From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=45473 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PGweQ-00057l-C9 for qemu-devel@nongnu.org; Fri, 12 Nov 2010 11:38:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PGweP-0007bb-4l for qemu-devel@nongnu.org; Fri, 12 Nov 2010 11:38:58 -0500 Received: from mx1.redhat.com ([209.132.183.28]:40986) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PGweO-0007bH-UC for qemu-devel@nongnu.org; Fri, 12 Nov 2010 11:38:57 -0500 Message-ID: <4CDD6DC6.2050107@redhat.com> Date: Fri, 12 Nov 2010 17:39:34 +0100 From: Kevin Wolf MIME-Version: 1.0 References: <1289576289-27888-1-git-send-email-ryanh@us.ibm.com> <1289576289-27888-2-git-send-email-ryanh@us.ibm.com> In-Reply-To: <1289576289-27888-2-git-send-email-ryanh@us.ibm.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH 1/2] Implement drive_del to decouple block removal from device removal List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ryan Harper Cc: Stefan Hajnoczi , Anthony Liguori , "Michael S. Tsirkin" , qemu-devel@nongnu.org, Markus Armbruster Am 12.11.2010 16:38, schrieb Ryan Harper: > Currently device hotplug removal code is tied to device removal via > ACPI. All pci devices that are removable via device_del() require the > guest to respond to the request. In some cases the guest may not > respond leaving the device still accessible to the guest. The management > layer doesn't currently have a reliable way to revoke access to host > resource in the presence of an uncooperative guest. > > This patch implements a new monitor command, drive_del, which > provides an explicit command to revoke access to a host block device. > > drive_del first quiesces the block device (qemu_aio_flush; > bdrv_flush() and bdrv_close()). This prevents further IO from being > submitted against the host device. Finally, drive_del cleans up > pointers between the drive object (host resource) and the device > object (guest resource). > > Signed-off-by: Ryan Harper > --- > blockdev.c | 39 +++++++++++++++++++++++++++++++++++++++ > blockdev.h | 1 + > hmp-commands.hx | 18 ++++++++++++++++++ > 3 files changed, 58 insertions(+), 0 deletions(-) > > diff --git a/blockdev.c b/blockdev.c > index 6cb179a..f6ac439 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -14,6 +14,8 @@ > #include "qemu-option.h" > #include "qemu-config.h" > #include "sysemu.h" > +#include "hw/qdev.h" > +#include "block_int.h" > > static QTAILQ_HEAD(drivelist, DriveInfo) drives = QTAILQ_HEAD_INITIALIZER(drives); > > @@ -597,3 +599,40 @@ int do_change_block(Monitor *mon, const char *device, > } > return monitor_read_bdrv_key_start(mon, bs, NULL, NULL); > } > + > +int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data) > +{ > + const char *id = qdict_get_str(qdict, "id"); > + BlockDriverState *bs; > + BlockDriverState **ptr; > + Property *prop; > + > + bs = bdrv_find(id); > + if (!bs) { > + qerror_report(QERR_DEVICE_NOT_FOUND, id); > + return -1; > + } > + > + /* quiesce block driver; prevent further io */ > + qemu_aio_flush(); > + bdrv_flush(bs); > + bdrv_close(bs); > + > + /* clean up guest state from pointing to host resource by > + * finding and removing DeviceState "drive" property */ > + for (prop = bs->peer->info->props; prop && prop->name; prop++) { > + if (prop->info->type == PROP_TYPE_DRIVE) { > + ptr = qdev_get_prop_ptr(bs->peer, prop); > + if ((*ptr) == bs) { > + bdrv_detach(bs, bs->peer); > + *ptr = NULL; > + break; > + } > + } > + } > + > + /* clean up host side */ > + drive_uninit(drive_get_by_blockdev(bs)); > + > + return 0; > +} > diff --git a/blockdev.h b/blockdev.h > index 653affc..2a0559e 100644 > --- a/blockdev.h > +++ b/blockdev.h > @@ -51,5 +51,6 @@ int do_eject(Monitor *mon, const QDict *qdict, QObject **ret_data); > int do_block_set_passwd(Monitor *mon, const QDict *qdict, QObject **ret_data); > int do_change_block(Monitor *mon, const char *device, > const char *filename, const char *fmt); > +int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data); > > #endif > diff --git a/hmp-commands.hx b/hmp-commands.hx > index e5585ba..d6dc18c 100644 > --- a/hmp-commands.hx > +++ b/hmp-commands.hx > @@ -68,6 +68,24 @@ Eject a removable medium (use -f to force it). > ETEXI > > { > + .name = "drive_del", > + .args_type = "id:s", > + .params = "device", > + .help = "remove host block device", > + .user_print = monitor_user_noop, > + .mhandler.cmd_new = do_drive_del, > + }, > + > +STEXI > +@item delete @var{device} > +@findex delete I think this should be @item drive_del and @findex drive_del. Kevin