On Thu, Jan 23, 2020 at 10:04:33AM -0800, Ben Gardon wrote: ... > -static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid, > - uint64_t extra_mem_pages, void *guest_code) > +#define PAGE_SHIFT_4K 12 > +#define PTES_PER_4K_PT 512 > + > +static struct kvm_vm *create_vm(enum vm_guest_mode mode, int vcpus, > + uint64_t vcpu_memory_bytes) > { > struct kvm_vm *vm; > - uint64_t extra_pg_pages = extra_mem_pages / 512 * 2; > + uint64_t pages = DEFAULT_GUEST_PHY_PAGES; > + > + /* Account for a few pages per-vCPU for stacks */ > + pages += DEFAULT_STACK_PGS * vcpus; > + > + /* > + * Reserve twice the ammount of memory needed to map the test region and > + * the page table / stacks region, at 4k, for page tables. Do the > + * calculation with 4K page size: the smallest of all archs. (e.g., 64K > + * page size guest will need even less memory for page tables). > + */ > + pages += (2 * pages) / PTES_PER_4K_PT; > + pages += ((2 * vcpus * vcpu_memory_bytes) >> PAGE_SHIFT_4K) / > + PTES_PER_4K_PT; pages needs to be rounded up to the next multiple of 16 in order for this to work on aarch64 machines with 64k pages. Thanks, drew