On 2018/12/13 下午10:31, Michael S. Tsirkin wrote:
Just to make sure I understand this. It looks to me we should:
- allow passing GIOVA->GPA through UAPI
- cache GIOVA->GPA somewhere but still use GIOVA->HVA in device IOTLB for
performance
Is this what you suggest?
Thanks
Not really. We already have GPA->HVA, so I suggested a flag to pass
GIOVA->GPA in the IOTLB.
This has advantages for security since a single table needs
then to be validated to ensure guest does not corrupt
QEMU memory.
I wonder how much we can gain through this. Currently, qemu IOMMU gives
GIOVA->GPA mapping, and qemu vhost code will translate GPA to HVA then
pass GIOVA->HVA to vhost. It looks no difference to me.
Thanks
