Am 13.09.2013 14:31, schrieb Michael S. Tsirkin: > On Fri, Sep 13, 2013 at 03:22:01PM +0300, Michael S. Tsirkin wrote: >> On Fri, Sep 13, 2013 at 01:14:43AM -0300, Eduardo Habkost wrote: >>> On Fri, Sep 13, 2013 at 12:03:40AM +0300, Michael S. Tsirkin wrote: >>>> On Thu, Sep 12, 2013 at 04:45:01PM -0300, Eduardo Habkost wrote: >>>>> On Thu, Sep 12, 2013 at 11:42:17AM +0300, Michael S. Tsirkin wrote: >>>>>> On Thu, Sep 12, 2013 at 11:23:46AM +0300, Gal Hammer wrote: >>>>>>> Hi, >>>>>>> >>>>>>> I've notice that the virtio-serial Windows' driver doesn't use MSI-X >>>>>>> vectors when running using upstream qemu or >>>>>>> qemu-kvm-1.2.2-13.fc18.x86_64. The same VM works with MSI-X when >>>>>>> using qemu-kvm-0.12.1.2-2.355.el6.x86_64. >>>>>>> >>>>>>> From what I saw, Windows is trying to enable MSI-X by writing a 2 >>>>>>> bytes value to device's PCI-config address 66h. >>>>>>> >>>>>>> So when everything works well the flow goes like this: >>>>>>> >>>>>>> pci_default_write_config value: 8000 len: 2 >>>>>>> pci_default_write_config value: 1 len: 2 >>>>>>> msix_enabled 0 (67) >>>>>>> pci_default_write_config value: e107 len: 2 >>>>>>> pci_default_write_config value: 1 len: 2 >>>>>>> msix_enabled 0 (67) >>>>>>> pci_default_write_config value: 8001 len: 2 >>>>>>> msix_enabled 1 (67) >>>>>>> >>>>>>> But on upstream it goes: >>>>>>> >>>>>>> pci_default_write_config addr: 66 value: 8000 size: 2 >>>>>>> pci_default_write_config addr: 66 value: 1 size: 2 >>>>>>> msix_enabled 0 (67) >>>>>>> pci_default_write_config addr: 66 value: e307 size: 2 (NOTE: Value >>>>>>> is diffrent!). >>>>>>> pci_default_write_config addr: 66 value: 1 size: 2 >>>>>>> msix_enabled 0 (67) >>>>>>> >>>>>>> (NOTE: Missing the write of 8001). >>>>>>> >>>>>>> My qemu's command line: >>>>>>> >>>>>>> ---< snip >--- >>>>>>> >>>>>>> /usr/bin/qemu-kvm -m 1G -smp 2 -enable-kvm -usb -device usb-tablet \ >>>>>>> -device >>>>>>> ide-drive,drive=drive-virtio0-0-0,id=virtio0-0-0,bootindex=1 \ >>>>>>> -drive >>>>>>> file=win7_32_viorng.qcow2,if=none,id=drive-virtio0-0-0,format=qcow2,werror=stop,rerror=stop,cache=none >>>>>>> \ >>>>>>> -monitor stdio \ >>>>>>> -vga qxl -spice id=on,disable-ticketing,port=5903 \ >>>>>>> -device virtio-serial-pci,id=virtio-serial0,vectors=2 \ >>>>>>> -chardev spicevmc,id=spicechannel0,name=vdagent >>>>>>> >>>>>>> ---< snip >--- >>>>>>> >>>>>>> Thanks, >>>>>>> >>>>>>> Gal. >>>>>> >>>>>> >>>>>> So it's a known change from qemu-kvm to qemu. >>>>>> With qemu-kvm the default cpu was kvm64. >>>>>> With qemu the default cpu is qemu64 even if you use -enable-kvm. >>>>>> >>>>>> Not an issue for libvirt as that specifies -cpu, >>>>>> but will be an issue for command-line users. >>>>>> >>>>>> Maybe we should change the default for new machine types and when >>>>>> -enable-kvm is specified? >>>>> >>>>> What about simply making qemu64 as good as kvm64 (on newer >>>>> machine-types)? >>>> >>>> This will likely mean extending tcg to emulate more CPU >>>> features. Do you want to spend cycles on this? >>> >>> Why? Features that are not supported by TCG are automatically removed on >>> from CPUID on X86CPU initialization. >>> >>>> >>>>> What exactly is missing on qemu64 that causes the above >>>>> problem? >>>> >>>> I remember windows checks that cpu is modern enough >>>> to enable msi-x. >>>> Dont' remember the exact details. >>> >>> It would be interesting to find out what exactly is necessary to make >>> this work. Adding new feature bits to qemu64 should be harmless for TCG, >>> but increasing family/model too much without adding new features may >>> require a little more testing to check if guests don't get confused. >> >> That's why I'm saying switching to kvm64 is easier. > > Thinking back I think it's the CPU model that does it. > Gal, could you please try adding -cpu qemu64,model=6?
Or try git://github.com/afaerber/qemu-cpu.git qom-cpu branch, which has Eduardo's model=6 patch already. (Please keep me in the loop.) Andreas > Also please try -cpu kvm64,model=2. > > >>> -- >>> Eduardo > -- SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg