KVM creates internal memslots between 3 and 4 GiB paddrs on the first vCPU creation. If memslot 0 is large enough it collides with these memslots an causes vCPU creation to fail. Instead of creating memslot 0 at paddr 0, start it 4G into the guest physical address space.
Signed-off-by: Ben Gardon bgardon@google.com --- tools/testing/selftests/kvm/lib/kvm_util.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 5b971c04f1643..427c88d32e988 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -130,9 +130,11 @@ _Static_assert(sizeof(vm_guest_mode_string)/sizeof(char *) == NUM_VM_MODES, * * Creates a VM with the mode specified by mode (e.g. VM_MODE_P52V48_4K). * When phy_pages is non-zero, a memory region of phy_pages physical pages - * is created and mapped starting at guest physical address 0. The file - * descriptor to control the created VM is created with the permissions - * given by perm (e.g. O_RDWR). + * is created, starting at 4G into the guest physical address space to avoid + * KVM internal memslots which map the region between 3G and 4G. If tests need + * to use the physical region between 0 and 3G, they can allocate another + * memslot for that region. The file descriptor to control the created VM is + * created with the permissions given by perm (e.g. O_RDWR). */ struct kvm_vm *_vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm) { @@ -231,7 +233,8 @@ struct kvm_vm *_vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm) vm->vpages_mapped = sparsebit_alloc(); if (phy_pages != 0) vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, - 0, 0, phy_pages, 0); + KVM_INTERNAL_MEMSLOTS_END_PADDR, + 0, phy_pages, 0);
return vm; }