Re: [PATCH v6 06/12] Add PV MSR to enable asynchronous page faultsdelivery.
From: Avi Kivity
Date:  Sat Oct 09 2010 - 14:44:19 EST
 On 10/07/2010 07:59 PM, Gleb Natapov wrote:
On Thu, Oct 07, 2010 at 02:58:26PM +0200, Avi Kivity wrote:
>   On 10/04/2010 05:56 PM, Gleb Natapov wrote:
>  >+
>  >+	Physical address points to 32 bit memory location that will be written
>  >+	to by the hypervisor at the time of asynchronous page fault injection to
>  >+	indicate type of asynchronous page fault. Value of 1 means that the page
>  >+	referred to by the page fault is not present. Value 2 means that the
>  >+	page is now available.
>
>  "The must not enable interrupts before the reason is read, or it may
>  be overwritten by another apf".
>
>  Document the fact that disabling interrupts disables APFs.
>
>  How does the guest distinguish betweem APFs and ordinary page faults?
>
>  What's the role of cr2?
>
>  When disabling APF, all pending APFs are flushed and may or may not
>  get a completion.
>
>  Is a "page available" notification guaranteed to arrive on the same
>  vcpu that took the "page not present" fault?
>
You mean documentation is lacking? :)
I mean you should be able to write guest support code without reading 
the host code, just the documentation.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
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