From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH 8/8] x86: remove the Xen-specific _PAGE_IOMAP PTE flag Date: Mon, 24 Feb 2014 09:51:03 -0800 Message-ID: <530B8687.6040406@zytor.com> References: <1393263564-14038-1-git-send-email-david.vrabel@citrix.com> <1393263564-14038-9-git-send-email-david.vrabel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1393263564-14038-9-git-send-email-david.vrabel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: David Vrabel , xen-devel@lists.xen.org Cc: x86@kernel.org, Boris Ostrovsky , Ingo Molnar , Thomas Gleixner List-Id: xen-devel@lists.xenproject.org On 02/24/2014 09:39 AM, David Vrabel wrote: > From: David Vrabel > > The _PAGE_IO_MAP PTE flag was only used by Xen PV guests to mark PTEs > that were used to map I/O regions that are 1:1 in the p2m. This > allowed Xen to obtain the correct PFN when converting the MFNs read > from a PTE back to their PFN. > > Xen guests no longer use _PAGE_IOMAP for this. Instead mfn_to_pfn() > returns the correct PFN by using a combination of the m2p and p2m to > determine if an MFN corresponds to a 1:1 mapping in the the p2m. > > Remove _PAGE_IOMAP, replacing it with _PAGE_UNUSED2 to allow for > future uses of the PTE flag. > > Signed-off-by: David Vrabel > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: "H. Peter Anvin" > Cc: x86@kernel.org > -- > This depends on the preceeding Xen changes, so I think it would be > best if this was acked by an x86 maintainer and merged via the Xen > tree. Acked-by: H. Peter Anvin Yay, a bit back! -hpa