On Wed, Aug 04, 2021 at 11:48:00AM +0800, Jason Wang wrote: >Hi: > >We currently try to enable device IOTLB when iommu_platform is >set. This may lead unnecessary trasnsactions between qemu and vhost >when vIOMMU is not used (which is the typical case for the encrypted >VM). > >So patch tries to use transport specific method to detect the enalbing >of vIOMMU and enable the device IOTLB only if vIOMMU is enalbed. > >Please review.
Tested-by: Chao Gao <chao....@intel.com> Tested with TDX; this series fixes the performance issue we saw in a TD when vhost was enabled. Thanks Chao > >Thanks > >Jason Wang (3): > virtio-bus: introduce iommu_enabled() > virtio-pci: implement iommu_enabled() > vhost: correctly detect the enabling IOMMU > > hw/virtio/vhost.c | 2 +- > hw/virtio/virtio-bus.c | 14 ++++++++++++++ > hw/virtio/virtio-pci.c | 14 ++++++++++++++ > include/hw/virtio/virtio-bus.h | 4 +++- > 4 files changed, 32 insertions(+), 2 deletions(-) > >-- >2.25.1 >