On Thu, Aug 05, 2021 at 04:03:58PM +0800, Dongdong Liu wrote: > > On 2021/8/5 7:29, Bjorn Helgaas wrote: > > On Wed, Aug 04, 2021 at 09:47:04PM +0800, Dongdong Liu wrote: > > > Enable VF 10-Bit Tag Requester when it's upstream component support > > > 10-bit Tag Completer. > > > > I think "upstream component" here means the PF, doesn't it? I don't > > think the PF is really an *upstream* component; there's no routing > > like with a switch. > > I want to say the switch and root port devices that support 10-Bit > Tag Completer. Sure, VF also needs to have 10-bit Tag Requester > Supported capability. OK. IIUC we're not talking about P2PDMA here; we're talking about regular DMA to host memory, which means I *think* only the Root Port is important, since it is the completer for DMA to host memory. We're not talking about P2PDMA to a switch BAR, where the switch would be the completer.
