From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v4 08/11] xen/arm: Handle remove foreign mapping Date: Mon, 16 Dec 2013 17:14:21 +0000 Message-ID: <52AF34ED.6070307@linaro.org> References: <1386963461-6520-1-git-send-email-julien.grall@linaro.org> <1386963461-6520-9-git-send-email-julien.grall@linaro.org> <20131216115131.GB35881@deinos.phlegethon.org> <52AF1D6E.7080402@linaro.org> <1387208403.21086.12.camel@kazak.uk.xensource.com> <52AF29C3.1030700@linaro.org> <1387211584.21086.27.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 1VsbkQ-0000Zw-1T for xen-devel@lists.xenproject.org; Mon, 16 Dec 2013 17:14:26 +0000 Received: by mail-wg0-f51.google.com with SMTP id b13so4941211wgh.30 for ; Mon, 16 Dec 2013 09:14:24 -0800 (PST) In-Reply-To: <1387211584.21086.27.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: Keir Fraser , patches@linaro.org, Tim Deegan , stefano.stabellini@citrix.com, Jan Beulich , xen-devel@lists.xenproject.org List-Id: xen-devel@lists.xenproject.org Here a new version of this patch. If needed I can resend the whole patch series. commit aa505db91a90bf00b216a5368b3721fdda02e437 Author: Julien Grall Date: Fri Dec 13 16:51:03 2013 +0000 xen/arm: Handle remove foreign mapping Modify get_page_from_gfn to take reference on foreign mapping. This will avoid specific handling in the common code. Signed-off-by: Julien Grall --- Changes in v4.2: - get_page_from_gfn: move foreign checking before get_page - add assert fdom != dom Changes in v4.1: - Remove specific p2m handling in common code - Handle foreign mapping in get_page_from_gfn Changes in v4: - Split patch #6 from dom0 pvh series v6.2 to retrieve only common code. - Rework commit title - Rename xen_rem_foreign_from_p2m in p2m_remove_foreign - Get the mfn from the pte. We are not sure that maddr given in parameters is valid Changes in v3: - Move put_page in create_p2m_entries - Move xenmem_rem_foreign_from_p2m in arch/arm/p2m.c Changes in v2: - Introduce the patch diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c index 39d8a03..f7bd7e2 100644 --- a/xen/arch/arm/p2m.c +++ b/xen/arch/arm/p2m.c @@ -317,10 +317,21 @@ static int create_p2m_entries(struct domain *d, break; case REMOVE: { - lpae_t pte; + lpae_t pte = third[third_table_offset(addr)]; + unsigned long mfn; + + maddr = (pte.bits & PADDR_MASK & PAGE_MASK); + mfn = paddr_to_pfn(maddr); + + /* TODO: Handle other p2m type */ + if ( pte.p2m.valid && p2m_is_foreign(pte.p2m.type) ) + { + ASSERT(mfn_valid(mfn)); + put_page(mfn_to_page(mfn)); + } + memset(&pte, 0x00, sizeof(pte)); write_pte(&third[third_table_offset(addr)], pte); - maddr += PAGE_SIZE; } break; } diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h index 0eb07a8..5ccfa7f 100644 --- a/xen/include/asm-arm/p2m.h +++ b/xen/include/asm-arm/p2m.h @@ -122,6 +122,18 @@ static inline struct page_info *get_page_from_gfn( if ( !mfn_valid(mfn) ) return NULL; page = mfn_to_page(mfn); + + /* get_page won't work on foreign mapping because the page doesn't + * belong to the current domain. + */ + if ( p2mt == p2m_map_foreign ) + { + struct domain *fdom = page_get_owner_and_reference(page); + ASSERT(fdom != NULL); + ASSERT(fdom != d); + return page; + } + if ( !get_page(page, d) ) return NULL; return page; -- Julien Grall