From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B82BC433E0 for ; Tue, 12 Jan 2021 19:49:29 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 3BB2B2311B for ; Tue, 12 Jan 2021 19:49:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3BB2B2311B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=citrix.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.65961.116980 (Exim 4.92) (envelope-from ) id 1kzPfL-0006Oy-IM; Tue, 12 Jan 2021 19:49:19 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 65961.116980; Tue, 12 Jan 2021 19:49:19 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kzPfL-0006Ob-Cg; Tue, 12 Jan 2021 19:49:19 +0000 Received: by outflank-mailman (input) for mailman id 65961; Tue, 12 Jan 2021 19:49:17 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kzPfJ-00064W-9l for xen-devel@lists.xenproject.org; Tue, 12 Jan 2021 19:49:17 +0000 Received: from esa4.hc3370-68.iphmx.com (unknown [216.71.155.144]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 106c2de9-507a-4377-82bf-b3d0916aba17; Tue, 12 Jan 2021 19:49:03 +0000 (UTC) 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: 106c2de9-507a-4377-82bf-b3d0916aba17 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1610480943; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=dQKNhP8sDS8/NNw+FPEKxJTqs+cEaD8DbMzBYrGIXcA=; b=etVESbrJmCDNsvpGpRab3vaCtGtXJx0Xy7TkGzCKOZhC/D8ZzkCa9WQk pG4ISFTsUoQ8fdlXNc3YNDHlDhC0FoFW5R/SwQQ/xLOvo4ixBh/O/4aWC cvXd5tpcSWMNK4Hwu6iO5ZE1iJir/co6At4J0VF0NAUSegxdCmzLahQZe 4=; Authentication-Results: esa4.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: QYqpyNo1SW6zUx9eaBUQRfimvj8kxiucS0ZbUabB7XlyEZIiGlwxOJLgQJp9IXVzaYy1Dqi6tB gZqfG0U4K4O6WfCLUGNmbzp8SIJdpsFPts1Ww+C0WEmqMKAM2/rJi/LBdLTuAKj9P30Bhh6WVp hC9G/QsEOWMUbMdrmNBCsb2EZ7/F5dsE7ogbTqXOFGFziRg1iFIeLj+LaMVfy17o0RIKC1ztK3 dCI8udxBVAlSKCsINIyV3WwFr8bZjfIXOb1ySQ6RdvG15ppa3nJDZGpaxGDdGuAvyuQqKMdmK8 Ujw= X-SBRS: 5.2 X-MesageID: 36235810 X-Ironport-Server: esa4.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.79,342,1602561600"; d="scan'208";a="36235810" From: Andrew Cooper To: Xen-devel CC: Andrew Cooper , George Dunlap , Ian Jackson , Jan Beulich , Stefano Stabellini , Wei Liu , Julien Grall , Paul Durrant , =?UTF-8?q?Micha=C5=82=20Leszczy=C5=84ski?= , Hubert Jasudowicz , Tamas K Lengyel Subject: [PATCH v3 5/7] xen/memory: Improve compat XENMEM_acquire_resource handling Date: Tue, 12 Jan 2021 19:48:39 +0000 Message-ID: <20210112194841.1537-6-andrew.cooper3@citrix.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20210112194841.1537-1-andrew.cooper3@citrix.com> References: <20210112194841.1537-1-andrew.cooper3@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit The frame_list is an input, or an output, depending on whether the calling domain is translated or not. The array does not need marshalling in both directions. Furthermore, the copy-in loop was very inefficient, copying 4 bytes at at time. Rewrite it to copy in all nr_frames at once, and then expand compat_pfn_t to xen_pfn_t in place. Re-position the copy-in loop to simplify continuation support in a future patch, and reduce the scope of certain variables. No change in guest observed behaviour. Signed-off-by: Andrew Cooper Reviewed-by: Paul Durrant --- CC: George Dunlap CC: Ian Jackson CC: Jan Beulich CC: Stefano Stabellini CC: Wei Liu CC: Julien Grall CC: Paul Durrant CC: Michał Leszczyński CC: Hubert Jasudowicz CC: Tamas K Lengyel --- xen/common/compat/memory.c | 65 ++++++++++++++++++++++++++++------------------ 1 file changed, 40 insertions(+), 25 deletions(-) diff --git a/xen/common/compat/memory.c b/xen/common/compat/memory.c index ed92e05b08..834c5e19d1 100644 --- a/xen/common/compat/memory.c +++ b/xen/common/compat/memory.c @@ -55,6 +55,8 @@ static int get_reserved_device_memory(xen_pfn_t start, xen_ulong_t nr, int compat_memory_op(unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) compat) { + struct vcpu *curr = current; + struct domain *currd = curr->domain; int split, op = cmd & MEMOP_CMD_MASK; long rc; unsigned int start_extent = cmd >> MEMOP_EXTENT_SHIFT; @@ -399,7 +401,7 @@ int compat_memory_op(unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) compat) case XENMEM_acquire_resource: { - xen_pfn_t *xen_frame_list; + xen_pfn_t *xen_frame_list = NULL; unsigned int max_nr_frames; if ( copy_from_guest(&cmp.mar, compat, 1) ) @@ -417,28 +419,10 @@ int compat_memory_op(unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) compat) if ( cmp.mar.nr_frames > max_nr_frames ) return -E2BIG; - if ( compat_handle_is_null(cmp.mar.frame_list) ) - xen_frame_list = NULL; - else - { + /* Marshal the frame list in the remainder of the xlat space. */ + if ( !compat_handle_is_null(cmp.mar.frame_list) ) xen_frame_list = (xen_pfn_t *)(nat.mar + 1); - if ( !compat_handle_okay(cmp.mar.frame_list, - cmp.mar.nr_frames) ) - return -EFAULT; - - for ( i = 0; i < cmp.mar.nr_frames; i++ ) - { - compat_pfn_t frame; - - if ( __copy_from_compat_offset( - &frame, cmp.mar.frame_list, i, 1) ) - return -EFAULT; - - xen_frame_list[i] = frame; - } - } - #define XLAT_mem_acquire_resource_HNDL_frame_list(_d_, _s_) \ set_xen_guest_handle((_d_)->frame_list, xen_frame_list) @@ -446,6 +430,31 @@ int compat_memory_op(unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) compat) #undef XLAT_mem_acquire_resource_HNDL_frame_list + if ( xen_frame_list && cmp.mar.nr_frames ) + { + /* + * frame_list is an input for translated guests, and an output + * for untranslated guests. Only copy in for translated guests. + */ + if ( paging_mode_translate(currd) ) + { + compat_pfn_t *compat_frame_list = (void *)xen_frame_list; + + if ( !compat_handle_okay(cmp.mar.frame_list, + cmp.mar.nr_frames) || + __copy_from_compat_offset( + compat_frame_list, cmp.mar.frame_list, + 0, cmp.mar.nr_frames) ) + return -EFAULT; + + /* + * Iterate backwards over compat_frame_list[] expanding + * compat_pfn_t to xen_pfn_t in place. + */ + for ( int x = cmp.mar.nr_frames - 1; x >= 0; --x ) + xen_frame_list[x] = compat_frame_list[x]; + } + } break; } default: @@ -590,8 +599,6 @@ int compat_memory_op(unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) compat) case XENMEM_acquire_resource: { - const xen_pfn_t *xen_frame_list = (xen_pfn_t *)(nat.mar + 1); - compat_pfn_t *compat_frame_list = (compat_pfn_t *)(nat.mar + 1); DEFINE_XEN_GUEST_HANDLE(compat_mem_acquire_resource_t); if ( compat_handle_is_null(cmp.mar.frame_list) ) @@ -601,9 +608,18 @@ int compat_memory_op(unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) compat) compat_mem_acquire_resource_t), nat.mar, nr_frames) ) return -EFAULT; + break; } - else + + /* + * frame_list is an input for translated guests, and an output for + * untranslated guests. Only copy out for untranslated guests. + */ + if ( !paging_mode_translate(currd) ) { + const xen_pfn_t *xen_frame_list = (xen_pfn_t *)(nat.mar + 1); + compat_pfn_t *compat_frame_list = (compat_pfn_t *)(nat.mar + 1); + /* * NOTE: the smaller compat array overwrites the native * array. @@ -625,7 +641,6 @@ int compat_memory_op(unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) compat) cmp.mar.nr_frames) ) return -EFAULT; } - break; } -- 2.11.0