Michael S. Tsirkin
2021-Feb-24 08:43 UTC
[PATCH] vdpa/mlx5: set_features should allow reset to zero
On Wed, Feb 24, 2021 at 04:26:43PM +0800, Jason Wang wrote:> Basically on first guest access QEMU would tell kernel whether > guest is using the legacy or the modern interface. > E.g. virtio_pci_config_read/virtio_pci_config_write will call ioctl(ENABLE_LEGACY, 1) > while virtio_pci_common_read will call ioctl(ENABLE_LEGACY, 0) > > > But this trick work only for PCI I think? > > Thanksccw has a revision it can check. mmio does not have transitional devices at all. -- MST
Jason Wang
2021-Feb-24 09:30 UTC
[PATCH] vdpa/mlx5: set_features should allow reset to zero
On 2021/2/24 4:43 ??, Michael S. Tsirkin wrote:> On Wed, Feb 24, 2021 at 04:26:43PM +0800, Jason Wang wrote: >> Basically on first guest access QEMU would tell kernel whether >> guest is using the legacy or the modern interface. >> E.g. virtio_pci_config_read/virtio_pci_config_write will call ioctl(ENABLE_LEGACY, 1) >> while virtio_pci_common_read will call ioctl(ENABLE_LEGACY, 0) >> >> >> But this trick work only for PCI I think? >> >> Thanks > ccw has a revision it can check. mmio does not have transitional devices > at all.Ok, then we can do the workaround in the qemu, isn't it? Thanks