Greg Kurz <gk...@linux.vnet.ibm.com> writes: >> > > I did some debugging: it looks like the guest kernel calls the OF >> > > quisece call to flush pending DMA and disables bus master on the >> > > virtio-blk device (PCI_COMMAND == 0x3). >> > >> > Getting confused, above you are talking about virtio-net and here it is >> > virtio-blk. >> > >> > Anyways, the routines still remains same for both of them. From SLOF >> > during init we set DRIVER_OK, and after using the device during the >> > quiesce, called from linux kernel VIRTIO_CONFIG_S_FAILED is set and then >> > a VIRTIO_DEVICE_RESET is done. >> >> BTW, you really should start enabling bus mastering, avoid relying >> on the work-around we have for broken guests. >> > > FWIW during my debug session, I see that SLOF enables bus mastering... > unfortunately, it gets disabled at some point after the guest kernel > is started (around the ppc64 prom_init() call).
Is it before quiesce call? Regards Nikunj
