From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH] xen/mm: Unmap page for direct mapped domain on decrease reservation Date: Tue, 27 Oct 2015 13:54:04 +0000 Message-ID: <562F81FC.3000800@citrix.com> References: <1445945605-26372-1-git-send-email-julien.grall@citrix.com> <562F855D02000078000AF1F9@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Zr4io-0003xN-Us for xen-devel@lists.xenproject.org; Tue, 27 Oct 2015 13:55:31 +0000 In-Reply-To: <562F855D02000078000AF1F9@prv-mh.provo.novell.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: Jan Beulich Cc: xen-devel@lists.xenproject.org, KeirFraser , Tim Deegan , ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com List-Id: xen-devel@lists.xenproject.org On 27/10/15 13:08, Jan Beulich wrote: >> --- a/xen/common/memory.c >> +++ b/xen/common/memory.c >> @@ -257,8 +257,16 @@ int guest_remove_page(struct domain *d, unsigned long gmfn) >> >> if ( test_and_clear_bit(_PGT_pinned, &page->u.inuse.type_info) ) >> put_page_and_type(page); >> - >> - if ( test_and_clear_bit(_PGC_allocated, &page->count_info) ) >> + >> + /* >> + * With the lack for iommu on some ARM platform, domain with DMA-capable > > I think it's "lack of", and I also wonder whether calling out ARM here > is really meaningful. > >> + * device must retrieve the same pfn when the hypercall populate_physmap >> + * is called. >> + * >> + * For this purpose, the page is kept allocated. > > ..., to match populate_physmap() behavior. (or some such) I saw that your already committed the patch. FWIW, I'm fine with both changes. Regards, -- Julien Grall