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. When requesting more than 3G, start memslot 0 at 4G in _vm_create.
Signed-off-by: Ben Gardon bgardon@google.com --- tools/testing/selftests/kvm/lib/kvm_util.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 41cf45416060f..886d58e6cac39 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -113,6 +113,8 @@ const char * const vm_guest_mode_string[] = { _Static_assert(sizeof(vm_guest_mode_string)/sizeof(char *) == NUM_VM_MODES, "Missing new mode strings?");
+#define KVM_INTERNAL_MEMSLOTS_START_PADDR (3UL << 30) +#define KVM_INTERNAL_MEMSLOTS_END_PADDR (4UL << 30) /* * VM Create * @@ -128,13 +130,16 @@ _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. If phy_pages is less that 3G, it is mapped starting at guest + * physical address 0. If phy_pages is greater than 3G it is mapped starting + * 4G into the guest physical address space to avoid KVM internal memslots + * which map the region between 3G and 4G. 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) { struct kvm_vm *vm; + uint64_t guest_paddr = 0;
DEBUG("Testing guest mode: %s\n", vm_guest_mode_string(mode));
@@ -227,9 +232,11 @@ struct kvm_vm *_vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm)
/* Allocate and setup memory for guest. */ vm->vpages_mapped = sparsebit_alloc(); + if (guest_paddr + phy_pages > KVM_INTERNAL_MEMSLOTS_START_PADDR) + guest_paddr = KVM_INTERNAL_MEMSLOTS_END_PADDR; if (phy_pages != 0) vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, - 0, 0, phy_pages, 0); + guest_paddr, 0, phy_pages, 0);
return vm; }