIGNED_PIRQ, therefore xc_domain_unbind_pt_irq is not
> actually called.

Right. I think it would be possible to hit the problem if the guest 
decide to relocate the BAR.

> Yes, I think it should be xc_domain_unbind_msi_irq.

I don't have any x86 platform. Can someone take this item?

Otherwise I will do a blind port.

Regards,

-- 
Julien Grall