From patchwork Wed May 15 14:26:21 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Fancellu X-Patchwork-Id: 13665325 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C62C9C25B7A for ; Wed, 15 May 2024 14:26:51 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.722425.1126375 (Exim 4.92) (envelope-from ) id 1s7Fad-0002dr-CP; Wed, 15 May 2024 14:26:43 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 722425.1126375; Wed, 15 May 2024 14:26:43 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1s7Fad-0002cl-5R; Wed, 15 May 2024 14:26:43 +0000 Received: by outflank-mailman (input) for mailman id 722425; Wed, 15 May 2024 14:26:42 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1s7Fac-0002KG-3E for xen-devel@lists.xenproject.org; Wed, 15 May 2024 14:26:42 +0000 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by se1-gles-flk1.inumbo.com (Halon) with ESMTP id 2504f786-12c7-11ef-b4bb-af5377834399; Wed, 15 May 2024 16:26:40 +0200 (CEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5782715A1; Wed, 15 May 2024 07:27:04 -0700 (PDT) Received: from e125770.cambridge.arm.com (e125770.arm.com [10.1.199.43]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AB4BE3F7A6; Wed, 15 May 2024 07:26:38 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 2504f786-12c7-11ef-b4bb-af5377834399 From: Luca Fancellu To: xen-devel@lists.xenproject.org Cc: Penny Zheng , Stefano Stabellini , Julien Grall , Bertrand Marquis , Michal Orzel , Volodymyr Babchuk , Penny Zheng Subject: [PATCH v2 3/7] xen/p2m: put reference for level 2 superpage Date: Wed, 15 May 2024 15:26:21 +0100 Message-Id: <20240515142626.3480640-4-luca.fancellu@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240515142626.3480640-1-luca.fancellu@arm.com> References: <20240515142626.3480640-1-luca.fancellu@arm.com> MIME-Version: 1.0 From: Penny Zheng We are doing foreign memory mapping for static shared memory, and there is a great possibility that it could be super mapped. But today, p2m_put_l3_page could not handle superpages. This commits implements a new function p2m_put_l2_superpage to handle 2MB superpages, specifically for helping put extra references for foreign superpages. Modify relinquish_p2m_mapping as well to take into account preemption when type is foreign memory and order is above 9 (2MB). Signed-off-by: Penny Zheng Signed-off-by: Luca Fancellu --- v2: - Do not handle 1GB super page as there might be some issue where a lot of calls to put_page(...) might be issued which could lead to free memory that is a long operation. v1: - patch from https://patchwork.kernel.org/project/xen-devel/patch/20231206090623.1932275-9-Penny.Zheng@arm.com/ --- xen/arch/arm/mmu/p2m.c | 57 +++++++++++++++++++++++++++++------------- 1 file changed, 40 insertions(+), 17 deletions(-) diff --git a/xen/arch/arm/mmu/p2m.c b/xen/arch/arm/mmu/p2m.c index 41fcca011cf4..29fdb3b87dd0 100644 --- a/xen/arch/arm/mmu/p2m.c +++ b/xen/arch/arm/mmu/p2m.c @@ -753,17 +753,9 @@ static int p2m_mem_access_radix_set(struct p2m_domain *p2m, gfn_t gfn, return rc; } -/* - * Put any references on the single 4K page referenced by pte. - * TODO: Handle superpages, for now we only take special references for leaf - * pages (specifically foreign ones, which can't be super mapped today). - */ -static void p2m_put_l3_page(const lpae_t pte) +/* Put any references on the single 4K page referenced by mfn. */ +static void p2m_put_l3_page(mfn_t mfn, p2m_type_t type) { - mfn_t mfn = lpae_get_mfn(pte); - - ASSERT(p2m_is_valid(pte)); - /* * TODO: Handle other p2m types * @@ -771,16 +763,44 @@ static void p2m_put_l3_page(const lpae_t pte) * flush the TLBs if the page is reallocated before the end of * this loop. */ - if ( p2m_is_foreign(pte.p2m.type) ) + if ( p2m_is_foreign(type) ) { ASSERT(mfn_valid(mfn)); put_page(mfn_to_page(mfn)); } /* Detect the xenheap page and mark the stored GFN as invalid. */ - else if ( p2m_is_ram(pte.p2m.type) && is_xen_heap_mfn(mfn) ) + else if ( p2m_is_ram(type) && is_xen_heap_mfn(mfn) ) page_set_xenheap_gfn(mfn_to_page(mfn), INVALID_GFN); } +/* Put any references on the superpage referenced by mfn. */ +static void p2m_put_l2_superpage(mfn_t mfn, p2m_type_t type) +{ + unsigned int i; + unsigned int level_order = XEN_PT_LEVEL_ORDER(3); + + for ( i = 0; i < XEN_PT_LPAE_ENTRIES; i++ ) + { + p2m_put_l3_page(mfn, type); + + mfn = mfn_add(mfn, 1 << level_order); + } +} + +/* Put any references on the page referenced by pte. */ +static void p2m_put_page(const lpae_t pte, unsigned int level) +{ + mfn_t mfn = lpae_get_mfn(pte); + + ASSERT(p2m_is_valid(pte)); + + /* We have a second level 2M superpage */ + if ( p2m_is_superpage(pte, level) && (level == 2) ) + return p2m_put_l2_superpage(mfn, pte.p2m.type); + else if ( level == 3 ) + return p2m_put_l3_page(mfn, pte.p2m.type); +} + /* Free lpae sub-tree behind an entry */ static void p2m_free_entry(struct p2m_domain *p2m, lpae_t entry, unsigned int level) @@ -809,9 +829,10 @@ static void p2m_free_entry(struct p2m_domain *p2m, #endif p2m->stats.mappings[level]--; - /* Nothing to do if the entry is a super-page. */ - if ( level == 3 ) - p2m_put_l3_page(entry); + /* TODO: Currently we don't handle 1GB super-page. */ + if ( level >= 2 ) + p2m_put_page(entry, level); + return; } @@ -1558,9 +1579,11 @@ int relinquish_p2m_mapping(struct domain *d) count++; /* - * Arbitrarily preempt every 512 iterations. + * Arbitrarily preempt every 512 iterations or when type is foreign + * mapping and the order is above 9 (2MB). */ - if ( !(count % 512) && hypercall_preempt_check() ) + if ( (!(count % 512) || (p2m_is_foreign(t) && (order > 9))) && + hypercall_preempt_check() ) { rc = -ERESTART; break;