Re: [libvirt] [PATCH 3/5] qemu: add usb-bot support from disks points of view
On Mo, 2013-09-02 at 13:57 +0100, Daniel P. Berrange wrote: On Mon, Sep 02, 2013 at 05:38:42PM +0800, Guannan Ren wrote: usb-bot only supports 16 luns(0~15) and they must be contiguous, (using lun 0 and 2 without 1 doesn't work). In this case qemu doesn't throw an error, we can not find the lun 2 in guests. So Adding a checking function in libvirt to prevent from this case. Hmm, this seems like a problematic restriction. It's how the hardware works. How does this work if we start off a guest with 3 disks attached to the usb-bot SCSI controller. Then hot-unplug the 2nd disk. You can't hotplug individual luns anyway. cheers, Gerd -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [PATCH 3/5] qemu: add usb-bot support from disks points of view
On Tue, Sep 03, 2013 at 09:51:52AM +0200, Gerd Hoffmann wrote: On Mo, 2013-09-02 at 13:57 +0100, Daniel P. Berrange wrote: On Mon, Sep 02, 2013 at 05:38:42PM +0800, Guannan Ren wrote: usb-bot only supports 16 luns(0~15) and they must be contiguous, (using lun 0 and 2 without 1 doesn't work). In this case qemu doesn't throw an error, we can not find the lun 2 in guests. So Adding a checking function in libvirt to prevent from this case. Hmm, this seems like a problematic restriction. It's how the hardware works. How does this work if we start off a guest with 3 disks attached to the usb-bot SCSI controller. Then hot-unplug the 2nd disk. You can't hotplug individual luns anyway. How does hotplug/unplug work in the context of usb-bot ? AFAIK we need to be able to run device_add usb_bot drive_add file... device_add scsi-hd And the reverse, to unplug it, if we're to have feature parity with usb-storage. Daniel -- |: http://berrange.com -o-http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [PATCH 3/5] qemu: add usb-bot support from disks points of view
Hi,
How does this work if we start off a guest with 3 disks
attached to the usb-bot SCSI controller. Then hot-unplug
the 2nd disk.
You can't hotplug individual luns anyway.
How does hotplug/unplug work in the context of usb-bot ?
AFAIK we need to be able to run
device_add usb_bot
drive_add file...
device_add scsi-hd
And the reverse, to unplug it, if we're to have feature parity with
usb-storage.
Hot-unplug is easy. You can remove the usb-bot device which will also
remove all child devices.
Hot-plug doesn't work at the moment, and I don't see any obvious way to
fix that properly :-(
We need some way to hotplug a *group* of devices (usb-bot + all
children) as usb-bot itself is hotpluggable but the individual scsi
devices connected to it are not.
I could allow hotplug on usb-bot as workaround, then you can do
stop
device_add usb_bot
device_add scsi-{hd,cd,whatever}
cont
but that would be more a gross hack than a solution ...
cheers,
Gerd
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Re: [libvirt] [PATCH 3/5] qemu: add usb-bot support from disks points of view
On 09/03/2013 08:06 AM, Gerd Hoffmann wrote:
Hi,
How does this work if we start off a guest with 3 disks
attached to the usb-bot SCSI controller. Then hot-unplug
the 2nd disk.
You can't hotplug individual luns anyway.
How does hotplug/unplug work in the context of usb-bot ?
AFAIK we need to be able to run
device_add usb_bot
drive_add file...
device_add scsi-hd
And the reverse, to unplug it, if we're to have feature parity with
usb-storage.
Hot-unplug is easy. You can remove the usb-bot device which will also
remove all child devices.
Hot-plug doesn't work at the moment, and I don't see any obvious way to
fix that properly :-(
We need some way to hotplug a *group* of devices (usb-bot + all
children) as usb-bot itself is hotpluggable but the individual scsi
devices connected to it are not.
There is another case where hot-plug/unplug of a group of devices would
be useful - if you want to hotplug/unplug a pci passthrough device using
vfio *and* that device is a part of an iommu group that contains other
devices *and* you're okay with having those other devices assigned to
the guest as well *AND* you want to use managed='yes' (where libvirt
automatically unbinds the devices from the host driver and binds them to
vfio-pci before passing them off to the guest), then you need to be able
to plug and unplug all the devices in that iommu group in a single
operation, otherwise the plug fails (due to attempting to assign one
device in a group when the other devices haven't been bound to vfio-pci
or pci-stub). As it stands now you can only hot-plug/unplug with vfio if
a device is in an iommu group all by itself, or if you don't use
managed='yes', and instead deal with binding the devices to vfio-pci
manually.
If none of that makes sense, consider yourself lucky :-)
I could allow hotplug on usb-bot as workaround, then you can do
stop
device_add usb_bot
device_add scsi-{hd,cd,whatever}
cont
but that would be more a gross hack than a solution ...
cheers,
Gerd
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[libvirt] [PATCH 3/5] qemu: add usb-bot support from disks points of view
usb-bot only supports 16 luns(0~15) and they must be contiguous,
(using lun 0 and 2 without 1 doesn't work). In this case qemu
doesn't throw an error, we can not find the lun 2 in guests. So
Adding a checking function in libvirt to prevent from this case.
---
src/conf/domain_conf.c | 59
src/conf/domain_conf.h | 4
src/libvirt_private.syms | 1 +
src/qemu/qemu_command.c | 32 ++
4 files changed, 96 insertions(+)
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 545c157..84dfe25 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -4287,6 +4287,65 @@ virDomainDiskDefAssignAddress(virDomainXMLOptionPtr
xmlopt,
return 0;
}
+bool
+virDomainDiskAttachedToUsbbotLunIsContiguous(virDomainDefPtr def)
+{
+size_t i;
+int controllerModel;
+virBitmapPtr units = NULL;
+bool is_set = false;
+bool ret = false;
+
+if (!(units = virBitmapNew(SCSI_CONTROLLER_USB_BOT_MODEL_MAX_LUNS)))
+goto cleanup;
+
+for (i = 0; i def-ndisks; i++) {
+virDomainDiskDefPtr disk = def-disks[i];
+int unitValue = disk-info.addr.drive.unit;
+
+if (disk-bus != VIR_DOMAIN_DISK_BUS_SCSI)
+continue;
+
+controllerModel =
+virDomainDeviceFindControllerModel(def, disk-info,
+
VIR_DOMAIN_CONTROLLER_TYPE_SCSI);
+if (controllerModel != VIR_DOMAIN_CONTROLLER_MODEL_SCSI_USB_BOT)
+continue;
+
+/* usb-bot only supports 16 luns */
+if (unitValue ~0xf) {
+virReportError(VIR_ERR_XML_ERROR,
+ _(The address unit value of disk '%s' is too big),
+ disk-src);
+goto cleanup;
+}
+
+if (virBitmapGetBit(units, unitValue, is_set) == 0 is_set) {
+virReportError(VIR_ERR_XML_ERROR,
+ _(The address unit value of disk '%s' is already
used),
+ disk-src);
+goto cleanup;
+}
+
+if (unitValue 0) {
+if (virBitmapGetBit(units, unitValue - 1, is_set) == 0
!is_set) {
+virReportError(VIR_ERR_XML_ERROR, %s,
+ _(The address unit value of disk
+ attached to usb-bot controller is not
contiguous));
+goto cleanup;
+}
+}
+
+ignore_value(virBitmapSetBit(units, unitValue));
+}
+
+ret = true;
+
+cleanup:
+virBitmapFree(units);
+return ret;
+}
+
static virSecurityLabelDefPtr
virSecurityLabelDefParseXML(xmlXPathContextPtr ctxt,
unsigned int flags)
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 3e69f84..9e2f477 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -778,6 +778,8 @@ typedef enum {
VIR_DOMAIN_CONTROLLER_MODEL_PCI_LAST
} virDomainControllerModelPCI;
+# define SCSI_CONTROLLER_USB_BOT_MODEL_MAX_LUNS 16
+
enum virDomainControllerModelSCSI {
VIR_DOMAIN_CONTROLLER_MODEL_SCSI_AUTO,
VIR_DOMAIN_CONTROLLER_MODEL_SCSI_BUSLOGIC,
@@ -2362,6 +2364,8 @@ void virDomainDiskInsertPreAlloced(virDomainDefPtr def,
int virDomainDiskDefAssignAddress(virDomainXMLOptionPtr xmlopt,
virDomainDiskDefPtr def);
+bool virDomainDiskAttachedToUsbbotLunIsContiguous(virDomainDefPtr def);
+
virDomainDiskDefPtr
virDomainDiskRemove(virDomainDefPtr def, size_t i);
virDomainDiskDefPtr
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 35f0f1b..c1f7da5 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -179,6 +179,7 @@ virDomainDeviceFindControllerModel;
virDomainDeviceInfoCopy;
virDomainDeviceInfoIterate;
virDomainDeviceTypeToString;
+virDomainDiskAttachedToUsbbotLunIsContiguous;
virDomainDiskBusTypeToString;
virDomainDiskCacheTypeFromString;
virDomainDiskCacheTypeToString;
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 5f08a72..f38e98f 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -4257,6 +4257,32 @@ qemuBuildDriveDevStr(virDomainDefPtr def,
disk-info.addr.drive.controller,
disk-info.addr.drive.bus,
disk-info.addr.drive.unit);
+} else if (controllerModel ==
VIR_DOMAIN_CONTROLLER_MODEL_SCSI_USB_BOT) {
+if (disk-info.addr.drive.target != 0) {
+virReportError(VIR_ERR_CONFIG_UNSUPPORTED, %s,
+ _(target must be 0 for controller
+ model 'usb-bot'));
+goto error;
+}
+
+if (disk-device != VIR_DOMAIN_DISK_DEVICE_LUN) {
+if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_SCSI_CD)) {
+if (disk-device == VIR_DOMAIN_DISK_DEVICE_CDROM)
+
Re: [libvirt] [PATCH 3/5] qemu: add usb-bot support from disks points of view
On Mon, Sep 02, 2013 at 05:38:42PM +0800, Guannan Ren wrote: usb-bot only supports 16 luns(0~15) and they must be contiguous, (using lun 0 and 2 without 1 doesn't work). In this case qemu doesn't throw an error, we can not find the lun 2 in guests. So Adding a checking function in libvirt to prevent from this case. Hmm, this seems like a problematic restriction. How does this work if we start off a guest with 3 disks attached to the usb-bot SCSI controller. Then hot-unplug the 2nd disk. Next time we need will need to start with with LUNs 0 and 2 populated only, otherwise we have ABI change upon migrate or save/restore. I think this restriction about contiguous luns must be removed if this device is to be usable with multiple luns. Daniel -- |: http://berrange.com -o-http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
