Having done a complete system upgrade a few days ago, now none of my wine programs nor my large virtual machines will work, giving me error messages about not being able to allocate memory. I had no problems with these before the upgrade.
The host machine has 2 GB of RAM.

Wine gives this error and will not run at all:

preloader: Warning: failed to reserve range 00110000-68000000
wine: failed to initialize: /usr/lib/wine/ntdll.dll.so: failed to map segment from shared object: Cannot allocate memory

Trying to run my Windows XP virtual machine in VirtualBox, it starts with the black XP boot-up screen, but then when i try to login, i get an error dialog-box with this message:

Unable to allocate and lock memory. The virtual machine will be paused. Please close applications to free up memory or close the VM.

with ErrorID: HostMemoryLow

But i never had a problem with this machine before, with exactly the same configuration.

Results in qemu are similar. I tried running my Windows XP qemu machine with varying amounts of memory, having varying degrees of success. It booted fine with RAM amounts up to 320 MB (but was extremely slow), but when i tried 336 MB, it seemed to boot to the desktop ok, but as soon as i tried to open Task Manager the whole machine aborted and i got a segmentation fault error. If i Results in qemu are similar. I tried running my Windows XP qemu machine with varying amounts of memory, having varying degrees of success. It booted fine with RAM amounts up to 320 MB (but was extremely slow), but when i tried 336 MB, it seemed to boot to the desktop ok, but as soon as i tried to open Task Manager the whole machine aborted and i got a segmentation fault error. If i try to run a machine with a larger amount of RAM, i get this:

"could not allocate physical memory".