diff options
| -rw-r--r-- | Makefile.objs | 1 | ||||
| -rw-r--r-- | block/file-posix.c | 30 | ||||
| -rw-r--r-- | docs/pr-manager.rst | 51 | ||||
| -rw-r--r-- | include/scsi/pr-manager.h | 56 | ||||
| -rw-r--r-- | qapi/block-core.json | 4 | ||||
| -rw-r--r-- | scsi/Makefile.objs | 2 | ||||
| -rw-r--r-- | scsi/pr-manager.c | 109 | ||||
| -rw-r--r-- | scsi/trace-events | 3 | ||||
| -rw-r--r-- | vl.c | 3 |
9 files changed, 258 insertions, 1 deletions
diff --git a/Makefile.objs b/Makefile.objs index 9e89100302..bdfa3b6177 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -171,6 +171,7 @@ trace-events-subdirs += qapi trace-events-subdirs += accel/tcg trace-events-subdirs += accel/kvm trace-events-subdirs += nbd +trace-events-subdirs += scsi trace-events-files = $(SRC_PATH)/trace-events $(trace-events-subdirs:%=$(SRC_PATH)/%/trace-events) diff --git a/block/file-posix.c b/block/file-posix.c index 6acbd56238..ab12a2b591 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -33,6 +33,9 @@ #include "block/raw-aio.h" #include "qapi/qmp/qstring.h" +#include "scsi/pr-manager.h" +#include "scsi/constants.h" + #if defined(__APPLE__) && (__MACH__) #include <paths.h> #include <sys/param.h> @@ -155,6 +158,8 @@ typedef struct BDRVRawState { bool page_cache_inconsistent:1; bool has_fallocate; bool needs_alignment; + + PRManager *pr_mgr; } BDRVRawState; typedef struct BDRVRawReopenState { @@ -402,6 +407,11 @@ static QemuOptsList raw_runtime_opts = { .type = QEMU_OPT_STRING, .help = "file locking mode (on/off/auto, default: auto)", }, + { + .name = "pr-manager", + .type = QEMU_OPT_STRING, + .help = "id of persistent reservation manager object (default: none)", + }, { /* end of list */ } }, }; @@ -413,6 +423,7 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, QemuOpts *opts; Error *local_err = NULL; const char *filename = NULL; + const char *str; BlockdevAioOptions aio, aio_default; int fd, ret; struct stat st; @@ -476,6 +487,16 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, abort(); } + str = qemu_opt_get(opts, "pr-manager"); + if (str) { + s->pr_mgr = pr_manager_lookup(str, &local_err); + if (local_err) { + error_propagate(errp, local_err); + ret = -EINVAL; + goto fail; + } + } + s->open_flags = open_flags; raw_parse_flags(bdrv_flags, &s->open_flags); @@ -2597,6 +2618,15 @@ static BlockAIOCB *hdev_aio_ioctl(BlockDriverState *bs, if (fd_open(bs) < 0) return NULL; + if (req == SG_IO && s->pr_mgr) { + struct sg_io_hdr *io_hdr = buf; + if (io_hdr->cmdp[0] == PERSISTENT_RESERVE_OUT || + io_hdr->cmdp[0] == PERSISTENT_RESERVE_IN) { + return pr_manager_execute(s->pr_mgr, bdrv_get_aio_context(bs), + s->fd, io_hdr, cb, opaque); + } + } + acb = g_new(RawPosixAIOData, 1); acb->bs = bs; acb->aio_type = QEMU_AIO_IOCTL; diff --git a/docs/pr-manager.rst b/docs/pr-manager.rst new file mode 100644 index 0000000000..b6089fb57c --- /dev/null +++ b/docs/pr-manager.rst @@ -0,0 +1,51 @@ +====================================== +Persistent reservation managers +====================================== + +SCSI persistent Reservations allow restricting access to block devices +to specific initiators in a shared storage setup. When implementing +clustering of virtual machines, it is a common requirement for virtual +machines to send persistent reservation SCSI commands. However, +the operating system restricts sending these commands to unprivileged +programs because incorrect usage can disrupt regular operation of the +storage fabric. + +For this reason, QEMU's SCSI passthrough devices, ``scsi-block`` +and ``scsi-generic`` (both are only available on Linux) can delegate +implementation of persistent reservations to a separate object, +the "persistent reservation manager". Only PERSISTENT RESERVE OUT and +PERSISTENT RESERVE IN commands are passed to the persistent reservation +manager object; other commands are processed by QEMU as usual. + +----------------------------------------- +Defining a persistent reservation manager +----------------------------------------- + +A persistent reservation manager is an instance of a subclass of the +"pr-manager" QOM class. + +Right now only one subclass is defined, ``pr-manager-helper``, which +forwards the commands to an external privileged helper program +over Unix sockets. The helper program only allows sending persistent +reservation commands to devices for which QEMU has a file descriptor, +so that QEMU will not be able to effect persistent reservations +unless it has access to both the socket and the device. + +``pr-manager-helper`` has a single string property, ``path``, which +accepts the path to the helper program's Unix socket. For example, +the following command line defines a ``pr-manager-helper`` object and +attaches it to a SCSI passthrough device:: + + $ qemu-system-x86_64 + -device virtio-scsi \ + -object pr-manager-helper,id=helper0,path=/var/run/qemu-pr-helper.sock + -drive if=none,id=hd,driver=raw,file.filename=/dev/sdb,file.pr-manager=helper0 + -device scsi-block,drive=hd + +Alternatively, using ``-blockdev``:: + + $ qemu-system-x86_64 + -device virtio-scsi \ + -object pr-manager-helper,id=helper0,path=/var/run/qemu-pr-helper.sock + -blockdev node-name=hd,driver=raw,file.driver=host_device,file.filename=/dev/sdb,file.pr-manager=helper0 + -device scsi-block,drive=hd diff --git a/include/scsi/pr-manager.h b/include/scsi/pr-manager.h new file mode 100644 index 0000000000..b2b37d63bc --- /dev/null +++ b/include/scsi/pr-manager.h @@ -0,0 +1,56 @@ +#ifndef PR_MANAGER_H +#define PR_MANAGER_H + +#include "qom/object.h" +#include "qapi/qmp/qdict.h" +#include "qapi/visitor.h" +#include "qom/object_interfaces.h" +#include "block/aio.h" + +#define TYPE_PR_MANAGER "pr-manager" + +#define PR_MANAGER_CLASS(klass) \ + OBJECT_CLASS_CHECK(PRManagerClass, (klass), TYPE_PR_MANAGER) +#define PR_MANAGER_GET_CLASS(obj) \ + OBJECT_GET_CLASS(PRManagerClass, (obj), TYPE_PR_MANAGER) +#define PR_MANAGER(obj) \ + OBJECT_CHECK(PRManager, (obj), TYPE_PR_MANAGER) + +struct sg_io_hdr; + +typedef struct PRManager { + /* <private> */ + Object parent; +} PRManager; + +/** + * PRManagerClass: + * @parent_class: the base class + * @run: callback invoked in thread pool context + */ +typedef struct PRManagerClass { + /* <private> */ + ObjectClass parent_class; + + /* <public> */ + int (*run)(PRManager *pr_mgr, int fd, struct sg_io_hdr *hdr); +} PRManagerClass; + +BlockAIOCB *pr_manager_execute(PRManager *pr_mgr, + AioContext *ctx, int fd, + struct sg_io_hdr *hdr, + BlockCompletionFunc *complete, + void *opaque); + +#ifdef CONFIG_LINUX +PRManager *pr_manager_lookup(const char *id, Error **errp); +#else +static inline PRManager *pr_manager_lookup(const char *id, Error **errp) +{ + /* The classes do not exist at all! */ + error_setg(errp, "No persistent reservation manager with id '%s'", id); + return NULL; +} +#endif + +#endif diff --git a/qapi/block-core.json b/qapi/block-core.json index bb11815608..c69a395804 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -2241,6 +2241,9 @@ # Driver specific block device options for the file backend. # # @filename: path to the image file +# @pr-manager: the id for the object that will handle persistent reservations +# for this device (default: none, forward the commands via SG_IO; +# since 2.11) # @aio: AIO backend (default: threads) (since: 2.8) # @locking: whether to enable file locking. If set to 'auto', only enable # when Open File Descriptor (OFD) locking API is available @@ -2250,6 +2253,7 @@ ## { 'struct': 'BlockdevOptionsFile', 'data': { 'filename': 'str', + '*pr-manager': 'str', '*locking': 'OnOffAuto', '*aio': 'BlockdevAioOptions' } } diff --git a/scsi/Makefile.objs b/scsi/Makefile.objs index 31b82a5a36..5496d2ae6a 100644 --- a/scsi/Makefile.objs +++ b/scsi/Makefile.objs @@ -1 +1,3 @@ block-obj-y += utils.o + +block-obj-$(CONFIG_LINUX) += pr-manager.o diff --git a/scsi/pr-manager.c b/scsi/pr-manager.c new file mode 100644 index 0000000000..87c45db5d4 --- /dev/null +++ b/scsi/pr-manager.c @@ -0,0 +1,109 @@ +/* + * Persistent reservation manager abstract class + * + * Copyright (c) 2017 Red Hat, Inc. + * + * Author: Paolo Bonzini <pbonzini@redhat.com> + * + * This code is licensed under the LGPL. + * + */ + +#include "qemu/osdep.h" +#include <scsi/sg.h> + +#include "qapi/error.h" +#include "block/aio.h" +#include "block/thread-pool.h" +#include "scsi/pr-manager.h" +#include "trace.h" + +typedef struct PRManagerData { + PRManager *pr_mgr; + struct sg_io_hdr *hdr; + int fd; +} PRManagerData; + +static int pr_manager_worker(void *opaque) +{ + PRManagerData *data = opaque; + PRManager *pr_mgr = data->pr_mgr; + PRManagerClass *pr_mgr_class = + PR_MANAGER_GET_CLASS(pr_mgr); + struct sg_io_hdr *hdr = data->hdr; + int fd = data->fd; + int r; + + g_free(data); + trace_pr_manager_run(fd, hdr->cmdp[0], hdr->cmdp[1]); + + /* The reference was taken in pr_manager_execute. */ + r = pr_mgr_class->run(pr_mgr, fd, hdr); + object_unref(OBJECT(pr_mgr)); + return r; +} + + +BlockAIOCB *pr_manager_execute(PRManager *pr_mgr, + AioContext *ctx, int fd, + struct sg_io_hdr *hdr, + BlockCompletionFunc *complete, + void *opaque) +{ + PRManagerData *data = g_new(PRManagerData, 1); + ThreadPool *pool = aio_get_thread_pool(ctx); + + trace_pr_manager_execute(fd, hdr->cmdp[0], hdr->cmdp[1], opaque); + data->pr_mgr = pr_mgr; + data->fd = fd; + data->hdr = hdr; + + /* The matching object_unref is in pr_manager_worker. */ + object_ref(OBJECT(pr_mgr)); + return thread_pool_submit_aio(pool, pr_manager_worker, + data, complete, opaque); +} + +static const TypeInfo pr_manager_info = { + .parent = TYPE_OBJECT, + .name = TYPE_PR_MANAGER, + .class_size = sizeof(PRManagerClass), + .abstract = true, + .interfaces = (InterfaceInfo[]) { + { TYPE_USER_CREATABLE }, + { } + } +}; + +PRManager *pr_manager_lookup(const char *id, Error **errp) +{ + Object *obj; + PRManager *pr_mgr; + + obj = object_resolve_path_component(object_get_objects_root(), id); + if (!obj) { + error_setg(errp, "No persistent reservation manager with id '%s'", id); + return NULL; + } + + pr_mgr = (PRManager *) + object_dynamic_cast(obj, + TYPE_PR_MANAGER); + if (!pr_mgr) { + error_setg(errp, + "Object with id '%s' is not a persistent reservation manager", + id); + return NULL; + } + + return pr_mgr; +} + +static void +pr_manager_register_types(void) +{ + type_register_static(&pr_manager_info); +} + + +type_init(pr_manager_register_types); diff --git a/scsi/trace-events b/scsi/trace-events new file mode 100644 index 0000000000..45f5b6e49b --- /dev/null +++ b/scsi/trace-events @@ -0,0 +1,3 @@ +# scsi/pr-manager.c +pr_manager_execute(int fd, int cmd, int sa, void *opaque) "fd=%d cmd=0x%02x service action=0x%02x opaque=%p" +pr_manager_run(int fd, int cmd, int sa) "fd=%d cmd=0x%02x service action=0x%02x" @@ -2893,7 +2893,8 @@ static int machine_set_property(void *opaque, */ static bool object_create_initial(const char *type) { - if (g_str_equal(type, "rng-egd")) { + if (g_str_equal(type, "rng-egd") || + g_str_has_prefix(type, "pr-manager-")) { return false; } |