From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v2 08/10] xen/arm: Implement xen_rem_foreign_from_p2m Date: Mon, 09 Dec 2013 17:08:25 +0000 Message-ID: <52A5F909.7070904@linaro.org> References: <1386560047-17500-1-git-send-email-julien.grall@linaro.org> <1386560047-17500-9-git-send-email-julien.grall@linaro.org> <1386606664.7812.55.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Vq4Jq-0007W7-Nh for xen-devel@lists.xenproject.org; Mon, 09 Dec 2013 17:08:30 +0000 Received: by mail-ea0-f171.google.com with SMTP id h10so1717740eak.30 for ; Mon, 09 Dec 2013 09:08:29 -0800 (PST) In-Reply-To: <1386606664.7812.55.camel@kazak.uk.xensource.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: Ian Campbell Cc: xen-devel@lists.xenproject.org, tim@xen.org, stefano.stabellini@citrix.com, patches@linaro.org List-Id: xen-devel@lists.xenproject.org On 12/09/2013 04:31 PM, Ian Campbell wrote: > On Mon, 2013-12-09 at 03:34 +0000, Julien Grall wrote: >> Signed-off-by: Julien Grall >> >> --- >> Changes in v2: >> - Introduce the patch >> --- >> xen/arch/arm/mm.c | 16 ++++++++++++++++ >> xen/include/asm-arm/p2m.h | 6 +----- >> 2 files changed, 17 insertions(+), 5 deletions(-) >> >> diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c >> index 960c872..ba51f6e 100644 >> --- a/xen/arch/arm/mm.c >> +++ b/xen/arch/arm/mm.c >> @@ -968,6 +968,22 @@ void share_xen_page_with_privileged_guests( >> share_xen_page_with_guest(page, dom_xen, readonly); >> } >> >> +int xenmem_rem_foreign_from_p2m(struct domain *d, unsigned long gpfn) >> +{ >> + unsigned long mfn = gmfn_to_mfn(d, gpfn); >> + if ( !mfn_valid(mfn) ) >> + { >> + gdprintk(XENLOG_WARNING, "Invalid mfn for gpfn:%lx domid:%d\n", >> + gpfn, d->domain_id); > > Is this guest triggerable? Or does it indicate a mistake when we made > the mapping? It indicates a mistake when we made the mapping. Perhaps an ASSERT is better here. > >> + return -EINVAL; >> + } >> + >> + guest_physmap_remove_page(d, gpfn, mfn, 0); >> + put_page(mfn_to_page(mfn)); > > Some of this could become a common helper with create_p2m_entries and > the relinquish stuff in the previous patch. The best solution is to move put_page in guest_physmap_remove_page. But as we didn't plan to handle refcount for each mapping in Xen 4.4, perhaps we can delay it? -- Julien Grall