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[Qemu-devel] [PATCH 5/5] scsi-bsg: Add initial support for BSG based SCS
From: |
Nicholas A. Bellinger |
Subject: |
[Qemu-devel] [PATCH 5/5] scsi-bsg: Add initial support for BSG based SCSIDeviceInfo |
Date: |
Wed, 24 Nov 2010 00:40:35 -0800 |
From: Nicholas Bellinger <address@hidden>
This patch adds initial support for using the Linux BSG interface with
write/read vectored
AIO as a QEMU backstore (SCSIDeviceInfo) with hw/scsi-bus.c compatible HBA
emulation.
So far it has been tested with x86_64 host and guest using hw/megasas.c and
TCM_Loop LLD
Port LUNs. Because this patch uses struct iovec for struct
sg_io_v4->d[out,in]_xferp payloads,
which currently requires a patch to linux/block/bsg.c:bsg_map_hdr() in order to
setup the
user -> kernel iovecs. This patch can be found in lio-core-2.6.git here:
commit fec4e8457c744de50e1ead69a36d5c4ee089d1ac
Author: Nicholas Bellinger <address@hidden>
Date: Sun Jun 13 23:13:20 2010 -0700
[BSG]: Add support for struct sg_io_v4->d[out,in]_iovec_count
This also will only currently work with paired user/kernel (eg: 64bit user /
64bit kernel)
because of different pointer sizes in struct iovec->iov_base.
There are also two FIXMEs in hw/scsi-bsg.c:bsg_generic_initfn() related to
extraction of
SCSI LUN and device type values using BSG and required by QEMU-KVM.
Signed-off-by: Nicholas A. Bellinger <address@hidden>
---
Makefile.objs | 2 +-
hw/scsi-bsg.c | 720 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 721 insertions(+), 1 deletions(-)
create mode 100644 hw/scsi-bsg.c
diff --git a/Makefile.objs b/Makefile.objs
index 0443c7e..842e70c 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -79,7 +79,7 @@ common-obj-$(CONFIG_DS1338) += ds1338.o
common-obj-y += i2c.o smbus.o smbus_eeprom.o
common-obj-y += eeprom93xx.o
common-obj-y += scsi-disk.o cdrom.o
-common-obj-y += scsi-generic.o scsi-bus.o
+common-obj-y += scsi-generic.o scsi-bsg.o scsi-bus.o
common-obj-y += usb.o usb-hub.o usb-$(HOST_USB).o usb-hid.o usb-msd.o
usb-wacom.o
common-obj-y += usb-serial.o usb-net.o usb-bus.o
common-obj-$(CONFIG_SSI) += ssi.o
diff --git a/hw/scsi-bsg.c b/hw/scsi-bsg.c
new file mode 100644
index 0000000..93936e0
--- /dev/null
+++ b/hw/scsi-bsg.c
@@ -0,0 +1,720 @@
+/*
+ * block layer implementation of the sg v4 interface for Linux hosts
+ *
+ * Copyright (c) 2010 Rising Tide Systems
+ * Written by Nicholas A. Bellinger <address@hidden>
+ *
+ * Based on hw/scsi-generic code by Laurent Vivier, Paul Brook, and Fabrice
Bellard
+ *
+ * This code is licenced under the LGPL.
+ */
+
+#include "qemu-common.h"
+#include "qemu-error.h"
+#include "block.h"
+#include "scsi.h"
+#include "block/raw-posix-aio.h"
+
+#ifdef __linux__
+
+#define DEBUG_BSG
+//#define DEBUG_BSG_IO
+
+#ifdef DEBUG_BSG
+#define DPRINTF(fmt, ...) \
+do { printf("scsi-bsg: " fmt , ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) do {} while(0)
+#endif
+
+#ifdef DEBUG_BSG_IO
+#define DPRINTF_BSG_IO(fmt, ...) DPRINTF(fmt , ## __VA_ARGS__)
+#else
+#define DPRINTF_BSG_IO(fmt, ...)
+#endif
+
+#define BADF(fmt, ...) \
+do { fprintf(stderr, "scsi-bsg: " fmt , ## __VA_ARGS__); } while (0)
+
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/epoll.h>
+#include <unistd.h>
+#include <scsi/sg.h>
+#include <linux/bsg.h>
+#include "scsi-defs.h"
+
+#define SCSI_SENSE_BUF_SIZE 96
+
+#define SG_ERR_DRIVER_TIMEOUT 0x06
+#define SG_ERR_DRIVER_SENSE 0x08
+
+typedef struct SCSIBSGState SCSIBSGState;
+
+typedef struct SCSIBSGReq {
+ SCSIRequest req;
+ uint8_t *buf;
+ int buflen;
+ int len;
+// QEMUIOVector iov;
+ struct iovec *saved_iov;
+ uint32_t saved_iov_num;
+ QEMUIOVector aio_iov;
+ struct sg_io_v4 bsg_hdr;
+} SCSIBSGReq;
+
+struct SCSIBSGState {
+ SCSIDevice qdev;
+ BlockDriverState *bs;
+ int lun;
+ int driver_status;
+ uint8_t sensebuf[SCSI_SENSE_BUF_SIZE];
+ uint8_t senselen;
+};
+
+static int bsg_read(int fd, void *p_read, int to_read)
+{
+ int err;
+
+ while (to_read > 0) {
+ err = read(fd, p_read, to_read);
+ if (err >= 0) {
+ to_read -= err;
+ p_read += err;
+ } else if (errno == EINTR)
+ continue;
+ else {
+ error_report("bsg device %d read failed, errno: %d\n",
+ fd, errno);
+ return errno;
+ }
+ }
+ return 0;
+}
+
+static int bsg_set_sense(SCSIBSGState *s, SCSISense sense)
+{
+ int len;
+
+ len = scsi_build_sense(sense, s->sensebuf, SCSI_SENSE_BUF_SIZE, 0);
+ s->driver_status = SG_ERR_DRIVER_SENSE;
+
+ return len;
+}
+
+static void bsg_clear_sense(SCSIBSGState *s)
+{
+ memset(s->sensebuf, 0, SCSI_SENSE_BUF_SIZE);
+ s->senselen = 0;
+ s->driver_status = 0;
+}
+
+static int bsg_get_sense(SCSIRequest *req, uint8_t *outbuf, int len)
+{
+ SCSIBSGState *s = DO_UPCAST(SCSIBSGState, qdev, req->dev);
+ int size = SCSI_SENSE_BUF_SIZE;
+
+ if (s->driver_status & SG_ERR_DRIVER_SENSE) {
+ if (len < SCSI_SENSE_BUF_SIZE)
+ size = len;
+ else
+ size = SCSI_SENSE_BUF_SIZE;
+
+ memcpy(outbuf, s->sensebuf, size);
+ }
+
+ return size;
+}
+
+static void bsg_command_complete(void *opaque, int ret)
+{
+ SCSIBSGReq *r = opaque;
+ SCSIBSGState *s = DO_UPCAST(SCSIBSGState, qdev, r->req.dev);
+
+ s->driver_status = r->bsg_hdr.driver_status;
+ if (s->driver_status)
+ s->senselen = SCSI_SENSE_BUF_SIZE;
+
+ if (ret != 0) {
+ switch (ret) {
+ case -ENODEV:
+ s->senselen = bsg_set_sense(s, SENSE_CODE(LUN_NOT_SUPPORTED));
+ break;
+ case -EINVAL:
+ s->senselen = bsg_set_sense(s, SENSE_CODE(INVALID_FIELD));
+ break;
+ case -EBADR:
+ s->senselen = bsg_set_sense(s, SENSE_CODE(TARGET_FAILURE));
+ break;
+ default:
+ s->senselen = bsg_set_sense(s, SENSE_CODE(IO_ERROR));
+ break;
+ }
+ scsi_req_print(&r->req);
+ error_report("%s: ret %d (%s)\n", __FUNCTION__,
+ ret, strerror(-ret));
+ s->driver_status = SG_ERR_DRIVER_SENSE;
+ r->req.status = CHECK_CONDITION;
+ } else {
+ if (s->driver_status & SG_ERR_DRIVER_TIMEOUT) {
+ scsi_req_print(&r->req);
+ r->req.status = BUSY;
+ error_report("%s: timeout\n", __FUNCTION__);
+ } else if (r->bsg_hdr.device_status) {
+ r->req.status = r->bsg_hdr.device_status;
+ } else if (s->driver_status & SG_ERR_DRIVER_SENSE) {
+ scsi_req_print(&r->req);
+ error_report("%s: driver sense\n", __FUNCTION__);
+ r->req.status = CHECK_CONDITION;
+ } else {
+ r->req.status = GOOD;
+ }
+ }
+ DPRINTF_BSG_IO("Command complete 0x%p tag=0x%x status=%d\n",
+ r, r->req.tag, r->req.status);
+
+ scsi_req_complete(&r->req);
+}
+
+static int bsg_execute_command(BlockDriverState *bdrv,
+ SCSIBSGReq *r,
+ BlockDriverCompletionFunc *complete)
+{
+ SCSIBSGState *s = DO_UPCAST(SCSIBSGState, qdev, r->req.dev);
+ /*
+ * Following linux/include/linux/bsg.h
+ */
+ /* [i] 'Q' to differentiate from v3 */
+ r->bsg_hdr.guard = 'Q';
+ r->bsg_hdr.protocol = BSG_PROTOCOL_SCSI;
+ r->bsg_hdr.subprotocol = BSG_SUB_PROTOCOL_SCSI_CMD;
+ r->bsg_hdr.request_len = r->req.cmd.len;
+ r->bsg_hdr.request = (unsigned long)r->req.cmd.buf;
+ r->bsg_hdr.max_response_len = sizeof(s->sensebuf);
+ /* SCSI: (auto)sense data */
+ r->bsg_hdr.response = (unsigned long)s->sensebuf;
+ /* Unlimited timeout */
+ r->bsg_hdr.timeout = UINT_MAX;
+ /* [i->o] unused internally */
+ r->bsg_hdr.usr_ptr = (unsigned long)r;
+ /* Bsg does Q_AT_HEAD by default */
+ r->bsg_hdr.flags = BSG_FLAG_Q_AT_TAIL;
+
+ qemu_iovec_reset(&r->aio_iov);
+ qemu_iovec_add(&r->aio_iov, &r->bsg_hdr, sizeof(r->bsg_hdr));
+
+ r->req.aiocb = paio_submit_len(bdrv, bdrv->fd, 0, &r->aio_iov,
+ sizeof(r->bsg_hdr), complete, r, QEMU_AIO_WRITE);
+ if (r->req.aiocb == NULL) {
+ BADF("execute_command: paio_submit_len() failed\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+static void bsg_setup_command(SCSIBSGReq *r)
+{
+ if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
+ r->bsg_hdr.dout_xferp = (unsigned long)r->buf;
+ r->bsg_hdr.dout_xfer_len = r->buflen;
+ } else if (r->req.cmd.mode == SCSI_XFER_FROM_DEV) {
+ r->bsg_hdr.din_xferp = (unsigned long)r->buf;
+ r->bsg_hdr.din_xfer_len = r->buflen;
+ }
+ DPRINTF_BSG_IO("setup BUF: %p, dxfer_len %u\n", r->buf, r->buflen);
+}
+
+static void bsg_setup_command_iov(SCSIBSGReq *r)
+{
+ struct iovec *iov = r->saved_iov;
+ int i;
+
+ if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
+ r->bsg_hdr.dout_iovec_count = r->saved_iov_num;
+ r->bsg_hdr.dout_xferp = (unsigned long)r->saved_iov;
+ r->bsg_hdr.dout_xfer_len = 0;
+ for (i = 0; i < r->saved_iov_num; i++)
+ r->bsg_hdr.dout_xfer_len += iov[i].iov_len;
+
+ } else if (r->req.cmd.mode == SCSI_XFER_FROM_DEV) {
+ r->bsg_hdr.din_iovec_count = r->saved_iov_num;
+ r->bsg_hdr.din_xferp = (unsigned long)r->saved_iov;
+ r->bsg_hdr.din_xfer_len = 0;
+ for (i = 0; i < r->saved_iov_num; i++)
+ r->bsg_hdr.din_xfer_len += iov[i].iov_len;
+ }
+
+ DPRINTF_BSG_IO("setup IOV: iovec_num: %u, iov: %p,"
+ " dout_xfer_len: %u din_xfer_len: %u\n",
+ r->saved_iov_num, r->saved_iov,
+ r->bsg_hdr.dout_xfer_len, r->bsg_hdr.din_xfer_len);
+}
+
+static void bsg_read_complete(void * opaque, int ret)
+{
+ SCSIBSGReq *r = (SCSIBSGReq *)opaque;
+ SCSIBSGState *s = DO_UPCAST(SCSIBSGState, qdev, r->req.dev);
+ struct sg_io_v4 io_hdr;
+ int err, len;
+
+ if (ret) {
+ DPRINTF("IO error ret %d\n", ret);
+ bsg_command_complete(r, ret);
+ return;
+ }
+
+ r->req.aiocb = NULL;
+
+ memset(&io_hdr, 0, sizeof(io_hdr));
+ /* [i] 'Q' to differentiate from v3 */
+ io_hdr.guard = 'Q';
+ err = bsg_read(s->bs->fd, &io_hdr, sizeof(io_hdr));
+ if (err) {
+ DPRINTF("bsg_read() failed with ret: %d\n", err);
+ bsg_command_complete(r, EBADR);
+ return;
+ }
+
+ len = r->bsg_hdr.din_xfer_len - r->bsg_hdr.din_resid;
+ DPRINTF_BSG_IO("BSG READ Data ready tag=0x%x len=%d\n", r->req.tag, len);
+
+ r->len = -1;
+ r->req.bus->complete(&r->req, SCSI_REASON_DATA, len);
+}
+
+/* Read more data from scsi device into buffer. */
+static void bsg_read_data(SCSIRequest *req)
+{
+ SCSIBSGState *s = DO_UPCAST(SCSIBSGState, qdev, req->dev);
+ SCSIBSGReq *r = DO_UPCAST(SCSIBSGReq, req, req);
+ int ret;
+
+ DPRINTF_BSG_IO("bsg_read_data 0x%x\n", req->tag);
+ if (r->len == -1) {
+ bsg_command_complete(r, 0);
+ return;
+ }
+
+ if (r->req.cmd.buf[0] == REQUEST_SENSE &&
+ s->driver_status & SG_ERR_DRIVER_SENSE) {
+ s->senselen = MIN(r->len, s->senselen);
+ memcpy(r->buf, s->sensebuf, s->senselen);
+ r->bsg_hdr.driver_status = 0;
+ r->bsg_hdr.device_status = 0;
+ r->bsg_hdr.max_response_len = s->senselen;
+ r->len = -1;
+ DPRINTF("Data ready tag=0x%x len=%d\n", r->req.tag, s->senselen);
+ DPRINTF("Sense: %d %d %d %d %d %d %d %d\n",
+ r->buf[0], r->buf[1], r->buf[2], r->buf[3],
+ r->buf[4], r->buf[5], r->buf[6], r->buf[7]);
+ r->req.bus->complete(&r->req, SCSI_REASON_DATA, s->senselen);
+ /* Clear sensebuf after REQUEST_SENSE */
+ bsg_clear_sense(s);
+ return;
+ }
+
+ if (r->buf != NULL)
+ bsg_setup_command(r);
+ else
+ bsg_setup_command_iov(r);
+
+ ret = bsg_execute_command(s->bs, r, bsg_read_complete);
+ if (ret == -1) {
+ bsg_command_complete(r, -EBADR);
+ return;
+ }
+}
+
+static void bsg_write_complete(void *opaque, int ret)
+{
+ SCSIBSGReq *r = (SCSIBSGReq *)opaque;
+ SCSIBSGState *s = DO_UPCAST(SCSIBSGState, qdev, r->req.dev);
+ struct sg_io_v4 io_hdr;
+ int err;
+
+ DPRINTF_BSG_IO("bsg_write_complete() ret = %d\n", ret);
+ if (ret) {
+ DPRINTF("IO error\n");
+ bsg_command_complete(r, ret);
+ return;
+ }
+
+ r->req.aiocb = NULL;
+
+ memset(&io_hdr, 0, sizeof(io_hdr));
+ /* [i] 'Q' to differentiate from v3 */
+ io_hdr.guard = 'Q';
+ err = bsg_read(s->bs->fd, &io_hdr, sizeof(io_hdr));
+ if (err) {
+ DPRINTF("bsg_read() failed with ret: %d\n", err);
+ bsg_command_complete(r, EBADR);
+ return;
+ }
+
+ /*
+ * Copied from hw/scsi-generic.c:scsi_write_complete(), is this still
+ * necessary for BSG..?
+ */
+ if (r->req.cmd.buf[0] == MODE_SELECT && r->req.cmd.buf[4] == 12 &&
+ s->qdev.type == TYPE_TAPE) {
+ s->qdev.blocksize = (r->buf[9] << 16) | (r->buf[10] << 8) | r->buf[11];
+ DPRINTF("block size %d\n", s->qdev.blocksize);
+ }
+
+ bsg_command_complete(r, ret);
+}
+
+static int bsg_write_data(SCSIRequest *req)
+{
+ SCSIBSGState *s = DO_UPCAST(SCSIBSGState, qdev, req->dev);
+ SCSIBSGReq *r = DO_UPCAST(SCSIBSGReq, req, req);
+ int ret;
+
+ DPRINTF_BSG_IO("bsg_write_data 0x%x\n", req->tag);
+
+ if (r->len == 0 && r->bsg_hdr.dout_xfer_len == 0) {
+ r->len = r->buflen;
+ r->req.bus->complete(&r->req, SCSI_REASON_DATA, r->len);
+ return 0;
+ }
+
+ ret = bsg_execute_command(s->bs, r, bsg_write_complete);
+ if (ret == -1) {
+ bsg_command_complete(r, -EBADR);
+ return 1;
+ }
+
+ return 0;
+}
+
+static void bsg_req_fixup(SCSIRequest *req)
+{
+ return;
+}
+
+static int bsg_get_blocksize(BlockDriverState *bdrv)
+{
+ uint8_t cmd[10];
+ uint8_t buf[8];
+ uint8_t sensebuf[8];
+ struct sg_io_v4 bsg_hdr;
+ int ret;
+
+ memset(cmd, 0, sizeof(cmd));
+ memset(buf, 0, sizeof(buf));
+ cmd[0] = READ_CAPACITY;
+
+ memset(&bsg_hdr, 0, sizeof(bsg_hdr));
+ bsg_hdr.guard = 'Q';
+ bsg_hdr.protocol = BSG_PROTOCOL_SCSI;
+ bsg_hdr.subprotocol = BSG_SUB_PROTOCOL_SCSI_CMD;
+ bsg_hdr.request_len = sizeof(cmd);
+ bsg_hdr.request = (unsigned long)cmd;
+ bsg_hdr.din_xfer_len = sizeof(buf);
+ bsg_hdr.din_xferp = (unsigned long)buf;
+ bsg_hdr.max_response_len = sizeof(sensebuf);
+ bsg_hdr.response = (unsigned long)sensebuf;
+ bsg_hdr.timeout = 6000; /* XXX */
+
+ ret = bdrv_ioctl(bdrv, SG_IO, (void *)&bsg_hdr);
+ if (ret < 0)
+ return -1;
+
+ return (buf[4] << 24) | (buf[5] << 16) | (buf[6] << 8) | buf[7];
+}
+
+static int bsg_get_stream_blocksize(BlockDriverState *bdrv)
+{
+ uint8_t cmd[6];
+ uint8_t buf[12];
+ uint8_t sensebuf[8];
+ struct sg_io_v4 bsg_hdr;
+ int ret;
+
+ memset(cmd, 0, sizeof(cmd));
+ memset(buf, 0, sizeof(buf));
+ cmd[0] = MODE_SENSE;
+ cmd[4] = sizeof(buf);
+
+ memset(&bsg_hdr, 0, sizeof(bsg_hdr));
+ bsg_hdr.guard = 'Q';
+ bsg_hdr.protocol = BSG_PROTOCOL_SCSI;
+ bsg_hdr.subprotocol = BSG_SUB_PROTOCOL_SCSI_CMD;
+ bsg_hdr.request_len = sizeof(cmd);
+ bsg_hdr.request = (unsigned long)cmd;
+ bsg_hdr.din_xfer_len = sizeof(buf);
+ bsg_hdr.din_xferp = (unsigned long)buf;
+ bsg_hdr.max_response_len = sizeof(sensebuf);
+ bsg_hdr.response = (unsigned long)sensebuf;
+ bsg_hdr.timeout = 6000; /* XXX */
+
+ ret = bdrv_ioctl(bdrv, SG_IO, (void *)&bsg_hdr);
+ if (ret < 0)
+ return -1;
+
+ return (buf[9] << 16) | (buf[10] << 8) | buf[11];
+}
+
+static void bsg_remove_request(SCSIRequest *);
+
+static void bsg_purge_requests(SCSIBSGState *s)
+{
+ SCSIBSGReq *r;
+
+ while (!QTAILQ_EMPTY(&s->qdev.requests)) {
+ r = DO_UPCAST(SCSIBSGReq, req, QTAILQ_FIRST(&s->qdev.requests));
+ if (r->req.aiocb) {
+ bdrv_aio_cancel(r->req.aiocb);
+ }
+ bsg_remove_request(&r->req);
+ }
+}
+
+static void bsg_reset(DeviceState *dev)
+{
+ SCSIBSGState *s = DO_UPCAST(SCSIBSGState, qdev.qdev, dev);
+
+ bsg_purge_requests(s);
+}
+
+static void bsg_destroy(SCSIDevice *d)
+{
+ SCSIBSGState *s = DO_UPCAST(SCSIBSGState, qdev, d);
+
+ bsg_purge_requests(s);
+ blockdev_mark_auto_del(s->qdev.conf.bs);
+}
+
+struct scsi_idlun {
+ uint32_t dev_id;
+ uint32_t host_unique_id;
+};
+
+static int bsg_generic_initfn(SCSIDevice *dev)
+{
+ SCSIBSGState *s = DO_UPCAST(SCSIBSGState, qdev, dev);
+
+ if (!s->qdev.conf.bs) {
+ error_report("scsi-bsg: drive property not set");
+ return -1;
+ }
+ s->bs = s->qdev.conf.bs;
+
+ /* check we are really using a /dev/bsg/ * file */
+ if (!bdrv_is_bsg(s->bs)) {
+ error_report("scsi-bsg: not BSG*");
+ return -1;
+ }
+#if 0
+ /* get LUN of the BSG */
+ if (bdrv_ioctl(s->bs, SG_GET_SCSI_ID, &scsiid)) {
+ error_report("scsi-bsg: SG_GET_SCSI_ID ioctl failed");
+ return -1;
+ }
+#endif
+// FIXME: Get SCSI lun from BSG
+ s->lun = 0;
+// FIXME: Get SCSI device type from BSG INQUIRY
+ s->qdev.type = TYPE_DISK;
+ DPRINTF("LUN %d\n", s->lun);
+ DPRINTF("device type %d\n", s->qdev.type);
+
+ if (s->qdev.type == TYPE_TAPE) {
+ s->qdev.blocksize = bsg_get_stream_blocksize(s->bs);
+ if (s->qdev.blocksize == -1)
+ s->qdev.blocksize = 0;
+ } else {
+ s->qdev.blocksize = bsg_get_blocksize(s->bs);
+ /* removable media returns 0 if not present */
+ if (s->qdev.blocksize <= 0) {
+ if (s->qdev.type == TYPE_ROM || s->qdev.type == TYPE_WORM)
+ s->qdev.blocksize = 2048;
+ else
+ s->qdev.blocksize = 512;
+ }
+ }
+ DPRINTF("block size %d\n", s->qdev.blocksize);
+ s->driver_status = 0;
+ memset(s->sensebuf, 0, sizeof(s->sensebuf));
+ return 0;
+}
+
+static SCSIRequest *bsg_new_request(SCSIDevice *d, uint32_t tag, uint32_t lun)
+{
+ return scsi_req_alloc(sizeof(SCSIBSGReq), d, tag, lun);
+}
+
+static SCSIRequest *bsg_new_request_iovec(SCSIDevice *d, uint32_t tag,
+ uint32_t lun, struct iovec *iov, int
iov_num)
+{
+ SCSIRequest *req;
+ SCSIBSGReq *r;
+
+ req = scsi_req_alloc(sizeof(SCSIBSGReq), d, tag, lun);
+ if (!req)
+ return NULL;
+
+ r = DO_UPCAST(SCSIBSGReq, req, req);
+ r->saved_iov = iov;
+ r->saved_iov_num = iov_num;
+
+ qemu_iovec_init(&r->aio_iov, 1);
+
+ r->buf = NULL;
+ r->buflen = 0;
+
+ return req;
+}
+
+static void bsg_remove_request(SCSIRequest *req)
+{
+ SCSIBSGReq *r = DO_UPCAST(SCSIBSGReq, req, req);
+
+ qemu_free(r->buf);
+ qemu_iovec_destroy(&r->aio_iov);
+ scsi_req_free(&r->req);
+}
+
+/*
+ * Used as a QEMU block completion callback by bsg_send_command()
+ * for SG_DXFER_NONE and zero-length SCSI_XFER_TO_DEV.
+ */
+static void bsg_complete_none(void *opaque, int ret)
+{
+ SCSIRequest *req = opaque;
+ SCSIBSGReq *r = DO_UPCAST(SCSIBSGReq, req, req);
+ SCSIBSGState *s = DO_UPCAST(SCSIBSGState, qdev, r->req.dev);
+ struct sg_io_v4 io_hdr;
+ int err;
+
+ req->aiocb = NULL;
+
+ memset(&io_hdr, 0, sizeof(io_hdr));
+ /* [i] 'Q' to differentiate from v3 */
+ io_hdr.guard = 'Q';
+
+ err = bsg_read(s->bs->fd, &io_hdr, sizeof(io_hdr));
+ if (err) {
+ DPRINTF("bsg_read() failed with ret: %d\n", err);
+ return;
+ }
+
+ bsg_command_complete(opaque, ret);
+}
+
+static int32_t bsg_send_command(SCSIRequest *req, uint8_t *cmd)
+{
+ SCSIBSGReq *r = DO_UPCAST(SCSIBSGReq, req, req);
+ SCSIBSGState *s = DO_UPCAST(SCSIBSGState, qdev, r->req.dev);
+ int ret;
+
+ if (cmd[0] != REQUEST_SENSE &&
+ (req->lun != s->lun || (cmd[1] >> 5) != s->lun)) {
+
+ DPRINTF("Unimplemented LUN %d\n", req->lun ? req->lun : cmd[1] >> 5);
+ bsg_command_complete(r, -ENODEV);
+ return 0;
+ }
+
+ if (-1 == scsi_req_parse(&r->req, cmd)) {
+ BADF("Unsupported command length, command %x\n", cmd[0]);
+ bsg_command_complete(r, -EINVAL);
+ return 0;
+ }
+ bsg_req_fixup(&r->req);
+
+ DPRINTF_BSG_IO("bsg_send_command: lun=%d tag=0x%x len %zd data=0x%02x",
+ req->lun, req->tag, r->req.cmd.xfer, cmd[0]);
+
+#ifdef DEBUG_BSG_IO
+ {
+ int i;
+ for (i = 1; i < r->req.cmd.len; i++) {
+ printf(" 0x%02x", cmd[i]);
+ }
+ printf("\n");
+ }
+#endif
+
+ if (r->req.cmd.xfer == 0) {
+ if (r->buf != NULL)
+ qemu_free(r->buf);
+ r->buflen = 0;
+ r->buf = NULL;
+ ret = bsg_execute_command(s->bs, r, bsg_complete_none);
+ if (ret == -1) {
+ bsg_command_complete(r, -EBADR);
+ return 0;
+ }
+ return 0;
+ }
+
+ if (!r->saved_iov_num) {
+ if (r->buflen != r->req.cmd.xfer) {
+ if (r->buf != NULL)
+ qemu_free(r->buf);
+
+ r->buf = qemu_malloc(r->req.cmd.xfer);
+ r->buflen = r->req.cmd.xfer;
+ }
+
+ memset(r->buf, 0, r->buflen);
+ }
+ r->len = r->req.cmd.xfer;
+ if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
+ r->len = 0;
+ return r->req.cmd.xfer;
+ }
+
+ return r->req.cmd.xfer;
+}
+
+/* Return a pointer to the data buffer. */
+static uint8_t *bsg_get_buf(SCSIRequest *req)
+{
+ SCSIBSGReq *r = DO_UPCAST(SCSIBSGReq, req, req);
+
+ return r->buf;
+}
+
+static void bsg_cancel_io(SCSIRequest *req)
+{
+ SCSIBSGReq *r = DO_UPCAST(SCSIBSGReq, req, req);
+
+ if (r->req.aiocb) {
+ bdrv_aio_cancel(r->req.aiocb);
+ r->req.aiocb = NULL;
+ }
+}
+
+static SCSIDeviceInfo bsg_info = {
+ .qdev.name = "scsi-bsg",
+ .qdev.desc = "pass through block layer scsi generic (/dev/bsg/*)",
+ .qdev.size = sizeof(SCSIBSGState),
+ .qdev.reset = bsg_reset,
+ .init = bsg_generic_initfn,
+ .destroy = bsg_destroy,
+ .alloc_req = bsg_new_request,
+ .alloc_req_iov = bsg_new_request_iovec,
+ .free_req = bsg_remove_request,
+ .send_command = bsg_send_command,
+ .read_data = bsg_read_data,
+ .write_data = bsg_write_data,
+ .cancel_io = bsg_cancel_io,
+ .get_buf = bsg_get_buf,
+ .get_sense = bsg_get_sense,
+ .qdev.props = (Property[]) {
+ DEFINE_BLOCK_PROPERTIES(SCSIBSGState, qdev.conf),
+ DEFINE_PROP_END_OF_LIST(),
+ },
+};
+
+static void bsg_register_devices(void)
+{
+ scsi_qdev_register(&bsg_info);
+}
+device_init(bsg_register_devices)
+
+#endif /* __linux__ */
--
1.5.6.5
- [Qemu-devel] [PATCH 5/5] scsi-bsg: Add initial support for BSG based SCSIDeviceInfo,
Nicholas A. Bellinger <=