FITRIM is a mounted filesystem feature to discard (or "trim") blocks which
are not in use by the filesystem. This is useful for solid-state drives
(SSDs) and thinly-provisioned storage. Provide access to the feature
from the host so that filesystems can be trimmed periodically or before
migration.
Here is an example using scsi_debug:
# modprobe scsi_debug lbpu=1 lbpws=1
# sg_vpd -p0xb2 /dev/sdb
Logical block provisioning VPD page (SBC):
Unmap command supported (LBPU): 1
Write same (16) with unmap bit supported (LBWS): 1
Write same (10) with unmap bit supported (LBWS10): 0
# mke2fs /dev/sdb
# cat /sys/bus/pseudo/drivers/scsi_debug/map
1-616,16257-16383
# mount /dev/sdb /run/media/pbonzini/test
# dd if=/dev/zero of=/run/media/pbonzini/test/file
# cat map
1-616,645-1588,1599-4026,4029-16383
# rm /run/media/pbonzini/test/file
# ./qemu-ga /dev/fd/0
{"execute":"guest-fstrim"}
{"return": {}}
# cat map
1-612
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
This command returns an array of:
[ifname, hwaddr, [ipaddr, ipaddr_family, prefix] ]
for each interface in the system.
Currently, only IPv4 and IPv6 are supported.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Implement guest-suspend-disk RPC for Windows. Functionally this should be
equivalent to the posix implementation.
Signed-off-by: Gal Hammer <ghammer@redhat.com>
As the command name implies, this command suspends the guest to disk.
The suspend operation is implemented by two functions: bios_supports_mode()
and guest_suspend(). Both functions are generic enough to be used by
other suspend modes (introduced by next commits).
Both functions will try to use the scripts provided by the pm-utils
package if it's available. If it's not available, a manual method,
which consists of directly writing to '/sys/power/state', will be used.
To reap terminated children, a new signal handler is installed in the
parent to catch SIGCHLD signals and a non-blocking call to waitpid()
is done to collect their exit statuses. The statuses, however, are
discarded.
The approach used to query the guest for suspend support deserves some
explanation. It's implemented by bios_supports_mode() and shown below:
qemu-ga
|
create pipe
|
fork()
-----------------
| |
| |
| fork()
| --------------------------
| | |
| | |
| | exec('pm-is-supported')
| |
| wait()
| write exit status to pipe
| exit
|
read pipe
This might look complex, but the resulting code is quite simple.
The purpose of that approach is to allow qemu-ga to reap its children
(semi-)automatically from its SIGCHLD handler.
Implementing this the obvious way, that's, doing the exec() call from
the first child process, would force us to introduce a more complex way
to reap qemu-ga's children. Like registering PIDs to be reaped and
having a way to wait for them when returning their exit status to
qemu-ga is necessary. The approach explained above avoids that complexity.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Implement guest-shutdown RPC for Windows. Functionally this should be
equivalent to the posix implementation.
Original patch by Gal Hammer <ghammer@redhat.com>
Various stubs and #ifdefs to compile for Windows using mingw
cross-build. Still has 1 linker error due to a dependency on the
forthcoming win32 versions of the GAChannel/transport class.
