Re: [PATCH Part2 v6 07/49] x86/sev: Invalid pages from direct map when adding it to RMP table

[Kalra, Ashish]

Hello Boris,

On 8/4/2022 7:11 AM, Borislav Petkov wrote:
> On Mon, Aug 01, 2022 at 11:57:09PM +0000, Kalra, Ashish wrote:
> > You mean set_memory_present() ?
>
> Right, that.
>
> We have set_memory_np() but set_memory_present(). Talk about
> consistence... ;-\

Following up on this, now, set_memory_present() is a static interface,
so will need do add a new external API like set_memory_p() similar
to set_memory_np().

Also, looking at arch/x86/include/asm/set_memory.h:
..
/*
 * The set_memory_* API can be used to change various attributes of a
 * virtual address range. The attributes include:
 * Cacheability  : UnCached, WriteCombining, WriteThrough, WriteBack
 * Executability : eXecutable, NoteXecutable
 * Read/Write    : ReadOnly, ReadWrite
 * Presence      : NotPresent
 * Encryption    : Encrypted, Decrypted
 *
..
int set_memory_np(unsigned long addr, int numpages);
..

So currently there is no interface defined for changing the attribute of 
a range to present or restoring the range in the direct map.

Thanks,
Ashish