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Subject: Re: [PATCH Part1 v5 17/38] x86/mm: Add support to validate memory
 when changing C-bit
To:     Borislav Petkov <bp@alien8.de>
References: <20210820151933.22401-1-brijesh.singh@amd.com>
 <20210820151933.22401-18-brijesh.singh@amd.com> <YSYkHhAMSOotEzXQ@zn.tnic>
From:   Brijesh Singh <brijesh.singh@amd.com>
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On 8/25/21 6:06 AM, Borislav Petkov wrote:
> 
> I really meant putting the beginning of that string at the very first
> position on the line:
> 
>                  if (WARN(hdr->end_entry > end_entry || cur_entry > hdr->cur_entry,
> "SEV-SNP: PSC processing going backward, end_entry %d (got %d) cur_entry %d (got %d)\n",
>                           end_entry, hdr->end_entry, cur_entry, hdr->cur_entry)) {
> 
> Exactly like this!
> 

Noted.

> ...
> 
>> +static void set_page_state(unsigned long vaddr, unsigned int npages, int op)
>> +{
>> +	unsigned long vaddr_end, next_vaddr;
>> +	struct snp_psc_desc *desc;
>> +
>> +	vaddr = vaddr & PAGE_MASK;
>> +	vaddr_end = vaddr + (npages << PAGE_SHIFT);
>> +
>> +	desc = kmalloc(sizeof(*desc), GFP_KERNEL_ACCOUNT);
> 
> And again, from previous review:
> 
> kzalloc() so that you don't have to memset() later in
> __set_page_state().
> 

I replied to your previous comment. Depending on the npages value, the 
__set_page_state() will be called multiple times and on each call it 
needs to clear desc before populate it. So, I do not see strong reason 
to use kzalloc() during the desc allocation. I thought you were okay 
with that explanation.


>> +	if (!desc)
>> +		panic("SEV-SNP: failed to alloc memory for PSC descriptor\n");
> 
> "allocate" fits just fine too.
> 

Noted.

thanks