Commit 290c5b54 authored by Ricardo Koller's avatar Ricardo Koller Committed by Marc Zyngier
Browse files

KVM: selftests: Add vm->memslots[] and enum kvm_mem_region_type 



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@google.com>
Cc: Andrew Jones <andrew.jones@linux.dev>
Signed-off-by: default avatarRicardo Koller <ricarkol@google.com>
Reviewed-by: default avatarAndrew Jones <andrew.jones@linux.dev>
Reviewed-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221017195834.2295901-8-ricarkol@google.com
parent bd3ed7e1

tools/testing/selftests/kvm/include/kvm_util_base.h

+24 −2
Original line number Diff line number Diff line
@@ -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
@@ -647,13 +669,13 @@ 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)

tools/testing/selftests/kvm/lib/kvm_util.c

+10 −8
Original line number Diff line number Diff line
@@ -185,13 +185,10 @@ 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");
@@ -287,9 +284,6 @@ 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;

}
@@ -335,8 +329,16 @@ 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);