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[Qemu-devel] [PATCH 55/55] scsi-disk: add scsi-block for device passthro
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PATCH 55/55] scsi-disk: add scsi-block for device passthrough |
Date: |
Mon, 31 Oct 2011 14:30:30 +0100 |
From: Paolo Bonzini <address@hidden>
scsi-block is a new device that supports device passthrough of Linux
block devices (i.e. /dev/sda, not /dev/sg0). It uses SG_IO for commands
other than I/O commands, and regular AIO read/writes for I/O commands.
Besides being simpler to configure (no mapping required to scsi-generic
device names), this removes the need for a large bounce buffer and,
in the future, will get scatter/gather support for free from scsi-disk.
Signed-off-by: Paolo Bonzini <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
hw/scsi-disk.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 118 insertions(+), 0 deletions(-)
diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index 352d41f..1c04872 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -39,6 +39,10 @@ do { fprintf(stderr, "scsi-disk: " fmt , ## __VA_ARGS__); }
while (0)
#include "blockdev.h"
#include "block_int.h"
+#ifdef __linux
+#include <scsi/sg.h>
+#endif
+
#define SCSI_DMA_BUF_SIZE 131072
#define SCSI_MAX_INQUIRY_LEN 256
@@ -1588,6 +1592,105 @@ static SCSIRequest *scsi_new_request(SCSIDevice *d,
uint32_t tag, uint32_t lun,
return req;
}
+#ifdef __linux__
+static int get_device_type(SCSIDiskState *s)
+{
+ BlockDriverState *bdrv = s->qdev.conf.bs;
+ uint8_t cmd[16];
+ uint8_t buf[36];
+ uint8_t sensebuf[8];
+ sg_io_hdr_t io_header;
+ int ret;
+
+ memset(cmd, 0, sizeof(cmd));
+ memset(buf, 0, sizeof(buf));
+ cmd[0] = INQUIRY;
+ cmd[4] = sizeof(buf);
+
+ memset(&io_header, 0, sizeof(io_header));
+ io_header.interface_id = 'S';
+ io_header.dxfer_direction = SG_DXFER_FROM_DEV;
+ io_header.dxfer_len = sizeof(buf);
+ io_header.dxferp = buf;
+ io_header.cmdp = cmd;
+ io_header.cmd_len = sizeof(cmd);
+ io_header.mx_sb_len = sizeof(sensebuf);
+ io_header.sbp = sensebuf;
+ io_header.timeout = 6000; /* XXX */
+
+ ret = bdrv_ioctl(bdrv, SG_IO, &io_header);
+ if (ret < 0 || io_header.driver_status || io_header.host_status) {
+ return -1;
+ }
+ s->qdev.type = buf[0];
+ s->removable = (buf[1] & 0x80) != 0;
+ return 0;
+}
+
+static int scsi_block_initfn(SCSIDevice *dev)
+{
+ SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, dev);
+ int sg_version;
+ int rc;
+
+ if (!s->qdev.conf.bs) {
+ error_report("scsi-block: drive property not set");
+ return -1;
+ }
+
+ /* check we are using a driver managing SG_IO (version 3 and after) */
+ if (bdrv_ioctl(s->qdev.conf.bs, SG_GET_VERSION_NUM, &sg_version) < 0 ||
+ sg_version < 30000) {
+ error_report("scsi-block: scsi generic interface too old");
+ return -1;
+ }
+
+ /* get device type from INQUIRY data */
+ rc = get_device_type(s);
+ if (rc < 0) {
+ error_report("scsi-block: INQUIRY failed");
+ return -1;
+ }
+
+ /* Make a guess for the block size, we'll fix it when the guest sends.
+ * READ CAPACITY. If they don't, they likely would assume these sizes
+ * anyway. (TODO: check in /sys).
+ */
+ if (s->qdev.type == TYPE_ROM || s->qdev.type == TYPE_WORM) {
+ s->qdev.blocksize = 2048;
+ } else {
+ s->qdev.blocksize = 512;
+ }
+ return scsi_initfn(&s->qdev);
+}
+
+static SCSIRequest *scsi_block_new_request(SCSIDevice *d, uint32_t tag,
+ uint32_t lun, uint8_t *buf,
+ void *hba_private)
+{
+ SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, d);
+
+ switch (buf[0]) {
+ case READ_6:
+ case READ_10:
+ case READ_12:
+ case READ_16:
+ case WRITE_6:
+ case WRITE_10:
+ case WRITE_12:
+ case WRITE_16:
+ case WRITE_VERIFY_10:
+ case WRITE_VERIFY_12:
+ case WRITE_VERIFY_16:
+ return scsi_req_alloc(&scsi_disk_reqops, &s->qdev, tag, lun,
+ hba_private);
+ }
+
+ return scsi_req_alloc(&scsi_generic_req_ops, &s->qdev, tag, lun,
+ hba_private);
+}
+#endif
+
#define DEFINE_SCSI_DISK_PROPERTIES() \
DEFINE_BLOCK_PROPERTIES(SCSIDiskState, qdev.conf), \
DEFINE_PROP_STRING("ver", SCSIDiskState, version), \
@@ -1623,6 +1726,21 @@ static SCSIDeviceInfo scsi_disk_info[] = {
DEFINE_SCSI_DISK_PROPERTIES(),
DEFINE_PROP_END_OF_LIST(),
},
+#ifdef __linux__
+ },{
+ .qdev.name = "scsi-block",
+ .qdev.fw_name = "disk",
+ .qdev.desc = "SCSI block device passthrough",
+ .qdev.size = sizeof(SCSIDiskState),
+ .qdev.reset = scsi_disk_reset,
+ .init = scsi_block_initfn,
+ .destroy = scsi_destroy,
+ .alloc_req = scsi_block_new_request,
+ .qdev.props = (Property[]) {
+ DEFINE_SCSI_DISK_PROPERTIES(),
+ DEFINE_PROP_END_OF_LIST(),
+ },
+#endif
},{
.qdev.name = "scsi-disk", /* legacy -device scsi-disk */
.qdev.fw_name = "disk",
--
1.7.6.4
- [Qemu-devel] [PATCH 29/55] scsi-disk: support READ DVD STRUCTURE, (continued)
- [Qemu-devel] [PATCH 29/55] scsi-disk: support READ DVD STRUCTURE, Kevin Wolf, 2011/10/31
- [Qemu-devel] [PATCH 25/55] scsi-disk: add stubs for more MMC commands, Kevin Wolf, 2011/10/31
- [Qemu-devel] [PATCH 43/55] scsi-generic: snoop READ CAPACITY commands to get block size, Kevin Wolf, 2011/10/31
- [Qemu-devel] [PATCH 32/55] qdev: switch children device list to QTAILQ, Kevin Wolf, 2011/10/31
- [Qemu-devel] [PATCH 19/55] atapi/scsi: unify definitions for MMC, Kevin Wolf, 2011/10/31
- [Qemu-devel] [PATCH 26/55] scsi-disk: store valid mode pages in a table, Kevin Wolf, 2011/10/31
- [Qemu-devel] [PATCH 39/55] scsi-generic: drop SCSIGenericState, Kevin Wolf, 2011/10/31
- [Qemu-devel] [PATCH 24/55] scsi-disk: fix coding style issues (braces), Kevin Wolf, 2011/10/31
- [Qemu-devel] [PATCH 31/55] scsi: move tcq/ndev to SCSIBusOps (now SCSIBusInfo), Kevin Wolf, 2011/10/31
- [Qemu-devel] [PATCH 34/55] scsi: implement REPORT LUNS for arbitrary LUNs, Kevin Wolf, 2011/10/31
- [Qemu-devel] [PATCH 55/55] scsi-disk: add scsi-block for device passthrough,
Kevin Wolf <=
- [Qemu-devel] [PATCH 41/55] scsi-generic: check ioctl statuses when SG_IO succeeds, Kevin Wolf, 2011/10/31
- [Qemu-devel] [PATCH 40/55] scsi-generic: remove scsi_req_fixup, Kevin Wolf, 2011/10/31
- [Qemu-devel] [PATCH 22/55] scsi: notify the device when unit attention is reported, Kevin Wolf, 2011/10/31
- Re: [Qemu-devel] [PULL 00/55] Block patches, Anthony Liguori, 2011/10/31