Commit ecebb966 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Paolo Bonzini
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KVM: selftests: Test KVM_SET_CPUID2 after KVM_RUN 



KVM forbids KVM_SET_CPUID2 after KVM_RUN was performed on a vCPU unless
the supplied CPUID data is equal to what was previously set. Test this.

Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220117150542.2176196-5-vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 9e6d484f

tools/testing/selftests/kvm/include/x86_64/processor.h

+7 −0
Original line number Diff line number Diff line
@@ -375,6 +375,8 @@ uint64_t kvm_get_feature_msr(uint64_t msr_index); 
struct kvm_cpuid2 *kvm_get_supported_cpuid(void);



struct kvm_cpuid2 *vcpu_get_cpuid(struct kvm_vm *vm, uint32_t vcpuid);

int __vcpu_set_cpuid(struct kvm_vm *vm, uint32_t vcpuid,

		     struct kvm_cpuid2 *cpuid);

void vcpu_set_cpuid(struct kvm_vm *vm, uint32_t vcpuid,

		    struct kvm_cpuid2 *cpuid);
@@ -418,6 +420,11 @@ uint64_t vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr); 
void vm_set_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr,

			     uint64_t pte);



/*

 * get_cpuid() - find matching CPUID entry and return pointer to it.

 */

struct kvm_cpuid_entry2 *get_cpuid(struct kvm_cpuid2 *cpuid, uint32_t function,

				   uint32_t index);

/*

 * set_cpuid() - overwrites a matching cpuid entry with the provided value.

 *		 matches based on ent->function && ent->index. returns true

tools/testing/selftests/kvm/lib/x86_64/processor.c

+29 −4
Original line number Diff line number Diff line
@@ -886,6 +886,17 @@ kvm_get_supported_cpuid_index(uint32_t function, uint32_t index) 
	return entry;

}





int __vcpu_set_cpuid(struct kvm_vm *vm, uint32_t vcpuid,

		     struct kvm_cpuid2 *cpuid)

{

	struct vcpu *vcpu = vcpu_find(vm, vcpuid);



	TEST_ASSERT(vcpu != NULL, "vcpu not found, vcpuid: %u", vcpuid);



	return ioctl(vcpu->fd, KVM_SET_CPUID2, cpuid);

}



/*

 * VM VCPU CPUID Set

 *
@@ -903,12 +914,9 @@ kvm_get_supported_cpuid_index(uint32_t function, uint32_t index) 
void vcpu_set_cpuid(struct kvm_vm *vm,

		uint32_t vcpuid, struct kvm_cpuid2 *cpuid)

{

	struct vcpu *vcpu = vcpu_find(vm, vcpuid);

	int rc;



	TEST_ASSERT(vcpu != NULL, "vcpu not found, vcpuid: %u", vcpuid);



	rc = ioctl(vcpu->fd, KVM_SET_CPUID2, cpuid);

	rc = __vcpu_set_cpuid(vm, vcpuid, cpuid);

	TEST_ASSERT(rc == 0, "KVM_SET_CPUID2 failed, rc: %i errno: %i",

		    rc, errno);
@@ -1384,6 +1392,23 @@ void assert_on_unhandled_exception(struct kvm_vm *vm, uint32_t vcpuid) 
	}

}



struct kvm_cpuid_entry2 *get_cpuid(struct kvm_cpuid2 *cpuid, uint32_t function,

				   uint32_t index)

{

	int i;



	for (i = 0; i < cpuid->nent; i++) {

		struct kvm_cpuid_entry2 *cur = &cpuid->entries[i];



		if (cur->function == function && cur->index == index)

			return cur;

	}



	TEST_FAIL("CPUID function 0x%x index 0x%x not found ", function, index);



	return NULL;

}



bool set_cpuid(struct kvm_cpuid2 *cpuid,

	       struct kvm_cpuid_entry2 *ent)

{

tools/testing/selftests/kvm/x86_64/cpuid_test.c

+30 −0
Original line number Diff line number Diff line
@@ -154,6 +154,34 @@ struct kvm_cpuid2 *vcpu_alloc_cpuid(struct kvm_vm *vm, vm_vaddr_t *p_gva, struct 
	return guest_cpuids;

}



static void set_cpuid_after_run(struct kvm_vm *vm, struct kvm_cpuid2 *cpuid)

{

	struct kvm_cpuid_entry2 *ent;

	int rc;

	u32 eax, ebx, x;



	/* Setting unmodified CPUID is allowed */

	rc = __vcpu_set_cpuid(vm, VCPU_ID, cpuid);

	TEST_ASSERT(!rc, "Setting unmodified CPUID after KVM_RUN failed: %d", rc);



	/* Changing CPU features is forbidden */

	ent = get_cpuid(cpuid, 0x7, 0);

	ebx = ent->ebx;

	ent->ebx--;

	rc = __vcpu_set_cpuid(vm, VCPU_ID, cpuid);

	TEST_ASSERT(rc, "Changing CPU features should fail");

	ent->ebx = ebx;



	/* Changing MAXPHYADDR is forbidden */

	ent = get_cpuid(cpuid, 0x80000008, 0);

	eax = ent->eax;

	x = eax & 0xff;

	ent->eax = (eax & ~0xffu) | (x - 1);

	rc = __vcpu_set_cpuid(vm, VCPU_ID, cpuid);

	TEST_ASSERT(rc, "Changing MAXPHYADDR should fail");

	ent->eax = eax;

}



int main(void)

{

	struct kvm_cpuid2 *supp_cpuid, *cpuid2;
@@ -175,5 +203,7 @@ int main(void) 
	for (stage = 0; stage < 3; stage++)

		run_vcpu(vm, VCPU_ID, stage);



	set_cpuid_after_run(vm, cpuid2);



	kvm_vm_free(vm);

}