[SCSI] vmw_pvscsi: SCSI driver for VMware's virtual HBA.

This is a driver for VMware's paravirtualized SCSI device,
which should improve disk performance for guests running
under control of VMware hypervisors that support such devices.

Signed-off-by: Alok N Kataria <akataria@vmware.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

MAINTAINERS

@@ -5696,6 +5696,14 @@ L:     netdev@vger.kernel.org
 S:     Maintained
 F:     drivers/net/vmxnet3/
 
+VMware PVSCSI driver
+M:	Alok Kataria <akataria@vmware.com>
+M:	VMware PV-Drivers <pv-drivers@vmware.com>
+L:	linux-scsi@vger.kernel.org
+S:	Maintained
+F:	drivers/scsi/vmw_pvscsi.c
+F:	drivers/scsi/vmw_pvscsi.h
+
 VOLTAGE AND CURRENT REGULATOR FRAMEWORK
 M:	Liam Girdwood <lrg@slimlogic.co.uk>
 M:	Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/scsi/Kconfig

@@ -621,6 +621,14 @@ config SCSI_FLASHPOINT
 	  substantial, so users of MultiMaster Host Adapters may not
 	  wish to include it.
 
+config VMWARE_PVSCSI
+	tristate "VMware PVSCSI driver support"
+	depends on PCI && SCSI && X86
+	help
+	  This driver supports VMware's para virtualized SCSI HBA.
+	  To compile this driver as a module, choose M here: the
+	  module will be called vmw_pvscsi.
+
 config LIBFC
 	tristate "LibFC module"
 	select SCSI_FC_ATTRS

drivers/scsi/Makefile

@@ -134,6 +134,7 @@ obj-$(CONFIG_SCSI_CXGB3_ISCSI)	+= libiscsi.o libiscsi_tcp.o cxgb3i/
 obj-$(CONFIG_SCSI_BNX2_ISCSI)	+= libiscsi.o bnx2i/
 obj-$(CONFIG_BE2ISCSI)		+= libiscsi.o be2iscsi/
 obj-$(CONFIG_SCSI_PMCRAID)	+= pmcraid.o
+obj-$(CONFIG_VMWARE_PVSCSI)	+= vmw_pvscsi.o
 
 obj-$(CONFIG_ARM)		+= arm/
 

drivers/scsi/vmw_pvscsi.h

@@ -0,0 +1,397 @@
+/*
+ * VMware PVSCSI header file
+ *
+ * Copyright (C) 2008-2009, VMware, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; version 2 of the License and no later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Maintained by: Alok N Kataria <akataria@vmware.com>
+ *
+ */
+
+#ifndef _VMW_PVSCSI_H_
+#define _VMW_PVSCSI_H_
+
+#include <linux/types.h>
+
+#define PVSCSI_DRIVER_VERSION_STRING   "1.0.1.0-k"
+
+#define PVSCSI_MAX_NUM_SG_ENTRIES_PER_SEGMENT 128
+
+#define MASK(n)        ((1 << (n)) - 1)        /* make an n-bit mask */
+
+#define PCI_VENDOR_ID_VMWARE		0x15AD
+#define PCI_DEVICE_ID_VMWARE_PVSCSI	0x07C0
+
+/*
+ * host adapter status/error codes
+ */
+enum HostBusAdapterStatus {
+   BTSTAT_SUCCESS       = 0x00,  /* CCB complete normally with no errors */
+   BTSTAT_LINKED_COMMAND_COMPLETED           = 0x0a,
+   BTSTAT_LINKED_COMMAND_COMPLETED_WITH_FLAG = 0x0b,
+   BTSTAT_DATA_UNDERRUN = 0x0c,
+   BTSTAT_SELTIMEO      = 0x11,  /* SCSI selection timeout */
+   BTSTAT_DATARUN       = 0x12,  /* data overrun/underrun */
+   BTSTAT_BUSFREE       = 0x13,  /* unexpected bus free */
+   BTSTAT_INVPHASE      = 0x14,  /* invalid bus phase or sequence requested by target */
+   BTSTAT_LUNMISMATCH   = 0x17,  /* linked CCB has different LUN from first CCB */
+   BTSTAT_SENSFAILED    = 0x1b,  /* auto request sense failed */
+   BTSTAT_TAGREJECT     = 0x1c,  /* SCSI II tagged queueing message rejected by target */
+   BTSTAT_BADMSG        = 0x1d,  /* unsupported message received by the host adapter */
+   BTSTAT_HAHARDWARE    = 0x20,  /* host adapter hardware failed */
+   BTSTAT_NORESPONSE    = 0x21,  /* target did not respond to SCSI ATN, sent a SCSI RST */
+   BTSTAT_SENTRST       = 0x22,  /* host adapter asserted a SCSI RST */
+   BTSTAT_RECVRST       = 0x23,  /* other SCSI devices asserted a SCSI RST */
+   BTSTAT_DISCONNECT    = 0x24,  /* target device reconnected improperly (w/o tag) */
+   BTSTAT_BUSRESET      = 0x25,  /* host adapter issued BUS device reset */
+   BTSTAT_ABORTQUEUE    = 0x26,  /* abort queue generated */
+   BTSTAT_HASOFTWARE    = 0x27,  /* host adapter software error */
+   BTSTAT_HATIMEOUT     = 0x30,  /* host adapter hardware timeout error */
+   BTSTAT_SCSIPARITY    = 0x34,  /* SCSI parity error detected */
+};
+
+/*
+ * Register offsets.
+ *
+ * These registers are accessible both via i/o space and mm i/o.
+ */
+
+enum PVSCSIRegOffset {
+	PVSCSI_REG_OFFSET_COMMAND        =    0x0,
+	PVSCSI_REG_OFFSET_COMMAND_DATA   =    0x4,
+	PVSCSI_REG_OFFSET_COMMAND_STATUS =    0x8,
+	PVSCSI_REG_OFFSET_LAST_STS_0     =  0x100,
+	PVSCSI_REG_OFFSET_LAST_STS_1     =  0x104,
+	PVSCSI_REG_OFFSET_LAST_STS_2     =  0x108,
+	PVSCSI_REG_OFFSET_LAST_STS_3     =  0x10c,
+	PVSCSI_REG_OFFSET_INTR_STATUS    = 0x100c,
+	PVSCSI_REG_OFFSET_INTR_MASK      = 0x2010,
+	PVSCSI_REG_OFFSET_KICK_NON_RW_IO = 0x3014,
+	PVSCSI_REG_OFFSET_DEBUG          = 0x3018,
+	PVSCSI_REG_OFFSET_KICK_RW_IO     = 0x4018,
+};
+
+/*
+ * Virtual h/w commands.
+ */
+
+enum PVSCSICommands {
+	PVSCSI_CMD_FIRST             = 0, /* has to be first */
+
+	PVSCSI_CMD_ADAPTER_RESET     = 1,
+	PVSCSI_CMD_ISSUE_SCSI        = 2,
+	PVSCSI_CMD_SETUP_RINGS       = 3,
+	PVSCSI_CMD_RESET_BUS         = 4,
+	PVSCSI_CMD_RESET_DEVICE      = 5,
+	PVSCSI_CMD_ABORT_CMD         = 6,
+	PVSCSI_CMD_CONFIG            = 7,
+	PVSCSI_CMD_SETUP_MSG_RING    = 8,
+	PVSCSI_CMD_DEVICE_UNPLUG     = 9,
+
+	PVSCSI_CMD_LAST              = 10  /* has to be last */
+};
+
+/*
+ * Command descriptor for PVSCSI_CMD_RESET_DEVICE --
+ */
+
+struct PVSCSICmdDescResetDevice {
+	u32	target;
+	u8	lun[8];
+} __packed;
+
+/*
+ * Command descriptor for PVSCSI_CMD_ABORT_CMD --
+ *
+ * - currently does not support specifying the LUN.
+ * - _pad should be 0.
+ */
+
+struct PVSCSICmdDescAbortCmd {
+	u64	context;
+	u32	target;
+	u32	_pad;
+} __packed;
+
+/*
+ * Command descriptor for PVSCSI_CMD_SETUP_RINGS --
+ *
+ * Notes:
+ * - reqRingNumPages and cmpRingNumPages need to be power of two.
+ * - reqRingNumPages and cmpRingNumPages need to be different from 0,
+ * - reqRingNumPages and cmpRingNumPages need to be inferior to
+ *   PVSCSI_SETUP_RINGS_MAX_NUM_PAGES.
+ */
+
+#define PVSCSI_SETUP_RINGS_MAX_NUM_PAGES        32
+struct PVSCSICmdDescSetupRings {
+	u32	reqRingNumPages;
+	u32	cmpRingNumPages;
+	u64	ringsStatePPN;
+	u64	reqRingPPNs[PVSCSI_SETUP_RINGS_MAX_NUM_PAGES];
+	u64	cmpRingPPNs[PVSCSI_SETUP_RINGS_MAX_NUM_PAGES];
+} __packed;
+
+/*
+ * Command descriptor for PVSCSI_CMD_SETUP_MSG_RING --
+ *
+ * Notes:
+ * - this command was not supported in the initial revision of the h/w
+ *   interface. Before using it, you need to check that it is supported by
+ *   writing PVSCSI_CMD_SETUP_MSG_RING to the 'command' register, then
+ *   immediately after read the 'command status' register:
+ *       * a value of -1 means that the cmd is NOT supported,
+ *       * a value != -1 means that the cmd IS supported.
+ *   If it's supported the 'command status' register should return:
+ *      sizeof(PVSCSICmdDescSetupMsgRing) / sizeof(u32).
+ * - this command should be issued _after_ the usual SETUP_RINGS so that the
+ *   RingsState page is already setup. If not, the command is a nop.
+ * - numPages needs to be a power of two,
+ * - numPages needs to be different from 0,
+ * - _pad should be zero.
+ */
+
+#define PVSCSI_SETUP_MSG_RING_MAX_NUM_PAGES  16
+
+struct PVSCSICmdDescSetupMsgRing {
+	u32	numPages;
+	u32	_pad;
+	u64	ringPPNs[PVSCSI_SETUP_MSG_RING_MAX_NUM_PAGES];
+} __packed;
+
+enum PVSCSIMsgType {
+	PVSCSI_MSG_DEV_ADDED          = 0,
+	PVSCSI_MSG_DEV_REMOVED        = 1,
+	PVSCSI_MSG_LAST               = 2,
+};
+
+/*
+ * Msg descriptor.
+ *
+ * sizeof(struct PVSCSIRingMsgDesc) == 128.
+ *
+ * - type is of type enum PVSCSIMsgType.
+ * - the content of args depend on the type of event being delivered.
+ */
+
+struct PVSCSIRingMsgDesc {
+	u32	type;
+	u32	args[31];
+} __packed;
+
+struct PVSCSIMsgDescDevStatusChanged {
+	u32	type;  /* PVSCSI_MSG_DEV _ADDED / _REMOVED */
+	u32	bus;
+	u32	target;
+	u8	lun[8];
+	u32	pad[27];
+} __packed;
+
+/*
+ * Rings state.
+ *
+ * - the fields:
+ *    . msgProdIdx,
+ *    . msgConsIdx,
+ *    . msgNumEntriesLog2,
+ *   .. are only used once the SETUP_MSG_RING cmd has been issued.
+ * - '_pad' helps to ensure that the msg related fields are on their own
+ *   cache-line.
+ */
+
+struct PVSCSIRingsState {
+	u32	reqProdIdx;
+	u32	reqConsIdx;
+	u32	reqNumEntriesLog2;
+
+	u32	cmpProdIdx;
+	u32	cmpConsIdx;
+	u32	cmpNumEntriesLog2;
+
+	u8	_pad[104];
+
+	u32	msgProdIdx;
+	u32	msgConsIdx;
+	u32	msgNumEntriesLog2;
+} __packed;
+
+/*
+ * Request descriptor.
+ *
+ * sizeof(RingReqDesc) = 128
+ *
+ * - context: is a unique identifier of a command. It could normally be any
+ *   64bit value, however we currently store it in the serialNumber variable
+ *   of struct SCSI_Command, so we have the following restrictions due to the
+ *   way this field is handled in the vmkernel storage stack:
+ *    * this value can't be 0,
+ *    * the upper 32bit need to be 0 since serialNumber is as a u32.
+ *   Currently tracked as PR 292060.
+ * - dataLen: contains the total number of bytes that need to be transferred.
+ * - dataAddr:
+ *   * if PVSCSI_FLAG_CMD_WITH_SG_LIST is set: dataAddr is the PA of the first
+ *     s/g table segment, each s/g segment is entirely contained on a single
+ *     page of physical memory,
+ *   * if PVSCSI_FLAG_CMD_WITH_SG_LIST is NOT set, then dataAddr is the PA of
+ *     the buffer used for the DMA transfer,
+ * - flags:
+ *   * PVSCSI_FLAG_CMD_WITH_SG_LIST: see dataAddr above,
+ *   * PVSCSI_FLAG_CMD_DIR_NONE: no DMA involved,
+ *   * PVSCSI_FLAG_CMD_DIR_TOHOST: transfer from device to main memory,
+ *   * PVSCSI_FLAG_CMD_DIR_TODEVICE: transfer from main memory to device,
+ *   * PVSCSI_FLAG_CMD_OUT_OF_BAND_CDB: reserved to handle CDBs larger than
+ *     16bytes. To be specified.
+ * - vcpuHint: vcpuId of the processor that will be most likely waiting for the
+ *   completion of the i/o. For guest OSes that use lowest priority message
+ *   delivery mode (such as windows), we use this "hint" to deliver the
+ *   completion action to the proper vcpu. For now, we can use the vcpuId of
+ *   the processor that initiated the i/o as a likely candidate for the vcpu
+ *   that will be waiting for the completion..
+ * - bus should be 0: we currently only support bus 0 for now.
+ * - unused should be zero'd.
+ */
+
+#define PVSCSI_FLAG_CMD_WITH_SG_LIST        (1 << 0)
+#define PVSCSI_FLAG_CMD_OUT_OF_BAND_CDB     (1 << 1)
+#define PVSCSI_FLAG_CMD_DIR_NONE            (1 << 2)
+#define PVSCSI_FLAG_CMD_DIR_TOHOST          (1 << 3)
+#define PVSCSI_FLAG_CMD_DIR_TODEVICE        (1 << 4)
+
+struct PVSCSIRingReqDesc {
+	u64	context;
+	u64	dataAddr;
+	u64	dataLen;
+	u64	senseAddr;
+	u32	senseLen;
+	u32	flags;
+	u8	cdb[16];
+	u8	cdbLen;
+	u8	lun[8];
+	u8	tag;
+	u8	bus;
+	u8	target;
+	u8	vcpuHint;
+	u8	unused[59];
+} __packed;
+
+/*
+ * Scatter-gather list management.
+ *
+ * As described above, when PVSCSI_FLAG_CMD_WITH_SG_LIST is set in the
+ * RingReqDesc.flags, then RingReqDesc.dataAddr is the PA of the first s/g
+ * table segment.
+ *
+ * - each segment of the s/g table contain a succession of struct
+ *   PVSCSISGElement.
+ * - each segment is entirely contained on a single physical page of memory.
+ * - a "chain" s/g element has the flag PVSCSI_SGE_FLAG_CHAIN_ELEMENT set in
+ *   PVSCSISGElement.flags and in this case:
+ *     * addr is the PA of the next s/g segment,
+ *     * length is undefined, assumed to be 0.
+ */
+
+struct PVSCSISGElement {
+	u64	addr;
+	u32	length;
+	u32	flags;
+} __packed;
+
+/*
+ * Completion descriptor.
+ *
+ * sizeof(RingCmpDesc) = 32
+ *
+ * - context: identifier of the command. The same thing that was specified
+ *   under "context" as part of struct RingReqDesc at initiation time,
+ * - dataLen: number of bytes transferred for the actual i/o operation,
+ * - senseLen: number of bytes written into the sense buffer,
+ * - hostStatus: adapter status,
+ * - scsiStatus: device status,
+ * - _pad should be zero.
+ */
+
+struct PVSCSIRingCmpDesc {
+	u64	context;
+	u64	dataLen;
+	u32	senseLen;
+	u16	hostStatus;
+	u16	scsiStatus;
+	u32	_pad[2];
+} __packed;
+
+/*
+ * Interrupt status / IRQ bits.
+ */
+
+#define PVSCSI_INTR_CMPL_0                 (1 << 0)
+#define PVSCSI_INTR_CMPL_1                 (1 << 1)
+#define PVSCSI_INTR_CMPL_MASK              MASK(2)
+
+#define PVSCSI_INTR_MSG_0                  (1 << 2)
+#define PVSCSI_INTR_MSG_1                  (1 << 3)
+#define PVSCSI_INTR_MSG_MASK               (MASK(2) << 2)
+
+#define PVSCSI_INTR_ALL_SUPPORTED          MASK(4)
+
+/*
+ * Number of MSI-X vectors supported.
+ */
+#define PVSCSI_MAX_INTRS        24
+
+/*
+ * Enumeration of supported MSI-X vectors
+ */
+#define PVSCSI_VECTOR_COMPLETION   0
+
+/*
+ * Misc constants for the rings.
+ */
+
+#define PVSCSI_MAX_NUM_PAGES_REQ_RING   PVSCSI_SETUP_RINGS_MAX_NUM_PAGES
+#define PVSCSI_MAX_NUM_PAGES_CMP_RING   PVSCSI_SETUP_RINGS_MAX_NUM_PAGES
+#define PVSCSI_MAX_NUM_PAGES_MSG_RING   PVSCSI_SETUP_MSG_RING_MAX_NUM_PAGES
+
+#define PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE \
+				(PAGE_SIZE / sizeof(struct PVSCSIRingReqDesc))
+
+#define PVSCSI_MAX_REQ_QUEUE_DEPTH \
+	(PVSCSI_MAX_NUM_PAGES_REQ_RING * PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE)
+
+#define PVSCSI_MEM_SPACE_COMMAND_NUM_PAGES     1
+#define PVSCSI_MEM_SPACE_INTR_STATUS_NUM_PAGES 1
+#define PVSCSI_MEM_SPACE_MISC_NUM_PAGES        2
+#define PVSCSI_MEM_SPACE_KICK_IO_NUM_PAGES     2
+#define PVSCSI_MEM_SPACE_MSIX_NUM_PAGES        2
+
+enum PVSCSIMemSpace {
+	PVSCSI_MEM_SPACE_COMMAND_PAGE		= 0,
+	PVSCSI_MEM_SPACE_INTR_STATUS_PAGE	= 1,
+	PVSCSI_MEM_SPACE_MISC_PAGE		= 2,
+	PVSCSI_MEM_SPACE_KICK_IO_PAGE		= 4,
+	PVSCSI_MEM_SPACE_MSIX_TABLE_PAGE	= 6,
+	PVSCSI_MEM_SPACE_MSIX_PBA_PAGE		= 7,
+};
+
+#define PVSCSI_MEM_SPACE_NUM_PAGES \
+	(PVSCSI_MEM_SPACE_COMMAND_NUM_PAGES +       \
+	 PVSCSI_MEM_SPACE_INTR_STATUS_NUM_PAGES +   \
+	 PVSCSI_MEM_SPACE_MISC_NUM_PAGES +          \
+	 PVSCSI_MEM_SPACE_KICK_IO_NUM_PAGES +       \
+	 PVSCSI_MEM_SPACE_MSIX_NUM_PAGES)
+
+#define PVSCSI_MEM_SPACE_SIZE        (PVSCSI_MEM_SPACE_NUM_PAGES * PAGE_SIZE)
+
+#endif /* _VMW_PVSCSI_H_ */