Message-ID: <45e6a0b5-77fa-6ca2-f3a3-9cf61fdb56a6@gmail.com>
Date:   Tue, 7 Feb 2023 21:49:48 +0800
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Subject: Re: [RFC PATCH V3 10/16] x86/hyperv: Add smp support for sev-snp
 guest
To:     Borislav Petkov <bp@alien8.de>
Cc:     Tom Lendacky <thomas.lendacky@amd.com>, luto@kernel.org,
        tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com,
        x86@kernel.org, hpa@zytor.com, seanjc@google.com,
        pbonzini@redhat.com, jgross@suse.com, tiala@microsoft.com,
        kirill@shutemov.name, jiangshan.ljs@antgroup.com,
        peterz@infradead.org, ashish.kalra@amd.com, srutherford@google.com,
        akpm@linux-foundation.org, anshuman.khandual@arm.com,
        pawan.kumar.gupta@linux.intel.com, adrian.hunter@intel.com,
        daniel.sneddon@linux.intel.com, alexander.shishkin@linux.intel.com,
        sandipan.das@amd.com, ray.huang@amd.com, brijesh.singh@amd.com,
        michael.roth@amd.com, venu.busireddy@oracle.com,
        sterritt@google.com, tony.luck@intel.com, samitolvanen@google.com,
        fenghua.yu@intel.com, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, linux-hyperv@vger.kernel.org,
        linux-arch@vger.kernel.org
References: <20230122024607.788454-1-ltykernel@gmail.com>
 <20230122024607.788454-11-ltykernel@gmail.com>
 <62ffd8b2-3d88-499e-ba13-1da26f664c6f@amd.com>
 <ce9b4a79-b877-211d-aee8-bbc02e6805b5@gmail.com> <Y+Fe390kWFnAh6gC@zn.tnic>
From:   Tianyu Lan <ltykernel@gmail.com>
In-Reply-To: <Y+Fe390kWFnAh6gC@zn.tnic>
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On 2/7/2023 4:11 AM, Borislav Petkov wrote:
> On Fri, Feb 03, 2023 at 03:00:44PM +0800, Tianyu Lan wrote:
>>> For the bits definition, use:
>>>
>>>               u64 sev_feature_snp            : 1,
>>>                   sev_feature_vtom            : 1,
>>>                   sev_feature_reflectvc        : 1,
>>>                   ...
>>>
>>
>> Good suggestion. Thanks.
> 
> Actually, I'd prefer if you used a named union and drop all this
> "sev_feature_" prefixes everywhere:
> 
>          union {
>                  struct {
>                          u64 snp                     : 1;
>                          u64 vtom                    : 1;
>                          u64 reflectvc               : 1;
>                          u64 restrict_injection      : 1;
>                          u64 alternate_injection     : 1;
>                          u64 full_debug              : 1;
>                          u64 reserved1               : 1;
>                          u64 snpbtb_isolation        : 1;
>                          u64 resrved2                : 56;
>                  };
>                  u64 val;
>          } sev_features;
> 
> 
> 
> so that you can do in code:
> 
> 	struct sev_es_save_area *sev;
> 
> 	...
> 
> 	sev->sev_features.snp = ...
> 
> and so on.

Hi Boris:
	Thanks a lot for your suggestion. Will update.