linux-kernel - Re: [PATCH V6 2/3] x86/tdx: Tidy reset

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Message-ID: <ed0c3a20-d739-456a-8675-3218592857e3@linux.intel.com>
Date: Fri, 25 Jul 2025 11:21:56 +0800
From: Binbin Wu <binbin.wu@...ux.intel.com>
To: Adrian Hunter <adrian.hunter@...el.com>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>, pbonzini@...hat.com,
 seanjc@...gle.com, vannapurve@...gle.com, Tony Luck <tony.luck@...el.com>,
 Borislav Petkov <bp@...en8.de>, Thomas Gleixner <tglx@...utronix.de>,
 Ingo Molnar <mingo@...hat.com>, x86@...nel.org, H Peter Anvin
 <hpa@...or.com>, linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
 rick.p.edgecombe@...el.com, kas@...nel.org, kai.huang@...el.com,
 reinette.chatre@...el.com, xiaoyao.li@...el.com,
 tony.lindgren@...ux.intel.com, isaku.yamahata@...el.com,
 yan.y.zhao@...el.com, chao.gao@...el.com
Subject: Re: [PATCH V6 2/3] x86/tdx: Tidy reset_pamt functions



On 7/24/2025 9:03 PM, Adrian Hunter wrote:
> tdx_quirk_reset_paddr() was renamed to reflect that, in fact, the clearing
> is necessary only for hardware with a certain quirk.  That is dealt with in
> a subsequent patch.
>
> Rename reset_pamt functions to contain "quirk" to reflect the new
> functionality, and remove the now misleading comment.
>
> Signed-off-by: Adrian Hunter <adrian.hunter@...el.com>

Reviewed-by: Binbin Wu <binbin.wu@...ux.intel.com>

> ---
>
>
> Changes in V6:
>
> 	None
>
> Changes in V5:
>
> 	New patch
>
>
>   arch/x86/virt/vmx/tdx/tdx.c | 16 ++++------------
>   1 file changed, 4 insertions(+), 12 deletions(-)
>
> diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
> index fc8d8e444f15..9e4638f68ba0 100644
> --- a/arch/x86/virt/vmx/tdx/tdx.c
> +++ b/arch/x86/virt/vmx/tdx/tdx.c
> @@ -660,17 +660,17 @@ void tdx_quirk_reset_page(struct page *page)
>   }
>   EXPORT_SYMBOL_GPL(tdx_quirk_reset_page);
>   
> -static void tdmr_reset_pamt(struct tdmr_info *tdmr)
> +static void tdmr_quirk_reset_pamt(struct tdmr_info *tdmr)
>   {
>   	tdmr_do_pamt_func(tdmr, tdx_quirk_reset_paddr);
>   }
>   
> -static void tdmrs_reset_pamt_all(struct tdmr_info_list *tdmr_list)
> +static void tdmrs_quirk_reset_pamt_all(struct tdmr_info_list *tdmr_list)
>   {
>   	int i;
>   
>   	for (i = 0; i < tdmr_list->nr_consumed_tdmrs; i++)
> -		tdmr_reset_pamt(tdmr_entry(tdmr_list, i));
> +		tdmr_quirk_reset_pamt(tdmr_entry(tdmr_list, i));
>   }
>   
>   static unsigned long tdmrs_count_pamt_kb(struct tdmr_info_list *tdmr_list)
> @@ -1142,15 +1142,7 @@ static int init_tdx_module(void)
>   	 * to the kernel.
>   	 */
>   	wbinvd_on_all_cpus();
> -	/*
> -	 * According to the TDX hardware spec, if the platform
> -	 * doesn't have the "partial write machine check"
> -	 * erratum, any kernel read/write will never cause #MC
> -	 * in kernel space, thus it's OK to not convert PAMTs
> -	 * back to normal.  But do the conversion anyway here
> -	 * as suggested by the TDX spec.
> -	 */
> -	tdmrs_reset_pamt_all(&tdx_tdmr_list);
> +	tdmrs_quirk_reset_pamt_all(&tdx_tdmr_list);
>   err_free_pamts:
>   	tdmrs_free_pamt_all(&tdx_tdmr_list);
>   err_free_tdmrs: