qm: display: enahnce and add cirrus description

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

diff --git a/qm.adoc b/qm.adoc
index 343dfee31e1b158758573f26c16eee3eb2a81581..a98803accb24712987b56092a276bce0b63421da 100644 (file)
--- a/qm.adoc
+++ b/qm.adoc
@@ -602,27 +602,32 @@ Display
 QEMU can virtualize a few types of VGA hardware. Some examples are:
 
 * *std*, the default, emulates a card with Bochs VBE extensions.
+* *cirrus*, this was once the default, it emulates a very old hardware module
+with all its problems. This display type should only be used if really
+necessary footnote:[https://www.kraxel.org/blog/2014/10/qemu-using-cirrus-considered-harmful/
+qemu: using cirrus considered harmful], e.g., if using Windows XP or earlier
 * *vmware*, is a VMWare SVGA-II compatible adapter.
 * *qxl*, is the QXL paravirtualized graphics card. Selecting this also
 enables SPICE for the VM.
 
 You can edit the amount of memory given to the virtual GPU, by setting
-the *memory* option. This can enable higher resolutions inside the VM,
+the 'memory' option. This can enable higher resolutions inside the VM,
 especially with SPICE/QXL.
 
-Selecting Multi-Monitor mode for SPICE (e.g., qxl2 for dual monitors) has
-some implications:
+As the memory is reserved by display device, selecting Multi-Monitor mode
+for SPICE (e.g., `qxl2` for dual monitors) has some implications:
 
-* Windows needs a device for each monitor, so if your ostype is some
-version of windows, {pve} gives the VM an extra device per monitor.
+* Windows needs a device for each monitor, so if your 'ostype' is some
+version of Windows, {pve} gives the VM an extra device per monitor.
 Each device gets the specified amount of memory.
+
 * Linux VMs, can always enable more virtual monitors, but selecting
 a Multi-Monitor mode multiplies the memory given to the device with
 the number of monitors.
 
-Selecting *serialX* as display disables the VGA output, and redirects
-the Web Console to the selected serial port. A configured memory setting
-will be ignored in that case.
+Selecting `serialX` as display 'type' disables the VGA output, and redirects
+the Web Console to the selected serial port. A configured display 'memory'
+setting will be ignored in that case.
 
 [[qm_usb_passthrough]]
 USB Passthrough