From patchwork Mon Jun 20 02:44:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Penny Zheng X-Patchwork-Id: 12886954 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 F39F6CCA47A for ; Mon, 20 Jun 2022 02:45:07 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.352185.578933 (Exim 4.92) (envelope-from ) id 1o37PF-0005CG-5N; Mon, 20 Jun 2022 02:44:49 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 352185.578933; Mon, 20 Jun 2022 02:44:49 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1o37PF-0005C6-2F; Mon, 20 Jun 2022 02:44:49 +0000 Received: by outflank-mailman (input) for mailman id 352185; Mon, 20 Jun 2022 02:44:48 +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 1o37PE-0005AM-9J for xen-devel@lists.xenproject.org; Mon, 20 Jun 2022 02:44:48 +0000 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by se1-gles-flk1.inumbo.com (Halon) with ESMTP id f10185ef-f042-11ec-b725-ed86ccbb4733; Mon, 20 Jun 2022 04:44:45 +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 15A7B1042; Sun, 19 Jun 2022 19:44:44 -0700 (PDT) Received: from a011292.shanghai.arm.com (a011292.shanghai.arm.com [10.169.190.94]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 4BC8F3F7D7; Sun, 19 Jun 2022 19:44:40 -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: f10185ef-f042-11ec-b725-ed86ccbb4733 From: Penny Zheng To: xen-devel@lists.xenproject.org Cc: wei.chen@arm.com, Penny Zheng , Stefano Stabellini , Julien Grall , Bertrand Marquis , Volodymyr Babchuk , Andrew Cooper , George Dunlap , Jan Beulich , Wei Liu , Penny Zheng Subject: [PATCH v7 2/9] xen: do not free reserved memory into heap Date: Mon, 20 Jun 2022 10:44:01 +0800 Message-Id: <20220620024408.203797-3-Penny.Zheng@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220620024408.203797-1-Penny.Zheng@arm.com> References: <20220620024408.203797-1-Penny.Zheng@arm.com> MIME-Version: 1.0 Pages used as guest RAM for static domain, shall be reserved to this domain only. So in case reserved pages being used for other purpose, users shall not free them back to heap, even when last ref gets dropped. free_staticmem_pages will be called by free_heap_pages in runtime for static domain freeing memory resource, so let's drop the __init flag. Signed-off-by: Penny Zheng Acked-by: Jan Beulich --- v7 changes: - protect free_staticmem_pages with heap_lock to match its reverse function acquire_staticmem_pages --- v6 changes: - adapt to PGC_static - remove #ifdef aroud function declaration --- v5 changes: - In order to avoid stub functions, we #define PGC_staticmem to non-zero only when CONFIG_STATIC_MEMORY - use "unlikely()" around pg->count_info & PGC_staticmem - remove pointless "if", since mark_page_free() is going to set count_info to PGC_state_free and by consequence clear PGC_staticmem - move #define PGC_staticmem 0 to mm.h --- v4 changes: - no changes --- v3 changes: - fix possible racy issue in free_staticmem_pages() - introduce a stub free_staticmem_pages() for the !CONFIG_STATIC_MEMORY case - move the change to free_heap_pages() to cover other potential call sites - fix the indentation --- v2 changes: - new commit --- xen/arch/arm/include/asm/mm.h | 4 +++- xen/common/page_alloc.c | 16 +++++++++++++--- xen/include/xen/mm.h | 2 -- 3 files changed, 16 insertions(+), 6 deletions(-) diff --git a/xen/arch/arm/include/asm/mm.h b/xen/arch/arm/include/asm/mm.h index daef12e740..066a869783 100644 --- a/xen/arch/arm/include/asm/mm.h +++ b/xen/arch/arm/include/asm/mm.h @@ -108,9 +108,11 @@ struct page_info /* Page is Xen heap? */ #define _PGC_xen_heap PG_shift(2) #define PGC_xen_heap PG_mask(1, 2) - /* Page is static memory */ +#ifdef CONFIG_STATIC_MEMORY +/* Page is static memory */ #define _PGC_static PG_shift(3) #define PGC_static PG_mask(1, 3) +#endif /* ... */ /* Page is broken? */ #define _PGC_broken PG_shift(7) diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c index 743e3543fd..f27fa90ec4 100644 --- a/xen/common/page_alloc.c +++ b/xen/common/page_alloc.c @@ -1443,6 +1443,13 @@ static void free_heap_pages( ASSERT(order <= MAX_ORDER); + if ( unlikely(pg->count_info & PGC_static) ) + { + /* Pages of static memory shall not go back to the heap. */ + free_staticmem_pages(pg, 1UL << order, need_scrub); + return; + } + spin_lock(&heap_lock); for ( i = 0; i < (1 << order); i++ ) @@ -2636,12 +2643,14 @@ struct domain *get_pg_owner(domid_t domid) #ifdef CONFIG_STATIC_MEMORY /* Equivalent of free_heap_pages to free nr_mfns pages of static memory. */ -void __init free_staticmem_pages(struct page_info *pg, unsigned long nr_mfns, - bool need_scrub) +void free_staticmem_pages(struct page_info *pg, unsigned long nr_mfns, + bool need_scrub) { mfn_t mfn = page_to_mfn(pg); unsigned long i; + spin_lock(&heap_lock); + for ( i = 0; i < nr_mfns; i++ ) { mark_page_free(&pg[i], mfn_add(mfn, i)); @@ -2652,9 +2661,10 @@ void __init free_staticmem_pages(struct page_info *pg, unsigned long nr_mfns, scrub_one_page(pg); } - /* In case initializing page of static memory, mark it PGC_static. */ pg[i].count_info |= PGC_static; } + + spin_unlock(&heap_lock); } /* diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h index 3be754da92..1c4ddb336b 100644 --- a/xen/include/xen/mm.h +++ b/xen/include/xen/mm.h @@ -85,13 +85,11 @@ bool scrub_free_pages(void); } while ( false ) #define FREE_XENHEAP_PAGE(p) FREE_XENHEAP_PAGES(p, 0) -#ifdef CONFIG_STATIC_MEMORY /* These functions are for static memory */ void free_staticmem_pages(struct page_info *pg, unsigned long nr_mfns, bool need_scrub); int acquire_domstatic_pages(struct domain *d, mfn_t smfn, unsigned int nr_mfns, unsigned int memflags); -#endif /* Map machine page range in Xen virtual address space. */ int map_pages_to_xen(