Re: [Qemu-devel] [PATCH v2] pci-assign: sync MSI/MSI-X cap and table with PCIDevice

[Paolo Bonzini <pbonzini@redhat.com>]

On 25/11/2016 18:05, Michael S. Tsirkin wrote:
> On Fri, Nov 25, 2016 at 10:55:22AM +0800, Peter Xu wrote:
>> Since commit e1d4fb2d ("kvm-irqchip: x86: add msi route notify fn"),
>> kvm_irqchip_add_msi_route() starts to use pci_get_msi_message() to fetch
>> MSI info. This requires that we setup MSI related fields in PCIDevice.
>> For most devices, that won't be a problem, as long as we are using
>> general interfaces like msi_init()/msix_init().
>>
>> However, for pci-assign devices, MSI/MSI-X is treated differently - PCI
>> assign devices are maintaining its own MSI table and cap information in
>> AssignedDevice struct. however that's not synced up with PCIDevice's
>> fields. That will leads to pci_get_msi_message() failed to find correct
>> MSI capability, even with an NULL msix_table.
>>
>> A quick fix is to sync up the two places: both the capability bits and
>> table address for MSI/MSI-X.
>>
>> Reported-by: Changlimin <changlimin@h3c.com>
>> Tested-by: Changlimin <changlimin@h3c.com>
>> Cc: qemu-stable@nongnu.org
>> Fixes: e1d4fb2d ("kvm-irqchip: x86: add msi route notify fn")
>> Signed-off-by: Peter Xu <peterx@redhat.com>
> 
> 
> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> 
> Paolo, want to pick this up?

Yes.

Paolo


> 
>> ---
>> Do we still support pci-assign?
>>
>> v2:
>> - add (uint8_t *) for msix_table assignment [Limin]
>> ---
>>  hw/i386/kvm/pci-assign.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/hw/i386/kvm/pci-assign.c b/hw/i386/kvm/pci-assign.c
>> index 8238fbc..87dcbdd 100644
>> --- a/hw/i386/kvm/pci-assign.c
>> +++ b/hw/i386/kvm/pci-assign.c
>> @@ -1251,6 +1251,7 @@ static int assigned_device_pci_cap_init(PCIDevice *pci_dev, Error **errp)
>>              error_propagate(errp, local_err);
>>              return -ENOTSUP;
>>          }
>> +        dev->dev.cap_present |= QEMU_PCI_CAP_MSI;
>>          dev->cap.available |= ASSIGNED_DEVICE_CAP_MSI;
>>          /* Only 32-bit/no-mask currently supported */
>>          ret = pci_add_capability2(pci_dev, PCI_CAP_ID_MSI, pos, 10,
>> @@ -1285,6 +1286,7 @@ static int assigned_device_pci_cap_init(PCIDevice *pci_dev, Error **errp)
>>              error_propagate(errp, local_err);
>>              return -ENOTSUP;
>>          }
>> +        dev->dev.cap_present |= QEMU_PCI_CAP_MSIX;
>>          dev->cap.available |= ASSIGNED_DEVICE_CAP_MSIX;
>>          ret = pci_add_capability2(pci_dev, PCI_CAP_ID_MSIX, pos, 12,
>>                                    &local_err);
>> @@ -1648,6 +1650,7 @@ static void assigned_dev_register_msix_mmio(AssignedDevice *dev, Error **errp)
>>          dev->msix_table = NULL;
>>          return;
>>      }
>> +    dev->dev.msix_table = (uint8_t *)dev->msix_table;
>>  
>>      assigned_dev_msix_reset(dev);
>>  
>> @@ -1665,6 +1668,7 @@ static void assigned_dev_unregister_msix_mmio(AssignedDevice *dev)
>>          error_report("error unmapping msix_table! %s", strerror(errno));
>>      }
>>      dev->msix_table = NULL;
>> +    dev->dev.msix_table = NULL;
>>  }
>>  
>>  static const VMStateDescription vmstate_assigned_device = {
>> -- 
>> 2.7.4
>>