Erik Skultety [Fri, 12 Mar 2021 10:53:13 +0000 (11:53 +0100)]
docs: html.in: Convert api to rst
There were a number of occurrences where we used nested inline markup
(verbatim + refs) which is currently not possible with RST syntax [1].
There is a possible workaround involving substitution definitions like
Substitutions cannot be made generic, hence we cannot create a template
for substitution and use a single template everywhere, so we'd end up
with a lot of clutter and convolution. Therefore, we can make an
exception and just link the data type without further style markup.
Pavel Hrdina [Mon, 15 Mar 2021 13:10:45 +0000 (14:10 +0100)]
qemu_driver: fix setting vcpu_quota if not all vCPUs are online
When switching to g_autoptr this was incorrectly changed from
'continue;' into 'return -1;' resulting into an error when user tries
to set vcpu_quota of running VM:
error: An error occurred, but the cause is unknown
Fixes: e4a8bbfaf2b4cdd741bb441873bb730f9134b714 Signed-off-by: Pavel Hrdina <phrdina@redhat.com> Reviewed-by: Erik Skultety <eskultet@redhat.com>
Michal Privoznik [Thu, 11 Mar 2021 14:37:07 +0000 (15:37 +0100)]
lib: Put some variable declarations on individual lines
In short, virXXXPtr type is going away. With big bang. And to
help us rewrite the code with a sed script, it's better if each
variable is declared on its own line.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
Michal Privoznik [Thu, 11 Mar 2021 07:29:42 +0000 (08:29 +0100)]
syntax-check: Fix and rename virSecurity rule
The aim of virSecurity rule is to discourage from using plain
virSecurityManager*() APIs within QEMU driver in favor of their
qemuSecurity*() counterparts. The reason is simple: namespaces;
virSecurityManager*() needs additional
virSecurityManagerTransactionCommit() call to enter given
namespace and do its work from there. And that's exactly what
those qemuSecurity*() wrappers do.
To help us ensure correctness (from this POV), we have a
syntax-check rule that forbids any occurrence of
"virSecurityManager" string under src/qemu/ (except for
qemu_security of course).
But with if we want to remove virSecurityManagerPtr type, then we
have to allow "virSecurityManager *". Therefore, change the rule
so that no call of a function with "virSecurityManager" prefix is
allowed. And also change the name to better reflect what is going
on.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
Michal Privoznik [Thu, 11 Mar 2021 05:17:07 +0000 (06:17 +0100)]
virsysinfo: Define and use auto cleanup func for virSysinfoDef properly
What we are using really is heap allocated structure rather than
stack allocated. And for that it's better to use g_autoptr() +
G_DEFINE_AUTOPTR_CLEANUP_FUNC() combo, as Glib documentation for
g_auto() reads:
This is meant to be used with stack-allocated structures and
non-pointer types. For the (more commonly used) pointer
version, see g_autoptr().
This will be even more visible, when virSysinfoDefPtr type is
gone. Stay tuned.
Fixes: cee3a900a0d6a8fc79554db22dc262632fe487a6 Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
Michal Privoznik [Thu, 25 Feb 2021 14:01:27 +0000 (15:01 +0100)]
qemu_shim: Don't hang if failed to start domain
The qemu shim spawns a separate thread in which the event loop is
ran. The virEventRunDefaultImpl() call is wrapped in a while()
loop, just like it should. There are few lines of code around
which try to ensure that domain is destroyed (when quitting) and
that the last round of event loop is ran after the
virDomainDestroy() call. Only after that the loop is quit from
and the thread quits.
However, if domain creation fails, there is no @dom to call
destroy over, the @quit flag is never set and while() never
exits. Set the flag regardless of @dom pointer.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1920337 Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Peter Krempa [Thu, 26 Nov 2020 18:07:03 +0000 (19:07 +0100)]
qemu: command: Generate commandline of 'sev0' sev-guest object via JSON
While the 'sev0' sev-guest object will never be hotplugged, but we want
to generate it through JSON so that we'll be able to validate all
parameters of '-object' against the QAPI schema once 'object-add' is
qapified in qemu.
Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
Peter Krempa [Thu, 26 Nov 2020 18:07:03 +0000 (19:07 +0100)]
qemu: command: Generate commandline of 'masterKey0' secret via JSON
While the 'masterKey0' secret object will never be hotplugged we want to
generate it through JSON so that we'll be able to validate all
parameters of '-object' against the QAPI schema once 'object-add' is
qapified in qemu.
Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
Recent changes which meant to fix daemon shutdown broke the exec-restart
capability of virtlogd and virtlockd, since the code actually closed all
the sockets and shut down all the internals.
Add virNetDaemonQuitExecRestart, which requests a shutdown of the
process, but keeps all the services open and registered since they are
preserved across the restart.
Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Michal Privoznik [Thu, 25 Feb 2021 17:20:51 +0000 (18:20 +0100)]
qemu_shim: Always pre-create root dir
This problem is reproducible only with secret driver. When
starting a domain via virt-qemu-run and both secret and
(nonexistent) root directory specified this is what happens:
1) virt-qemu-run opens "secret:///embed?root=$rootdir"
connection, which results in the secret driver initialization
(done in secretStateInitialize()). During this process, the
driver creates its own configDir (derived from $rootdir)
including those parents which don't exists yet. This is all
done with the mode S_IRWXU and thus results in the $rootdir
being created with very restrictive mode (specifically, +x is
missing for group and others).
2) now, virt-qemu-run opens "qemu:///embed?root=$rootdir" and
calls virDomainCreateXML(). This results in the master-key.aes
being written somewhere under the $rootdir and telling qemu
where to find it.
But because the secret driver created $rootdir with too
restrictive mode, qemu can't access the file (even though it
knows the full path) and fails to start.
It looks like the best solution is to pre-create the root
directory before opening any connection (letting any driver
initialize itself) and set its mode to something less
restrictive.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1859873 Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Michal Privoznik [Thu, 25 Feb 2021 15:29:22 +0000 (16:29 +0100)]
virConnectOpen: Require root dir to be absolute path
In theory, users might want to use a relative path as a root
directory for embed drivers. But in practice, nothing in driver
initialization (specifically QEMU driver since it's the only one
that supports embedding now), is prepared for that. Document and
enforce absolute paths.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1883725 Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Michal Privoznik [Thu, 25 Feb 2021 14:29:16 +0000 (15:29 +0100)]
docs: Lift restriction on running API from the event loop thread
Since v6.2.0-rc1~238 (and friends) QMP processing was moved to a
per-domain thread. Therefore, it is now safe to call APIs from
the event loop thread (e.g. just like qemu shim is doing in
qemuShimEventLoop(). However, it is still important to let the
event loop run after each API call (obviously).
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Andrea Bolognani <abologna@redhat.com>
'res->owners' is allocated to 'res->nOwners' elements, but unfortunately
'res->nOwners' doesn't contain the proper value until after the
allocation so 0 elements are allocated. The following loop which assumes
that the array has the right number of elements then accesses the
pointer out of bounds. The bug was also faithfully converted from
VIR_ALLOC_N to g_new0.
Fixes: 4a3d6ed5ee0 Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Peter Krempa [Fri, 12 Mar 2021 09:12:51 +0000 (10:12 +0100)]
virLockSpacePreExecRestart: Avoid use-after-free
Recent refactor marked 'object' which is returned from the function as
autofree but forgot to use g_steal_pointer in the return statement to
prevent freeing it.
Fixes: 9a1651f64d7 Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Peter Krempa [Thu, 11 Mar 2021 15:18:50 +0000 (16:18 +0100)]
qemuBackupJobTerminate: Fix job termination for inactive VMs
Commit cb29e4e801d didn't take into account that the VM can be inactive
when it's destroyed. This means that the job would remain active also
when the VM became inactive.
To fix this properly:
1) Remove the bogus VM liveness check and early return
(reverts the aforementioned commit)
2) Conditionalize the stats assignment only when the stats object is
present
(properly fix the crash when VM dies when reconnecting)
3) end the asyncjob only when it was already set
(prevent corruption of priv->jobs_queued)
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1937598 Fixes: cb29e4e801d Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
Peter Krempa [Thu, 11 Mar 2021 15:14:17 +0000 (16:14 +0100)]
backup: Store 'apiFlags' in private section of virDomainBackupDef
'qemuBackupJobTerminate' needs the API flags to see whether
VIR_DOMAIN_BACKUP_BEGIN_REUSE_EXTERNAL. Unfortunately when called via
qemuProcessReconnect()->qemuProcessStop() early (e.g. if the qemu
process died while we were reconnecting) the job is cleared temporarily
so that other APIs can be called. This would mean that we couldn't clean
up the files in some cases.
Save the 'apiFlags' inside the backup object and set it from the
'qemuDomainJobObj' 'apiFlags' member when reconnecting to a VM.
Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
Peter Krempa [Wed, 10 Mar 2021 13:33:06 +0000 (14:33 +0100)]
virSystemdCreateMachine: Use proper format string for uint64_t when constructing gvariant
g_variant_new_parsed uses '%t' for a uint64_t rather than printf-like
%llu. Additionally ensure that the passed value is a uint64_t since the
argument used is a 'unsigned int'.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1937287 Fixes: bf5f2ed09c2 Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Peter Krempa [Tue, 2 Mar 2021 13:26:24 +0000 (14:26 +0100)]
util: virstring: Remove virStrncpy
The function is now unused and motivated users to write crazy parsers
which were hard to understand, had pointless error paths just to avoid
few memory allocations.
Remove the function as we're fine with g_strndup and virStrcpy.
Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
This is similar to my earlier commit which documented lxc.conf
location. Just like LXC, the libxl driver has only the system
connection and thus only few places need changing.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Andrea Bolognani <abologna@redhat.com>
manpages: Remove reference to a session daemon for libxl
The libxl driver has no session daemon therefore its split daemon
(virtxend) has to be ran as root. Any attempt to start it with
euid != 0 fails. This is why the daemon does not look under any
of XDG_* paths either.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Andrea Bolognani <abologna@redhat.com>
This is similar to my earlier commit which documented qemu.conf
locations. Luckily, the LXC driver has only the system connection
and not session or embed one.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Andrea Bolognani <abologna@redhat.com>
manpages: Remove reference to a session daemon for LXC
The LXC driver has no session daemon therefore its split daemon
(virtlxcd) has to be ran as root. Any attempt to start it with
euid != 0 fails. This is why the daemon does not look under any
of XDG_* paths either.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Andrea Bolognani <abologna@redhat.com>
syntax-check: Update list of gethostname exceptions
The only place where gethostname() is acceptable is in
virGetHostnameImpl() which lives in src/util/virutil.c.
Reflect this in the list of exceptions for the syntax-check rule.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
virutil: Do not use g_get_host_name() to obtain hostname
The problem is that g_get_host_name() caches the hostname in a
thread local variable. Therefore, it doesn't reflect any
subsequent hostname changes. While this might be acceptable for
logs where the hostname is printed exactly once when the libvirtd
starts up, it is not optimal for virGetHostnameImpl() which is
what our public virConnectGetHostname() API calls. If the
hostname at the moment of the first API invocation happens to
start with "localhost" or contains a dot, then no further
hostname changes will ever be reflected.
With this, XML fails if config video type 'ramfb' contains
address, since address is not supported for 'ramfb' video
devices. Previously it didn't raise error.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1891416 Signed-off-by: Kristina Hanicova <khanicov@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com> Signed-off-by: Ján Tomko <jtomko@redhat.com>
This introduces support for the QEMU audio settings that are common to
all audio backends. These are expressed in the QAPI schema as settings
common to all backends, but in reality some backends ignore some of
them. For example, some backends are output only. The parser isn't
attempting to apply restrictions that QEMU itself doesn't apply.
The -audiodev arg is a new way to configure audio devices in QEMU to
replace the QEMU_AUDIO_DRV env variable. This arg is not visible in
the "query-command-line-options" output since it is entirely QAPI
driven, not QemuOpts. It also isn't in "query-qmp-schema" though
since there's no QMP command that uses the Audiodev type yet.
So probe for the existance of this feature by looking for the
-vnc "audiodev" property. This won't let us determine which
precise audio backends QEMU has been built with, but for now
that's no worse than with env variables today.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
qemu: populate <audio> element with default config
Currently the QEMU driver secretly sets the QEMU_AUDIO_DRV env variable
- VNC - set to "none", unless passthrough of host env variable is set
- SPICE - always set to "spice"
- SDL - always passthrough host env
- No graphics - set to "none", unless passthrough of host env variable is set
The setting of the QEMU_AUDIO_DRV env variable is done in the code which
configures graphics.
If no <audio> element is present, we now auto-populate <audio> elements
to reflect this historical default config. This avoids need to set audio
env when processing graphics.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
conf: rename and improve virDomainDefFindAudioForSound
The virDomainDefFindAudioForSound only takes a virDomainSoundDefPtr as
its arg, but we want to use the same functionality for VNC graphics.
In addition if audio ID is zero, then we want to return the first
available audio backend.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
conf: add coverage for all QEMU audio backend types
The current <audio> element only allows an "OSS" audio backend, as this
is all that BHyve needed. This is now extended to cover most QEMU audio
backends. These backends all have a variety of attributes they support,
but this initial impl does the bare minimum, relying on built-in
defaults for everything. The only QEMU backend omitted is "dsound" since
the libvirt QEMU driver is not built on Windows platforms.
The SDL audio driver names are based on the SDL 2.0 drivers. It is not
intended to support SDL 1.2 drivers.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
To prepare for the introduction for more backend specific audio options,
move the OSS options into a dedicated struct and introduce separate
helper methods for parse/format/free.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
conf: add helper to test for sound device codec support
The check for ICH6 || ICH9 is repeated in many places in the code. The
new virDomainSoundModelSupportsCodecs() method provides a helper to
standardize this check.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
conf: don't force existance of audio child elements
The attributes on the elements are optional, so we should not force the
elements themselves to be present, especially since we omit them when
formating the XML thus breaking round-tripping.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Aleksei Zakharov [Fri, 19 Feb 2021 20:08:34 +0000 (23:08 +0300)]
qemu: add per-vcpu delay stats
This patch adds delay time (steal time inside guest) to libvirt
domain per-vcpu stats. Delay time is an important performance metric.
It is a consequence of the overloaded CPU. Knowledge of the delay
time of a virtual machine helps to understand if it is affected and
estimate the impact.
As a result, it is possible to react exactly when needed and
rebalance the load between hosts. This is used by cloud providers
to provide quality of service, especially when the CPU is
oversubscribed.
It's more convenient to work with this metric in a context of a
libvirt domain. Any monitoring software may use this information.
Signed-off-by: Aleksei Zakharov <zaharov@selectel.ru> Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
The preprocessor macro we use to check whether we're on Linux
has not been spelled properly, and so we will always report the
error message intended for other platforms.
Fixes: 879bcee08ce0f91f556fddfe452c3fbed5318468 Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Allow the directory to be chosen at installation time, to support local
conventions e.g. versioning.
Signed-off-by: Chris Mayo <aklhfex@gmail.com> Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
virnetdevbandwidth: Don't generate burst outside of boundaries
When generating TC rules for domain's outbound traffic, Libvirt
will use the 'average' as the default for 'burst' - it's been
this way since the feature introduction in v0.9.4-rc1~22. The
reason is that 'average' considers 'burst' for policing. However,
when parsing its command line TC uses an unsigned int (with
overflow detection) to store the 'burst' size. This means, that
the upper limit for the value is UINT_MAX, well UINT_MAX / 1024
because we are putting the value in KiB onto the command line.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1912210 Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Laine Stump <laine@redhat.com>
Up until now we've implicitly relied on the fact that failures
reported from this function were simply ignored, but that's
about to change and so we need a proper mock.
Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
This behavior reflects the needs of the QEMU driver and has no
place in a generic module such as virProcess.
Thanks to the changes made with the previous commit, it is now
safe to remove these checks and make all virProcessSetMax*()
functions finally behave the same way.
Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
qemu: Set limits only when explicitly asked to do so
The current code is written under the assumption that, for all
limits except the core size, asking for the limit to be set to
zero is a no-op, and so the operation is performed
unconditionally.
While this is the behavior we want for the QEMU driver, the
virCommand and virProcess facilities are generic, and should not
implement this kind of policy: asking for a limit to be set to
zero should result in that limit being set to zero every single
time.
Add some checks in the QEMU driver, effectively moving the
policy where it belongs.
Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
qemuProcessLaunch() is the correct place to set process limits,
and in fact is where we were dealing with almost all of them,
but the memory locking limit was handled in
qemuBuildCommandLine() instead for some reason.
The code is rewritten so that the desired limit is calculated
and applied in separated steps, which will help with further
changes, but this doesn't alter the behavior.
Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Andrea Bolognani [Tue, 23 Feb 2021 17:52:26 +0000 (18:52 +0100)]
util: Introduce virProcess{Get,Set}Limit()
These functions abstract part of the existing logic, which is
the same in all virProcessSetMax*() functions, and changes it
so that which underlying syscall is used depends on their
availability rather than on the context in which they are
called: since prlimit() and {g,s}etrlimit() have slightly
different requirements, using the same one every single time
should make for a more consistent experience.
As part of the change, we also remove the special case for
passing zero to virProcessSetMax*() functions: we have removed
all callers that depended on that functionality in the previous
commit, so this is now safe to do and makes the semantics
simpler.
This commit is better viewed with 'git show -w'.
Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Currently, the functions accept either an explicit pid or zero,
in which case the current process should be modified: the latter
might sound like a convenient little feature, but in reality
obtaining the pid of the current process is a single additional
function call away, so it hardly makes a difference.
Removing the few cases in which we're passing zero will allow us
to simplify and improve the functions later.
Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
The <graphics type="vnc" .... powerControl="yes"/> option instructs the
VNC server to enable an extension that lets the client perform a
graceful shutdown, reboot and hard reset.
This is enabled by default since it cannot be assumed that the VNC
client user has administrator rights over the guest OS. In the case
where the VNC user is a guest administrator though, it is reasonable
to allow direct power control host side too.
Reviewed-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
virDevMapperGetTargetsImpl: Use correct length when copying into dm.name
For reasons unknown, when rewriting this code and dropping
libdevmapper I've mistakenly used incorrect length of dm.name. In
linux/dm-ioctl.h the dm_ioctl struct is defined as follows:
After decryption, this results in the following size: 3241737483.
Fixes: 22494556542c676d1b9e7f1c1f2ea13ac17e1e3e Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Peter Krempa [Fri, 5 Mar 2021 09:38:49 +0000 (10:38 +0100)]
virFirewallApply: Fix possible NULL dereference on error
Commit bbc25f0d03d443efd35381463efc81b01cb6ae96 juggled around some
error reporting. Unfortunately virFirewallApply tries to report the
errno stored in the firewall object and we'd try to do that when the
firewall object is NULL too. Report EINVAL if 'firewall' is NULL.
Found by Coverity.
Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Peter Krempa [Thu, 4 Mar 2021 17:09:42 +0000 (18:09 +0100)]
virBufferAdd: Ensure that the buffer is initialized also when len == 0
There's an optimization in virBufferAdd which returns early when the
length of the added string is 0 (given that auto-indent is disabled).
The optimization causes inconsistent behaviour between these two cases:
virBufferAdd(buf, "", 0); // this doesn't initialize the buffer
and
virBufferAdd(buf, "", -1); //this initializes the buffer
Since using an empty string is used to prime the buffer to an empty
string it can be confusing. Remove the optimization.
This fixes such a wrong initialization done in x86FeatureNames.
Note that our code in many places expects that if no virBuffer APIs are
used on a buffer object, then NULL should be retured, so we can't always
prime the buffer to an empty string.
Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
Peter Krempa [Wed, 3 Mar 2021 09:20:00 +0000 (10:20 +0100)]
virIndexToDiskName: Make 'idx' unsigned and remove check
We can remove the check that 'idx' is negative by forcing callers to
pass unsigned numbers, which they do already or have a check that 'idx'
is positive.
This in turn allows us to remove most return value NULL checks.
Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
projects / thirdparty / libvirt.git / log
