Commit 80b7859a authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: selftests: Add a read-only mprotect() phase to mmu_stress_test 



Add a third phase of mmu_stress_test to verify that mprotect()ing guest
memory to make it read-only doesn't cause explosions, e.g. to verify KVM
correctly handles the resulting mmu_notifier invalidations.

Reviewed-by: default avatarJames Houghton <jthoughton@google.com>
Reviewed-by: default avatarAndrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20241128005547.4077116-13-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 82b542e1

tools/testing/selftests/kvm/mmu_stress_test.c

+18 −4
Original line number Diff line number Diff line
@@ -28,6 +28,10 @@ static void guest_code(uint64_t start_gpa, uint64_t end_gpa, uint64_t stride) 
		GUEST_SYNC(i);

	}



	for (gpa = start_gpa; gpa < end_gpa; gpa += stride)

		*((volatile uint64_t *)gpa);

	GUEST_SYNC(2);



	GUEST_ASSERT(0);

}
@@ -95,6 +99,10 @@ static void *vcpu_worker(void *data) 
	run_vcpu(vcpu, 1);

	rendezvous_with_boss();



	/* Stage 2, read all of guest memory, which is now read-only. */

	run_vcpu(vcpu, 2);

	rendezvous_with_boss();



	return NULL;

}
@@ -175,7 +183,7 @@ int main(int argc, char *argv[]) 
	const uint64_t start_gpa = SZ_4G;

	const int first_slot = 1;



	struct timespec time_start, time_run1, time_reset, time_run2;

	struct timespec time_start, time_run1, time_reset, time_run2, time_ro;

	uint64_t max_gpa, gpa, slot_size, max_mem, i;

	int max_slots, slot, opt, fd;

	bool hugepages = false;
@@ -279,14 +287,20 @@ int main(int argc, char *argv[]) 
	rendezvous_with_vcpus(&time_reset, "reset");

	rendezvous_with_vcpus(&time_run2, "run 2");



	mprotect(mem, slot_size, PROT_READ);

	rendezvous_with_vcpus(&time_ro, "mprotect RO");



	time_ro    = timespec_sub(time_ro,     time_run2);

	time_run2  = timespec_sub(time_run2,   time_reset);

	time_reset = timespec_sub(time_reset,  time_run1);

	time_run1  = timespec_sub(time_run1,   time_start);



	pr_info("run1 = %ld.%.9lds, reset = %ld.%.9lds, run2 =  %ld.%.9lds\n",

	pr_info("run1 = %ld.%.9lds, reset = %ld.%.9lds, run2 = %ld.%.9lds, "

		"ro = %ld.%.9lds\n",

		time_run1.tv_sec, time_run1.tv_nsec,

		time_reset.tv_sec, time_reset.tv_nsec,

		time_run2.tv_sec, time_run2.tv_nsec);

		time_run2.tv_sec, time_run2.tv_nsec,

		time_ro.tv_sec, time_ro.tv_nsec);



	/*

	 * Delete even numbered slots (arbitrary) and unmap the first half of