On 2015/1/29 22:12, Bjorn Helgaas wrote:
> On Thu, Jan 29, 2015 at 7:15 AM, Jan Beulich <JBeulich@xxxxxxxx> wrote:
>>>>> On 29.01.15 at 04:54, <wangyijing@xxxxxxxxxx> wrote:
>>> --- a/drivers/pci/msi.c
>>> +++ b/drivers/pci/msi.c
>>> @@ -694,11 +694,16 @@ static void __iomem *msix_map_region(struct pci_dev *dev, unsigned nr_entries)
>>> {
>>> resource_size_t phys_addr;
>>> u32 table_offset;
>>> + unsigned long flags;
>>> u8 bir;
>>>
>>> pci_read_config_dword(dev, dev->msix_cap + PCI_MSIX_TABLE,
>>> &table_offset);
>>> bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
>>> + flags = pci_resource_flags(dev, bir);
>>> + if (!flags || (flags & IORESOURCE_UNSET))
>>> + return NULL;
>>
>> Mind explaining what relevance the checking of flags against zero has
>> (also in the Xen counterpart)? The patch description says nothing in
>> this regard...
>
> It's buried in there:
>
>> reset_resource() -->res->start/end/flags = 0
>
> If we fail to assign resources to a BAR, in some cases we set
> res->flags = 0. There are other cases where we set IORESOURCE_UNSET,
> and that's the direction I want to go for all situations where we
> don't assign resources. But right now, we have a mix where flags is
> zero in some cases (including the one Zhang found), and has
> IORESOURCE_UNSET in others.
>
> I'll try to wordsmith this in the changelog when I apply this.
Thanks to Bjorn help explain, sorry for my poor description.
>
> Bjorn
>
> .
>
--
Thanks!
Yijing
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
