On Mon, Nov 19, 2012 at 01:36:42PM +0100, Alexander Graf wrote:
>
> Aren't atomic reads expensive? Doing one on every guest HPTE modification
> (when nobody is listening) sounds quite excessive. Wouldn't it be cheaper to
> just always update the bit?
As Scott said, it's just an ordinary load.
On 19.11.2012, at 18:20, Scott Wood wrote:
> On 11/19/2012 06:36:42 AM, Alexander Graf wrote:
>> On 14.11.2012, at 05:32, Paul Mackerras wrote:
>> > +/*
>> > + * Note modification of an HPTE; set the HPTE modified bit
>> > + * if it wasn't modified before and anyone is interested.
>> > + */
>> >
On 11/19/2012 06:36:42 AM, Alexander Graf wrote:
On 14.11.2012, at 05:32, Paul Mackerras wrote:
> +/*
> + * Note modification of an HPTE; set the HPTE modified bit
> + * if it wasn't modified before and anyone is interested.
> + */
> +static inline void note_hpte_modification(struct kvm *kvm,
>
On 14.11.2012, at 05:32, Paul Mackerras wrote:
> This uses a bit in our record of the guest view of the HPTE to record
> when the HPTE gets modified. We use a reserved bit for this, and ensure
> that this bit is always cleared in HPTE values returned to the guest.
> The recording of modified HPT
This uses a bit in our record of the guest view of the HPTE to record
when the HPTE gets modified. We use a reserved bit for this, and ensure
that this bit is always cleared in HPTE values returned to the guest.
The recording of modified HPTEs is only done if other code indicates
its interest by s
