599 2010-12-15 06:47:44 +0000 [poky] qemu running with KVM needs root permission 2011-01-07 17:26:47 +0000 1 1 7 Build System, Metadata & Runtime Meta-yocto meta-yocto 1.0 x86 Multiple VERIFIED FIXED High normal 1.0 M2 1 jiajun.xu edwin.zhai edwin.zhai kevin.tian kunwei.tian poky.bs.watcher poky.watcher richard.purdie sgw --- --- Program Management --- oldest_to_newest 11184 0 jiajun.xu 2010-12-15 06:47:44 +0000 Testing Env: Poky gitinfo: 3a78838d4f1db75d06b5d3df042638f34cf328f5 After KVM feature is enabled in poky, now qemu can run with KVM enabled. But it needs root permission currently. Pls. check following log: ######### jxu49@vt-nhm4:~/osel/poky-m2/build$ poky-qemu qemux86 kvm images/qemux86/bzImage-2.6.37+git0+ee0a10ab687b29c4d22d47e5b28bc8b3ebb7a8d9_0+87aacc373557f8849dde8618fbe1f7f8f2af6038-r14-qemux86-20101211200958.bin images/qemux86/poky-image- poky-image-minimal-qemux86-20101211235049.rootfs.ext3 poky-image-sato-qemux86-20101211224433.rootfs.ext3 poky-image-sdk-qemux86-20101211220547.rootfs.ext3 jxu49@vt-nhm4:~/osel/poky-m2/build$ poky-qemu qemux86 kvm images/qemux86/bzImage-2.6.37+git0+ee0a10ab687b29c4d22d47e5b28bc8b3ebb7a8d9_0+87aacc373557f8849dde8618fbe1f7f8f2af6038- r14-qemux86-20101211200958.bin images/qemux86/poky-image-sato-qemux86-20101211224433.rootfs.ext3 Continuing with the following parameters: KERNEL: [images/qemux86/bzImage-2.6.37+git0+ee0a10ab687b29c4d22d47e5b28bc8b3ebb7a8d9_0+87aacc373557f8849dde8618fbe1f7f8f2af6038-r14-qemux86-20101211200958.bin] ROOTFS: [images/qemux86/poky-image-sato-qemux86-20101211224433.rootfs.ext3] FSTYPE: [ext3] Acquiring lockfile for tap0... Setting up tap interface under sudo [sudo] password for jxu49: Acquiring lockfile for tap1... Warning: distccd not present, no distcc support loaded. Running qemu... /home/jxu49/osel/poky-m2/build/tmp/sysroots/i686-linux/usr/bin/qemu -kernel images/qemux86/bzImage-2.6.37+git0+ee0a10ab687b29c4d22d47e5b28bc8b3ebb7a8d9_0+87aacc373557f8849dde8618fbe1f7f8f2af6038-r14-qemux86-20101211200958.bin -net nic,vlan=0 -net tap,vlan=0,ifname=tap1,script=no,downscript=no -hda images/qemux86/poky-image-sato-qemux86-20101211224433.rootfs.ext3 -show-cursor -usb -usbdevice wacom-tablet -vga vmware -enable-gl -k en-us -no-reboot --append "vga=0 root=/dev/hda mem=128M ip=192.168.7.4::192.168.7.3:255.255.255.0 " Enabling opengl Could not access KVM kernel module: Permission denied failed to initialize KVM Set 'tap1' nonpersistent Releasing lockfile of preconfigured tap device 'tap1' ########### 11229 1 edwin.zhai 2010-12-17 01:11:02 +0000 ubuntu required root privilege to access kvm module for security reason. One fix is to use "sudo" to run qemu. Another one is change the ownership of "/dev/kvm", which is more reasonable. Other distribution like RH and Debian seems has something similar, so step 1~3 are probably not needed. Jiajun, Can you have a try on following steps? I'll make documents for those in our wiki 1. As root to insert all modules # modprobe kvm-intel 2. Add a new group named "kvm", and add current user to it $sudo addgroup --system kvm $sudo adduser $USER kvm 3. Change the ownership and mod $ sudo chown root:kvm /dev/kvm $ sudo chmod 0660 /dev/kvm The output of "ls -l /dev/kvm" should be like this: crw-rw----+ 1 root kvm 10, 232 2010-07-02 09:27 /dev/kvm 4. to make it works, need logout then login with current user, now you can access kvm module as non-root user. 11244 2 edwin.zhai 2010-12-20 05:10:39 +0000 I have created a howto @ https://oldwiki.pokylinux.org/wiki2/index.php/How_to_enable_KVM_for_Poky_qemu I have no edit right on the public wiki. Once I get it, I can move it to public wiki. Jiajun, It works on my part. Can you have a try with the ownership changing part. If it works, I can mark it as fix. Thanks, 11263 3 richard.purdie 2010-12-21 06:39:01 +0000 Edwin: Firstly, can we detect whether we have permission to access the kvm device and only use it if we have permission? If we don't have permission can we print a warning to the user about how to enable the speedup? Secondly, you can get edit permissions on the wiki by creating an account and confirming your email address. 11266 4 edwin.zhai 2010-12-21 17:15:16 +0000 (In reply to comment #3) > Edwin: > > Firstly, can we detect whether we have permission to access the kvm device and > only use it if we have permission? If we don't have permission can we print a > warning to the user about how to enable the speedup? This was also what Ke suggested and I'm doing. The issue here is I have no idea of how to open the "/dev/kvm" with rw mode in bash to check if we have the right. I don't want to write a C program using "open" system call, or check the ownership and rw permission of "/dev/kvm" against current user in a complicated way. > > Secondly, you can get edit permissions on the wiki by creating an account and > confirming your email address. Done. Thanks 11267 5 edwin.zhai 2010-12-21 17:29:57 +0000 Move bkm to https://wiki.yoctoproject.org/wiki/How_to_enable_KVM_for_Poky_qemu 11268 6 kevin.tian 2010-12-21 17:38:28 +0000 (In reply to comment #4) > (In reply to comment #3) > > Edwin: > > > > Firstly, can we detect whether we have permission to access the kvm device and > > only use it if we have permission? If we don't have permission can we print a > > warning to the user about how to enable the speedup? > This was also what Ke suggested and I'm doing. The issue here is I have no idea > of how to open the "/dev/kvm" with rw mode in bash to check if we have the > right. I don't want to write a C program using "open" system call, or check the > ownership and rw permission of "/dev/kvm" against current user in a complicated > way. how about using "9<>/dev/kvm"? 11315 7 edwin.zhai 2010-12-26 21:23:05 +0000 got fixed in poky/master @ 983bd9a77e4afdb2890245653f39d6c6d093a655 11321 8 jiajun.xu 2010-12-27 07:17:25 +0000 Kunwei, Could you help to verify the bug by following Edwin's BKM, https://wiki.yoctoproject.org/wiki/How_to_enable_KVM_for_Poky_qemu? 11364 9 kunwei.tian 2010-12-30 21:45:34 +0000 According to Edwin's methods，this problem was resolved.So verified it as fixed.