I use it all the time, but I have not updated to a more recent kernel yet. I am at LinuxCon, so I am unlikely to try it until I get home. > On Aug 21, 2014, at 2:50 PM, Christopher Covington <cov@xxxxxxxxxxxxxx> wrote: > > Hi Richard, > >> On 11/25/2013 10:49 AM, Richard Yao wrote: >> I booted a Gentoo Linux installation in QEMU with a 9P rootfs as follows: >> >> sudo qemu-kvm -cpu host -m 1024 -kernel >> /mnt/test/usr/src/linux-3.13-rc1/arch/x86/boot/bzImage -append >> 'root=/dev/root rootfstype=9p rootflags=trans=virtio,version=9p2000.L ro >> console=ttyS0' -serial stdio -fsdev >> local,id=root,path=/mnt/test,security_model=none -device >> virtio-9p-pci,fsdev=root,mount_tag=/dev/root >> >> The system boots fine, but attempting to load any module will fail: >> >> localhost ~ # modprobe crc32 >> qemu-system-x86_64: virtio: trying to map MMIO memory >> >> The behavior is consistent no matter what combination of things that I >> try. So far, I have tried Linux 3.10.7-gentoo (Gentoo patchset) and >> Linux 3.13-rc1. I have tried QEMU 1.4.2, QEMU 1.6.1 and QEMU HEAD. I >> have also tried booting without KVM, but the behavior is the same: >> >> sudo qemu-kvm --no-kvm -m 1024 -kernel >> /mnt/test/usr/src/linux-3.13-rc1/arch/x86/boot/bzImage -append >> 'root=/dev/root rootfstype=9p rootflags=trans=virtio,version=9p2000.L ro >> console=ttyS0' -serial stdio -fsdev >> local,id=root,path=/mnt/test,security_model=none -device >> virtio-9p-pci,fsdev=root,mount_tag=/dev/root > > Have you used this setup recently? > > With my 3.15.0+ kernel, qemu-system-x86_64 substituted for qemu-kvm, and the > path changed from your arguments I get: > > 9pnet_virtio: no channels available > VFS: Cannot open root device "root" or unknown-block(0,0): error -2 > Please append a correct "root=" boot option; here are the available partitions: > 0b00 1048575 sr0 driver: sr > Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 > > Thanks, > 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@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
