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pseries: rework PAPR virtual SCSI

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The patch reimplements handling of indirect requests in order to
simplify upcoming live migration support.
- all pointers (except SCSIRequest*) were replaces with integer
indexes and offsets;
- DMA'ed srp_direct_buf kept untouched (ie. BE format);
- vscsi_fetch_desc() is added, now it is the only place where
descriptors are fetched and byteswapped;
- vscsi_req struct fields converted to migration-friendly types;
- many dprintf()'s fixed.

This also removed an unused field 'lun' from the spapr_vscsi device
which is assigned, but never used.  So, remove it.

[David Gibson: removed unused 'lun']
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-id: 1374175984-8930-7-git-send-email-aliguori@us.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Alexey Kardashevskiy 2013-07-18 14:32:59 -05:00 committed by Anthony Liguori
parent a83000f5e3
commit 8ca8a17c9a
1 changed files with 130 additions and 93 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

223
hw/scsi/spapr_vscsi.c
View File

@ -75,20 +75,19 @@ typedef struct vscsi_req {
/* SCSI request tracking */
SCSIRequest *sreq;
uint32_t qtag; /* qemu tag != srp tag */
int lun;
int active;
long data_len;
int writing;
int senselen;
bool active;
uint32_t data_len;
bool writing;
uint32_t senselen;
uint8_t sense[SCSI_SENSE_BUF_SIZE];
/* RDMA related bits */
uint8_t dma_fmt;
struct srp_direct_buf ext_desc;
struct srp_direct_buf *cur_desc;
struct srp_indirect_buf *ind_desc;
int local_desc;
int total_desc;
uint16_t local_desc;
uint16_t total_desc;
uint16_t cdb_offset;
uint16_t cur_desc_num;
uint16_t cur_desc_offset;
} vscsi_req;
#define TYPE_VIO_SPAPR_VSCSI_DEVICE "spapr-vscsi"
@ -264,93 +263,138 @@ static int vscsi_send_rsp(VSCSIState *s, vscsi_req *req,
return 0;
}
static inline void vscsi_swap_desc(struct srp_direct_buf *desc)
static inline struct srp_direct_buf vscsi_swap_desc(struct srp_direct_buf desc)
{
desc->va = be64_to_cpu(desc->va);
desc->len = be32_to_cpu(desc->len);
desc.va = be64_to_cpu(desc.va);
desc.len = be32_to_cpu(desc.len);
return desc;
}
static int vscsi_fetch_desc(VSCSIState *s, struct vscsi_req *req,
unsigned n, unsigned buf_offset,
struct srp_direct_buf *ret)
{
struct srp_cmd *cmd = &req->iu.srp.cmd;
switch (req->dma_fmt) {
case SRP_NO_DATA_DESC: {
dprintf("VSCSI: no data descriptor\n");
return 0;
}
case SRP_DATA_DESC_DIRECT: {
memcpy(ret, cmd->add_data + req->cdb_offset, sizeof(*ret));
assert(req->cur_desc_num == 0);
dprintf("VSCSI: direct segment\n");
break;
}
case SRP_DATA_DESC_INDIRECT: {
struct srp_indirect_buf *tmp = (struct srp_indirect_buf *)
(cmd->add_data + req->cdb_offset);
if (n < req->local_desc) {
*ret = tmp->desc_list[n];
dprintf("VSCSI: indirect segment local tag=0x%x desc#%d/%d\n",
req->qtag, n, req->local_desc);
} else if (n < req->total_desc) {
int rc;
struct srp_direct_buf tbl_desc = vscsi_swap_desc(tmp->table_desc);
unsigned desc_offset = n * sizeof(struct srp_direct_buf);
if (desc_offset >= tbl_desc.len) {
dprintf("VSCSI: #%d is ouf of range (%d bytes)\n",
n, desc_offset);
return -1;
}
rc = spapr_vio_dma_read(&s->vdev, tbl_desc.va + desc_offset,
ret, sizeof(struct srp_direct_buf));
if (rc) {
dprintf("VSCSI: spapr_vio_dma_read -> %d reading ext_desc\n",
rc);
return -1;
}
dprintf("VSCSI: indirect segment ext. tag=0x%x desc#%d/%d { va=%"PRIx64" len=%x }\n",
req->qtag, n, req->total_desc, tbl_desc.va, tbl_desc.len);
} else {
dprintf("VSCSI: Out of descriptors !\n");
return 0;
}
break;
}
default:
fprintf(stderr, "VSCSI: Unknown format %x\n", req->dma_fmt);
return -1;
}
*ret = vscsi_swap_desc(*ret);
if (buf_offset > ret->len) {
dprintf(" offset=%x is out of a descriptor #%d boundary=%x\n",
buf_offset, req->cur_desc_num, ret->len);
return -1;
}
ret->va += buf_offset;
ret->len -= buf_offset;
dprintf(" cur=%d offs=%x ret { va=%"PRIx64" len=%x }\n",
req->cur_desc_num, req->cur_desc_offset, ret->va, ret->len);
return ret->len ? 1 : 0;
}
static int vscsi_srp_direct_data(VSCSIState *s, vscsi_req *req,
uint8_t *buf, uint32_t len)
{
struct srp_direct_buf *md = req->cur_desc;
struct srp_direct_buf md;
uint32_t llen;
int rc = 0;
dprintf("VSCSI: direct segment 0x%x bytes, va=0x%llx desc len=0x%x\n",
len, (unsigned long long)md->va, md->len);
rc = vscsi_fetch_desc(s, req, req->cur_desc_num, req->cur_desc_offset, &md);
if (rc < 0) {
return -1;
} else if (rc == 0) {
return 0;
}
llen = MIN(len, md->len);
llen = MIN(len, md.len);
if (llen) {
if (req->writing) { /* writing = to device = reading from memory */
rc = spapr_vio_dma_read(&s->vdev, md->va, buf, llen);
rc = spapr_vio_dma_read(&s->vdev, md.va, buf, llen);
} else {
rc = spapr_vio_dma_write(&s->vdev, md->va, buf, llen);
rc = spapr_vio_dma_write(&s->vdev, md.va, buf, llen);
}
}
md->len -= llen;
md->va += llen;
if (rc) {
return -1;
}
req->cur_desc_offset += llen;
return llen;
}
static int vscsi_srp_indirect_data(VSCSIState *s, vscsi_req *req,
uint8_t *buf, uint32_t len)
{
struct srp_direct_buf *td = &req->ind_desc->table_desc;
struct srp_direct_buf *md = req->cur_desc;
struct srp_direct_buf md;
int rc = 0;
uint32_t llen, total = 0;
dprintf("VSCSI: indirect segment 0x%x bytes, td va=0x%llx len=0x%x\n",
len, (unsigned long long)td->va, td->len);
dprintf("VSCSI: indirect segment 0x%x bytes\n", len);
/* While we have data ... */
while (len) {
/* If we have a descriptor but it's empty, go fetch a new one */
if (md && md->len == 0) {
/* More local available, use one */
if (req->local_desc) {
md = ++req->cur_desc;
--req->local_desc;
--req->total_desc;
td->va += sizeof(struct srp_direct_buf);
} else {
md = req->cur_desc = NULL;
}
rc = vscsi_fetch_desc(s, req, req->cur_desc_num, req->cur_desc_offset, &md);
if (rc < 0) {
return -1;
} else if (rc == 0) {
break;
}
/* No descriptor at hand, fetch one */
if (!md) {
if (!req->total_desc) {
dprintf("VSCSI: Out of descriptors !\n");
break;
}
md = req->cur_desc = &req->ext_desc;
dprintf("VSCSI: Reading desc from 0x%llx\n",
(unsigned long long)td->va);
rc = spapr_vio_dma_read(&s->vdev, td->va, md,
sizeof(struct srp_direct_buf));
if (rc) {
dprintf("VSCSI: spapr_vio_dma_read -> %d reading ext_desc\n",
rc);
break;
}
vscsi_swap_desc(md);
td->va += sizeof(struct srp_direct_buf);
--req->total_desc;
}
dprintf("VSCSI: [desc va=0x%llx,len=0x%x] remaining=0x%x\n",
(unsigned long long)md->va, md->len, len);
/* Perform transfer */
llen = MIN(len, md->len);
llen = MIN(len, md.len);
if (req->writing) { /* writing = to device = reading from memory */
rc = spapr_vio_dma_read(&s->vdev, md->va, buf, llen);
rc = spapr_vio_dma_read(&s->vdev, md.va, buf, llen);
} else {
rc = spapr_vio_dma_write(&s->vdev, md->va, buf, llen);
rc = spapr_vio_dma_write(&s->vdev, md.va, buf, llen);
}
if (rc) {
dprintf("VSCSI: spapr_vio_dma_r/w(%d) -> %d\n", req->writing, rc);
@ -361,10 +405,18 @@ static int vscsi_srp_indirect_data(VSCSIState *s, vscsi_req *req,
len -= llen;
buf += llen;
total += llen;
md->va += llen;
md->len -= llen;
/* Update current position in the current descriptor */
req->cur_desc_offset += llen;
if (md.len == llen) {
/* Go to the next descriptor if the current one finished */
++req->cur_desc_num;
req->cur_desc_offset = 0;
}
}
return rc ? -1 : total;
}
@ -412,14 +464,13 @@ static int data_out_desc_size(struct srp_cmd *cmd)
static int vscsi_preprocess_desc(vscsi_req *req)
{
struct srp_cmd *cmd = &req->iu.srp.cmd;
int offset, i;
offset = cmd->add_cdb_len & ~3;
req->cdb_offset = cmd->add_cdb_len & ~3;
if (req->writing) {
req->dma_fmt = cmd->buf_fmt >> 4;
} else {
offset += data_out_desc_size(cmd);
req->cdb_offset += data_out_desc_size(cmd);
req->dma_fmt = cmd->buf_fmt & ((1U << 4) - 1);
}
@ -427,31 +478,18 @@ static int vscsi_preprocess_desc(vscsi_req *req)
case SRP_NO_DATA_DESC:
break;
case SRP_DATA_DESC_DIRECT:
req->cur_desc = (struct srp_direct_buf *)(cmd->add_data + offset);
req->total_desc = req->local_desc = 1;
vscsi_swap_desc(req->cur_desc);
dprintf("VSCSI: using direct RDMA %s, 0x%x bytes MD: 0x%llx\n",
req->writing ? "write" : "read",
req->cur_desc->len, (unsigned long long)req->cur_desc->va);
break;
case SRP_DATA_DESC_INDIRECT:
req->ind_desc = (struct srp_indirect_buf *)(cmd->add_data + offset);
vscsi_swap_desc(&req->ind_desc->table_desc);
req->total_desc = req->ind_desc->table_desc.len /
sizeof(struct srp_direct_buf);
case SRP_DATA_DESC_INDIRECT: {
struct srp_indirect_buf *ind_tmp = (struct srp_indirect_buf *)
(cmd->add_data + req->cdb_offset);
req->total_desc = be32_to_cpu(ind_tmp->table_desc.len) /
sizeof(struct srp_direct_buf);
req->local_desc = req->writing ? cmd->data_out_desc_cnt :
cmd->data_in_desc_cnt;
for (i = 0; i < req->local_desc; i++) {
vscsi_swap_desc(&req->ind_desc->desc_list[i]);
}
req->cur_desc = req->local_desc ? &req->ind_desc->desc_list[0] : NULL;
dprintf("VSCSI: using indirect RDMA %s, 0x%x bytes %d descs "
"(%d local) VA: 0x%llx\n",
req->writing ? "read" : "write",
be32_to_cpu(req->ind_desc->len),
req->total_desc, req->local_desc,
(unsigned long long)req->ind_desc->table_desc.va);
cmd->data_in_desc_cnt;
break;
}
default:
fprintf(stderr,
"vscsi_preprocess_desc: Unknown format %x\n", req->dma_fmt);
@ -499,8 +537,8 @@ static void vscsi_command_complete(SCSIRequest *sreq, uint32_t status, size_t re
vscsi_req *req = sreq->hba_private;
int32_t res_in = 0, res_out = 0;
dprintf("VSCSI: SCSI cmd complete, r=0x%x tag=0x%x status=0x%x, req=%p\n",
reason, sreq->tag, status, req);
dprintf("VSCSI: SCSI cmd complete, tag=0x%x status=0x%x, req=%p\n",
sreq->tag, status, req);
if (req == NULL) {
fprintf(stderr, "VSCSI: Can't find request for tag 0x%x\n", sreq->tag);
return;
@ -509,7 +547,7 @@ static void vscsi_command_complete(SCSIRequest *sreq, uint32_t status, size_t re
if (status == CHECK_CONDITION) {
req->senselen = scsi_req_get_sense(req->sreq, req->sense,
sizeof(req->sense));
dprintf("VSCSI: Sense data, %d bytes:\n", len);
dprintf("VSCSI: Sense data, %d bytes:\n", req->senselen);
dprintf(" %02x %02x %02x %02x %02x %02x %02x %02x\n",
req->sense[0], req->sense[1], req->sense[2], req->sense[3],
req->sense[4], req->sense[5], req->sense[6], req->sense[7]);
@ -621,12 +659,11 @@ static int vscsi_queue_cmd(VSCSIState *s, vscsi_req *req)
} return 1;
}
req->lun = lun;
req->sreq = scsi_req_new(sdev, req->qtag, lun, srp->cmd.cdb, req);
n = scsi_req_enqueue(req->sreq);
dprintf("VSCSI: Queued command tag 0x%x CMD 0x%x ID %d LUN %d ret: %d\n",
req->qtag, srp->cmd.cdb[0], id, lun, n);
dprintf("VSCSI: Queued command tag 0x%x CMD 0x%x LUN %d ret: %d\n",
req->qtag, srp->cmd.cdb[0], lun, n);
if (n) {
/* Transfer direction must be set before preprocessing the