diff mbox series

[v2,2/3] KVM: selftests: Extend @shape to allow creation of VM without in-kernel APIC

Message ID 20240401152032.4284-3-manali.shukla@amd.com
State New
Headers show
Series Add a test case for KVM_X86_DISABLE_EXIT | expand

Commit Message

Manali Shukla April 1, 2024, 3:20 p.m. UTC
Currently, all the VMs are created with in-kernel APIC support in KVM
selftests because KVM_CREATE_IRQCHIP ioctl is called by default from
kvm_arch_vm_post_create().

Carve out space in the @shape passed to the various VM creation helpers to
allow using the shape to control creation of a VM without in-kernel APIC
support or with in-kernel APIC support.

This is a preparatory patch to create a vm without in-kernel APIC support for
the KVM_X86_DISABLE_EXITS_HLT test.

Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Manali Shukla <manali.shukla@amd.com>
---
 .../selftests/kvm/include/kvm_util_base.h       | 17 ++++++++++++++++-
 tools/testing/selftests/kvm/lib/kvm_util.c      |  1 +
 .../selftests/kvm/lib/x86_64/processor.c        |  4 +++-
 3 files changed, 20 insertions(+), 2 deletions(-)

Comments

Sean Christopherson April 1, 2024, 5:15 p.m. UTC | #1
On Mon, Apr 01, 2024, Manali Shukla wrote:
> Currently, all the VMs are created with in-kernel APIC support in KVM
> selftests because KVM_CREATE_IRQCHIP ioctl is called by default from
> kvm_arch_vm_post_create().
> 
> Carve out space in the @shape passed to the various VM creation helpers to
> allow using the shape to control creation of a VM without in-kernel APIC
> support or with in-kernel APIC support.
> 
> This is a preparatory patch to create a vm without in-kernel APIC support for
> the KVM_X86_DISABLE_EXITS_HLT test.

Ugh, when I suggested creating a VM without an in-kernel APIC as away to easily
test that HLT doesn't exit, I wasn't thinking about the side effects of creating
a runnable VM without an in-kernel APIC.  The other downside is that practically
no one uses a userspace local APIC these days, i.e. the selftest isn't a great
representation of real world setups.

Given that KVM already provides vcpu->stat.halt_exits, using a stats FD for
verifying exiting behavior is probably a better option.  The other check that
could be added would be to verify that mp_state is always RUNNABLE (which is a
bug/gap in KVM as migrating a vCPU that was halted in the guest won't resume in
a halted state on the target).
diff mbox series

Patch

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index 4a40b332115d..c94cfbdf0150 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -130,6 +130,7 @@  struct kvm_vm {
 	 * memslot.
 	 */
 	uint32_t memslots[NR_MEM_REGIONS];
+	uint8_t flags;
 };
 
 struct vcpu_reg_sublist {
@@ -197,11 +198,14 @@  enum vm_guest_mode {
 	NUM_VM_MODES,
 };
 
+#define NO_IRQCHIP  0x01
+
 struct vm_shape {
 	uint32_t type;
 	uint8_t  mode;
 	uint8_t  subtype;
-	uint16_t padding;
+	uint8_t  flags;
+	uint8_t padding;
 };
 
 kvm_static_assert(sizeof(struct vm_shape) == sizeof(uint64_t));
@@ -218,6 +222,17 @@  kvm_static_assert(sizeof(struct vm_shape) == sizeof(uint64_t));
 	shape;					\
 })
 
+#define VM_SHAPE_FLAGS(__FLAGS)			\
+({						\
+	struct vm_shape shape = {		\
+		.mode = VM_MODE_DEFAULT,	\
+		.type = VM_TYPE_DEFAULT,	\
+		.flags = __FLAGS		\
+	};					\
+						\
+	shape;					\
+})
+
 #if defined(__aarch64__)
 
 extern enum vm_guest_mode vm_mode_default;
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index adc51b0712ca..86546f603959 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -226,6 +226,7 @@  struct kvm_vm *____vm_create(struct vm_shape shape)
 	vm->mode = shape.mode;
 	vm->type = shape.type;
 	vm->subtype = shape.subtype;
+	vm->flags = shape.flags;
 
 	vm->pa_bits = vm_guest_mode_params[vm->mode].pa_bits;
 	vm->va_bits = vm_guest_mode_params[vm->mode].va_bits;
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 49288fe10cd3..e5ca92feae67 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -574,7 +574,9 @@  static void vcpu_setup(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
 
 void kvm_arch_vm_post_create(struct kvm_vm *vm)
 {
-	vm_create_irqchip(vm);
+	if (!(vm->flags & NO_IRQCHIP))
+		vm_create_irqchip(vm);
+
 	sync_global_to_guest(vm, host_cpu_is_intel);
 	sync_global_to_guest(vm, host_cpu_is_amd);