Commit e65faf71 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: selftests: Add struct and helpers to wrap binary stats cache 

Add a struct and helpers to manage the binary stats cache, which is
currently used only for VM-scoped stats.  This will allow expanding the
selftests infrastructure to provide support for vCPU-scoped binary stats,
which, except for the ioctl to get the stats FD are identical to VM-scoped
stats.

Defer converting __vm_get_stat() to a scope-agnostic helper to a future
patch, as getting the stats FD from KVM needs to be moved elsewhere
before it can be made completely scope-agnostic.

Link: https://lore.kernel.org/r/20250111005049.1247555-6-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent b0c3f5df

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

+7 −4
Original line number Diff line number Diff line
@@ -46,6 +46,12 @@ struct userspace_mem_region { 
	struct hlist_node slot_node;

};



struct kvm_binary_stats {

	int fd;

	struct kvm_stats_header header;

	struct kvm_stats_desc *desc;

};



struct kvm_vcpu {

	struct list_head list;

	uint32_t id;
@@ -99,10 +105,7 @@ struct kvm_vm { 


	struct kvm_vm_arch arch;



	/* Cache of information for binary stats interface */

	int stats_fd;

	struct kvm_stats_header stats_header;

	struct kvm_stats_desc *stats_desc;

	struct kvm_binary_stats stats;



	/*

	 * KVM region slots. These are the default memslots used by page

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

+27 −20
Original line number Diff line number Diff line
@@ -657,6 +657,20 @@ userspace_mem_region_find(struct kvm_vm *vm, uint64_t start, uint64_t end) 
	return NULL;

}



static void kvm_stats_release(struct kvm_binary_stats *stats)

{

	int ret;



	if (!stats->desc)

		return;



	free(stats->desc);

	stats->desc = NULL;



	ret = close(stats->fd);

	TEST_ASSERT(!ret,  __KVM_SYSCALL_ERROR("close()", ret));

}



__weak void vcpu_arch_free(struct kvm_vcpu *vcpu)

{
@@ -711,13 +725,7 @@ void kvm_vm_release(struct kvm_vm *vmp) 
	TEST_ASSERT(!ret,  __KVM_SYSCALL_ERROR("close()", ret));



	/* Free cached stats metadata and close FD */

	if (vmp->stats_desc) {

		free(vmp->stats_desc);

		vmp->stats_desc = NULL;



		ret = close(vmp->stats_fd);

		TEST_ASSERT(!ret,  __KVM_SYSCALL_ERROR("close()", ret));

	}

	kvm_stats_release(&vmp->stats);

}



static void __vm_mem_region_delete(struct kvm_vm *vm,
@@ -2214,34 +2222,33 @@ void read_stat_data(int stats_fd, struct kvm_stats_header *header, 
 *

 * Read the data values of a specified stat from the binary stats interface.

 */

void __vm_get_stat(struct kvm_vm *vm, const char *stat_name, uint64_t *data,

void __vm_get_stat(struct kvm_vm *vm, const char *name, uint64_t *data,

		   size_t max_elements)

{

	struct kvm_binary_stats *stats = &vm->stats;

	struct kvm_stats_desc *desc;

	size_t size_desc;

	int i;



	if (!vm->stats_desc) {

		vm->stats_fd = vm_get_stats_fd(vm);

		read_stats_header(vm->stats_fd, &vm->stats_header);

		vm->stats_desc = read_stats_descriptors(vm->stats_fd,

							&vm->stats_header);

	if (!stats->desc) {

		stats->fd = vm_get_stats_fd(vm);

		read_stats_header(stats->fd, &stats->header);

		stats->desc = read_stats_descriptors(stats->fd, &stats->header);

	}



	size_desc = get_stats_descriptor_size(&vm->stats_header);

	size_desc = get_stats_descriptor_size(&stats->header);



	for (i = 0; i < vm->stats_header.num_desc; ++i) {

		desc = (void *)vm->stats_desc + (i * size_desc);

	for (i = 0; i < stats->header.num_desc; ++i) {

		desc = (void *)stats->desc + (i * size_desc);



		if (strcmp(desc->name, stat_name))

		if (strcmp(desc->name, name))

			continue;



		read_stat_data(vm->stats_fd, &vm->stats_header, desc,

			       data, max_elements);

		read_stat_data(stats->fd, &stats->header, desc, data, max_elements);

		return;

	}



	TEST_FAIL("Unable to find stat '%s'", stat_name);

	TEST_FAIL("Unable to find stat '%s'", name);

}



__weak void kvm_arch_vm_post_create(struct kvm_vm *vm)