Re: [PATCH v13 02/22] KVM: selftests: Update kvm_init_vm_address_properties() for TDX

[Xiaoyao Li <xiaoyao.li@intel.com>]

On 5/22/2026 7:16 AM, Lisa Wang wrote:
> From: Isaku Yamahata <isaku.yamahata@intel.com>
> 
> Initialize the TDX S-bit and the GPA tag mask in
> kvm_init_vm_address_properties() for TDX VMs, similar to how the C-bit
> is initialized for SEV VMs.
> 
> The TDX S-bit is used to distinguish between shared and private guest
> physical addresses. Its position is determined by the guest physical
> address width, which is either 48 or 52 bits for current TDX
> implementations.
> 
> Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
> Co-developed-by: Adrian Hunter <adrian.hunter@intel.com>
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> Co-developed-by: Sagi Shahar <sagis@google.com>
> Signed-off-by: Sagi Shahar <sagis@google.com>
> Reviewed-by: Ira Weiny <ira.weiny@intel.com>
> Signed-off-by: Lisa Wang <wyihan@google.com>

Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>

> ---
>   tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h | 14 ++++++++++++++
>   tools/testing/selftests/kvm/lib/x86/processor.c        | 12 ++++++++++--
>   2 files changed, 24 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
> new file mode 100644
> index 000000000000..f647e6ca6b34
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
> @@ -0,0 +1,14 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef SELFTESTS_TDX_TDX_UTIL_H
> +#define SELFTESTS_TDX_TDX_UTIL_H
> +
> +#include <stdbool.h>
> +
> +#include "kvm_util.h"
> +
> +static inline bool is_tdx_vm(struct kvm_vm *vm)
> +{
> +	return vm->type == KVM_X86_TDX_VM;
> +}
> +
> +#endif /* SELFTESTS_TDX_TDX_UTIL_H */
> diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
> index b51467d70f6e..b68ad1dc7e02 100644
> --- a/tools/testing/selftests/kvm/lib/x86/processor.c
> +++ b/tools/testing/selftests/kvm/lib/x86/processor.c
> @@ -11,6 +11,7 @@
>   #include "smm.h"
>   #include "svm_util.h"
>   #include "sev.h"
> +#include "tdx/tdx_util.h"
>   #include "vmx.h"
>   
>   #ifndef NUM_INTERRUPTS
> @@ -1311,12 +1312,19 @@ void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits)
>   
>   void kvm_init_vm_address_properties(struct kvm_vm *vm)
>   {
> +	u32 gpa_bits = kvm_cpu_property(X86_PROPERTY_GUEST_MAX_PHY_ADDR);
> +
> +	vm->arch.sev_fd = -1;
> +
>   	if (is_sev_vm(vm)) {
>   		vm->arch.sev_fd = open_sev_dev_path_or_exit();
>   		vm->arch.c_bit = BIT_ULL(this_cpu_property(X86_PROPERTY_SEV_C_BIT));
>   		vm->gpa_tag_mask = vm->arch.c_bit;
> -	} else {
> -		vm->arch.sev_fd = -1;
> +	} else if (is_tdx_vm(vm)) {
> +		TEST_ASSERT(gpa_bits == 48 || gpa_bits == 52,
> +			    "TDX: bad X86_PROPERTY_GUEST_MAX_PHY_ADDR value: %u", gpa_bits);
> +		vm->arch.s_bit = BIT_ULL(gpa_bits - 1);
> +		vm->gpa_tag_mask = vm->arch.s_bit;
>   	}
>   }
>   
>