On Wed, Apr 22, 2020 at 01:14:44PM -0400, Jon Derrick
wrote:> The two patches (Linux & QEMU) add support for passthrough VMD devices
> in QEMU/KVM. VMD device 28C0 already supports passthrough natively by
> providing the Host Physical Address in a shadow register to the guest
> for correct bridge programming.
>
> The QEMU patch emulates the 28C0 mode by creating a shadow register and
> advertising its support by using QEMU's subsystem vendor/id.
> The Linux patch matches the QEMU subsystem vendor/id to use the shadow
> register.
Please pick a different PCI ID for Qemu vs real hardware so that we
can properly quirk them if they end up behaving differently due to
hardware or software bugs.