On Thu, May 11, 2023 at 03:20:52PM +0800, Jason Wang wrote: > On Thu, May 11, 2023 at 12:08 AM Parav Pandit <[email protected]> wrote: > > > > > > > > On 5/10/2023 12:22 AM, Jason Wang wrote: > > > On Wed, May 10, 2023 at 11:51 AM Jason Wang <[email protected]> wrote: > > > > > > > > Just to make sure we are at the same page. > > > > > > 1) if the hardware has configq and we need to make it work for current > > > virtio-pci driver, hypervisor needs to trap guest PCI access and > > > translate it to configq command. This means the hypervisor needs to > > > hide the configq from guests. In this case the configq needs a > > > dedicated DMA address which is what PASID can help. > > > > > 2) if the hardware can report the device states, unless we want to > > > migrate L2 guest, hypervisor should hide it from L1, so PASID is > > > required to isolate the DMA for guest traffic and device state. > > > > A configq negotiates + discovers new fields for the PCI PF, VF, SF/SIOV > > devices over PCIe or other transports. > > So no need to hide/mediate for hw based devices, like cvq and like data vqs. > > As discussed, I may misunderstand the function of the configq. If it > works like cvq, then yes. We don't need PASID. > > But if we want to report device state via let's say migration q, it > requires PASID since it is used by the hypervisor. > > Thanks
I don't exactly get this part. With SRIOV migration q normally would be part of the PF, accessing hypervisor memory. > > > > For vdpa kind of use case it can work like cvq mediation, which I > > believe is happening without PASID today. > > > > This publicly archived list offers a means to provide input to the > > OASIS Virtual I/O Device (VIRTIO) TC. > > > > In order to verify user consent to the Feedback License terms and > > to minimize spam in the list archive, subscription is required > > before posting. > > > > Subscribe: [email protected] > > Unsubscribe: [email protected] > > List help: [email protected] > > List archive: https://lists.oasis-open.org/archives/virtio-comment/ > > Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf > > List Guidelines: > > https://www.oasis-open.org/policies-guidelines/mailing-lists > > Committee: https://www.oasis-open.org/committees/virtio/ > > Join OASIS: https://www.oasis-open.org/join/ > > --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
