add ivshmem documentation

[pve-docs.git] / qm.adoc

diff --git a/qm.adoc b/qm.adoc
index 43f250a4d7c7875f526cbd5743a45bf22b04fcd7..77fec9871b5927444f439f035ed4065e1bcc24e0 100644 (file)
--- a/qm.adoc
+++ b/qm.adoc
@@ -703,6 +703,25 @@ you need to set the client resolution in the OVMF menu(which you can reach
 with a press of the ESC button during boot), or you have to choose
 SPICE as the display type.
 
+[[qm_ivshmem]]
+Inter-VM shared memory
+~~~~~~~~~~~~~~~~~~~~~~
+
+You can add a Inter-VM shared memory device (`ivshmem`) to be able to
+share memory between the host and a guest, or between multiple guests.
+
+To add such a device, you can use `qm`:
+
+  qm set <vmid> -ivshmem size=32,name=foo
+
+Where the size is in MiB. The file will be located under
+`/dev/shm/pve-shm-$name` (the default name is the vmid).
+
+A usecase for such a device is Looking Glass
+footnote:[Looking Glass: https://looking-glass.hostfission.com/]
+which enables high performance, low-latency display mirroring between
+host and guest.
+
 [[qm_startup_and_shutdown]]
 Automatic Start and Shutdown of Virtual Machines
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -1030,6 +1049,16 @@ ifndef::wiki[]
 include::qm-pci-passthrough.adoc[]
 endif::wiki[]
 
+Hookscripts
+~~~~~~~~~~~
+
+You can add a hook script to VMs with the config property `hookscript`.
+
+ qm set 100 -hookscript local:snippets/hookscript.pl
+
+It will be called during various phases of the guests lifetime.
+For an example and documentation see the example script under
+`/usr/share/pve-docs/examples/guest-example-hookscript.pl`.
 
 Managing Virtual Machines with `qm`
 ------------------------------------