[Qemu-devel] [PATCH v4 0/4] usb-msd: Add usb-storage, removable=on|off property

[Qemu-devel] [PATCH v4 0/4] usb-msd: Add usb-storage, removable=on|off property

[Stefan Hajnoczi]

Allow overriding the SCSI INQUIRY removable (RMB) bit for scsi-disk and usb-msd
devices.  In particular this addresses the problem that some usb-msd devices
have the bit set while other do not have it set.  Now the user can choose and
get desired guest behavior.

qemu -usb
    -drive if=none,file=test.img,cache=none,id=disk0
    -device usb-storage,drive=disk0,removable=on

The default is off.

v4:
 * Explicitly state that scsi-generic does not support the removable bit override
 * Try to make the scsi_bus_legacy_add_drive() commit description clearer

v3:
 * Document removable property in qdev-device-use.txt
 * Use bit number 0 instead of bit 1 for the qdev property

v2:
 * Rewritten to override the bit at the scsi-disk level

[Qemu-devel] [PATCH v4 1/4] scsi-disk: Allow overriding SCSI INQUIRY removable bit

[Stefan Hajnoczi]

Provide the "removable" qdev property bit to override the SCSI INQUIRY
removable (RMB) bit for non-CDROM devices.  This will be used by USB
Mass Storage Devices, which sometimes have this guest-visible bit set
and sometimes do not.  They therefore requires a means for user
configuration.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
 hw/scsi-disk.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index 6cb317c..488eedd 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -72,6 +72,7 @@ struct SCSIDiskState
     /* The qemu block layer uses a fixed 512 byte sector size.
        This is the number of 512 byte blocks in a single scsi sector.  */
     int cluster_size;
+    uint32_t removable;
     uint64_t max_lba;
     QEMUBH *bh;
     char *version;
@@ -552,6 +553,7 @@ static int scsi_disk_emulate_inquiry(SCSIRequest *req, uint8_t *outbuf)
         memcpy(&outbuf[16], "QEMU CD-ROM     ", 16);
     } else {
         outbuf[0] = 0;
+        outbuf[1] = s->removable ? 0x80 : 0;
         memcpy(&outbuf[16], "QEMU HARDDISK   ", 16);
     }
     memcpy(&outbuf[8], "QEMU    ", 8);
@@ -1295,6 +1297,7 @@ static SCSIDeviceInfo scsi_disk_info = {
         DEFINE_BLOCK_PROPERTIES(SCSIDiskState, qdev.conf),
         DEFINE_PROP_STRING("ver",  SCSIDiskState, version),
         DEFINE_PROP_STRING("serial",  SCSIDiskState, serial),
+        DEFINE_PROP_BIT("removable", SCSIDiskState, removable, 0, false),
         DEFINE_PROP_END_OF_LIST(),
     },
 };
-- 
1.7.2.3

[Qemu-devel] [PATCH v4 2/4] scsi: Allow scsi_bus_legacy_add_drive() to set removable bit

[Stefan Hajnoczi]

scsi-disk devices may wish to override the removable bit.  Add support
for a qdev property on SCSI devices.  This is will be used by usb-msd.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
 hw/pci-hotplug.c |    2 +-
 hw/scsi-bus.c    |    8 ++++++--
 hw/scsi.h        |    3 ++-
 hw/usb-msd.c     |    2 +-
 4 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/hw/pci-hotplug.c b/hw/pci-hotplug.c
index 716133c..270a982 100644
--- a/hw/pci-hotplug.c
+++ b/hw/pci-hotplug.c
@@ -90,7 +90,7 @@ static int scsi_hot_add(Monitor *mon, DeviceState *adapter,
      * specified).
      */
     dinfo->unit = qemu_opt_get_number(dinfo->opts, "unit", -1);
-    scsidev = scsi_bus_legacy_add_drive(scsibus, dinfo->bdrv, dinfo->unit);
+    scsidev = scsi_bus_legacy_add_drive(scsibus, dinfo->bdrv, dinfo->unit, false);
     if (!scsidev) {
         return -1;
     }
diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index 7febb86..ceeb4ec 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -87,7 +87,8 @@ void scsi_qdev_register(SCSIDeviceInfo *info)
 }
 
 /* handle legacy '-drive if=scsi,...' cmd line args */
-SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockDriverState *bdrv, int unit)
+SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockDriverState *bdrv,
+                                      int unit, bool removable)
 {
     const char *driver;
     DeviceState *dev;
@@ -95,6 +96,9 @@ SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockDriverState *bdrv, int
     driver = bdrv_is_sg(bdrv) ? "scsi-generic" : "scsi-disk";
     dev = qdev_create(&bus->qbus, driver);
     qdev_prop_set_uint32(dev, "scsi-id", unit);
+    if (qdev_prop_exists(dev, "removable")) {
+        qdev_prop_set_bit(dev, "removable", removable);
+    }
     if (qdev_prop_set_drive(dev, "drive", bdrv) < 0) {
         qdev_free(dev);
         return NULL;
@@ -117,7 +121,7 @@ int scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
             continue;
         }
         qemu_opts_loc_restore(dinfo->opts);
-        if (!scsi_bus_legacy_add_drive(bus, dinfo->bdrv, unit)) {
+        if (!scsi_bus_legacy_add_drive(bus, dinfo->bdrv, unit, false)) {
             res = -1;
             break;
         }
diff --git a/hw/scsi.h b/hw/scsi.h
index bf02adf..846fbba 100644
--- a/hw/scsi.h
+++ b/hw/scsi.h
@@ -94,7 +94,8 @@ static inline SCSIBus *scsi_bus_from_device(SCSIDevice *d)
     return DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
 }
 
-SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockDriverState *bdrv, int unit);
+SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockDriverState *bdrv,
+                                      int unit, bool removable);
 int scsi_bus_legacy_handle_cmdline(SCSIBus *bus);
 
 SCSIRequest *scsi_req_alloc(size_t size, SCSIDevice *d, uint32_t tag, uint32_t lun);
diff --git a/hw/usb-msd.c b/hw/usb-msd.c
index 729d96c..ccdf8ff 100644
--- a/hw/usb-msd.c
+++ b/hw/usb-msd.c
@@ -515,7 +515,7 @@ static int usb_msd_initfn(USBDevice *dev)
 
     usb_desc_init(dev);
     scsi_bus_new(&s->bus, &s->dev.qdev, 0, 1, usb_msd_command_complete);
-    s->scsi_dev = scsi_bus_legacy_add_drive(&s->bus, bs, 0);
+    s->scsi_dev = scsi_bus_legacy_add_drive(&s->bus, bs, 0, false);
     if (!s->scsi_dev) {
         return -1;
     }
-- 
1.7.2.3

[Qemu-devel] [PATCH v4 3/4] usb-msd: Propagate removable bit to SCSI device

[Stefan Hajnoczi]

USB Mass Storage Devices sometimes have the RMB (removable) bit set in
the SCSI INQUIRY response.  Thumbdrives tend to have the bit set whereas
hard disks do not.

Operating systems differentiate between removable devices and fixed
devices.  Under Linux, the anaconda installer looks for removable
devices.  Under Windows, only fixed devices may have more than one
partition and AutoRun is also affected by the removable bit.

For these reasons, allow USB Mass Storage Devices to override the
removable bit:

qemu -usb
     -drive if=none,file=test.img,cache=none,id=disk0
     -device usb-storage,drive=disk0,removable=on

The default is off.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
 hw/usb-msd.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/hw/usb-msd.c b/hw/usb-msd.c
index ccdf8ff..11722c7 100644
--- a/hw/usb-msd.c
+++ b/hw/usb-msd.c
@@ -51,6 +51,7 @@ typedef struct {
     SCSIBus bus;
     BlockConf conf;
     SCSIDevice *scsi_dev;
+    uint32_t removable;
     int result;
     /* For async completion.  */
     USBPacket *packet;
@@ -515,7 +516,7 @@ static int usb_msd_initfn(USBDevice *dev)
 
     usb_desc_init(dev);
     scsi_bus_new(&s->bus, &s->dev.qdev, 0, 1, usb_msd_command_complete);
-    s->scsi_dev = scsi_bus_legacy_add_drive(&s->bus, bs, 0, false);
+    s->scsi_dev = scsi_bus_legacy_add_drive(&s->bus, bs, 0, !!s->removable);
     if (!s->scsi_dev) {
         return -1;
     }
@@ -607,6 +608,7 @@ static struct USBDeviceInfo msd_info = {
     .usbdevice_init = usb_msd_init,
     .qdev.props     = (Property[]) {
         DEFINE_BLOCK_PROPERTIES(MSDState, conf),
+        DEFINE_PROP_BIT("removable", MSDState, removable, 0, false),
         DEFINE_PROP_END_OF_LIST(),
     },
 };
-- 
1.7.2.3

[Qemu-devel] [PATCH v4 4/4] docs: Document scsi-disk and usb-storage removable parameter

[Stefan Hajnoczi]

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
 docs/qdev-device-use.txt |   13 +++++++++++--
 1 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/docs/qdev-device-use.txt b/docs/qdev-device-use.txt
index f2f9b75..4bb2be8 100644
--- a/docs/qdev-device-use.txt
+++ b/docs/qdev-device-use.txt
@@ -80,7 +80,11 @@ The -device argument differs in detail for each kind of drive:
   This SCSI controller a single SCSI bus, named ID.0.  Put a disk on
   it:
 
-  -device scsi-disk,drive=DRIVE-ID,bus=ID.0,scsi-id=SCSI-ID
+  -device scsi-disk,drive=DRIVE-ID,bus=ID.0,scsi-id=SCSI-ID,removable=RMB
+
+  The (optional) removable parameter lets you override the SCSI INQUIRY
+  removable (RMB) bit for non CD-ROM devices.  It is ignored for CD-ROM devices
+  which are always removable.  RMB is "on" or "off".
 
 * if=floppy
 
@@ -116,7 +120,12 @@ For USB devices, the old way is actually different:
 Provides much less control than -drive's HOST-OPTS...  The new way
 fixes that:
 
-    -device usb-storage,drive=DRIVE-ID
+    -device usb-storage,drive=DRIVE-ID,removable=RMB
+
+The removable parameter gives control over the SCSI INQUIRY removable (RMB)
+bit.  USB thumbdrives usually set removable=on, while USB hard disks set
+removable=off.  See the if=scsi description above for details on the removable
+parameter, which applies only to scsi-disk devices and not to scsi-generic.
 
 === Character Devices ===
 
-- 
1.7.2.3

[Qemu-devel] Re: [PATCH v4 0/4] usb-msd: Add usb-storage, removable=on|off property

[Kevin Wolf]

Am 24.01.2011 16:34, schrieb Stefan Hajnoczi:
> Allow overriding the SCSI INQUIRY removable (RMB) bit for scsi-disk and usb-msd
> devices.  In particular this addresses the problem that some usb-msd devices
> have the bit set while other do not have it set.  Now the user can choose and
> get desired guest behavior.
> 
> qemu -usb
>     -drive if=none,file=test.img,cache=none,id=disk0
>     -device usb-storage,drive=disk0,removable=on
> 
> The default is off.
> 
> v4:
>  * Explicitly state that scsi-generic does not support the removable bit override
>  * Try to make the scsi_bus_legacy_add_drive() commit description clearer
> 
> v3:
>  * Document removable property in qdev-device-use.txt
>  * Use bit number 0 instead of bit 1 for the qdev property
> 
> v2:
>  * Rewritten to override the bit at the scsi-disk level
> 

Thanks, updated the patches in the block branch.

Kevin