On Thu, Apr 04, 2019 at 10:40:38AM -0300, Daniel Henrique Barboza wrote: > The NVLink2 support in QEMU implements the detection of NVLink2 > capable devices by verifying the attributes of the VFIO mem region > QEMU allocates for the NVIDIA GPUs. To properly allocate an > adequate amount of memLock, Libvirt needs this information before > a QEMU instance is even created, thus querying QEMU is not > possible and opening a VFIO window is too much. > > An alternative is presented in this patch. Making the following > assumptions: > > - if we want GPU RAM to be available in the guest, an NVLink2 bridge > must be passed through; > > - an unknown PCI device can be classified as a NVLink2 bridge > if its device tree node has 'ibm,gpu', 'ibm,nvlink', > 'ibm,nvlink-speed' and 'memory-region'. > > This patch introduces a helper called @ppc64VFIODeviceIsNV2Bridge > that checks the device tree node of a given PCI device and > check if it meets the criteria to be a NVLink2 bridge. This > new function will be used in a follow-up patch that, using the > first assumption, will set up the rlimits of the guest > accordingly. > > Signed-off-by: Daniel Henrique Barboza <danielhb413@xxxxxxxxx> > --- Reviewed-by: Erik Skultety <eskultet@xxxxxxxxxx> -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
