Re: [PATCH v2 1/5] mmu: extend the is_present check to 32 bits

From: Paolo Bonzini
Date: Thu Sep 01 2016 - 11:16:26 EST




On 01/09/2016 16:20, Li, Liang Z wrote:
> Intel SDM doesn't describe whether the A bit will be set or not when
> CPU accesses a no present EPT page table entry

Bits in a non-present page table entry are entirely for use by the OS.
The processor will never touch it. This includes both P=0 in non-EPT
page tables and XWR=000 in EPT page tables.

Paolo