Re: [Qemu-devel] [PATCH V2] hw/virtio: Add PCIe capability to virtio devices

[Marcel Apfelbaum <marcel@redhat.com>]

On 10/28/2015 07:34 PM, Michael S. Tsirkin wrote:
> On Wed, Oct 28, 2015 at 07:16:06PM +0200, Marcel Apfelbaum wrote:
>> The virtio devices are converted to PCI-Express
>> if they are plugged into a PCI-Express bus and
>> the 'modern' protocol is enabled.
>>
>> Devices plugged directly into the Root Complex as
>> Integrated Endpoints remain PCI.
>>
>> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
>> ---
>>
>> v1 -> v2:
>>   - Addressed Michael S. Tsirkin's comments:
>>     - Added the minimum required capabilities for PCIe devices
>>     - Integrated Endpoints remain PCI
>>
>>   - Use pcie_endpoint_cap_init instead of manually creating the pcie capability.
>>
>>   - Regarding Gerd Hoffman's comments:
>>     - Creating virtio-pcie devices:
>>       For the moment I prefer to not duplicate the virtio definitions,
>>       at least until we don't have a consensus (Personally I don't like it)
>>     - Removing the IO bar:
>>       This would be my next patch on the "virtio to express" series, I plan
>>       to remove it only for "modern" devices.
>>
>> Any comments would be appreciated,
>> Thanks,
>> Marcel
>>
>>   hw/virtio/virtio-pci.c | 19 +++++++++++++++++++
>>   1 file changed, 19 insertions(+)
>
> Looks good to me.  One minor point: need to make this conditional on 2.5
> machine type.

Hi Michael,

Makes sense to make this for 2.5+ machines.

Thanks for the review,
Marcel


>
>> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
>> index f55dd2b..12d0ebb 100644
>> --- a/hw/virtio/virtio-pci.c
>> +++ b/hw/virtio/virtio-pci.c
>> @@ -1592,6 +1592,25 @@ static void virtio_pci_realize(PCIDevice *pci_dev, Error **errp)
>>
>>       address_space_init(&proxy->modern_as, &proxy->modern_cfg, "virtio-pci-cfg-as");
>>
>> +    if (!(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_MODERN)
>> +        && pci_bus_is_express(pci_dev->bus)
>> +        && !pci_bus_is_root(pci_dev->bus)) {
>> +        int pos;
>> +
>> +        pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS;
>> +        pos = pcie_endpoint_cap_init(pci_dev, 0);
>> +        assert(pos > 0);
>> +
>> +        pos = pci_add_capability(pci_dev, PCI_CAP_ID_PM, 0, PCI_PM_SIZEOF);
>> +        assert(pos > 0);
>> +
>> +        /*
>> +         * Indicates that this function complies with revision 1.2 of the
>> +         * PCI Power Management Interface Specification.
>> +         */
>> +        pci_set_word(pci_dev->config + pos + PCI_PM_PMC, 0x3);
>> +    }
>> +
>>       virtio_pci_bus_new(&proxy->bus, sizeof(proxy->bus), proxy);
>>       if (k->realize) {
>>           k->realize(proxy, errp);
>> --
>> 2.1.0