scsi: introduce SCSIReqOps

This will let allow requests to be dispatched through different callbacks,
either common or per-device.

This patch adjusts the API, the next one will move members to SCSIReqOps.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

hw/scsi-bus.c

@@ -133,12 +133,12 @@ int scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
     return res;
 }
 
-SCSIRequest *scsi_req_alloc(size_t size, SCSIDevice *d, uint32_t tag,
+SCSIRequest *scsi_req_alloc(SCSIReqOps *reqops, SCSIDevice *d, uint32_t tag,
                             uint32_t lun, void *hba_private)
 {
     SCSIRequest *req;
 
-    req = qemu_mallocz(size);
+    req = qemu_mallocz(reqops->size);
     req->refcount = 1;
     req->bus = scsi_bus_from_device(d);
     req->dev = d;
@@ -147,6 +147,7 @@ SCSIRequest *scsi_req_alloc(size_t size, SCSIDevice *d, uint32_t tag,
     req->hba_private = hba_private;
     req->status = -1;
     req->sense_len = 0;
+    req->ops = reqops;
     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
     return req;
 }

hw/scsi-disk.c

@@ -76,19 +76,6 @@ struct SCSIDiskState
 static int scsi_handle_rw_error(SCSIDiskReq *r, int error, int type);
 static int scsi_disk_emulate_command(SCSIDiskReq *r, uint8_t *outbuf);
 
-static SCSIRequest *scsi_new_request(SCSIDevice *d, uint32_t tag,
-                                     uint32_t lun, void *hba_private)
-{
-    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, d);
-    SCSIRequest *req;
-    SCSIDiskReq *r;
-
-    req = scsi_req_alloc(sizeof(SCSIDiskReq), &s->qdev, tag, lun, hba_private);
-    r = DO_UPCAST(SCSIDiskReq, req, req);
-    r->iov.iov_base = qemu_blockalign(s->bs, SCSI_DMA_BUF_SIZE);
-    return req;
-}
-
 static void scsi_free_request(SCSIRequest *req)
 {
     SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req);
@@ -1225,6 +1212,23 @@ static int scsi_disk_initfn(SCSIDevice *dev)
     return scsi_initfn(dev, scsi_type);
 }
 
+static SCSIReqOps scsi_disk_reqops = {
+    .size         = sizeof(SCSIDiskReq),
+};
+
+static SCSIRequest *scsi_new_request(SCSIDevice *d, uint32_t tag,
+                                     uint32_t lun, void *hba_private)
+{
+    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, d);
+    SCSIRequest *req;
+    SCSIDiskReq *r;
+
+    req = scsi_req_alloc(&scsi_disk_reqops, &s->qdev, tag, lun, hba_private);
+    r = DO_UPCAST(SCSIDiskReq, req, req);
+    r->iov.iov_base = qemu_blockalign(s->bs, SCSI_DMA_BUF_SIZE);
+    return req;
+}
+
 #define DEFINE_SCSI_DISK_PROPERTIES()                           \
     DEFINE_BLOCK_PROPERTIES(SCSIDiskState, qdev.conf),          \
     DEFINE_PROP_STRING("ver",  SCSIDiskState, version),         \

hw/scsi-generic.c

@@ -63,15 +63,6 @@ struct SCSIGenericState
     int lun;
 };
 
-static SCSIRequest *scsi_new_request(SCSIDevice *d, uint32_t tag, uint32_t lun,
-                                     void *hba_private)
-{
-    SCSIRequest *req;
-
-    req = scsi_req_alloc(sizeof(SCSIGenericReq), d, tag, lun, hba_private);
-    return req;
-}
-
 static void scsi_free_request(SCSIRequest *req)
 {
     SCSIGenericReq *r = DO_UPCAST(SCSIGenericReq, req, req);
@@ -498,6 +489,19 @@ static int scsi_generic_initfn(SCSIDevice *dev)
     return 0;
 }
 
+static SCSIReqOps scsi_generic_req_ops = {
+    .size         = sizeof(SCSIGenericReq),
+};
+
+static SCSIRequest *scsi_new_request(SCSIDevice *d, uint32_t tag, uint32_t lun,
+                                     void *hba_private)
+{
+    SCSIRequest *req;
+
+    req = scsi_req_alloc(&scsi_generic_req_ops, d, tag, lun, hba_private);
+    return req;
+}
+
 static SCSIDeviceInfo scsi_generic_info = {
     .qdev.name    = "scsi-generic",
     .qdev.desc    = "pass through generic scsi device (/dev/sg*)",

hw/scsi.h

@@ -14,6 +14,7 @@ typedef struct SCSIBusOps SCSIBusOps;
 typedef struct SCSIDevice SCSIDevice;
 typedef struct SCSIDeviceInfo SCSIDeviceInfo;
 typedef struct SCSIRequest SCSIRequest;
+typedef struct SCSIReqOps SCSIReqOps;
 
 enum SCSIXferMode {
     SCSI_XFER_NONE,      /*  TEST_UNIT_READY, ...            */
@@ -32,6 +33,7 @@ typedef struct SCSISense {
 struct SCSIRequest {
     SCSIBus           *bus;
     SCSIDevice        *dev;
+    SCSIReqOps        *ops;
     uint32_t          refcount;
     uint32_t          tag;
     uint32_t          lun;
@@ -69,6 +71,10 @@ int cdrom_read_toc(int nb_sectors, uint8_t *buf, int msf, int start_track);
 int cdrom_read_toc_raw(int nb_sectors, uint8_t *buf, int msf, int session_num);
 
 /* scsi-bus.c */
+struct SCSIReqOps {
+    size_t size;
+};
+
 typedef int (*scsi_qdev_initfn)(SCSIDevice *dev);
 struct SCSIDeviceInfo {
     DeviceInfo qdev;
@@ -144,7 +150,7 @@ extern const struct SCSISense sense_code_LUN_FAILURE;
 
 int scsi_sense_valid(SCSISense sense);
 
-SCSIRequest *scsi_req_alloc(size_t size, SCSIDevice *d, uint32_t tag,
+SCSIRequest *scsi_req_alloc(SCSIReqOps *reqops, SCSIDevice *d, uint32_t tag,
                             uint32_t lun, void *hba_private);
 SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
                           void *hba_private);