fixup: s/devies/devices/

[pve-docs.git] / qm.adoc

diff --git a/qm.adoc b/qm.adoc
index 0019ad1bbbe58331f7b333a72dc6dbf0b0905bc0..4f9ae15f9710102bbae15da40154fc733d0f75a7 100644 (file)
--- a/qm.adoc
+++ b/qm.adoc
@@ -484,7 +484,7 @@ host.
 .Fixed Memory Allocation
 [thumbnail="screenshot/gui-create-vm-memory.png"]
 
-When setting memory and minimum memory to the same amount
+ghen setting memory and minimum memory to the same amount
 {pve} will simply allocate what you specify to your VM.
 
 Even when using a fixed memory size, the ballooning device gets added to the
@@ -703,6 +703,29 @@ 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 an Inter-VM shared memory device (`ivshmem`), which allows one to
+share memory between the host and a guest, or also 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).
+
+NOTE: Currently the device will get deleted as soon as any VM using it got
+shutdown or stopped. Open connections will still persist, but new connections
+to the exact same device cannot be made anymore.
+
+A use case for such a device is the Looking Glass
+footnote:[Looking Glass: https://looking-glass.hostfission.com/] project,
+which enables high performance, low-latency display mirroring between
+host and guest.
+
 [[qm_startup_and_shutdown]]
 Automatic Start and Shutdown of Virtual Machines
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -829,7 +852,7 @@ migrate a VM to a totally different storage. You can also change the
 disk image *Format* if the storage driver supports several formats.
 +
 
-NOTE: A full clone need to read and copy all VM image data. This is
+NOTE: A full clone needs to read and copy all VM image data. This is
 usually much slower than creating a linked clone.
 +
 
@@ -840,7 +863,7 @@ never includes any additional snapshots from the original VM.
 
 Linked Clone::
 
-Modern storage drivers supports a way to generate fast linked
+Modern storage drivers support a way to generate fast linked
 clones. Such a clone is a writable copy whose initial contents are the
 same as the original data. Creating a linked clone is nearly
 instantaneous, and initially consumes no additional space.
@@ -857,8 +880,8 @@ can convert any VM into a read-only <<qm_templates, Template>>). Such
 templates can later be used to create linked clones efficiently.
 +
 
-NOTE: You cannot delete the original template while linked clones
-exists.
+NOTE: You cannot delete an original template while linked clones
+exist.
 +
 
 It is not possible to change the *Target storage* for linked clones,
@@ -869,7 +892,7 @@ The *Target node* option allows you to create the new VM on a
 different node. The only restriction is that the VM is on shared
 storage, and that storage is also available on the target node.
 
-To avoid resource conflicts, all network interface MAC addresses gets
+To avoid resource conflicts, all network interface MAC addresses get
 randomized, and we generate a new 'UUID' for the VM BIOS (smbios1)
 setting.
 
@@ -1030,6 +1053,16 @@ 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`
 ------------------------------------