Markus Armbruster <arm...@redhat.com> writes: > Nikunj A Dadhania <nik...@linux.vnet.ibm.com> writes: > >> Markus Armbruster <arm...@redhat.com> writes: >> >>> Nikunj A Dadhania <nik...@linux.vnet.ibm.com> writes: >>> >>>> Current DEFAULT_RAM_SIZE(128MB) enforced by QEMU would not work for >>>> all machines. Introduce a default_ram_size as part of MachineClass. >>>> >>>> The below patches has following behaviour: >>>> >>>> 1) If the user does not provide "-m" option, machine's default ram >>>> size will be picked. >>>> >>>> 2) In case the user provides memory that is lesser than machine's >>>> default ram size, we upscale the ram_size to machine's >>>> default_ram_size. A warning is displayed for the change that qemu >>>> has done. >>> >>> Please do not "improve" the user's explicit order that way. Either >>> execute the order as is, or reject it as invalid. >> >> If there is consensus for doing this, I can change the patches >> accordingly. >> >> Rejection is also change of behaviour. Because till now, a VM would >> start with any memory size, even if it's less that 128MB >> (default_ram_size). With rejection, all those VMs would fail booting >> displaying the warning. Is this OK? > > I'd stick to "don't reject".
Agree, i have already sent v4 with those changes, as there were multiple opinions against changing the behaviour. > Yes, the failure mode is ugly. But protecting the user from it is > also somewhat problematic, because we don't generally know how much > RAM the actual guest requires, and it's an incompatible change. Seems > not worth it. > > Back in 2012, we discussed rejecting RAM size less than 1MiB for PC > machines, because SeaBIOS requires at least that much, and decided > against it. See > http://www.seabios.org/pipermail/seabios/2012-August/004343.html > > If you want to pursue "reject" anyway, please make sure to split this > into two separate patches: one patch to make the default ram size > machine-specific, and another patch to reject user requests for less. > > [...] Thanks, Nikunj
