The vm_create() helpers are hardcoded to place most page types (code,
page-tables, stacks, etc) in the same memslot #0, and always backed with
anonymous 4K. There are a couple of issues with that. First, tests
willing to differ a bit, like placing page-tables in a different backing
source type must replicate much of what's already done by the vm_create()
functions. Second, the hardcoded assumption of memslot #0 holding most
things is spread everywhere; this makes it very hard to change.
Fix the above issues by having selftests specify how they want memory to be
laid out. Start by changing ____vm_create() to not create memslot #0; a
test (to come) will specify all memslots used by the VM. Then, add the
vm->memslots[] array to specify the right memslot for different memory
allocators, e.g.,: lib/elf should use the vm->[MEM_REGION_CODE] memslot.
This will be used as a way to specify the page-tables memslots (to be
backed by huge pages for example).
There is no functional change intended. The current commit lays out memory
exactly as before. A future commit will change the allocators to get the
region they should be using, e.g.,: like the page table allocators using
the pt memslot.
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Andrew Jones <andrew.jones@xxxxxxxxx>
Signed-off-by: Ricardo Koller <ricarkol@xxxxxxxxxx>
Reviewed-by: Andrew Jones <andrew.jones@xxxxxxxxx>
---
.../selftests/kvm/include/kvm_util_base.h | 26 +++++++++++++++++--
tools/testing/selftests/kvm/lib/kvm_util.c | 18 +++++++------
2 files changed, 34 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index b2dbe253d4d0..5c0044ceae13 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -65,6 +65,14 @@ struct userspace_mem_regions {
DECLARE_HASHTABLE(slot_hash, 9);
};
+enum kvm_mem_region_type {
+ MEM_REGION_CODE,
+ MEM_REGION_DATA,
+ MEM_REGION_PT,
+ MEM_REGION_TEST_DATA,
+ NR_MEM_REGIONS,
+};
+
struct kvm_vm {
int mode;
unsigned long type;
@@ -93,6 +101,13 @@ struct kvm_vm {
int stats_fd;
struct kvm_stats_header stats_header;
struct kvm_stats_desc *stats_desc;
+
+ /*
+ * KVM region slots. These are the default memslots used by page
+ * allocators, e.g., lib/elf uses the memslots[MEM_REGION_CODE]
+ * memslot.
+ */
+ uint32_t memslots[NR_MEM_REGIONS];
};
@@ -105,6 +120,13 @@ struct kvm_vm {
struct userspace_mem_region *
memslot2region(struct kvm_vm *vm, uint32_t memslot);
+static inline struct userspace_mem_region *vm_get_mem_region(struct kvm_vm *vm,
+ enum kvm_mem_region_type type)
+{
+ assert(type < NR_MEM_REGIONS);
+ return memslot2region(vm, vm->memslots[type]);
+}
+
/* Minimum allocated guest virtual and physical addresses */
#define KVM_UTIL_MIN_VADDR 0x2000
#define KVM_GUEST_PAGE_TABLE_MIN_PADDR 0x180000
@@ -643,13 +665,13 @@ vm_paddr_t vm_alloc_page_table(struct kvm_vm *vm);
* __vm_create() does NOT create vCPUs, @nr_runnable_vcpus is used purely to
* calculate the amount of memory needed for per-vCPU data, e.g. stacks.
*/
-struct kvm_vm *____vm_create(enum vm_guest_mode mode, uint64_t nr_pages);
+struct kvm_vm *____vm_create(enum vm_guest_mode mode);
struct kvm_vm *__vm_create(enum vm_guest_mode mode, uint32_t nr_runnable_vcpus,
uint64_t nr_extra_pages);
static inline struct kvm_vm *vm_create_barebones(void)
{
- return ____vm_create(VM_MODE_DEFAULT, 0);
+ return ____vm_create(VM_MODE_DEFAULT);
}
static inline struct kvm_vm *vm_create(uint32_t nr_runnable_vcpus)
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 5a9f080ff888..a2d0c11457c0 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -143,13 +143,10 @@ const struct vm_guest_mode_params vm_guest_mode_params[] = {
_Static_assert(sizeof(vm_guest_mode_params)/sizeof(struct vm_guest_mode_params) == NUM_VM_MODES,
"Missing new mode params?");
-struct kvm_vm *____vm_create(enum vm_guest_mode mode, uint64_t nr_pages)
+struct kvm_vm *____vm_create(enum vm_guest_mode mode)
{
struct kvm_vm *vm;
- pr_debug("%s: mode='%s' pages='%ld'\n", __func__,
- vm_guest_mode_string(mode), nr_pages);
-
vm = calloc(1, sizeof(*vm));
TEST_ASSERT(vm != NULL, "Insufficient Memory");
@@ -245,9 +242,6 @@ struct kvm_vm *____vm_create(enum vm_guest_mode mode, uint64_t nr_pages)
/* Allocate and setup memory for guest. */
vm->vpages_mapped = sparsebit_alloc();
- if (nr_pages != 0)
- vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
- 0, 0, nr_pages, 0);
return vm;
}
@@ -293,8 +287,16 @@ struct kvm_vm *__vm_create(enum vm_guest_mode mode, uint32_t nr_runnable_vcpus,
uint64_t nr_pages = vm_nr_pages_required(mode, nr_runnable_vcpus,
nr_extra_pages);
struct kvm_vm *vm;
+ int i;
+
+ pr_debug("%s: mode='%s' pages='%ld'\n", __func__,
+ vm_guest_mode_string(mode), nr_pages);
+
+ vm = ____vm_create(mode);
- vm = ____vm_create(mode, nr_pages);
+ vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, 0, nr_pages, 0);
+ for (i = 0; i < NR_MEM_REGIONS; i++)
+ vm->memslots[i] = 0;
kvm_vm_elf_load(vm, program_invocation_name);
--
2.37.3.968.ga6b4b080e4-goog
