Re: [Xen-devel] mark pages in p2m_ram_paging_out state read-only

[Tim Deegan <tim@xxxxxxx>]

At 17:53 +0100 on 14 Nov (1321293182), Olaf Hering wrote:
> 
> I was wondering why ept_p2m_type_to_flags() removes all permissions from
> a gfn in state p2m_ram_paging_out. If the guest happens to read or
> execute from that page while the pager writes that gfn to disk, wouldnt
> it be enough to remove the write bit to prevent writes from the guest?
> If the page is read-only the guest could continue to make progress until
> the gfn is really evicted and the p2mt changes to p2m_ram_paged.
> 
> I havent actually tried the patch below, but is there any reason it
> would break the guest?

As long as we change the p2m type before scrubbing or freeing the page,
that seems like it shuold be fine. 

Tim.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel