Re: [RFC PATCH v5 06/29] KVM: selftests: TDX: Use KVM_TDX_CAPABILITIES to validate TDs' attribute configuration

[Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>]

On 12/13/2023 4:46 AM, Sagi Shahar wrote:
> From: Ackerley Tng <ackerleytng@xxxxxxxxxx>
>
> This also exercises the KVM_TDX_CAPABILITIES ioctl.
>
> Suggested-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
> Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>
> Signed-off-by: Ryan Afranji <afranji@xxxxxxxxxx>
> Signed-off-by: Sagi Shahar <sagis@xxxxxxxxxx>
> ---
>   .../selftests/kvm/lib/x86_64/tdx/tdx_util.c   | 69 ++++++++++++++++++-
>   1 file changed, 66 insertions(+), 3 deletions(-)

Nit: Can also dump 'supported_gpaw' in tdx_read_capabilities().

Reviewed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>

> diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx_util.c
> index 9b69c733ce01..6b995c3f6153 100644
> --- a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx_util.c
> +++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx_util.c
> @@ -27,10 +27,9 @@ static char *tdx_cmd_str[] = {
>   };
>   #define TDX_MAX_CMD_STR (ARRAY_SIZE(tdx_cmd_str))
>   
> -static void tdx_ioctl(int fd, int ioctl_no, uint32_t flags, void *data)
> +static int _tdx_ioctl(int fd, int ioctl_no, uint32_t flags, void *data)
>   {
>   	struct kvm_tdx_cmd tdx_cmd;
> -	int r;
>   
>   	TEST_ASSERT(ioctl_no < TDX_MAX_CMD_STR, "Unknown TDX CMD : %d\n",
>   		    ioctl_no);
> @@ -40,11 +39,58 @@ static void tdx_ioctl(int fd, int ioctl_no, uint32_t flags, void *data)
>   	tdx_cmd.flags = flags;
>   	tdx_cmd.data = (uint64_t)data;
>   
> -	r = ioctl(fd, KVM_MEMORY_ENCRYPT_OP, &tdx_cmd);
> +	return ioctl(fd, KVM_MEMORY_ENCRYPT_OP, &tdx_cmd);
> +}
> +
> +static void tdx_ioctl(int fd, int ioctl_no, uint32_t flags, void *data)
> +{
> +	int r;
> +
> +	r = _tdx_ioctl(fd, ioctl_no, flags, data);
>   	TEST_ASSERT(r == 0, "%s failed: %d  %d", tdx_cmd_str[ioctl_no], r,
>   		    errno);
>   }
>   
> +static struct kvm_tdx_capabilities *tdx_read_capabilities(struct kvm_vm *vm)
> +{
> +	int i;
> +	int rc = -1;
> +	int nr_cpuid_configs = 4;
> +	struct kvm_tdx_capabilities *tdx_cap = NULL;
> +
> +	do {
> +		nr_cpuid_configs *= 2;
> +
> +		tdx_cap = realloc(
> +			tdx_cap, sizeof(*tdx_cap) +
> +			nr_cpuid_configs * sizeof(*tdx_cap->cpuid_configs));
> +		TEST_ASSERT(tdx_cap != NULL,
> +			    "Could not allocate memory for tdx capability nr_cpuid_configs %d\n",
> +			    nr_cpuid_configs);
> +
> +		tdx_cap->nr_cpuid_configs = nr_cpuid_configs;
> +		rc = _tdx_ioctl(vm->fd, KVM_TDX_CAPABILITIES, 0, tdx_cap);
> +	} while (rc < 0 && errno == E2BIG);
> +
> +	TEST_ASSERT(rc == 0, "KVM_TDX_CAPABILITIES failed: %d %d",
> +		    rc, errno);
> +
> +	pr_debug("tdx_cap: attrs: fixed0 0x%016llx fixed1 0x%016llx\n"
> +		 "tdx_cap: xfam fixed0 0x%016llx fixed1 0x%016llx\n",
> +		 tdx_cap->attrs_fixed0, tdx_cap->attrs_fixed1,
> +		 tdx_cap->xfam_fixed0, tdx_cap->xfam_fixed1);
> +
> +	for (i = 0; i < tdx_cap->nr_cpuid_configs; i++) {
> +		const struct kvm_tdx_cpuid_config *config =
> +			&tdx_cap->cpuid_configs[i];
> +		pr_debug("cpuid config[%d]: leaf 0x%x sub_leaf 0x%x eax 0x%08x ebx 0x%08x ecx 0x%08x edx 0x%08x\n",
> +			 i, config->leaf, config->sub_leaf,
> +			 config->eax, config->ebx, config->ecx, config->edx);
> +	}
> +
> +	return tdx_cap;
> +}
> +
>   #define XFEATURE_MASK_CET (XFEATURE_MASK_CET_USER | XFEATURE_MASK_CET_KERNEL)
>   
>   static void tdx_apply_cpuid_restrictions(struct kvm_cpuid2 *cpuid_data)
> @@ -78,6 +124,21 @@ static void tdx_apply_cpuid_restrictions(struct kvm_cpuid2 *cpuid_data)
>   	}
>   }
>   
> +static void tdx_check_attributes(struct kvm_vm *vm, uint64_t attributes)
> +{
> +	struct kvm_tdx_capabilities *tdx_cap;
> +
> +	tdx_cap = tdx_read_capabilities(vm);
> +
> +	/* TDX spec: any bits 0 in attrs_fixed0 must be 0 in attributes */
> +	TEST_ASSERT_EQ(attributes & ~tdx_cap->attrs_fixed0, 0);
> +
> +	/* TDX spec: any bits 1 in attrs_fixed1 must be 1 in attributes */
> +	TEST_ASSERT_EQ(attributes & tdx_cap->attrs_fixed1, tdx_cap->attrs_fixed1);
> +
> +	free(tdx_cap);
> +}
> +
>   static void tdx_td_init(struct kvm_vm *vm, uint64_t attributes)
>   {
>   	const struct kvm_cpuid2 *cpuid;
> @@ -91,6 +152,8 @@ static void tdx_td_init(struct kvm_vm *vm, uint64_t attributes)
>   	memset(init_vm, 0, sizeof(*init_vm));
>   	memcpy(&init_vm->cpuid, cpuid, kvm_cpuid2_size(cpuid->nent));
>   
> +	tdx_check_attributes(vm, attributes);
> +
>   	init_vm->attributes = attributes;
>   
>   	tdx_apply_cpuid_restrictions(&init_vm->cpuid);