https://bugzilla.kernel.org/show_bug.cgi?id=47451 Summary: need to re-load driver in guest to make a hot-plug VF work Product: Virtualization Version: unspecified Kernel Version: 3.5.0 Platform: All OS/Version: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: kvm AssignedTo: virtualization_kvm@xxxxxxxxxxxxxxxxxxxx ReportedBy: yongjie.ren@xxxxxxxxx Regression: Yes Environment: ------------ Host OS (ia32/ia32e/IA64):ia32e Guest OS (ia32/ia32e/IA64):ia32e Guest OS Type (Linux/Windows):Linux (RHEL6u3) kvm.git Commit:37e41afa97307a3e54b200a5c9179ada1632a844(master branch) qemu-kvm Commit:28c3a9b197900c88f27b14f8862a7a15c00dc7f0(master branch) Host Kernel Version:3.5.0-rc6 (Also exists in 3.6.0-rc3) Hardware:Romley-EP (SandyBridge system) Bug detailed description: -------------------------- After hot plugging a VF to a Linux guest (e.g.RHEL6.3) in qemu monitor, the VF cannot work in the guest by. I need to remove the VF driver (e.g. igbvf, ixgbevf) and probe it again, then the VF can work in guest. NIC: Intel 82599 NIC, Intel 82576 NIC It needn't reload VF driver in hot-plug case when using an old kernel. It's a regression in kernel. (commits are in kvm.git and qemu-kvm.git tree) kvm + qemu-kvm =result 37e41afa + 28c3a9b1 =bad 322728e5 + 28c3a9b1 =good Note: 1. When assigning a VF in qemu-kvm command line (not hot-plug), VF can work fine after boot-up. 2. It's easier to reproduce this in guest with 512/1024MB memory and 1/2 vCPUs. 3. Can't always reproduce with 2048MB and 2vCPUs. (Not very stable.) Reproduce steps: ---------------- 1.start up a host with kvm 2.qemu-system-x86_64 -m 512 smp 2 –net none –hda /root/rhel6u3.img 3.switch to qemu monitor (ctrl+Alt+2) 4.device_add pci-assign,host=02:10.0,id=mynic (02:10.0 is VF's BDF number.) 5.switch to guest (ctrl+Alt+1) 6.check network of the VF. (it can't work) 7. remove VF driver in guest ('rmmod igbvf') 8. re-probe VF driver in guest ('modprobe igbvf') 9. check network of the VF. (It should work this time.) Current result: ---------------- The VF cannot work in the guest by default. Need to re-load VF driver in guest. Expected result: ---------------- VF works well in the guest by default after hot-plug. -- Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are watching the assignee of the bug.-- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
