Commit 16fc7cb4 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: selftests: Add infrastructure for getting vCPU binary stats 



Now that the binary stats cache infrastructure is largely scope agnostic,
add support for vCPU-scoped stats.  Like VM stats, open and cache the
stats FD when the vCPU is created so that it's guaranteed to be valid when
vcpu_get_stats() is invoked.

Account for the extra per-vCPU file descriptor in kvm_set_files_rlimit(),
so that tests that create large VMs don't run afoul of resource limits.

To sanity check that the infrastructure actually works, and to get a bit
of bonus coverage, add an assert in x86's xapic_ipi_test to verify that
the number of HLTs executed by the test matches the number of HLT exits
observed by KVM.

Tested-by: default avatarManali Shukla <Manali.Shukla@amd.com>
Link: https://lore.kernel.org/r/20250111005049.1247555-9-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 9b56532b

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

+12 −8
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ struct kvm_vcpu { 
#ifdef __x86_64__

	struct kvm_cpuid2 *cpuid;

#endif

	struct kvm_binary_stats stats;

	struct kvm_dirty_gfn *dirty_gfns;

	uint32_t fetch_index;

	uint32_t dirty_gfns_count;
@@ -534,17 +535,20 @@ void read_stat_data(int stats_fd, struct kvm_stats_header *header, 
		    struct kvm_stats_desc *desc, uint64_t *data,

		    size_t max_elements);



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

		   size_t max_elements);

void kvm_get_stat(struct kvm_binary_stats *stats, const char *name,

		  uint64_t *data, size_t max_elements);



#define vm_get_stat(vm, stat)				\

#define __get_stat(stats, stat)							\

({										\

	uint64_t data;								\

										\

	__vm_get_stat(vm, #stat, &data, 1);		\

	kvm_get_stat(stats, #stat, &data, 1);					\

	data;									\

})



#define vm_get_stat(vm, stat) __get_stat(&(vm)->stats, stat)

#define vcpu_get_stat(vcpu, stat) __get_stat(&(vcpu)->stats, stat)



void vm_create_irqchip(struct kvm_vm *vm);



static inline int __vm_create_guest_memfd(struct kvm_vm *vm, uint64_t size,

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

+13 −19
Original line number Diff line number Diff line
@@ -415,10 +415,11 @@ static uint64_t vm_nr_pages_required(enum vm_guest_mode mode, 
void kvm_set_files_rlimit(uint32_t nr_vcpus)

{

	/*

	 * Number of file descriptors required, nr_vpucs vCPU fds + an arbitrary

	 * number for everything else.

	 * Each vCPU will open two file descriptors: the vCPU itself and the

	 * vCPU's binary stats file descriptor.  Add an arbitrary amount of

	 * buffer for all other files a test may open.

	 */

	int nr_fds_wanted = nr_vcpus + 100;

	int nr_fds_wanted = nr_vcpus * 2 + 100;

	struct rlimit rl;



	/*
@@ -746,6 +747,8 @@ static void vm_vcpu_rm(struct kvm_vm *vm, struct kvm_vcpu *vcpu) 
	ret = close(vcpu->fd);

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



	kvm_stats_release(&vcpu->stats);



	list_del(&vcpu->list);



	vcpu_arch_free(vcpu);
@@ -1339,6 +1342,11 @@ struct kvm_vcpu *__vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id) 
	TEST_ASSERT(vcpu->run != MAP_FAILED,

		    __KVM_SYSCALL_ERROR("mmap()", (int)(unsigned long)MAP_FAILED));



	if (kvm_has_cap(KVM_CAP_BINARY_STATS_FD))

		vcpu->stats.fd = vcpu_get_stats_fd(vcpu);

	else

		vcpu->stats.fd = -1;



	/* Add to linked-list of VCPUs. */

	list_add(&vcpu->list, &vm->vcpus);
@@ -2251,23 +2259,9 @@ void read_stat_data(int stats_fd, struct kvm_stats_header *header, 
		    desc->name, size, ret);

}



/*

 * Read the data of the named stat

 *

 * Input Args:

 *   vm - the VM for which the stat should be read

 *   stat_name - the name of the stat to read

 *   max_elements - the maximum number of 8-byte values to read into data

 *

 * Output Args:

 *   data - the buffer into which stat data should be read

 *

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

 */

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

		   size_t max_elements)

void kvm_get_stat(struct kvm_binary_stats *stats, 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;

tools/testing/selftests/kvm/x86/xapic_ipi_test.c

+2 −0
Original line number Diff line number Diff line
@@ -465,6 +465,8 @@ int main(int argc, char *argv[]) 
	cancel_join_vcpu_thread(threads[0], params[0].vcpu);

	cancel_join_vcpu_thread(threads[1], params[1].vcpu);



	TEST_ASSERT_EQ(data->hlt_count, vcpu_get_stat(params[0].vcpu, halt_exits));



	fprintf(stderr,

		"Test successful after running for %d seconds.\n"

		"Sending vCPU sent %lu IPIs to halting vCPU\n"