Message-ID: <855e4043-d337-722e-77a0-5c2be246d2b5@gmail.com>
Date:   Fri, 3 Feb 2023 13:58:21 +0800
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Subject: Re: [RFC PATCH V3 08/16] x86/hyperv: Initialize cpu and memory for
 sev-snp enlightened guest
To:     "Michael Kelley (LINUX)" <mikelley@microsoft.com>,
        "luto@kernel.org" <luto@kernel.org>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "mingo@redhat.com" <mingo@redhat.com>,
        "bp@alien8.de" <bp@alien8.de>,
        "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
        "x86@kernel.org" <x86@kernel.org>, "hpa@zytor.com" <hpa@zytor.com>,
        "seanjc@google.com" <seanjc@google.com>,
        "pbonzini@redhat.com" <pbonzini@redhat.com>,
        "jgross@suse.com" <jgross@suse.com>,
        Tianyu Lan <Tianyu.Lan@microsoft.com>,
        "kirill@shutemov.name" <kirill@shutemov.name>,
        "jiangshan.ljs@antgroup.com" <jiangshan.ljs@antgroup.com>,
        "peterz@infradead.org" <peterz@infradead.org>,
        "ashish.kalra@amd.com" <ashish.kalra@amd.com>,
        "srutherford@google.com" <srutherford@google.com>,
        "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
        "anshuman.khandual@arm.com" <anshuman.khandual@arm.com>,
        "pawan.kumar.gupta@linux.intel.com" 
        <pawan.kumar.gupta@linux.intel.com>,
        "adrian.hunter@intel.com" <adrian.hunter@intel.com>,
        "daniel.sneddon@linux.intel.com" <daniel.sneddon@linux.intel.com>,
        "alexander.shishkin@linux.intel.com" 
        <alexander.shishkin@linux.intel.com>,
        "sandipan.das@amd.com" <sandipan.das@amd.com>,
        "ray.huang@amd.com" <ray.huang@amd.com>,
        "brijesh.singh@amd.com" <brijesh.singh@amd.com>,
        "michael.roth@amd.com" <michael.roth@amd.com>,
        "thomas.lendacky@amd.com" <thomas.lendacky@amd.com>,
        "venu.busireddy@oracle.com" <venu.busireddy@oracle.com>,
        "sterritt@google.com" <sterritt@google.com>,
        "tony.luck@intel.com" <tony.luck@intel.com>,
        "samitolvanen@google.com" <samitolvanen@google.com>,
        "fenghua.yu@intel.com" <fenghua.yu@intel.com>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
        "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
References: <20230122024607.788454-1-ltykernel@gmail.com>
 <20230122024607.788454-9-ltykernel@gmail.com>
 <BYAPR21MB168803F19A65E356758A6046D7D09@BYAPR21MB1688.namprd21.prod.outlook.com>
From:   Tianyu Lan <ltykernel@gmail.com>
In-Reply-To: <BYAPR21MB168803F19A65E356758A6046D7D09@BYAPR21MB1688.namprd21.prod.outlook.com>
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On 2/1/2023 2:20 AM, Michael Kelley (LINUX) wrote:
>> +struct memory_map_entry {
>> +	u64 starting_gpn;
>> +	u64 numpages;
>> +	u16 type;
>> +	u16 flags;
>> +	u32 reserved;
>> +};
> Am I correct that this structure is defined by Hyper-V?  If so, it seems
> like it should go in hyperv-tlfs.h, along with the definition of
> EN_SEV_SNP_PROCESSOR_INFO_ADDR (which is also defined by
> Hyper-V?)
>

Yes, it's Hyper-V data structure and will move to hyperv-tlfs.h.


>> +			if (e820_end < ram_end) {
>> +				pr_info("Hyper-V: add e820 entry [mem %#018Lx-%#018Lx]\n", e820_end, ram_end - 1);
>> +				e820__range_add(e820_end, ram_end - e820_end,
>> +						E820_TYPE_RAM);
>> +				for (page = e820_end; page < ram_end; page += PAGE_SIZE)
>> +					pvalidate((unsigned long)__va(page), RMP_PG_SIZE_4K, true);
>> +			}
>> +		}
>> +	}
>> +
> For SNP vTOM mode, most of the supporting code is placed in
> arch/x86/hyperv/ivm.c, which is built only if CONFIG_HYPERV
> is defined.  arch/x86/kernel/cpu/mshyperv.c is built for*any*
> flavor of guest (i.e., CONFIG_HYPERVISOR_GUEST).  I'm thinking
> all this code should go as a supporting function in ivm.c, to
> avoid overloading mshyperv.c.  Take a look at how hv_vtom_init()
> is handled in my patch set.
> 
> Breaking it out as a separate supporting function might also
> help reduce the deep indentation problem a bit. ????

Good idea. Will update in the next version.
Thanks for your suggestion.
>