Introduces the XEN pvSCSI frontend. With pvSCSI it is possible for a XEN domU
to issue SCSI commands to a SCSI LUN assigned to that domU. The SCSI commands
are passed to the pvSCSI backend in a driver domain (usually Dom0) which is
owner of the physical device. This allows e.g. to use SCSI tape drives in a
XEN domU.
The code is taken from the pvSCSI implementation in XEN done by Fujitsu based
on Linux kernel 2.6.18.
Changes from the original version are:
- port to upstream kernel
- put all code in just one source file
- move module to appropriate location in kernel tree
- adapt to Linux style guide
- some minor code simplifications
- replace constants with defines
- remove not used defines
- add support for larger SG lists by putting them in a granted page
Signed-off-by: Juergen Gross
Xen related parts
Acked-by: David Vrabel
---
drivers/scsi/Kconfig |9 +
drivers/scsi/Makefile|1 +
drivers/scsi/xen-scsifront.c | 1024 ++
3 files changed, 1034 insertions(+)
create mode 100644 drivers/scsi/xen-scsifront.c
diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 18a3358..9130df1 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -576,6 +576,15 @@ config VMWARE_PVSCSI
To compile this driver as a module, choose M here: the
module will be called vmw_pvscsi.
+config XEN_SCSI_FRONTEND
+ tristate "XEN SCSI frontend driver"
+ depends on SCSI && XEN
+ help
+ The XEN SCSI frontend driver allows the kernel to access SCSI Devices
+ within another guest OS (usually Dom0).
+ Only needed if the kernel is running in a XEN guest and generic
+ SCSI access to a device is needed.
+
config HYPERV_STORAGE
tristate "Microsoft Hyper-V virtual storage driver"
depends on SCSI && HYPERV
diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index 5f0d299..59f1ce6 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -141,6 +141,7 @@ obj-$(CONFIG_SCSI_ESAS2R) += esas2r/
obj-$(CONFIG_SCSI_PMCRAID) += pmcraid.o
obj-$(CONFIG_SCSI_VIRTIO) += virtio_scsi.o
obj-$(CONFIG_VMWARE_PVSCSI)+= vmw_pvscsi.o
+obj-$(CONFIG_XEN_SCSI_FRONTEND)+= xen-scsifront.o
obj-$(CONFIG_HYPERV_STORAGE) += hv_storvsc.o
obj-$(CONFIG_ARM) += arm/
diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c
new file mode 100644
index 000..0aceb70
--- /dev/null
+++ b/drivers/scsi/xen-scsifront.c
@@ -0,0 +1,1024 @@
+/*
+ * Xen SCSI frontend driver
+ *
+ * Copyright (c) 2008, FUJITSU Limited
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#include
+#include
+#include
+#include
+
+#include
+#include
+#include
+#include
+#include
+
+#include
+#include
+#include
+
+#include
+
+
+#define GRANT_INVALID_REF 0
+
+#define VSCSIFRONT_OP_ADD_LUN 1
+#define VSCSIFRONT_OP_DEL_LUN 2
+
+/* Tuning point. */
+#define VSCSIIF_DEFAULT_CMD_PER_LUN 10
+#define VSCSIIF_MAX_TARGET 64
+#define VSCSIIF_MAX_LUN 255
+
+#define VSCSIIF_RING_SIZE __CONST_RING_SIZE(vscsiif, PAGE_SIZE)
+#define VSCSIIF_MAX_REQS VSCSIIF_RING_SIZE
+
+#define vscsiif_grants_sg(_sg) (PFN_UP((_sg) * \
+ sizeof(struct scsiif_request_segment)))
+
+struct vscsifrnt_shadow {
+ /* command between backend and frontend */
+ unsigned char act;
+ uint16_t rqid;
+
+ unsigned int nr_grants; /* number
