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libvirt/tests/qemuxml2argvdata/qemuxml2argv-event_idx.args

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qemu: support event_idx parameter for virtio disk and net devices In some versions of qemu, both virtio-blk-pci and virtio-net-pci devices can have an event_idx setting that determines some details of event processing. When it is enabled, it "reduces the number of interrupts and exits for the guest". qemu will automatically enable this feature when it is available, but there may be cases where this new feature could actually make performance worse (NB: no such case has been found so far). As a safety switch in case such a situation is encountered in the field, this patch adds a new attribute "event_idx" to the <driver> element of both disk and interface devices. event_idx can be set to "on" (to force event_idx on in case qemu has it disabled by default) or "off" (for force event_idx off). In the case that event_idx support isn't present in qemu, the attribute is ignored (this on the advice of the qemu developer). docs/formatdomain.html.in: document the new flag (marking it as "don't mess with this!" docs/schemas/domain.rng: add event_idx in appropriate places src/conf/domain_conf.[ch]: add event_idx to parser and formatter src/libvirt_private.syms: export virDomainVirtioEventIdx(From|To)String src/qemu/qemu_capabilities.[ch]: detect and report event_idx in disk/net src/qemu/qemu_command.c: add event_idx parameter to qemu commandline when appropriate. tests/qemuxml2argvdata/qemuxml2argv-event_idx.args, tests/qemuxml2argvdata/qemuxml2argv-event_idx.xml, tests/qemuxml2argvtest.c, tests/qemuxml2xmltest.c: test cases for event_idx.
2011-08-13 06:32:45 +00:00
LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=none \
/usr/bin/qemu -S -M pc-0.13 -m 1024 -smp 1 -nodefaults \
-monitor unix:/tmp/test-monitor,server,nowait -no-acpi \
-boot dc -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x6 \
-drive file=/var/lib/libvirt/images/f14.img,if=none,id=drive-virtio-disk0 \
qemu: add new disk device='lun' for bus='virtio' & type='block' In the past, generic SCSI commands issued from a guest to a virtio disk were always passed through to the underlying disk by qemu, and the kernel would also pass them on. As a result of CVE-2011-4127 (see: http://seclists.org/oss-sec/2011/q4/536), qemu now honors its scsi=on|off device option for virtio-blk-pci (which enables/disables passthrough of generic SCSI commands), and the kernel will only allow the commands for physical devices (not for partitions or logical volumes). The default behavior of qemu is still to allow sending generic SCSI commands to physical disks that are presented to a guest as virtio-blk-pci devices, but libvirt prefers to disable those commands in the standard virtio block devices, enabling it only when specifically requested (hopefully indicating that the requester understands what they're asking for). For this purpose, a new libvirt disk device type (device='lun') has been created. device='lun' is identical to the default device='disk', except that: 1) It is only allowed if bus='virtio', type='block', and the qemu version is "new enough" to support it ("new enough" == qemu 0.11 or better), otherwise the domain will fail to start and a CONFIG_UNSUPPORTED error will be logged). 2) The option "scsi=on" will be added to the -device arg to allow SG_IO commands (if device !='lun', "scsi=off" will be added to the -device arg so that SG_IO commands are specifically forbidden). Guests which continue to use disk device='disk' (the default) will no longer be able to use SG_IO commands on the disk; those that have their disk device changed to device='lun' will still be able to use SG_IO commands. *docs/formatdomain.html.in - document the new device attribute value. *docs/schemas/domaincommon.rng - allow it in the RNG *tests/* - update the args of several existing tests to add scsi=off, and add one new test that will test scsi=on. *src/conf/domain_conf.c - update domain XML parser and formatter *src/qemu/qemu_(command|driver|hotplug).c - treat VIR_DOMAIN_DISK_DEVICE_LUN *almost* identically to VIR_DOMAIN_DISK_DEVICE_DISK, except as indicated above. Note that no support for this new device value was added to any hypervisor drivers other than qemu, because it's unclear what it might mean (if anything) to those drivers.
2012-01-05 03:48:38 +00:00
-device virtio-blk-pci,event_idx=on,scsi=off,bus=pci.0,addr=0x4,drive=drive-virtio-disk0,id=virtio-disk0 \
qemu: support event_idx parameter for virtio disk and net devices In some versions of qemu, both virtio-blk-pci and virtio-net-pci devices can have an event_idx setting that determines some details of event processing. When it is enabled, it "reduces the number of interrupts and exits for the guest". qemu will automatically enable this feature when it is available, but there may be cases where this new feature could actually make performance worse (NB: no such case has been found so far). As a safety switch in case such a situation is encountered in the field, this patch adds a new attribute "event_idx" to the <driver> element of both disk and interface devices. event_idx can be set to "on" (to force event_idx on in case qemu has it disabled by default) or "off" (for force event_idx off). In the case that event_idx support isn't present in qemu, the attribute is ignored (this on the advice of the qemu developer). docs/formatdomain.html.in: document the new flag (marking it as "don't mess with this!" docs/schemas/domain.rng: add event_idx in appropriate places src/conf/domain_conf.[ch]: add event_idx to parser and formatter src/libvirt_private.syms: export virDomainVirtioEventIdx(From|To)String src/qemu/qemu_capabilities.[ch]: detect and report event_idx in disk/net src/qemu/qemu_command.c: add event_idx parameter to qemu commandline when appropriate. tests/qemuxml2argvdata/qemuxml2argv-event_idx.args, tests/qemuxml2argvdata/qemuxml2argv-event_idx.xml, tests/qemuxml2argvtest.c, tests/qemuxml2xmltest.c: test cases for event_idx.
2011-08-13 06:32:45 +00:00
-drive file=/var/lib/libvirt/Fedora-14-x86_64-Live-KDE.iso,if=none,media=cdrom,id=drive-ide0-1-0 \
-device ide-drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 \
-device virtio-net-pci,event_idx=off,vlan=0,id=net0,mac=52:54:00:e5:48:58,bus=pci.0,addr=0x3 \
-net user,vlan=0,name=hostnet0 -serial pty -usb -vnc 127.0.0.1:-809 -std-vga \
-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x5
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