On 02/23/2017 03:26 PM, Matt Fleming wrote:
On Tue, 21 Feb, at 11:23:52AM, Michal Privoznik wrote:
Jim,
what is the actual problem? I've tried to reproduce this by running vm with 3.5G RAM backed by 1GB huge pages and the guest runs just fine. I mean kvm guest. This is because at the cmd line level there is aligned value:
-m size=4194304k,slots=16,maxmem=8388608k
This is result of qemuDomainAlignMemorySizes(). So perhaps there's a bug somewhere in the function?
Quite possibly. Some memory values work fine and appear to be rounded to the next gigabyte boundary. One KiB values that fails for me is,
<memory unit='KiB'>52428801</memory> <currentMemory unit='KiB'>52428801</currentMemory>
Which results in qemu-kvm ... -m 51201
I currently don't have access to a host with 50+GB of RAM, so I start small: <memory unit='KiB'>3145739</memory> <currentMemory unit='KiB'>3145739</currentMemory> <memoryBacking> <hugepages> <page size='1048576' unit='KiB'/> </hugepages> </memoryBacking> -m 3073 And this works just fine. One thing that I've noticed is that we don't take into account sizes of huge pages in qemuDomainAlignMemorySizes(). But then again - what is the scenario you're seeing? What's the error message? Michal