Re: [RFC PATCH V3 08/16] x86/hyperv: Initialize cpu and memory for sev-snp enlightened guest

[Tianyu Lan <ltykernel@gmail.com>]

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.
>