2022-06-03 17:06:05

by Sean Christopherson

Subject: [PATCH v2 049/144] KVM: selftests: Return the created vCPU from vm_vcpu_add()

Return the created vCPU from vm_vcpu_add() so that callers don't need to
manually retrieve the vCPU that was just added. Opportunistically drop
the "heavy" function comment, it adds a lot of lines of "code" but not
much value, e.g. it's pretty obvious that @vm is a virtual machine...

Signed-off-by: Sean Christopherson <[email protected]>
---
.../selftests/kvm/include/kvm_util_base.h | 2 +-
tools/testing/selftests/kvm/lib/kvm_util.c | 27 +++++++------------
2 files changed, 10 insertions(+), 19 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index d2c7fb391fc7..fbc54e920383 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -324,7 +324,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
void vm_mem_region_set_flags(struct kvm_vm *vm, uint32_t slot, uint32_t flags);
void vm_mem_region_move(struct kvm_vm *vm, uint32_t slot, uint64_t new_gpa);
void vm_mem_region_delete(struct kvm_vm *vm, uint32_t slot);
-void vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid);
+struct kvm_vcpu *vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid);
vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min);
vm_vaddr_t vm_vaddr_alloc_pages(struct kvm_vm *vm, int nr_pages);
vm_vaddr_t vm_vaddr_alloc_page(struct kvm_vm *vm);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 99d6c5a8659e..8348fa19690a 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -397,8 +397,7 @@ struct kvm_vcpu *vm_recreate_with_one_vcpu(struct kvm_vm *vm)
{
kvm_vm_restart(vm);

- vm_vcpu_add(vm, 0);
- return vcpu_get(vm, 0);
+ return vm_vcpu_add(vm, 0);
}

/*
@@ -1063,33 +1062,23 @@ static int vcpu_mmap_sz(void)
}

/*
- * VM VCPU Add
- *
- * Input Args:
- * vm - Virtual Machine
- * vcpuid - VCPU ID
- *
- * Output Args: None
- *
- * Return: None
- *
- * Adds a virtual CPU to the VM specified by vm with the ID given by vcpuid.
- * No additional VCPU setup is done.
+ * Adds a virtual CPU to the VM specified by vm with the ID given by vcpu_id.
+ * No additional vCPU setup is done. Returns the vCPU.
*/
-void vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid)
+struct kvm_vcpu *vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
{
struct kvm_vcpu *vcpu;

/* Confirm a vcpu with the specified id doesn't already exist. */
- TEST_ASSERT(!vcpu_find(vm, vcpuid), "vCPU%d already exists\n", vcpuid);
+ TEST_ASSERT(!vcpu_find(vm, vcpu_id), "vCPU%d already exists\n", vcpu_id);

/* Allocate and initialize new vcpu structure. */
vcpu = calloc(1, sizeof(*vcpu));
TEST_ASSERT(vcpu != NULL, "Insufficient Memory");

vcpu->vm = vm;
- vcpu->id = vcpuid;
- vcpu->fd = __vm_ioctl(vm, KVM_CREATE_VCPU, (void *)(unsigned long)vcpuid);
+ vcpu->id = vcpu_id;
+ vcpu->fd = __vm_ioctl(vm, KVM_CREATE_VCPU, (void *)(unsigned long)vcpu_id);
TEST_ASSERT(vcpu->fd >= 0, KVM_IOCTL_ERROR(KVM_CREATE_VCPU, vcpu->fd));

TEST_ASSERT(vcpu_mmap_sz() >= sizeof(*vcpu->run), "vcpu mmap size "
@@ -1102,6 +1091,8 @@ void vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid)

/* Add to linked-list of VCPUs. */
list_add(&vcpu->list, &vm->vcpus);
+
+ return vcpu;
}

/*
--
2.36.1.255.ge46751e96f-goog

2022-06-08 15:54:14

by Andrew Jones

Subject: Re: [PATCH v2 049/144] KVM: selftests: Return the created vCPU from vm_vcpu_add()

On Fri, Jun 03, 2022 at 12:41:56AM +0000, Sean Christopherson wrote:
> Return the created vCPU from vm_vcpu_add() so that callers don't need to
> manually retrieve the vCPU that was just added. Opportunistically drop
> the "heavy" function comment, it adds a lot of lines of "code" but not
> much value, e.g. it's pretty obvious that @vm is a virtual machine...

I agree and would like to see all the heavy function comments reduced.
Maybe you do that somewhere in next 100 patches :-)

Thanks,
drew