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=-12.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 EF979C4363D for ; Tue, 22 Sep 2020 18:25:15 +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 9AC7A239D2 for ; Tue, 22 Sep 2020 18:25:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=citrix.com header.i=@citrix.com header.b="EFwciUQY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9AC7A239D2 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 localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kKmyQ-0008GW-0k; Tue, 22 Sep 2020 18:25:06 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kKmyP-0008GC-15 for xen-devel@lists.xenproject.org; Tue, 22 Sep 2020 18:25:05 +0000 X-Inumbo-ID: 5abe9782-d070-44d8-9f0e-6dd95fd55647 Received: from esa2.hc3370-68.iphmx.com (unknown [216.71.145.153]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 5abe9782-d070-44d8-9f0e-6dd95fd55647; Tue, 22 Sep 2020 18:25:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1600799104; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=DIebahfK17iSM+wvw7c9wbKbOGEtBVrBQ2p8g+TwCC8=; b=EFwciUQYjWLt5I8QMzUA+7muXidcOWbYPcBqtsPriG0LWT/OS10hcCcy 2Zk1fI0gjoyyOsEXlPkWD0B3k2NX0lQl9S6xH889zL7VTlwGOPoVjdgo6 6xAH/YkkIqGC30DVI8xs+WWdHJoi5OMxNwYSWnNBnF0us/j/uBe0jaJq+ E=; Authentication-Results: esa2.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: CIL0SFbCI+H2x0JROLZfnhW7ogjL/419mywgnwHWUhqo70XbyD5lqwkQzAifcWkdZKBA0aRKQN ZnPWEeo+eSOu1fB0iARKQyy9at2fRG5KrW3bVNqEhYNequfG4ldtbc2hmFobazDteDrQefO4Hf EbudCO5bx/cN0oKIkuR7vk5ChNZTHR1Rum07O8yUbj4cxVJuOgS1Ylhji1OgYAes/HbDbtmmbW ScKRHZi7ACw3OTpvtpZ4dh+9TUL6wSf8MCc+ZaAfxfoNTXikx0QFShD6RlXhLISajIvPZF7oZs WFM= X-SBRS: 2.7 X-MesageID: 27300354 X-Ironport-Server: esa2.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.77,291,1596513600"; d="scan'208";a="27300354" 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 v2 02/11] xen/gnttab: Rework resource acquisition Date: Tue, 22 Sep 2020 19:24:35 +0100 Message-ID: <20200922182444.12350-3-andrew.cooper3@citrix.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20200922182444.12350-1-andrew.cooper3@citrix.com> References: <20200922182444.12350-1-andrew.cooper3@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" The existing logic doesn't function in the general case for mapping a guests grant table, due to arbitrary 32 frame limit, and the default grant table limit being 64. In order to start addressing this, rework the existing grant table logic by implementing a single gnttab_acquire_resource(). This is far more efficient than the previous acquire_grant_table() in memory.c because it doesn't take the grant table write lock, and attempt to grow the table, for every single frame. The new gnttab_acquire_resource() function subsumes the previous two gnttab_get_{shared,status}_frame() helpers. No functional change. Signed-off-by: Andrew Cooper --- 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 v2: * Fix CentOS 6 build by initialising vaddrs to NULL * Add ASSERT_UNREACHABLE() and gt->status typecheck --- xen/common/grant_table.c | 102 +++++++++++++++++++++++++++++++----------- xen/common/memory.c | 42 +---------------- xen/include/xen/grant_table.h | 19 +++----- 3 files changed, 84 insertions(+), 79 deletions(-) diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c index a5d3ed8bda..912f07be47 100644 --- a/xen/common/grant_table.c +++ b/xen/common/grant_table.c @@ -4013,6 +4013,81 @@ static int gnttab_get_shared_frame_mfn(struct domain *d, return 0; } +int gnttab_acquire_resource( + struct domain *d, unsigned int id, unsigned long frame, + unsigned int nr_frames, xen_pfn_t mfn_list[]) +{ + struct grant_table *gt = d->grant_table; + unsigned int i = nr_frames, tot_frames; + mfn_t tmp; + void **vaddrs = NULL; + int rc; + + /* Input sanity. */ + if ( !nr_frames ) + return -EINVAL; + + /* Overflow checks */ + if ( frame + nr_frames < frame ) + return -EINVAL; + + tot_frames = frame + nr_frames; + if ( tot_frames != frame + nr_frames ) + return -EINVAL; + + /* Grow table if necessary. */ + grant_write_lock(gt); + switch ( id ) + { + case XENMEM_resource_grant_table_id_shared: + rc = gnttab_get_shared_frame_mfn(d, tot_frames - 1, &tmp); + break; + + case XENMEM_resource_grant_table_id_status: + if ( gt->gt_version != 2 ) + { + default: + rc = -EINVAL; + break; + } + rc = gnttab_get_status_frame_mfn(d, tot_frames - 1, &tmp); + break; + } + + /* Any errors from growing the table? */ + if ( rc ) + goto out; + + switch ( id ) + { + case XENMEM_resource_grant_table_id_shared: + vaddrs = gt->shared_raw; + break; + + case XENMEM_resource_grant_table_id_status: + /* Check that void ** is a suitable representation for gt->status. */ + BUILD_BUG_ON(!__builtin_types_compatible_p( + typeof(gt->status), grant_status_t **)); + vaddrs = (void **)gt->status; + break; + } + + if ( !vaddrs ) + { + ASSERT_UNREACHABLE(); + rc = -EINVAL; + goto out; + } + + for ( i = 0; i < nr_frames; ++i ) + mfn_list[i] = virt_to_mfn(vaddrs[frame + i]); + + out: + grant_write_unlock(gt); + + return rc; +} + int gnttab_map_frame(struct domain *d, unsigned long idx, gfn_t gfn, mfn_t *mfn) { int rc = 0; @@ -4047,33 +4122,6 @@ int gnttab_map_frame(struct domain *d, unsigned long idx, gfn_t gfn, mfn_t *mfn) return rc; } -int gnttab_get_shared_frame(struct domain *d, unsigned long idx, - mfn_t *mfn) -{ - struct grant_table *gt = d->grant_table; - int rc; - - grant_write_lock(gt); - rc = gnttab_get_shared_frame_mfn(d, idx, mfn); - grant_write_unlock(gt); - - return rc; -} - -int gnttab_get_status_frame(struct domain *d, unsigned long idx, - mfn_t *mfn) -{ - struct grant_table *gt = d->grant_table; - int rc; - - grant_write_lock(gt); - rc = (gt->gt_version == 2) ? - gnttab_get_status_frame_mfn(d, idx, mfn) : -EINVAL; - grant_write_unlock(gt); - - return rc; -} - static void gnttab_usage_print(struct domain *rd) { int first = 1; diff --git a/xen/common/memory.c b/xen/common/memory.c index 1bab0e80c2..177fc378d9 100644 --- a/xen/common/memory.c +++ b/xen/common/memory.c @@ -1007,44 +1007,6 @@ static long xatp_permission_check(struct domain *d, unsigned int space) return xsm_add_to_physmap(XSM_TARGET, current->domain, d); } -static int acquire_grant_table(struct domain *d, unsigned int id, - unsigned long frame, - unsigned int nr_frames, - xen_pfn_t mfn_list[]) -{ - unsigned int i = nr_frames; - - /* Iterate backwards in case table needs to grow */ - while ( i-- != 0 ) - { - mfn_t mfn = INVALID_MFN; - int rc; - - switch ( id ) - { - case XENMEM_resource_grant_table_id_shared: - rc = gnttab_get_shared_frame(d, frame + i, &mfn); - break; - - case XENMEM_resource_grant_table_id_status: - rc = gnttab_get_status_frame(d, frame + i, &mfn); - break; - - default: - rc = -EINVAL; - break; - } - - if ( rc ) - return rc; - - ASSERT(!mfn_eq(mfn, INVALID_MFN)); - mfn_list[i] = mfn_x(mfn); - } - - return 0; -} - static int acquire_resource( XEN_GUEST_HANDLE_PARAM(xen_mem_acquire_resource_t) arg) { @@ -1099,8 +1061,8 @@ static int acquire_resource( switch ( xmar.type ) { case XENMEM_resource_grant_table: - rc = acquire_grant_table(d, xmar.id, xmar.frame, xmar.nr_frames, - mfn_list); + rc = gnttab_acquire_resource(d, xmar.id, xmar.frame, xmar.nr_frames, + mfn_list); break; default: diff --git a/xen/include/xen/grant_table.h b/xen/include/xen/grant_table.h index 98603604b8..5a2c75b880 100644 --- a/xen/include/xen/grant_table.h +++ b/xen/include/xen/grant_table.h @@ -56,10 +56,10 @@ int mem_sharing_gref_to_gfn(struct grant_table *gt, grant_ref_t ref, int gnttab_map_frame(struct domain *d, unsigned long idx, gfn_t gfn, mfn_t *mfn); -int gnttab_get_shared_frame(struct domain *d, unsigned long idx, - mfn_t *mfn); -int gnttab_get_status_frame(struct domain *d, unsigned long idx, - mfn_t *mfn); + +int gnttab_acquire_resource( + struct domain *d, unsigned int id, unsigned long frame, + unsigned int nr_frames, xen_pfn_t mfn_list[]); #else @@ -93,14 +93,9 @@ static inline int gnttab_map_frame(struct domain *d, unsigned long idx, return -EINVAL; } -static inline int gnttab_get_shared_frame(struct domain *d, unsigned long idx, - mfn_t *mfn) -{ - return -EINVAL; -} - -static inline int gnttab_get_status_frame(struct domain *d, unsigned long idx, - mfn_t *mfn) +static inline int gnttab_acquire_resource( + struct domain *d, unsigned int id, unsigned long frame, + unsigned int nr_frames, xen_pfn_t mfn_list[]) { return -EINVAL; } -- 2.11.0