Hi Peter, On 06/20/2013 07:08 AM, Pawel Moll wrote: > On Thu, 2013-06-20 at 11:29 +0100, Peter Maydell wrote: >> I'm (finally) trying to add virtio-mmio support properly to >> QEMU now Fred has put all the refactoring foundations in place. >> >> 1. One question I've run into is: what should a virtio-mmio transport >> with no backend look like to the guest OS? The spec as written >> seems to assume that there's always some backend present. >> (The idea is that QEMU might just always instantiate say 8 >> mmio transports, and then whether they actually have a >> blk/net/whatever backend depends on user options). >> >> It looks as if the current linux driver insists (if it sees a >> device tree node) that the MagicValue register at least is >> correct (otherwise it complains). So one possibility would >> be "MagicValue/Version/VendorID must read as usual, DeviceID >> should read as some special "nothing here" value (0?), everything >> else can RAZ/WI".
Might it be reasonably easy to just not enumerate unused transports in the device tree or kernel parameters? Regards, Christopher -- Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by the Linux Foundation. _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
