> From: Zhu, Lingshan <lingshan....@intel.com> > Sent: Tuesday, September 12, 2023 6:39 PM > > On 9/12/2023 6:41 PM, Parav Pandit wrote: > >> From: Zhu, Lingshan <lingshan....@intel.com> > >> Sent: Tuesday, September 12, 2023 4:05 PM I mean, why do you think my > >> series can not work with P2P > > Because it misses the intermediate mode STOP that we have in series [1]. > > > > [1] > > https://lists.oasis-open.org/archives/virtio-comment/202309/msg00071.h > > tml > Again, when SUSPEND: > 1) the device freezes, means stop operation in both data-path and > control-path, > except the device status Exactly, including the RESET_VQ command also cannot be served because device is frozen.
> 2) a new feature bit will be introduced in V2, to allow RESET_VQ after SUSPEND RESET_VQ after suspend is simply wrong. Because device is already suspended to not respond to some extra RESET_VQ command. > 3) if there is a device doing P2P against the device. > They should be pass-through-ed to the same guest and should be suspended as > well for LM, or it is a security problem. There is no security problem. Multiple passthrough devices and P2P is already there in PCI using ACS for probably a decade now.
