The xml outputed by HAL backend for scsi generic device:
<device>
<name>pci_8086_2922_scsi_host_scsi_device_lun0_scsi_generic</name>
<path>/sys/devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/scsi_generic/sg0</path>
<parent>pci_8086_2922_scsi_host_scsi_device_lun0</parent>
<capability type='scsi_generic'>
<char>/dev/sg0</char>
</capability>
</device>
Since scsi generic device doesn't have DEVTYPE property set, the
only way to know if it's a scsi generic device or not is to read
the "SUBSYSTEM" property.
The XML of the scsi generic device will be like:
<device>
<name>scsi_generic_sg0</name>
<path>/sys/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/scsi_generic/sg0</path>
<parent>scsi_0_0_0_0</parent>
<capability type='scsi_generic'>
<char>/dev/sg0</char>
</capability>
</device>
Checking if the "devtype" is NULL along with each "if" statements
is bad. It wastes the performance, and also not good for reading.
And also when the "devtype" is NULL, the logic is also not clear.
This reorgnizes the logic of with "if...else" and a bunch of "else if".
Other changes:
* Change the function style.
* Remove the useless debug statement.
* Get rid of the goto
* New helper udevDeviceHasProperty to simplify the logic for checking
if a property is existing for the device.
* Add comment to clarify "PCI devices don't set the DEVTYPE property"
* s/sysfs path/sysfs name/, as udev_device_get_sysname returns the
name instead of the full path. E.g. "sg0"
* Refactor the comment for setting VIR_NODE_DEV_CAP_NET cap type
a bit.
The name format is constructed by libvirt, it's not that clear to
get what the device's sysfs path should be. This exposes the device's
sysfs path by a new tag <path>.
Since the sysfspath is filled during enumerating the devices by
either udev or HAL. It's an output-only tag.
https://bugzilla.redhat.com/show_bug.cgi?id=964177
Though both libvirt and QEMU's document say RTC_CHANGE returns
the offset from the host UTC, qemu actually returns the offset
from the specified date instead when specific date is provided
(-rtc base=$date).
It's not safe for qemu to fix it in code, it worked like that
for 3 years, changing it now may break other QEMU use cases.
What qemu tries to do is to fix the document:
http://lists.gnu.org/archive/html/qemu-devel/2013-05/msg04782.html
And in libvirt side, instead of replying on the value from qemu,
this converts the offset returned from qemu to the offset from
host UTC, by:
/*
* a: the offset from qemu RTC_CHANGE event
* b: The specified date (-rtc base=$date)
* c: the host date when libvirt gets the RTC_CHANGE event
* offset: What libvirt will report
*/
offset = a + (b - c);
The specified date (-rtc base=$date) is recorded in clock's def as
an internal only member (may be useful to exposed outside?).
Internal only XML tag "basetime" is introduced to not lose the
guest's basetime after libvirt restarting/reloading:
<clock offset='variable' adjustment='304' basis='utc' basetime='1370423588'/>
As the document for "virsh-resize" says:
<...>
Attempts to shrink the volume will fail unless I<--shrink> is present;
</...>
This makes sense as it at least prevent the user shrinking the important
data of volume without a notice.
The document for "vol-resize" says the new capacity will be sparse
unless "--allocate" is specified, however, the "--allocate" flag
is never implemented. This implements the "--allocate" flag for
fs backend's raw type volume, based on posix_fallocate and the
syscall SYS_fallocate.
With unknown good reasons, the attribute "bus" of scsi device
address is always set to 0, same for attribute "target". (See
virDomainDiskDefAssignAddress).
Though we might need to change the algorithm to honor "bus"
and "target" too, that's a different issue. The address generator
for scsi host device in this patch just follows the unknown
good reasons, only considering the "controller" and "unit".
It walks through all scsi controllers and their units, to see
if the address $controller:0:0:$unit can be used (if not used
by any disk or scsi host device yet), if found one, it sits on
it, otherwise, it creates a new controller (actually the controller
is implicitly created by someone else), and sits on
$new_controller:0:0:0 instead.
And error out if the casted value is not same with the original
one, which prevents the bug on platform(s) where uid_t/gid_t
has different size with long.
Changes:
* Free all the strings at "cleanup", instead of freeing them
in the middle
* Remove xmlFree
* s/tmppath/target_path/, to make it more sensible
* Add new goto label "error"
Introduced by commit 1daa4ba33a. vshCommandOptStringReq returns
0 on *success* or the option is not required && not present, both
are right result. Error out when returning 0 is not correct.
the caller, it doesn't have to check wether it
Only a few cases are allowed:
1) The expression is empty for "for" loop, E.g.
for (i = 0; ; i++)
2) An empty statement
while (write(statuswrite, &status, 1) == -1 &&
errno == EINTR)
; /* empty */
3) ";" is inside double-quote, I.e, as part of const string. E.g.
vshPrint(ctl, "a ; b ; cd;\n");
The "for" loop in src/rpc/virnettlscontext.c is the special case,
1) applies for it, so change it together in this patch.
Since 0d70656afd, it starts to access the sysfs files to build
the qemu command line (by virSCSIDeviceGetSgName, which is to find
out the scsi generic device name by adpater:bus:target:unit), there
is no way to work around, qemu wants to see the scsi generic device
like "/dev/sg6" anyway.
And there might be other places which need to access sysfs files
when building qemu command line in future.
Instead of increasing the arguments of qemuBuildCommandLine, this
introduces a new callback for qemuBuildCommandLine, and thus tests
can register their own callbacks for sysfs test input files accessing.
* src/qemu/qemu_command.h: (New callback struct
qemuBuildCommandLineCallbacks;
extern buildCommandLineCallbacks)
* src/qemu/qemu_command.c: (wire up the callback struct)
* src/qemu/qemu_driver.c: (Use the new syntax of qemuBuildCommandLine)
* src/qemu/qemu_hotplug.c: Likewise
* src/qemu/qemu_process.c: Likewise
* tests/testutilsqemu.[ch]: (Helper testSCSIDeviceGetSgName;
callback struct testCallbacks;)
* tests/qemuxml2argvtest.c: (Use testCallbacks)
* src/tests/qemuxmlnstest.c: (Like above)
Changes:
* Remove useless comments
* Remove useless blank lines
* If the struct member is a enum type, comment it like
/* enum fooBar */
* Break the long lines
* Prefer the common function style for the inline function
Changes:
* Remove the useless space in "for" statement (e.g.
for (i = 0 ; i < something ; i++)
* Change the function's style to:
void
foo(bar)
{
printf("foo is not bar\n");
}
* Don't lose "{}" for "if...else" branches if one of the branch
has more than one line block. Example of the old ones:
if (a) {
printf("a is not funny");
} else
printf("a is funny");
* Remove the 1 space before "goto" label.
* Remove the useless blank line(s)
* Add blank line if it can make the code more clear to eyes.
QEMU might support more values for "-drive discard", so using Bi-state
values (on/off) for it doesn't make sense.
"on" maps to "unmap", "off" maps to "ignore":
<...>
@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and
controls whether @dfn{discard} (also known as @dfn{trim} or @dfn{unmap})
requests are ignored or passed to the filesystem. Some machine types
may not support discard requests.
</...>
This adds the shared device entry when starting domain (more
exactly, when preparing host devices), and remove the entry
when destroying domain (when reattaching host devices).
This changes the helpers qemu{Add,Remove}SharedDisk into
qemu{Add,Remove}SharedDevice, as most of the code in the helpers
can be reused for scsi host device.
To track the shared scsi host device, first it finds out the
device path (e.g. /dev/s[dr]*) which is mapped to the sg device,
and use device ID of the found device path (/dev/s[dr]*) as the
hash key. This is because of the device ID is not unique between
between /dev/s[dr]* and /dev/sg*, e.g.
% sg_map
/dev/sg0 /dev/sda
/dev/sg1 /dev/sr0
% ls -l /dev/sda
brw-rw----. 1 root disk 8, 0 May 2 19:26 /dev/sda
%ls -l /dev/sg0
crw-rw----. 1 root disk 21, 0 May 2 19:26 /dev/sg0
"Shared disk" is not only the thing we should care about after "scsi
hostdev" is introduced. A same scsi device can be used as "disk" for
one domain, and as "scsi hostdev" for another domain at the same time.
That's why this patch renames qemu_driver->sharedDisks. Related functions
and structs are also renamed.
The reason for it's not exposed for such long time is that the
enums for VirtioEventIdx and CopyOnReadType have same enum values
and Correspondingstrings. This fixes the bug and adds test.
QEMU introduced "discard" option for drive since commit a9384aff53,
<...>
@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and
controls whether @dfn{discard} (also known as @dfn{trim} or @dfn{unmap})
requests are ignored or passed to the filesystem. Some machine types
may not support discard requests.
</...>
This patch exposes the support in libvirt.
QEMU supported "discard" for "-drive" since v1.5.0-rc0:
% git tag --contains a9384aff53
contains
v1.5.0-rc0
v1.5.0-rc1
So this only detects the capability bit using virQEMUCapsProbeQMPCommandLine.
QEMU introduced command line "-mem-merge=on|off" (defaults to on) to
enable/disable the memory merge (KSM) at guest startup. This exposes
it by new XML:
<memoryBacking>
<nosharepages/>
</memoryBacking>
The XML tag is same with what we used internally for old RHEL.
It's better to put the usb related codes into qemuDomainAttachHostUsbDevice
instead of qemuDomainAttachHostDevice.
And in the old qemuDomainAttachHostDevice, just stealing the "usb" from
driver->activeUsbHostdevs leaks the memory.
To not introduce more redundant code, helpers are added for
both "selinux", "dac", and "apparmor" backends.
Signed-off-by: Han Cheng <hanc.fnst@cn.fujitsu.com>
Signed-off-by: Osier Yang <jyang@redhat>
v2.5 - v3:
* Splitted from 8/10 of v2.5
* Don't forget the other backends (DAC, and apparmor)
Osier Yang