On Mon, Jul 8, 2024 at 4:15 PM Stefano Garzarella <sgarzare@xxxxxxxxxx> wrote: > > Hi Cindy, Jason, > > On Mon, Jul 08, 2024 at 03:59:34PM GMT, Jason Wang wrote: > >On Mon, Jul 8, 2024 at 3:06 PM Cindy Lu <lulu@xxxxxxxxxx> wrote: > >> > >> On Fri, 5 Jul 2024 at 20:42, Stefano Garzarella <sgarzare@xxxxxxxxxx> wrote: > >> > > >> > On Fri, Jul 05, 2024 at 07:30:51AM GMT, Michael S. Tsirkin wrote: > >> > >On Fri, Jul 05, 2024 at 01:28:21PM +0200, Stefano Garzarella wrote: > >> > >> The vDPA block simulator always allocated a 128 MiB ram-disk, but some > >> > >> filesystems (e.g. XFS) may require larger minimum sizes (see > >> > >> https://issues.redhat.com/browse/RHEL-45951). > >> > >> > >> > >> So to allow us to test these filesystems, let's add a module parameter > >> > >> to control the size of the simulated virtio-blk devices. > >> > >> The value is mapped directly to the `capacity` field of the virtio-blk > >> > >> configuration space, so it must be expressed in sector numbers of 512 > >> > >> bytes. > >> > >> > >> > >> The default value (0x40000) is the same as the previous value, so the > >> > >> behavior without setting `capacity` remains unchanged. > >> > >> > >> > >> Before this patch or with this patch without setting `capacity`: > >> > >> $ modprobe vdpa-sim-blk > >> > >> $ vdpa dev add mgmtdev vdpasim_blk name blk0 > >> > >> virtio_blk virtio6: 1/0/0 default/read/poll queues > >> > >> virtio_blk virtio6: [vdb] 262144 512-byte logical blocks (134 MB/128 MiB) > >> > >> > >> > >> After this patch: > >> > >> $ modprobe vdpa-sim-blk capacity=614400 > >> > >> $ vdpa dev add mgmtdev vdpasim_blk name blk0 > >> > >> virtio_blk virtio6: 1/0/0 default/read/poll queues > >> > >> virtio_blk virtio6: [vdb] 614400 512-byte logical blocks (315 MB/300 MiB) > >> > >> > >> > >> Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx> > >> > > > >> > >What a hack. Cindy was working on adding control over config > >> > >space, why can't that be used? > >> > > >> > If it can be used easily with virtio-blk device too, it will be great. > >> > @Cindy do you plan to support that changes for a virtio-blk device too? > >> > > >> Hi Stefano > >> I plan to add support to change the vdpa device's configuration after > >> it is created. > > > >I think for Stefano's case, we can just implement it via provisioning > >parameters? > > Yep, I think we don't need to change it after creation, but specifying > while creating should be enough. > > So, IIUC we can already do it, implementing something similar to > vdpasim_net_setup_config() to call during vdpasim_blk_dev_add(), right? Right. > > What about when we have `shared_backend` set to true for the > vdpa_sim_blk.ko? In this case the backend is supposed to be shared > between all the devices to test live migration. This seems to be another topic. > > Maybe we can just change the size of the shared ramdisk to be reflected > to all devices. > > Suggestions? Could we specify the path to tmpfs or others during provisioning instead? It seems more general (but more work). > > @Cindy do you want to work on this for blk as well? > If you don't have time, I'll look at it when I can allocate some time. > > > > >Thanks Thanks > > > >> In the first step, I want to use the vdpa tool to add > >> support for changing the MAC address for the network device. the next > >> step will also add MTU settings etc > >> here is the link > >> https://lore.kernel.org/all/20240708064820.88955-1-lulu@xxxxxxxxxx/T/#t > >> > > I'll take a look, thanks for ccing me! > > Stefano > > >> in the device part, the device needs to implement its function of > >> int (*dev_set_attr)(struct vdpa_mgmt_dev *mdev, struct vdpa_device *dev, > >> const struct vdpa_dev_set_config *config); > >> the configuration will be passed by struct vdpa_dev_set_config. I'm > >> not sure if this kind of design is suitable for you? Really thanks and > >> any comments are welcome > >> thanks > >> Cindy > >> > >> > >> > In the mean time, for the simulator I thought that this change was fine. > >> > It's just used for testing and debugging... > >> > > >> > My main question is how to use that when we have `shared_backend` set to > >> > true, since we use that setting to test for example live migration. In > >> > that case, how do we handle the size of the shared ramdisk between > >> > devices? > >> > > >> > Thanks, > >> > Stefano > >> > > >> > > >
