Commit Graph

13304 Commits

Author SHA1 Message Date
Eric Blake
082274ea41 qemu: simplify string cleanup
No need to open code a string list cleanup, if we are nice
to the caller by guaranteeing a NULL-terminated result.

* src/qemu/qemu_monitor_json.c (qemuMonitorJSONGetCPUDefinitions)
(qemuMonitorJSONGetCommands, qemuMonitorJSONGetEvents)
(qemuMonitorJSONGetObjectTypes, qemuMonitorJSONGetObjectProps):
Use simpler cleanup.

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-05-13 15:15:54 -06:00
Eric Blake
764bb5e5aa qemu: use bool in monitor struct
Follows on the heels of other bool cleanups, such as commit 93002b98.

* src/qemu/qemu_monitor.h (qemuMonitorOpen, qemuMonitorOpenFD):
Update json parameter type.
* src/qemu/qemu_monitor.c (qemuMonitorOpen, qemuMonitorOpenFD):
Likewise.
(_qemuMonitor): Adjust field type.
* src/qemu/qemu_domain.h (_qemuDomainObjPrivate): Likewise.
* src/qemu/qemu_domain.c (qemuDomainObjPrivateXMLParse): Adjust
client.
* src/qemu/qemu_process.c (qemuProcessStart): Likewise.
* tests/qemumonitortestutils.c (qemuMonitorTestNew): Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-05-13 15:15:54 -06:00
Eric Blake
547a7c778a json: support removing a value from an object
In an upcoming patch, I need the way to safely transfer a nested
virJSON object out of its parent container for independent use,
even after the parent is freed.

* src/util/virjson.h (virJSONValueObjectRemoveKey): New function.
(_virJSONObject, _virJSONArray): Use correct type.
* src/util/virjson.c (virJSONValueObjectRemoveKey): Implement it.
* src/libvirt_private.syms (virjson.h): Export it.
* tests/jsontest.c (mymain): Test it.

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-05-13 15:15:54 -06:00
Gene Czarcinski
ccff335f83 Support for static routes on a virtual bridge
network: static route support for <network>

This patch adds the <route> subelement of <network> to define a static
route.  the address and prefix (or netmask) attribute identify the
destination network, and the gateway attribute specifies the next hop
address (which must be directly reachable from the containing
<network>) which is to receive the packets destined for
"address/(prefix|netmask)".

These attributes are translated into an "ip route add" command that is
executed when the network is started. The command used is of the
following form:

  ip route add <address>/<prefix> via <gateway> \
               dev <virbr-bridge> proto static metric <metric>

Tests are done to validate that the input data are correct.  For
example, for a static route ip definition, the address must be a
network address and not a host address.  Additional checks are added
to ensure that the specified gateway is directly reachable via this
network (i.e. that the gateway IP address is in the same subnet as one
of the IP's defined for the network).

prefix='0' is supported for both family='ipv4' address='0.0.0.0'
netmask='0.0.0.0' or prefix='0', and for family='ipv6' address='::',
prefix=0', although care should be taken to not override a desired
system default route.

Anytime an attempt is made to define a static route which *exactly*
duplicates an existing static route (for example, address=::,
prefix=0, metric=1), the following error message will be sent to
syslog:

    RTNETLINK answers: File exists

This can be overridden by decreasing the metric value for the route
that should be preferred, or increasing the metric for the route that
shouldn't be preferred (and is thus in place only in anticipation that
the preferred route may be removed in the future).  Caution should be
used when manipulating route metrics, especially for a default route.

Note: The use of the command-line interface should be replaced by
direct use of libnl so that error conditions can be handled better.  But,
that is being left as an exercise for another day.

Signed-off-by: Gene Czarcinski <gene@czarc.net>
Signed-off-by: Laine Stump <laine@laine.org>
2013-05-13 16:14:40 -04:00
Eric Blake
84f3777a79 build: avoid shadowed variable in fdstreamtest
On RHEL 6.4 (gcc 4.4.7), I got:

fdstreamtest.c: In function 'testFDStreamReadCommon':
fdstreamtest.c:44: error: declaration of 'tmpfile' shadows a global declaration [-Wshadow]

* tests/fdstreamtest.c (testFDStreamReadCommon)
(testFDStreamWriteCommon): Rename 'tmpfile' variable.

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-05-13 13:38:18 -06:00
Daniel P. Berrange
3407e3b3a2 Don't overwrite useful message when creating macvlan fails
Currently we report a bogus error message when macvlan
creation fails:

error: Failed to start domain migtest
error: operation failed: Unable to create macvlan device

With this removed, we see the real error:

error: Failed to start domain migtest
error: Unable to get index for interface p31p1: No such device

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-13 17:32:55 +01:00
Daniel P. Berrange
8845d8dfa3 Remove & ban use of select() for waiting for I/O
Use of the select() system call is inherantly dangerous since
applications will hit a buffer overrun if any FD number exceeds
the size of the select set size (typically 1024). Replace the
two uses of select() with poll() and use cfg.mk to ban any
future use of select().

NB: This changes the phyp driver so that it uses an infinite
timeout, instead of busy-waiting for 1ms at a time.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-13 17:32:43 +01:00
Han Cheng
8f76ad9992 qemu: Add hotplug support for scsi host device
This adds both attachment and detachment support for scsi host
device.

Signed-off-by: Han Cheng <hanc.fnst@cn.fujitsu.com>
Signed-off-by: Osier Yang <jyang@redhat>
2013-05-14 00:12:42 +08:00
Jim Fehlig
bbe97ae968 Fix starting domains when kernel has no cgroups support
Found that I was unable to start existing domains after updating
to a kernel with no cgroups support

  # zgrep CGROUP /proc/config.gz
  # CONFIG_CGROUPS is not set
  # virsh start test
  error: Failed to start domain test
  error: Unable to initialize /machine cgroup: Cannot allocate memory

virCgroupPartitionNeedsEscaping() correctly returns errno (ENOENT) when
attempting to open /proc/cgroups on such a system, but it was being
dropped in virCgroupSetPartitionSuffix().

Change virCgroupSetPartitionSuffix() to propagate errors returned by
its callees.  Also check for ENOENT in qemuInitCgroup() when determining
if cgroups support is available.
2013-05-13 09:27:46 -06:00
Ján Tomko
a011479d47 .gitignore: add fchosttest 2013-05-13 17:16:54 +02:00
Osier Yang
7d763acaf2 qemu: Refactor helpers for USB device attachment
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.
2013-05-13 21:51:55 +08:00
Daniel P. Berrange
0ced83dcfb Escaping leading '.' in cgroup names
Escaping a leading '.' with '_' in the cgroup names

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-13 14:28:46 +01:00
Han Cheng
ea74c07636 qemu: Introduce activeScsiHostdevs list for scsi host devices
Although virtio-scsi supports SCSI PR (Persistent Reservations),
the device on host may do not support it. To avoid losing data,
Just like PCI and USB pass through devices, only one live guest
is allowed per SCSI host pass through device."

Signed-off-by: Han Cheng <hanc.fnst@cn.fujitsu.com>
2013-05-13 21:26:06 +08:00
Michal Privoznik
31532cabe8 Adapt to VIR_STRDUP and VIR_STRNDUP in src/vbox/* 2013-05-13 14:50:03 +02:00
Daniel P. Berrange
6b5f12c805 Support NBD backed disks/filesystems in LXC driver
The LXC driver can already configure <disk> or <filesystem>
devices to use the loop device. This extends it to also allow
for use of the NBD device, to support non-raw formats.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-13 13:15:19 +01:00
Daniel P. Berrange
13579d4544 Add 'nbd' as a valid filesystem driver type
The <filesystem> element can now accept a <driver type='nbd'/>
as an alternative to 'loop'. The benefit of NBD is support
for non-raw disk image formats.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-13 13:15:19 +01:00
Daniel P. Berrange
8aabd597b3 Add a helper API for setting up a NBD device with qemu-nbd
Add a virFileNBDDeviceAssociate method, which given a filename
will setup a NBD device, using qemu-nbd as the server.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-13 13:15:19 +01:00
Daniel P. Berrange
1eeff53d7d Fix error handling of readdir() in virFileLoopDeviceOpen
To correctly handle errors from readdir() you must set 'errno'
to zero before invoking it & check its value afterwards to
distinguish error from EOF.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-13 13:15:19 +01:00
Daniel P. Berrange
c8fa7e8c55 Re-arrange code setting up ifs/disk loop devices for LXC
The current code for setting up loop devices to LXC disks first
does a switch() based on the disk format, then looks at the
disk driver name. Reverse this so it first looks at the driver
name, and then the disk format. This is more useful since the
list of supported disk formats depends on what driver is used.

The code for setting loop devices for LXC fs entries also needs
to have the same logic added, now the XML schema supports this.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-13 13:15:19 +01:00
Daniel P. Berrange
ada14b86cc Add support for storage format in FS <driver>
Extend the <driver> element in filesystem devices to
allow a storage format to be set. The new attribute
uses 'format' to reflect the storage format. This is
different from the <driver> element in disk devices
which use 'type' to reflect the storage format. This
is because the 'type' attribute on filesystem devices
is already used for the driver backend, for which the
disk devices use the 'name' attribute. Arggggh.

Anyway for disks we have

   <driver name="qemu" type="raw"/>

And for filesystems this change means we now have

   <driver type="loop" format="raw"/>

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-13 13:15:19 +01:00
Michal Privoznik
23fbda20a7 security_apparmor.c: Include virscsi.h
After introducing AppArmorSetSecuritySCSILabel() in 2691cd5f
we are using virSCSIDevicePtr type without proper include.
2013-05-13 14:01:14 +02:00
Osier Yang
2691cd5fe8 security: Manage the security label for scsi host device
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)
2013-05-13 19:08:40 +08:00
Han Cheng
6eb42e38e8 qemu: Allow the scsi-generic device in cgroup
This adds the scsi-generic device into the device controller's
whitelist, so that it's allowed to used by the qemu process.

Signed-off-by: Han Cheng <hanc.fnst@cn.fujitsu.com>
Signed-off-by: Osier Yang <jyang@redhat.com>
2013-05-13 19:08:34 +08:00
Osier Yang
bab6ee6b30 qemu: Support bootindex for scsi host device 2013-05-13 19:08:32 +08:00
Daniel P. Berrange
486a86eb18 Add docs about cgroups layout and usage
Describe the new cgroups layout, how to customize placement
of guests and what virsh commands are used to access the
parameters.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-13 12:04:42 +01:00
Osier Yang
f4bb7b4807 Introduce <readonly> for hostdev
Since it's generic enough to be used by other types in future, I
put it in <hostdev> as sub-element, though now it's only used by
scsi host device.
2013-05-13 19:02:40 +08:00
Osier Yang
dcd632af72 rng: Interleave hostdev elements 2013-05-13 18:51:16 +08:00
Han Cheng
0d70656afd qemu: Build qemu command line for scsi host device
Except the scsi host device's controller is "lsilogic", mapping
between the libvirt attributes and scsi-generic properties is:

  libvirt     qemu
-----------------------------------------
  controller  bus ($libvirt_controller.0)
  bus         channel
  target      scsi-id
  unit        lun

For scsi host device with "lsilogic" controller, the mapping is:
('target (libvirt)' must be 0, as it's not used; 'unit (libvirt)
must <= 7).

  libvirt            qemu
----------------------------------------------------------
  controller && bus  bus ($libvirt_controller.$libvirt_bus)
  unit               scsi-id

It's not good to hardcode/hard-check limits of these attributes,
and even worse, these limits are not documented, one has to find
out by either testing or reading the qemu code, I'm looking forward
to qemu expose limits like these one day). For example, exposing
"max_target", "max_lun" for megasas:

static const struct SCSIBusInfo megasas_scsi_info = {
    .tcq = true,
    .max_target = MFI_MAX_LD,
    .max_lun = 255,

    .transfer_data = megasas_xfer_complete,
    .get_sg_list = megasas_get_sg_list,
    .complete = megasas_command_complete,
    .cancel = megasas_command_cancel,
};

Example of the qemu command line (lsilogic controller):

  -drive file=/dev/sg2,if=none,id=drive-hostdev-scsi_host7-0-0-0 \
  -device scsi-generic,bus=scsi0.0,scsi-id=8,\
  drive=drive-hostdev-scsi_host7-0-0-0,id=hostdev-scsi_host7-0-0-0

Example of the qemu command line (virtio-scsi controller):

  -drive file=/dev/sg2,if=none,id=drive-hostdev-scsi_host7-0-0-0 \
  -device scsi-generic,bus=scsi0.0,channel=0,scsi-id=128,lun=128,\
  drive=drive-hostdev-scsi_host7-0-0-0,id=hostdev-scsi_host7-0-0-0

Signed-off-by: Han Cheng <hanc.fnst@cn.fujitsu.com>
Signed-off-by: Osier Yang <jyang@redhat.com>
2013-05-13 18:50:16 +08:00
Han Cheng
7486584c9f utils: util functions for scsi hostdev
This patch adds util functions for scsi hostdev.

Signed-off-by: Han Cheng <hanc.fnst@cn.fujitsu.com>
Signed-off-by: Osier Yang <jyang@redhat.com>
2013-05-13 18:40:50 +08:00
Han Cheng
b238c0bec1 qemu: New cap flags for scsi-generic
Adding two cap flags for scsi-generic:
  QEMU_CAPS_SCSI_GENERIC
  QEMU_CAPS_SCSI_GENERIC_BOOTINDEX

Signed-off-by: Han Cheng <hanc.fnst@cn.fujitsu.com>
Signed-off-by: Osier Yang <jyang@redhat.com>
2013-05-13 18:30:26 +08:00
Osier Yang
9677ff08ce node_device: Clean up unused macros
All of these macros are now unused, so remove.
2013-05-13 18:29:02 +08:00
Han Cheng
5c811dcec5 conf: Generic XMLs for scsi hostdev
An example of the scsi hostdev XML:

    <hostdev mode='subsystem' type='scsi'>
      <source>
        <adapter name='scsi_host0'/>
        <address bus='0' target='0' unit='0'/>
      </source>
      <address type='drive' controller='0' bus='0' target='4' unit='8'/>
    </hostdev>

Controller is implicitly added for scsi hostdev, though the scsi
controller's model defaults to "lsilogic", which might be not what
the user wants (same problem exists for virtio-scsi disk). It's
the existing problem, will be addressed later.

The device address must be specified manually. Later patch will let
libvirt generate it automatically.

This only introduces the generic XMLs for scsi hostdev, later patches
will add other elements, e.g. <readonly>, <shareable>.

Signed-off-by: Han Cheng <hanc.fnst@cn.fujitsu.com>
Signed-off-by: Osier Yang <jyang@redhat.com>
2013-05-13 18:23:50 +08:00
Osier Yang
9706d85fe9 tests: Add tests for fc_host
Since the NPIV machine is not easy to get, it's very likely to
introduce regressions when doing changes on the existing code.
This patch dumps part of the sysfs files (the necessary ones)
of fc_host as test input data, to test the related util functions.
It could be extended for more fc_host related testing in future.
2013-05-13 17:24:18 +08:00
Osier Yang
b7ab719528 util: Honor the passed sysfs_prefix
The helper works for default sysfs_prefix, but for user specified
prefix, it doesn't work. (Detected when writing test cases. A later
patch will add the test cases for fc_host).
2013-05-13 17:19:54 +08:00
Osier Yang
1a59ae919d util: Update the comment for virGetFCHostNameByWWN
The returned result is something like "host5" acutally.
2013-05-13 17:18:52 +08:00
Osier Yang
c56c273be6 util: Change virIsCapable* to return bool
Function name with "aIsB" generally means its return value is
in Bi-state (true/false).
2013-05-13 17:17:26 +08:00
Osier Yang
b595588fef util: Don't miss the slash in constructed path
In case of the caller can pass a "prefix" (or "sysfs_prefix")
without the trailing slash, and Unix-Like system always eats
up the redundant "slash" in the filepath, let's add it explicitly.
2013-05-13 17:14:51 +08:00
Osier Yang
e106c0112a util: Fix regression introduced by commit 4360a09844
Which refactored the old code, and introduced new helper
virIsCapableVport, but the path for checking with access() is not
correctly constructed.
2013-05-13 17:12:55 +08:00
Osier Yang
b76284afb1 util: Fix regression of wwn reading
Introduced by commit 244ce462e2, which refactored the helper for wwn
reading, however, it forgot to change the old "strndup" and "sizeof(buf)",
"sizeof(buf)" operates on the fixed length array ("buf") in the old code,
but now "buf" is a pointer.

Before the fix:

% virsh nodedev-dumpxml scsi_host5
<device>
  <name>scsi_host5</name>
  <parent>pci_0000_04_00_1</parent>
  <capability type='scsi_host'>
    <host>5</host>
    <capability type='fc_host'>
      <wwnn>2001001b</wwnn>
      <wwpn>2101001b</wwpn>
      <fabric_wwn>2001000d</fabric_wwn>
    </capability>
  </capability>
</device>

With the fix:

% virsh nodedev-dumpxml scsi_host5
<device>
  <name>scsi_host5</name>
  <parent>pci_0000_04_00_1</parent>
  <capability type='scsi_host'>
    <host>5</host>
    <capability type='fc_host'>
      <wwnn>0x2001001b32a9da4e</wwnn>
      <wwpn>0x2101001b32a9da4e</wwpn>
      <fabric_wwn>0x2001000dec9877c1</fabric_wwn>
    </capability>
  </capability>
</device>
2013-05-13 17:10:59 +08:00
Eric Blake
d34ef01779 build: fix use of mmap
Commit bfe7721d introduced a regression, but only on platforms
like FreeBSD that lack posix_fallocate and where mmap serves as
a nice fallback for safezero.

util/virfile.c: In function 'safezero':
util/virfile.c:837: error: 'PROT_READ' undeclared (first use in this function)

* src/util/virutil.c (includes): Move use of <sys/mman.h>...
* src/util/virfile.c (includes): ...to the file that uses mmap.

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-05-10 20:52:57 -06:00
Eric Blake
12bd22c70d build: update to latest gnulib, for syntax-check
This picks up a fix for a syntax-check weakness mentioned here:
https://www.redhat.com/archives/libvir-list/2013-May/msg00811.html

* .gnulib: Update to latest, for maint.mk improvement.

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-05-10 20:52:57 -06:00
Daniel P. Berrange
0902f696a9 Update hellolibvirt to demo virGetLastErrorMessage()
Update the hellolibvirt example program to demonstrate use of
the virGetLastErrorMessage() API for quick error reporting

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-10 19:57:18 +01:00
Daniel P. Berrange
31989e66c6 Add a test case for the fdstream file read/write code
Add a test case which exercises the virFDStreamOpenFile
and virFDStreamCreateFile methods. Ensure that both the
synchronous and non-blocking iohelper code paths work.
This validates the regression recently fixed which
broke reading in non-blocking mode

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-10 19:57:18 +01:00
Daniel P. Berrange
8ab7d8ee40 Allow the iohelper path to be customized by test programs
Currently the fdstream function hardcodes the location
of the iohelper to LIBEXECDIR "/libvirt_iohelper". This
is not convenient when trying to write test cases which
use this code. Add a virFDStreamSetIOHelper method to
allow the test cases to point to the location of the
un-installed iohelper binary.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-10 19:57:18 +01:00
Daniel P. Berrange
69c6a58a1d Add a virGetLastErrorMessage() function
Apps using libvirt will often have code like

   if (virXXXX() < 0) {
      virErrorPtr err = virGetLastError();
      fprintf(stderr, "Something failed: %s\n",
              err && err->message ? err->message :
              "unknown error");
      return -1;
   }

Checking for a NULL error object or message leads to very
verbose code. A virGetLastErrorMessage() helper from libvirt
can simplify this to

   if (virXXXX() < 0) {
      fprintf(stderr, "Something failed: %s\n",
              virGetLastErrorMessage());
      return -1;
   }

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-10 19:57:18 +01:00
Daniel P. Berrange
a2214c5257 Fix iohelper usage with streams opened for read
In b2878ed860 we added the O_NOCTTY
flag when opening files in the stream code. Unfortunately a later
piece of code was comparing the flags == O_RDONLY, without masking
out the non-access mode flags. This broke the iohelper when used
with streams for read, since it caused us to attach the stream
output pipe to the stream input FD instead of output FD :-(

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-10 19:57:18 +01:00
Daniel P. Berrange
f493d83fbd Cope with missing swap cgroup controls
It is possible to build a kernel without swap cgroup controls
present. This causes a fatal error when querying memory
parameters. Treat missing swap controls as meaning "unlimited".
The fatal error remains if the user tries to actually change
the limit.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-10 19:57:18 +01:00
Roman Bogorodskiy
95934171fb portability: fix virNetDevSetMAC and virNetDevExists on BSD
- provide virNetDevSetMAC() implementation based on SIOCSIFLLADDR
  ioctl.
- adjust virNetDevExists() to check for ENXIO error because
  FreeBSD throws it when device doesn't exist

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-05-10 11:13:21 -06:00
Laine Stump
bfe7721d50 util: move virFile* functions from virutil.c to virfile.c
These all existed before virfile.c was created, and for some reason
weren't moved.

This is mostly straightfoward, although the syntax rule prohibiting
write() had to be changed to have an exception for virfile.c instead
of virutil.c.

This movement pointed out that there is a function called
virBuildPath(), and another almost identical function called
virFileBuildPath(). They really should be a single function, which
I'll take care of as soon as I figure out what the arglist should look
like.
2013-05-10 13:09:30 -04:00
Laine Stump
a2c1bedbd8 util: fix virFileOpenAs return value and resulting error logs
This resolves:

     https://bugzilla.redhat.com/show_bug.cgi?id=851411
     https://bugzilla.redhat.com/show_bug.cgi?id=955500

The first problem was that virFileOpenAs was returning fd (-1) in one
of the error cases rather than ret (-errno), so the caller thought
that the error was EPERM rather than ENOENT.

The second problem was that some log messages in the general purpose
qemuOpenFile() function would always say "Failed to create" even if
the caller hadn't included O_CREAT (i.e. they were trying to open an
existing file).

This fixes virFileOpenAs to jump down to the error return (which
returns ret instead of fd) in the previously mentioned incorrect
failure case of virFileOpenAs(), removes all error logging from
virFileOpenAs() (since the callers report it), and modifies
qemuOpenFile to appropriately use "open" or "create" in its log
messages.

NB: I seriously considered removing logging from all callers of
virFileOpenAs(), but there is at least one case where the caller
doesn't want virFileOpenAs() to log any errors, because it's just
going to try again (qemuOpenFile()). We can't simply make a silent
variation of virFileOpenAs() though, because qemuOpenFile() can't make
the decision about whether or not it wants to retry until after
virFileOpenAs() has already returned an error code.

Likewise, I also considered changing virFileOpenAs() to return -1 with
errno set on return, and may still do that, but only as a separate
patch, as it obscures the intent of this patch too much.
2013-05-10 13:09:25 -04:00