...and cleanup the callers to report it when it *is* an error.

In many cases It's useful for virPCIGetNetName() to not log an error
and simply return a NULL pointer when the given device isn't bound to
a net driver (e.g. we're looking at a VF that is permanently bound to
vfio-pci). The existing code would silently return an error in this
case, which could eventually lead to the dreaded "An error occurred
but the cause is unknown" log message.

This patch changes virPCIGetNetName() to still return success if the
device simply isn't bound to a net driver, and adjusts all the callers
that require a non-null netname to check for that condition and log an
error when it happens.

Previously the MAC address text was required to be terminated with a
NULL. After this, it can be terminated with a space or any control
character.

vf in virNetDevMacVLanDeleteWithVPortProfile() is initialized to -1
and never set. It's not set for a good reason - because it doesn't
make sense during macvtap device setup to refer to a VF device as
"PF:VF#". This patch replaces the two uses of "vf" with "-1", and
removes the local variable, so that it's more clear we are always
calling the utility functions with vf set to -1.

This will make an upcoming functional change more straightforward.

This function is only called in two places, and the ifindex,
nltarget_kernel, and getPidFunc args are never used (and never will
be).

ifindex - we always know the name of the device, and never know the
ifindex - if we really did need the ifindex we would have to get it
from the name using virNetDevGetIndex(). In practice, we just send -1
to virNetDevSetVfConfig(), which doesn't bother to learn the real
ifindex (you only need a name *or* an ifindex for the netlink command
to succeed, not both).

nltarget_kernel - messages to set the config of an SRIOV VF will
always go to netlink in the kernel, not to another user process, so
this arg is always true (there are other uses of netlink messages
where the message might need to go to another user process, but never
in the case of RTM_SETLINK for SRIOV).

getPidFunc - this arg is only used if nltarget_kernel is false, and it
never is.

None of this has any functional effect, it just makes it easier to
follow what's happening when virNetDevSetVfConfig() is called.

virNetDevParseVfConfig() assumed that both the MAC address and VLAN
tag pointers were valid, so even if you only wanted one or the other,
you would need a variable to hold the returned value for both. This
patch checks each for a NULL pointer before filling it in.

Decorate unused arguments of the virNetDevGetMaster() stub
with ATTRIBUTE_UNUSED to fix build on systems where this
stub is used.

Since the source code checks 'ifname' for NULL before using, the prototype
doesn't need the NONNULL

The source code will check for NULL arguments for 'macvtap_macaddr' and
'vmuuid', so no need for the NONNULL in the prototypes. Following the stack
for both arguments to virNetDevVPortProfileOpSetLink also shows called
functions would handle a NULL value.

Additionally, modified the prototype to use the same 'macvtap_macaddr'
name as the source code for consistency.

Since the code checks and handles a NULL 'path', no need for the NONNULL

Since the code checks and handles a NULL 'net_bandwidth' parameter,
so no need for NONNNULL.

The API checks each parameter for NULL anyway and would error, so need
to add NONNULL on prototype.

The code checks and handles a NULL 'migrate', so no need for NONNULL

Since the function handles a NULL 'mgr' condition, no need for the NONNULL

Since the code checks 'mgr == NULL' anyway, no need for the prototype
to have the NONNULL arg check.  Also add an error message to indicate what
the failure is so that there isn't a failed for some reason error.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

The comparison code used STREQ_NULLABLE anyway for both 'drv_name' and
'dom_name', so no need. Add a NULLSTR on the 'dom_name' too.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

The comparison code used STREQ_NULLABLE anyway for both 'drv_name' and
'dom_name', so no need. Add a NULLSTR on the 'dom_name' too.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

The called function uses a STRNEQ_NULLABLE anyway for both 'drv_name' and
'dom_name', so no need.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

The code checks and handles a NULL 'str', so just remove the NONNULL.

Update the error message to add the NULLSTR() around 'str' also.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Rather than returning an int and a *bitmap pointer, just return and
check a NULL bitmap pointer

The 'ifindex' argument is not a pointer, so no need for NONNULL in prototype

This patch splits out the part of virNetDevTapCreateInBridgePort()
that would need to be re-done if an existing tap device had to be
re-attached to a bridge, and puts it into a separate function. This
can be used both when an existing domain interface config is updated
to change its connection, and also to re-attach to the "same" bridge
when a network has been stopped and restarted. So far it is used for
nothing.

This function provides the bridge/bond device that the given network
device is attached to. The return value is 0 or -1, and the master
device is a char** argument to the function - this is needed in order
to allow for a "success" return from a device that has no master.

The only reason that the ethtool features weren't being retrieved in
an unprivileged libvirtd was because they required ioctl(), and the
ioctl was using an AF_PACKET socket, which requires root. Now that we
are using AF_UNIX for ioctl(), this restriction can be removed.

The exact family of the socket created for the fd used by ioctl(7)
doesn't matter, it just needs to be a socket and not a file. But for
some reason when macvtap support was added, it used
AF_PACKET/SOCK_DGRAM sockets for its ioctls; we later used the same
AF_PACKET/SOCK_DGRAM socket for new ioctls we added, and eventually
modified the other pre-existing ioctl sockets (for creating/deleting
bridges) to also use AF_PACKET/SOCK_DGRAM (that code originally used
AF_UNIX/SOCK_STREAM).

The problem with using AF_PACKET (intended for sending/receiving "raw"
packets, i.e. packets that can be some protocol other than TCP or UDP)
is that it requires root privileges. This meant that none of the
ioctls in virnetdev.c or virnetdevip.c would work when running
libvirtd unprivileged.

This packet solves that problem by changing the family to AF_UNIX when
creating the socket used for any ioctl().

When enabling IPv6 on all interfaces, we may get the host Router
Advertisement routes discarded. To avoid this, the user needs to set
accept_ra to 2 for the interfaces with such routes.

See https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt
on this topic.

To avoid user mistakenly losing routes on their hosts, check
accept_ra values before enabling IPv6 forwarding. If a RA route is
detected, but neither the corresponding device nor global accept_ra
is set to 2, the network will fail to start.

Add a function getting the name of a network interface out of its index.

virNetlinkCommand() processes only one response message, while some
netlink commands, like route dumping, need to process several.
Add virNetlinkDumpCommand() as a virNetlinkCommand() sister.

Allow to reuse as much as possible from virNetlinkCommand(). This
comment prepares for the introduction of virNetlinkDumpCommand()
only differing by how it handles the responses.

While connecting to qemu monitor, the first thing we do is wait
for it to show up. However, we are doing it with some timeout to
avoid indefinite waits (e.g. when qemu doesn't create the monitor
socket at all). After beaa447a we are using exponential back
off timeout meaning, after the first connection attempt we wait
1ms, then 2ms, then 4 and so on.  This allows us to bring down
wait time for small domains where qemu initializes quickly.
However, on the other end of this scale are some domains with
huge amounts of guest memory. Now imagine that we've gotten up to
wait time of 15 seconds. The next one is going to be 30 seconds,
and the one after that whole minute. Well, okay - with current
code we are not going to wait longer than 30 seconds in total,
but this is going to change in the next commit.

The exponential back off is usable only for first few iterations.
Then it needs to be caped (one second was chosen as the limit)
and switch to constant wait time.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

The function is actually in virutil.c, but prototyped in virfile.h.
This patch fixes that by renaming the function to virWaitForDevices,
adding the prototype in virutil.h and libvirt_private.syms, and then
changing the callers to use the new name.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

This patch adds support and documentation
for the emulation_faults perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

This patch adds support and documentation
for the alignment_faults perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

This patch adds support and documentation
for the page_faults_maj perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

This patch adds support and documentation
for the page_faults_min perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

This patch adds support and documentation
for the cpu_migrations perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

This patch adds support and documentation
for the context_switches perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

This patch adds support and documentation
for the page_faults perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

This patch adds support and documentation for
the task_clock perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>

This patch adds support and documentation for
the cpu_clock perf event.
Signed-off-by: NNitesh Konkar <nitkon12@linux.vnet.ibm.com>