[dpdk-dev] [PATCH v2 7/7] virtio: add 1.0 support

Xie, Huawei huawei.xie at intel.com
Thu Jan 14 09:08:28 CET 2016


On 1/14/2016 3:58 PM, Yuanhan Liu wrote:
> On Thu, Jan 14, 2016 at 07:51:08AM +0000, Xie, Huawei wrote:
>> On 1/14/2016 3:49 PM, Yuanhan Liu wrote:
>>> On Thu, Jan 14, 2016 at 07:47:17AM +0000, Xie, Huawei wrote:
>>>> On 1/12/2016 2:58 PM, Yuanhan Liu wrote:
>>>>> Modern (v1.0) virtio pci device defines several pci capabilities.
>>>> [snip]
>>>>> +static void
>>>>> +modern_notify_queue(struct virtio_hw *hw __rte_unused, struct virtqueue *vq)
>>>>> +{
>>>>> +	modern_write16(1, vq->notify_addr);
>>>>> +}
>>>> Does virtio 1.0 only supports MMIO? MMIO has long VMEXIT latency than
>>>> PORT IO.
>>> Virtio 1.0 supports three transport layer, including MMIO and PCI. And
>>> we use PCI only in our pmd driver.
>> I don't mean that MMIO but use memory mapped IO for configuration.
> Then, yes.

00:03.0 Ethernet controller: Red Hat, Inc Virtio network device
        Subsystem: Red Hat, Inc Device 0001
        Physical Slot: 3
        Flags: bus master, fast devsel, latency 0, IRQ 10
        I/O ports at c100 [size=32]
        Memory at febd1000 (32-bit, non-prefetchable) [size=4K]
        Memory at fe000000 (64-bit, prefetchable) [size=8M]
        Expansion ROM at feb40000 [disabled] [size=256K]
        Capabilities: [98] MSI-X: Enable+ Count=3 Masked-
        Capabilities: [84] Vendor Specific Information: Len=14 <?>
        Capabilities: [70] Vendor Specific Information: Len=14 <?>
        Capabilities: [60] Vendor Specific Information: Len=10 <?>
        Capabilities: [50] Vendor Specific Information: Len=10 <?>
        Capabilities: [40] Vendor Specific Information: Len=10 <?>
        Kernel driver in use: igb_uio
        Kernel modules: virtio_pci

c100 is still there. For the notification, try PORT IO if possible.

>
> 	--yliu
>



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