Re: [Xen-devel] [PATCH] x86/shadow: use single (atomic) MOV for emulated writes

[Tim Deegan <tim@xxxxxxx>]

At 15:29 -0500 on 16 Jan (1579188566), Jason Andryuk wrote:
> This is the corresponding change to the shadow code as made by
> bf08a8a08a2e "x86/HVM: use single (atomic) MOV for aligned emulated
> writes" to the non-shadow HVM code.
> 
> The bf08a8a08a2e commit message:
> Using memcpy() may result in multiple individual byte accesses
> (depending how memcpy() is implemented and how the resulting insns,
> e.g. REP MOVSB, get carried out in hardware), which isn't what we
> want/need for carrying out guest insns as correctly as possible. Fall
> back to memcpy() only for accesses not 2, 4, or 8 bytes in size.
> 
> Signed-off-by: Jason Andryuk <jandryuk@xxxxxxxxx>

Acked-by: Tim Deegan <tim@xxxxxxx>

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