On Thu, Jun 07, 2018 at 10:14:38PM +0200, Laszlo Ersek wrote:
On 06/07/18 21:58, Ján Tomko wrote:
Does a size of 0 MiB make sense? It's divisible by 1 MiB.
"-global mch.extended-tseg-mbytes=0" makes QEMU behave as if it lacked the extended TSEG feature; the guest will believe that only the standard 1 / 2 / 8 MB TSEG sizes are available, and pick one of those.
Technically, in QEMU the extended TSEG feature is disabled for older machine types by setting "mch.extended-tseg-mbytes" to zero:
[include/hw/i386/pc.h]
#define PC_COMPAT_2_9 \ HW_COMPAT_2_9 \ {\ .driver = "mch",\ .property = "extended-tseg-mbytes",\ .value = stringify(0),\ },\
I'm unsure whether this -- i.e., disabling the feature -- is useful to expose through the domain config. Probably not.
I wouldn't want to disable that option now in a way that we won't be able to fix later. So from my point of view it makes sense.