Re: [RFC][PATCH 12/34] x86/cpu/intel: Actually use "address configuration" infrastructure for MKTME

Kirill A. Shutemov
2024-02-23T11:42:46Z

On Thu, Feb 22, 2024 at 10:39:42AM -0800, Dave Hansen wrote:
>
> From: Dave Hansen <dave.hansen@linux.intel.com>
>
> Now that the TME detection is only called once at boot, stop twiddling
> 'boot_cpu_data' directly and move over to 'bsp_addr_config'.
>
> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
> ---
>
> b/arch/x86/kernel/cpu/intel.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff -puN arch/x86/kernel/cpu/intel.c~intel-addr-reduce arch/x86/kernel/cpu/intel.c
> --- a/arch/x86/kernel/cpu/intel.c~intel-addr-reduce 2024-02-22 10:08:54.296682462 -0800
> +++ b/arch/x86/kernel/cpu/intel.c 2024-02-22 10:08:54.296682462 -0800
> @@ -401,11 +401,8 @@ detect_keyid_bits:
> mktme_status = MKTME_ENABLED;
> }
>
> - /*
> - * KeyID bits effectively lower the number of physical address
> - * bits. Update cpuinfo_x86::x86_phys_bits accordingly.
> - */
> - c->x86_phys_bits -= keyid_bits;
> + /* KeyID bits effectively lower the number of physical address bits */
> + bsp_addr_config.phys_addr_reduction_bits = keyid_bits;

Do we expect reduction_bits to stack? Like can multiple features steal
physical bits? Make use "+= keyid_bits" here?

--
Kiryl Shutsemau / Kirill A. Shutemov