On Wed, Aug 17, 2022 at 05:43:22PM +0800, Zhu, Lingshan wrote: > > > On 8/17/2022 5:39 PM, Michael S. Tsirkin wrote: > > On Wed, Aug 17, 2022 at 05:13:59PM +0800, Zhu, Lingshan wrote: > > > > > > On 8/17/2022 4:55 PM, Michael S. Tsirkin wrote: > > > > On Wed, Aug 17, 2022 at 10:14:26AM +0800, Zhu, Lingshan wrote: > > > > > Yes it is a little messy, and we can not check _F_VERSION_1 because of > > > > > transitional devices, so maybe this is the best we can do for now > > > > I think vhost generally needs an API to declare config space endian-ness > > > > to kernel. vdpa can reuse that too then. > > > Yes, I remember you have mentioned some IOCTL to set the endian-ness, > > > for vDPA, I think only the vendor driver knows the endian, > > > so we may need a new function vdpa_ops->get_endian(). > > > In the last thread, we say maybe it's better to add a comment for now. > > > But if you think we should add a vdpa_ops->get_endian(), I can work > > > on it for sure! > > > > > > Thanks > > > Zhu Lingshan > > I think QEMU has to set endian-ness. No one else knows. > Yes, for SW based vhost it is true. But for HW vDPA, only > the device & driver knows the endian, I think we can not > "set" a hardware's endian. QEMU knows the guest endian-ness and it knows that device is accessed through the legacy interface. It can accordingly send endian-ness to the kernel and kernel can propagate it to the driver. > So if you think we should add a vdpa_ops->get_endian(), > I will drop these comments in the next version of > series, and work on a new patch for get_endian(). > > Thanks, > Zhu Lingshan Guests don't get endian-ness from devices so this seems pointless. -- MST
