@@ -43,7 +43,7 @@
*
* A string specifying the backend device: either a 4-tuple "h:c:t:l"
* (host, controller, target, lun, all integers), or a WWN (e.g.
- * "naa.60014054ac780582").
+ * "naa.60014054ac780582:0").
*
* v-dev
* Values: string
@@ -87,6 +87,75 @@
* response structures.
*/
+/*
+ * Xenstore format in practice
+ * ===========================
+ *
+ * The backend driver uses a single_host:many_devices notation to manage domU
+ * devices. Everything is stored in /local/domain/<backend_domid>/backend/vscsi/.
+ * The xenstore layout looks like this (dom0 is assumed to be the backend_domid):
+ *
+ * <domid>/<vhost>/feature-host = "0"
+ * <domid>/<vhost>/frontend = "/local/domain/<domid>/device/vscsi/0"
+ * <domid>/<vhost>/frontend-id = "<domid>"
+ * <domid>/<vhost>/online = "1"
+ * <domid>/<vhost>/state = "4"
+ * <domid>/<vhost>/vscsi-devs/dev-0/p-dev = "8:0:2:1" or "naa.wwn:lun"
+ * <domid>/<vhost>/vscsi-devs/dev-0/state = "4"
+ * <domid>/<vhost>/vscsi-devs/dev-0/v-dev = "0:0:0:0"
+ * <domid>/<vhost>/vscsi-devs/dev-1/p-dev = "8:0:2:2"
+ * <domid>/<vhost>/vscsi-devs/dev-1/state = "4"
+ * <domid>/<vhost>/vscsi-devs/dev-1/v-dev = "0:0:1:0"
+ *
+ * The frontend driver maintains its state in
+ * /local/domain/<domid>/device/vscsi/.
+ *
+ * <vhost>/backend = "/local/domain/0/backend/vscsi/<domid>/<vhost>"
+ * <vhost>/backend-id = "0"
+ * <vhost>/event-channel = "20"
+ * <vhost>/ring-ref = "43"
+ * <vhost>/state = "4"
+ * <vhost>/vscsi-devs/dev-0/state = "4"
+ * <vhost>/vscsi-devs/dev-1/state = "4"
+ *
+ * In addition to the entries for backend and frontend these flags are stored
+ * for the toolstack:
+ *
+ * <domid>/<vhost>/vscsi-devs/dev-1/p-devname = "/dev/$device"
+ * <domid>/<vhost>/libxl_ctrl_index = "0"
+ *
+ *
+ * Backend/frontend protocol
+ * =========================
+ *
+ * To create a vhost along with a device:
+ * <domid>/<vhost>/feature-host = "0"
+ * <domid>/<vhost>/frontend = "/local/domain/<domid>/device/vscsi/0"
+ * <domid>/<vhost>/frontend-id = "<domid>"
+ * <domid>/<vhost>/online = "1"
+ * <domid>/<vhost>/state = "1"
+ * <domid>/<vhost>/vscsi-devs/dev-0/p-dev = "8:0:2:1"
+ * <domid>/<vhost>/vscsi-devs/dev-0/state = "1"
+ * <domid>/<vhost>/vscsi-devs/dev-0/v-dev = "0:0:0:0"
+ * Wait for <domid>/<vhost>/state + <domid>/<vhost>/vscsi-devs/dev-0/state become 4
+ *
+ * To add another device to a vhost:
+ * <domid>/<vhost>/state = "7"
+ * <domid>/<vhost>/vscsi-devs/dev-1/p-dev = "8:0:2:2"
+ * <domid>/<vhost>/vscsi-devs/dev-1/state = "1"
+ * <domid>/<vhost>/vscsi-devs/dev-1/v-dev = "0:0:1:0"
+ * Wait for <domid>/<vhost>/state + <domid>/<vhost>/vscsi-devs/dev-1/state become 4
+ *
+ * To remove a device from a vhost:
+ * <domid>/<vhost>/state = "7"
+ * <domid>/<vhost>/vscsi-devs/dev-1/state = "5"
+ * Wait for <domid>/<vhost>/state to become 4
+ * Wait for <domid>/<vhost>/vscsi-devs/dev-1/state become 6
+ * Remove <domid>/<vhost>/vscsi-devs/dev-1/{state,p-dev,v-dev,p-devname}
+ * Remove <domid>/<vhost>/vscsi-devs/dev-1/
+ *
+ */
+
/* Requests from the frontend to the backend */
/*
@@ -117,7 +186,8 @@
* (plus the set VSCSIIF_SG_GRANT bit), the number of scsiif_request_segment
* elements referencing the target data buffers is calculated from the lengths
* of the seg[] elements (the sum of all valid seg[].length divided by the
- * size of one scsiif_request_segment structure).
+ * size of one scsiif_request_segment structure). The frontend may use a mix of
+ * direct and indirect requests.
*/
#define VSCSIIF_ACT_SCSI_CDB 1
@@ -154,12 +224,14 @@
/*
* based on Linux kernel 2.6.18, still valid
+ *
* Changing these values requires support of multiple protocols via the rings
* as "old clients" will blindly use these values and the resulting structure
* sizes.
*/
#define VSCSIIF_MAX_COMMAND_SIZE 16
#define VSCSIIF_SENSE_BUFFERSIZE 96
+#define VSCSIIF_PAGE_SIZE 4096
struct scsiif_request_segment {
grant_ref_t gref;
@@ -167,7 +239,8 @@ struct scsiif_request_segment {
uint16_t length;
};
-#define VSCSIIF_SG_PER_PAGE (PAGE_SIZE / sizeof(struct scsiif_request_segment))
+#define VSCSIIF_SG_PER_PAGE (VSCSIIF_PAGE_SIZE / \
+ sizeof(struct scsiif_request_segment))
/* Size of one request is 252 bytes */
struct vscsiif_request {
@@ -207,6 +280,58 @@ struct vscsiif_response {
uint32_t reserved[36];
};
+/* SCSI I/O status from vscsiif_response->rslt */
+#define XEN_VSCSIIF_RSLT_STATUS(x) ((x) & 0x00ff)
+
+/* Host I/O status from vscsiif_response->rslt */
+#define XEN_VSCSIIF_RSLT_HOST(x) (((x) & 0x00ff0000) >> 16)
+#define XEN_VSCSIIF_RSLT_HOST_OK 0
+/* Couldn't connect before timeout */
+#define XEN_VSCSIIF_RSLT_HOST_NO_CONNECT 1
+/* Bus busy through timeout */
+#define XEN_VSCSIIF_RSLT_HOST_BUS_BUSY 2
+/* Timed out for other reason */
+#define XEN_VSCSIIF_RSLT_HOST_TIME_OUT 3
+/* Bad target */
+#define XEN_VSCSIIF_RSLT_HOST_BAD_TARGET 4
+/* Abort for some other reason */
+#define XEN_VSCSIIF_RSLT_HOST_ABORT 5
+/* Parity error */
+#define XEN_VSCSIIF_RSLT_HOST_PARITY 6
+/* Internal error */
+#define XEN_VSCSIIF_RSLT_HOST_ERROR 7
+/* Reset by somebody */
+#define XEN_VSCSIIF_RSLT_HOST_RESET 8
+/* Unexpected interrupt */
+#define XEN_VSCSIIF_RSLT_HOST_BAD_INTR 9
+/* Force command past mid-layer */
+#define XEN_VSCSIIF_RSLT_HOST_PASSTHROUGH 10
+/* Retry requested */
+#define XEN_VSCSIIF_RSLT_HOST_SOFT_ERROR 11
+/* Hidden retry requested */
+#define XEN_VSCSIIF_RSLT_HOST_IMM_RETRY 12
+/* Requeue command requested */
+#define XEN_VSCSIIF_RSLT_HOST_REQUEUE 13
+/* Transport error disrupted I/O */
+#define XEN_VSCSIIF_RSLT_HOST_TRANSPORT_DISRUPTED 14
+/* Transport class fastfailed */
+#define XEN_VSCSIIF_RSLT_HOST_TRANSPORT_FAILFAST 15
+/* Permanent target failure */
+#define XEN_VSCSIIF_RSLT_HOST_TARGET_FAILURE 16
+/* Permanent nexus failure on path */
+#define XEN_VSCSIIF_RSLT_HOST_NEXUS_FAILURE 17
+/* Space allocation on device failed */
+#define XEN_VSCSIIF_RSLT_HOST_ALLOC_FAILURE 18
+/* Medium error */
+#define XEN_VSCSIIF_RSLT_HOST_MEDIUM_ERROR 19
+/* Transport marginal errors */
+#define XEN_VSCSIIF_RSLT_HOST_TRANSPORT_MARGINAL 20
+
+/* Result values of reset operations */
+#define XEN_VSCSIIF_RSLT_RESET_SUCCESS 0x2002
+#define XEN_VSCSIIF_RSLT_RESET_FAILED 0x2003
+
DEFINE_RING_TYPES(vscsiif, struct vscsiif_request, struct vscsiif_response);
-#endif /*__XEN__PUBLIC_IO_SCSI_H__*/
+
+#endif /*__XEN__PUBLIC_IO_SCSI_H__*/
Update include/xen/interface/io/vscsiif.h to its newest version. Signed-off-by: Juergen Gross <jgross@suse.com> --- include/xen/interface/io/vscsiif.h | 133 ++++++++++++++++++++++++++++- 1 file changed, 129 insertions(+), 4 deletions(-)