Messages in this thread |  | | From | Paolo Bonzini <> | Subject | Re: [PATCH] selftests: kvm: fix overlapping addresses in memslot_perf_test | Date | Sat, 29 May 2021 12:20:16 +0200 |
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On 28/05/21 21:51, Maciej S. Szmigiero wrote: > On 28.05.2021 21:11, Paolo Bonzini wrote: >> The memory that is allocated in vm_create is already mapped close to >> GPA 0, because test_execute passes the requested memory to >> prepare_vm. This causes overlapping memory regions and the >> test crashes. For simplicity just move MEM_GPA higher. >> >> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > > I am not sure that I understand the issue correctly, is vm_create_default() > already reserving low GPAs (around 0x10000000) on some arches or run > environments?
It maps the number of pages you pass in the second argument, see vm_create.
if (phy_pages != 0) vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, 0, phy_pages, 0);
In this case:
data->vm = vm_create_default(VCPU_ID, mempages, guest_code);
called here:
if (!prepare_vm(data, nslots, maxslots, tdata->guest_code, mem_size, slot_runtime)) {
where mempages is mem_size, which is declared as:
uint64_t mem_size = tdata->mem_size ? : MEM_SIZE_PAGES;
but actually a better fix is just to pass a small fixed value (e.g. 1024) to vm_create_default, since all other regions are added by hand.
Paolo
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