Re: [PATCH V7 1/8] KVM: selftests: Extend VM creation's @mode to allow control of VM subtype

[Sean Christopherson <seanjc@google.com>]

On Mon, Dec 18, 2023, Peter Gonda wrote:
> Carve out space in the @mode passed to the various VM creation helpers to
> allow using the mode to control the subtype of VM, e.g. to identify x86's
> SEV VMs (which are "regular" VMs as far as KVM is concerned).
> 
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Sean Christopherson <seanjc@google.com>
> Cc: Vishal Annapurve <vannapurve@google.com>
> Cc: Ackerley Tng <ackerleytng@google.com>
> Cc: Andrew Jones <andrew.jones@linux.dev>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: Michael Roth <michael.roth@amd.com>
> Signed-off-by: Peter Gonda <pgonda@google.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>

SoB order is messed up.

> ---
>  .../selftests/kvm/include/kvm_util_base.h     | 82 ++++++++++++-------
>  tools/testing/selftests/kvm/lib/guest_modes.c |  2 +-
>  tools/testing/selftests/kvm/lib/kvm_util.c    | 34 ++++----
>  3 files changed, 73 insertions(+), 45 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
> index a18db6a7b3cf..ca99cc41685d 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util_base.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
> @@ -43,6 +43,48 @@
>  typedef uint64_t vm_paddr_t; /* Virtual Machine (Guest) physical address */
>  typedef uint64_t vm_vaddr_t; /* Virtual Machine (Guest) virtual address */
>  
> +enum vm_guest_mode {
> +	VM_MODE_P52V48_4K,
> +	VM_MODE_P52V48_64K,
> +	VM_MODE_P48V48_4K,
> +	VM_MODE_P48V48_16K,
> +	VM_MODE_P48V48_64K,
> +	VM_MODE_P40V48_4K,
> +	VM_MODE_P40V48_16K,
> +	VM_MODE_P40V48_64K,
> +	VM_MODE_PXXV48_4K,	/* For 48bits VA but ANY bits PA */
> +	VM_MODE_P47V64_4K,
> +	VM_MODE_P44V64_4K,
> +	VM_MODE_P36V48_4K,
> +	VM_MODE_P36V48_16K,
> +	VM_MODE_P36V48_64K,
> +	VM_MODE_P36V47_16K,
> +	NUM_VM_MODES,
> +};
> +
> +enum vm_subtype {
> +	VM_SUBTYPE_DEFAULT,
> +	VM_SUBTYPE_SEV,
> +	NUM_VM_SUBTYPES,
> +};

Now that "struct vm_shape" exists, this can be much more simply:

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index 9e5afc472c14..c62b3fa4e9f6 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -90,6 +90,7 @@ enum kvm_mem_region_type {
 struct kvm_vm {
        int mode;
        unsigned long type;
+       uint8_t subtype;
        int kvm_fd;
        int fd;
        unsigned int pgtable_levels;
@@ -191,10 +192,14 @@ enum vm_guest_mode {
 };
 
 struct vm_shape {
-       enum vm_guest_mode mode;
-       unsigned int type;
+       uint32_t type;
+       uint8_t  mode;
+       uint8_t  subtype;
+       uint16_t padding;
 };
 
+kvm_static_assert(sizeof(struct vm_shape) == sizeof(uint64_t));
+
 #define VM_TYPE_DEFAULT                        0
 
 #define VM_SHAPE(__mode)                       \
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 1b197426f29f..b95640c935e2 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->pa_bits = vm_guest_mode_params[vm->mode].pa_bits;
        vm->va_bits = vm_guest_mode_params[vm->mode].va_bits;