On Thu, Jan 14, 2016 at 08:08:28AM +0000, Xie, Huawei wrote:

On 1/14/2016 3:58 PM, Yuanhan Liu wrote:

quoted

On Thu, Jan 14, 2016 at 07:51:08AM +0000, Xie, Huawei wrote:

quoted

On 1/14/2016 3:49 PM, Yuanhan Liu wrote:

quoted

On Thu, Jan 14, 2016 at 07:47:17AM +0000, Xie, Huawei wrote:

quoted

On 1/12/2016 2:58 PM, Yuanhan Liu wrote:

quoted

Modern (v1.0) virtio pci device defines several pci capabilities.

[snip]

quoted

+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.

Yes,

For the notification, try PORT IO if possible.

But it doesn't seem right to me to mix legacy registers in modern pci device.

	--yliu