Re: [PATCH] x86/tdx: Dump attributes and TD_CTLS on boot

[Nikolay Borisov]

On 2.12.24 г. 9:24 ч., Kirill A. Shutemov wrote:
> Dump TD configuration on boot. Attributes and TD_CTLS define TD
> behavior. This information is useful for tracking down bugs.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>

Reviewed-by: Nikolay Borisov <nik.borisov@xxxxxxxx>


> ---
>   arch/x86/coco/tdx/Makefile        |  2 +-
>   arch/x86/coco/tdx/debug.c         | 69 +++++++++++++++++++++++++++++++
>   arch/x86/coco/tdx/tdx.c           | 27 ++++++++----
>   arch/x86/include/asm/shared/tdx.h | 39 +++++++++++++++--
>   arch/x86/include/asm/tdx.h        |  3 ++
>   5 files changed, 128 insertions(+), 12 deletions(-)
>   create mode 100644 arch/x86/coco/tdx/debug.c
>
> diff --git a/arch/x86/coco/tdx/Makefile b/arch/x86/coco/tdx/Makefile
> index 2c7dcbf1458b..b3c47d3700e2 100644
> --- a/arch/x86/coco/tdx/Makefile
> +++ b/arch/x86/coco/tdx/Makefile
> @@ -1,3 +1,3 @@
>   # SPDX-License-Identifier: GPL-2.0
>   
> -obj-y += tdx.o tdx-shared.o tdcall.o
> +obj-y += debug.o tdcall.o tdx.o tdx-shared.o
> diff --git a/arch/x86/coco/tdx/debug.c b/arch/x86/coco/tdx/debug.c
> new file mode 100644
> index 000000000000..cef847c8bb67
> --- /dev/null
> +++ b/arch/x86/coco/tdx/debug.c
> @@ -0,0 +1,69 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#undef pr_fmt
> +#define pr_fmt(fmt)     "tdx: " fmt
> +
> +#include <linux/array_size.h>
> +#include <linux/printk.h>
> +#include <asm/tdx.h>
> +
> +#define DEF_TDX_ATTR_NAME(_name) [TDX_ATTR_##_name##_BIT] = __stringify(_name)
> +
> +static __initdata const char *tdx_attributes[] = {
> +	DEF_TDX_ATTR_NAME(DEBUG),
> +	DEF_TDX_ATTR_NAME(HGS_PLUS_PROF),
> +	DEF_TDX_ATTR_NAME(PERF_PROF),
> +	DEF_TDX_ATTR_NAME(PMT_PROF),
> +	DEF_TDX_ATTR_NAME(ICSSD),
> +	DEF_TDX_ATTR_NAME(LASS),
> +	DEF_TDX_ATTR_NAME(SEPT_VE_DISABLE),
> +	DEF_TDX_ATTR_NAME(MIGRTABLE),
> +	DEF_TDX_ATTR_NAME(PKS),
> +	DEF_TDX_ATTR_NAME(KL),
> +	DEF_TDX_ATTR_NAME(TPA),
> +	DEF_TDX_ATTR_NAME(PERFMON),
> +};
> +
> +#define DEF_TD_CTLS_NAME(_name) [TD_CTLS_##_name##_BIT] = __stringify(_name)
> +
> +static __initdata const char *tdcs_td_ctls[] = {
> +	DEF_TD_CTLS_NAME(PENDING_VE_DISABLE),
> +	DEF_TD_CTLS_NAME(ENUM_TOPOLOGY),
> +	DEF_TD_CTLS_NAME(VIRT_CPUID2),
> +	DEF_TD_CTLS_NAME(REDUCE_VE),
> +	DEF_TD_CTLS_NAME(LOCK),

nit: That's a bit wasteful for sparsely populated fields but I guess the 
extra complexity of having a struct in the array with the bit definition 
and the name isn't worth the space saving.

> +};
> +

<snip>