From patchwork Tue Sep 20 20:43:58 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 672436 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3sdvt539jwz9sBr for ; Wed, 21 Sep 2016 06:46:05 +1000 (AEST) Received: from localhost ([::1]:37991 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bmRvW-0004l6-SX for incoming@patchwork.ozlabs.org; Tue, 20 Sep 2016 16:46:02 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42249) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bmRtx-0003SY-2K for qemu-devel@nongnu.org; Tue, 20 Sep 2016 16:44:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bmRtu-0006Iu-Ck for qemu-devel@nongnu.org; Tue, 20 Sep 2016 16:44:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34100) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bmRtp-0006Fp-UM; Tue, 20 Sep 2016 16:44:18 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6B33C9E615; Tue, 20 Sep 2016 20:44:17 +0000 (UTC) Received: from localhost (ovpn-204-20.brq.redhat.com [10.40.204.20]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u8KKiFwY000412 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 20 Sep 2016 16:44:16 -0400 From: Max Reitz To: qemu-block@nongnu.org Date: Tue, 20 Sep 2016 22:43:58 +0200 Message-Id: <1474404241-23029-6-git-send-email-mreitz@redhat.com> In-Reply-To: <1474404241-23029-1-git-send-email-mreitz@redhat.com> References: <1474404241-23029-1-git-send-email-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Tue, 20 Sep 2016 20:44:17 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL v4 5/8] blockdev: Add dynamic module loading for block drivers X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Marc Mari Extend the current module interface to allow for block drivers to be loaded dynamically on request. The only block drivers that can be converted into modules are the drivers that don't perform any init operation except for registering themselves. In addition, only the protocol drivers are being modularized, as they are the only ones which see significant performance benefits. The format drivers do not generally link to external libraries, so modularizing them is of no benefit from a performance perspective. All the necessary module information is located in a new structure found in module_block.h This spoils the purpose of 5505e8b76f (block/dmg: make it modular). Before this patch, if module build is enabled, block-dmg.so is linked to libbz2, whereas the main binary is not. In downstream, theoretically, it means only the qemu-block-extra package depends on libbz2, while the main QEMU package needn't to. With this patch, we (temporarily) change the case so that the main QEMU depends on libbz2 again. Signed-off-by: Marc Marí Signed-off-by: Colin Lord Reviewed-by: Stefan Hajnoczi Message-id: 1471008424-16465-4-git-send-email-clord@redhat.com Reviewed-by: Max Reitz [mreitz: Do a signed comparison against the length of block_driver_modules[], so it will not cause a compile error when empty] Signed-off-by: Max Reitz --- Makefile | 3 --- block.c | 62 +++++++++++++++++++++++++++++++++++++++++++++------ block/Makefile.objs | 3 +-- include/qemu/module.h | 3 +++ util/module.c | 38 +++++++++---------------------- 5 files changed, 70 insertions(+), 39 deletions(-) diff --git a/Makefile b/Makefile index b7d1200..f103616 100644 --- a/Makefile +++ b/Makefile @@ -247,9 +247,6 @@ Makefile: $(version-obj-y) $(version-lobj-y) libqemustub.a: $(stub-obj-y) libqemuutil.a: $(util-obj-y) -block-modules = $(foreach o,$(block-obj-m),"$(basename $(subst /,-,$o))",) NULL -util/module.o-cflags = -D'CONFIG_BLOCK_MODULES=$(block-modules)' - ###################################################################### qemu-img.o: qemu-img-cmds.h diff --git a/block.c b/block.c index 66ed1c0..afaff93 100644 --- a/block.c +++ b/block.c @@ -27,6 +27,7 @@ #include "block/blockjob.h" #include "block/nbd.h" #include "qemu/error-report.h" +#include "module_block.h" #include "qemu/module.h" #include "qapi/qmp/qerror.h" #include "qapi/qmp/qbool.h" @@ -242,17 +243,40 @@ BlockDriverState *bdrv_new(void) return bs; } -BlockDriver *bdrv_find_format(const char *format_name) +static BlockDriver *bdrv_do_find_format(const char *format_name) { BlockDriver *drv1; + QLIST_FOREACH(drv1, &bdrv_drivers, list) { if (!strcmp(drv1->format_name, format_name)) { return drv1; } } + return NULL; } +BlockDriver *bdrv_find_format(const char *format_name) +{ + BlockDriver *drv1; + int i; + + drv1 = bdrv_do_find_format(format_name); + if (drv1) { + return drv1; + } + + /* The driver isn't registered, maybe we need to load a module */ + for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) { + if (!strcmp(block_driver_modules[i].format_name, format_name)) { + block_module_load_one(block_driver_modules[i].library_name); + break; + } + } + + return bdrv_do_find_format(format_name); +} + static int bdrv_is_whitelisted(BlockDriver *drv, bool read_only) { static const char *whitelist_rw[] = { @@ -461,6 +485,19 @@ static BlockDriver *find_hdev_driver(const char *filename) return drv; } +static BlockDriver *bdrv_do_find_protocol(const char *protocol) +{ + BlockDriver *drv1; + + QLIST_FOREACH(drv1, &bdrv_drivers, list) { + if (drv1->protocol_name && !strcmp(drv1->protocol_name, protocol)) { + return drv1; + } + } + + return NULL; +} + BlockDriver *bdrv_find_protocol(const char *filename, bool allow_protocol_prefix, Error **errp) @@ -469,6 +506,7 @@ BlockDriver *bdrv_find_protocol(const char *filename, char protocol[128]; int len; const char *p; + int i; /* TODO Drivers without bdrv_file_open must be specified explicitly */ @@ -495,15 +533,25 @@ BlockDriver *bdrv_find_protocol(const char *filename, len = sizeof(protocol) - 1; memcpy(protocol, filename, len); protocol[len] = '\0'; - QLIST_FOREACH(drv1, &bdrv_drivers, list) { - if (drv1->protocol_name && - !strcmp(drv1->protocol_name, protocol)) { - return drv1; + + drv1 = bdrv_do_find_protocol(protocol); + if (drv1) { + return drv1; + } + + for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) { + if (block_driver_modules[i].protocol_name && + !strcmp(block_driver_modules[i].protocol_name, protocol)) { + block_module_load_one(block_driver_modules[i].library_name); + break; } } - error_setg(errp, "Unknown protocol '%s'", protocol); - return NULL; + drv1 = bdrv_do_find_protocol(protocol); + if (!drv1) { + error_setg(errp, "Unknown protocol '%s'", protocol); + } + return drv1; } /* diff --git a/block/Makefile.objs b/block/Makefile.objs index 55da626..3da471e 100644 --- a/block/Makefile.objs +++ b/block/Makefile.objs @@ -1,4 +1,4 @@ -block-obj-y += raw_bsd.o qcow.o vdi.o vmdk.o cloop.o bochs.o vpc.o vvfat.o +block-obj-y += raw_bsd.o qcow.o vdi.o vmdk.o cloop.o bochs.o vpc.o vvfat.o dmg.o block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o qcow2-cache.o block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o block-obj-y += qed-check.o @@ -40,7 +40,6 @@ gluster.o-libs := $(GLUSTERFS_LIBS) ssh.o-cflags := $(LIBSSH2_CFLAGS) ssh.o-libs := $(LIBSSH2_LIBS) archipelago.o-libs := $(ARCHIPELAGO_LIBS) -block-obj-m += dmg.o dmg.o-libs := $(BZIP2_LIBS) qcow.o-libs := -lz linux-aio.o-libs := -laio diff --git a/include/qemu/module.h b/include/qemu/module.h index 2370708..dc2c9d4 100644 --- a/include/qemu/module.h +++ b/include/qemu/module.h @@ -52,9 +52,12 @@ typedef enum { #define qapi_init(function) module_init(function, MODULE_INIT_QAPI) #define type_init(function) module_init(function, MODULE_INIT_QOM) +#define block_module_load_one(lib) module_load_one("block-", lib) + void register_module_init(void (*fn)(void), module_init_type type); void register_dso_module_init(void (*fn)(void), module_init_type type); void module_call_init(module_init_type type); +void module_load_one(const char *prefix, const char *lib_name); #endif diff --git a/util/module.c b/util/module.c index 86e3f7a..a5f7fbd 100644 --- a/util/module.c +++ b/util/module.c @@ -87,14 +87,11 @@ void register_dso_module_init(void (*fn)(void), module_init_type type) QTAILQ_INSERT_TAIL(&dso_init_list, e, node); } -static void module_load(module_init_type type); - void module_call_init(module_init_type type) { ModuleTypeList *l; ModuleEntry *e; - module_load(type); l = find_type(type); QTAILQ_FOREACH(e, l, node) { @@ -145,6 +142,7 @@ static int module_load_file(const char *fname) ret = -EINVAL; } else { QTAILQ_FOREACH(e, &dso_init_list, node) { + e->init(); register_module_init(e->init, e->type); } ret = 0; @@ -159,14 +157,10 @@ out: } #endif -static void module_load(module_init_type type) +void module_load_one(const char *prefix, const char *lib_name) { #ifdef CONFIG_MODULES char *fname = NULL; - const char **mp; - static const char *block_modules[] = { - CONFIG_BLOCK_MODULES - }; char *exec_dir; char *dirs[3]; int i = 0; @@ -177,15 +171,6 @@ static void module_load(module_init_type type) return; } - switch (type) { - case MODULE_INIT_BLOCK: - mp = block_modules; - break; - default: - /* no other types have dynamic modules for now*/ - return; - } - exec_dir = qemu_get_exec_dir(); dirs[i++] = g_strdup_printf("%s", CONFIG_QEMU_MODDIR); dirs[i++] = g_strdup_printf("%s/..", exec_dir ? : ""); @@ -194,16 +179,15 @@ static void module_load(module_init_type type) g_free(exec_dir); exec_dir = NULL; - for ( ; *mp; mp++) { - for (i = 0; i < ARRAY_SIZE(dirs); i++) { - fname = g_strdup_printf("%s/%s%s", dirs[i], *mp, HOST_DSOSUF); - ret = module_load_file(fname); - g_free(fname); - fname = NULL; - /* Try loading until loaded a module file */ - if (!ret) { - break; - } + for (i = 0; i < ARRAY_SIZE(dirs); i++) { + fname = g_strdup_printf("%s/%s%s%s", + dirs[i], prefix, lib_name, HOST_DSOSUF); + ret = module_load_file(fname); + g_free(fname); + fname = NULL; + /* Try loading until loaded a module file */ + if (!ret) { + break; } }