tools/kvm/9p: Simplify the handler

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

diff --git a/tools/kvm/include/net/9p/9p.h b/tools/kvm/include/net/9p/9p.h
index cc115923c8b3f77b1f88bd7a02d9b4e57ec2667c..61ecff396cd1ba51b4c2117895379aa684e19eac 100644 (file)
--- a/tools/kvm/include/net/9p/9p.h
+++ b/tools/kvm/include/net/9p/9p.h
@@ -635,7 +635,6 @@ struct p9_twrite {
        u32 fid;
        u64 offset;
        u32 count;
-       u8 *data;
 };
 
 struct p9_rwrite {

diff --git a/tools/kvm/virtio/9p.c b/tools/kvm/virtio/9p.c
index 83da12c7d0864e5ee008173627d879be349c83e2..24acb585e89910fb883a8736127474947ae31be2 100644 (file)
--- a/tools/kvm/virtio/9p.c
+++ b/tools/kvm/virtio/9p.c
@@ -68,6 +68,15 @@ struct p9_dev {
        struct pci_device_header pci_hdr;
 };
 
+struct p9_pdu {
+       u32 queue_head;
+       int offset;
+       u16 out_iov_cnt;
+       u16 in_iov_cnt;
+       struct iovec in_iov[VIRTQUEUE_NUM];
+       struct iovec out_iov[VIRTQUEUE_NUM];
+};
+
 /* Warning: Immediately use value returned from this function */
 static const char *rel_to_abs(struct p9_dev *p9dev,
                              const char *path, char *abs_path)
@@ -185,12 +194,12 @@ static void set_p9msg_hdr(struct p9_msg *msg, u32 size, u8 cmd, u16 tag)
        };
 }
 
-static bool virtio_p9_version(struct p9_dev *p9dev, struct p9_msg *msg,
-                             u32 len, struct iovec *iov,
-                             int outiovcnt, int iniovcnt, u32 *outlen)
+static bool virtio_p9_version(struct p9_dev *p9dev,
+                             struct p9_pdu *pdu, u32 *outlen)
 {
-       struct p9_msg *outmsg = iov[0].iov_base;
-       struct p9_rversion *rversion = (struct p9_rversion *)outmsg->msg;
+       struct p9_msg *inmsg  = pdu->in_iov[0].iov_base;
+       struct p9_msg *outmsg = pdu->out_iov[0].iov_base;
+       struct p9_rversion *rversion = (struct p9_rversion *)inmsg->msg;
 
        rversion->msize         = 4096;
        rversion->version.len   = strlen(VIRTIO_P9_VERSION);
@@ -198,35 +207,35 @@ static bool virtio_p9_version(struct p9_dev *p9dev, struct p9_msg *msg,
 
        *outlen = VIRTIO_P9_HDR_LEN +
                rversion->version.len + sizeof(u16) + sizeof(u32);
-       set_p9msg_hdr(outmsg, *outlen, P9_RVERSION, msg->tag);
+       set_p9msg_hdr(inmsg, *outlen, P9_RVERSION, outmsg->tag);
 
        return true;
 }
 
-static bool virtio_p9_clunk(struct p9_dev *p9dev, struct p9_msg *msg,
-                           u32 len, struct iovec *iov,
-                           int outiovcnt, int iniovcnt, u32 *outlen)
+static bool virtio_p9_clunk(struct p9_dev *p9dev,
+                           struct p9_pdu *pdu, u32 *outlen)
 {
-       struct p9_msg *outmsg = iov[0].iov_base;
-       struct p9_tclunk *tclunk = (struct p9_tclunk *)msg->msg;
+       struct p9_msg *inmsg  = pdu->in_iov[0].iov_base;
+       struct p9_msg *outmsg = pdu->out_iov[0].iov_base;
+       struct p9_tclunk *tclunk = (struct p9_tclunk *)outmsg->msg;
 
        close_fid(p9dev, tclunk->fid);
 
        *outlen = VIRTIO_P9_HDR_LEN;
-       set_p9msg_hdr(outmsg, *outlen, P9_RCLUNK, msg->tag);
+       set_p9msg_hdr(inmsg, *outlen, P9_RCLUNK, outmsg->tag);
 
        return true;
 }
 
-static bool virtio_p9_open(struct p9_dev *p9dev, struct p9_msg *msg,
-                          u32 len, struct iovec *iov,
-                          int outiovcnt, int iniovcnt, u32 *outlen)
+static bool virtio_p9_open(struct p9_dev *p9dev,
+                          struct p9_pdu *pdu, u32 *outlen)
 {
-       struct p9_msg *outmsg   = iov[0].iov_base;
-       struct p9_topen *topen  = (struct p9_topen *)msg->msg;
-       struct p9_ropen *ropen  = (struct p9_ropen *)outmsg->msg;
-       struct p9_fid *new_fid  = &p9dev->fids[topen->fid];
        struct stat st;
+       struct p9_msg *inmsg  = pdu->in_iov[0].iov_base;
+       struct p9_msg *outmsg = pdu->out_iov[0].iov_base;
+       struct p9_topen *topen  = (struct p9_topen *)outmsg->msg;
+       struct p9_ropen *ropen  = (struct p9_ropen *)inmsg->msg;
+       struct p9_fid *new_fid  = &p9dev->fids[topen->fid];
 
        if (lstat(new_fid->abs_path, &st) < 0)
                return false;
@@ -240,28 +249,29 @@ static bool virtio_p9_open(struct p9_dev *p9dev, struct p9_msg *msg,
                new_fid->fd     = open(new_fid->abs_path, omode2uflags(topen->mode));
 
        *outlen = VIRTIO_P9_HDR_LEN + sizeof(*ropen);
-       set_p9msg_hdr(outmsg, *outlen, P9_ROPEN, msg->tag);
+       set_p9msg_hdr(inmsg, *outlen, P9_ROPEN, outmsg->tag);
 
        return true;
 }
 
-static bool virtio_p9_create(struct p9_dev *p9dev, struct p9_msg *msg,
-                            u32 len, struct iovec *iov,
-                            int outiovcnt, int iniovcnt, u32 *outlen)
+static bool virtio_p9_create(struct p9_dev *p9dev,
+                            struct p9_pdu *pdu, u32 *outlen)
 {
-       struct p9_msg *outmsg           = iov[0].iov_base;
-       struct p9_tcreate *tcreate      = (struct p9_tcreate *)msg->msg;
-       struct p9_rcreate *rcreate      = (struct p9_rcreate *)outmsg->msg;
-       struct p9_fid *fid              = &p9dev->fids[tcreate->fid];
-       struct stat st;
        u8 mode;
        u32 perm;
+       struct stat st;
+       struct p9_msg *inmsg  = pdu->in_iov[0].iov_base;
+       struct p9_msg *outmsg = pdu->out_iov[0].iov_base;
+       struct p9_tcreate *tcreate      = (struct p9_tcreate *)outmsg->msg;
+       struct p9_rcreate *rcreate      = (struct p9_rcreate *)inmsg->msg;
+       struct p9_fid *fid              = &p9dev->fids[tcreate->fid];
+
 
        rcreate->iounit = 0;
 
        /* Get last byte of the variable length struct */
-       mode = *((u8 *)msg + msg->size - 1);
-       perm = *(u32 *)((u8 *)msg + msg->size - 5);
+       mode = *((u8 *)outmsg + outmsg->size - 1);
+       perm = *(u32 *)((u8 *)outmsg + outmsg->size - 5);
 
        sprintf(fid->path, "%s/%.*s", fid->path, tcreate->name.len, (char *)&tcreate->name.str);
 
@@ -281,21 +291,22 @@ static bool virtio_p9_create(struct p9_dev *p9dev, struct p9_msg *msg,
        st2qid(&st, &rcreate->qid);
 
        *outlen = VIRTIO_P9_HDR_LEN + sizeof(*rcreate);
-       set_p9msg_hdr(outmsg, *outlen, P9_RCREATE, msg->tag);
+       set_p9msg_hdr(inmsg, *outlen, P9_RCREATE, outmsg->tag);
 
        return true;
 }
 
-static bool virtio_p9_walk(struct p9_dev *p9dev, struct p9_msg *msg,
-                          u32 len, struct iovec *iov,
-                          int outiovcnt, int iniovcnt, u32 *outlen)
+static bool virtio_p9_walk(struct p9_dev *p9dev,
+                          struct p9_pdu *pdu, u32 *outlen)
 {
-       struct p9_msg *outmsg   = iov[0].iov_base;
-       struct p9_twalk *twalk  = (struct p9_twalk *)msg->msg;
-       struct p9_rwalk *rwalk  = (struct p9_rwalk *)outmsg->msg;
+       u8 i;
+       struct p9_msg *inmsg  = pdu->in_iov[0].iov_base;
+       struct p9_msg *outmsg = pdu->out_iov[0].iov_base;
+       struct p9_twalk *twalk  = (struct p9_twalk *)outmsg->msg;
+       struct p9_rwalk *rwalk  = (struct p9_rwalk *)inmsg->msg;
        struct p9_str *str      = twalk->wnames;
        struct p9_fid *new_fid  = &p9dev->fids[twalk->newfid];
-       u8 i;
+
 
        rwalk->nwqid = 0;
        if (twalk->nwname) {
@@ -307,7 +318,8 @@ static bool virtio_p9_walk(struct p9_dev *p9dev, struct p9_msg *msg,
                        struct stat st;
 
                        /* Format the new path we're 'walk'ing into */
-                       sprintf(tmp, "%s/%.*s", fid->path, str->len, (char *)&str->str);
+                       sprintf(tmp, "%s/%.*s", fid->path,
+                               str->len, (char *)&str->str);
 
                        if (lstat(rel_to_abs(p9dev, tmp, full_path), &st) < 0)
                                break;
@@ -324,22 +336,23 @@ static bool virtio_p9_walk(struct p9_dev *p9dev, struct p9_msg *msg,
                new_fid->fid    = twalk->newfid;
        }
 
-       *outlen = VIRTIO_P9_HDR_LEN + sizeof(u16) + sizeof(struct p9_qid) * rwalk->nwqid;
-       set_p9msg_hdr(outmsg, *outlen, P9_RWALK, msg->tag);
+       *outlen = VIRTIO_P9_HDR_LEN + sizeof(u16) +
+               sizeof(struct p9_qid)*rwalk->nwqid;
+       set_p9msg_hdr(inmsg, *outlen, P9_RWALK, outmsg->tag);
 
        return true;
 }
 
-static bool virtio_p9_attach(struct p9_dev *p9dev, struct p9_msg *msg,
-                            u32 len, struct iovec *iov,
-                            int outiovcnt, int iniovcnt, u32 *outlen)
+static bool virtio_p9_attach(struct p9_dev *p9dev,
+                            struct p9_pdu *pdu, u32 *outlen)
 {
-       struct p9_msg *outmsg = iov[0].iov_base;
-       struct p9_rattach *rattach = (struct p9_rattach *)outmsg->msg;
-       struct p9_tattach *tattach = (struct p9_tattach *)msg->msg;
+       u32 i;
        struct stat st;
        struct p9_fid *fid;
-       u32 i;
+       struct p9_msg *inmsg  = pdu->in_iov[0].iov_base;
+       struct p9_msg *outmsg = pdu->out_iov[0].iov_base;
+       struct p9_rattach *rattach = (struct p9_rattach *)inmsg->msg;
+       struct p9_tattach *tattach = (struct p9_tattach *)outmsg->msg;
 
        /* Reset everything */
        for (i = 0; i < VIRTIO_P9_MAX_FID; i++)
@@ -356,7 +369,7 @@ static bool virtio_p9_attach(struct p9_dev *p9dev, struct p9_msg *msg,
        strcpy(fid->path, "/");
 
        *outlen = VIRTIO_P9_HDR_LEN + sizeof(*rattach);
-       set_p9msg_hdr(outmsg, *outlen, P9_RATTACH, msg->tag);
+       set_p9msg_hdr(inmsg, *outlen, P9_RATTACH, outmsg->tag);
 
        return true;
 }
@@ -401,14 +414,14 @@ static u32 virtio_p9_fill_stat(struct p9_dev *p9dev, const char *name,
        return rstat->stat.size + sizeof(u16);
 }
 
-static bool virtio_p9_read(struct p9_dev *p9dev, struct p9_msg *msg,
-                          u32 len, struct iovec *iov,
-                          int outiovcnt, int iniovcnt, u32 *outlen)
+static bool virtio_p9_read(struct p9_dev *p9dev,
+                          struct p9_pdu *pdu, u32 *outlen)
 {
-       struct p9_msg *outmsg   = iov[0].iov_base;
-       struct p9_tread *tread  = (struct p9_tread *)msg->msg;
-       struct p9_rread *rread  = (struct p9_rread *)outmsg->msg;
-       struct p9_rstat *rstat  = (struct p9_rstat *)iov[1].iov_base;
+       struct p9_msg *inmsg  = pdu->in_iov[0].iov_base;
+       struct p9_msg *outmsg = pdu->out_iov[0].iov_base;
+       struct p9_tread *tread  = (struct p9_tread *)outmsg->msg;
+       struct p9_rread *rread  = (struct p9_rread *)inmsg->msg;
+       struct p9_rstat *rstat  = (struct p9_rstat *)pdu->in_iov[1].iov_base;
        struct p9_fid *fid      = &p9dev->fids[tread->fid];
        struct stat st;
 
@@ -430,29 +443,30 @@ static bool virtio_p9_read(struct p9_dev *p9dev, struct p9_msg *msg,
                        cur = readdir(fid->dir);
                }
        } else {
-               iov[0].iov_base += VIRTIO_P9_HDR_LEN + sizeof(u32);
-               iov[0].iov_len -= VIRTIO_P9_HDR_LEN + sizeof(u32);
-               rread->count = preadv(fid->fd, iov, iniovcnt, tread->offset);
+               pdu->in_iov[0].iov_base += VIRTIO_P9_HDR_LEN + sizeof(u32);
+               pdu->in_iov[0].iov_len -= VIRTIO_P9_HDR_LEN + sizeof(u32);
+               rread->count = preadv(fid->fd, pdu->in_iov,
+                                     pdu->in_iov_cnt, tread->offset);
                if (rread->count > tread->count)
                        rread->count = tread->count;
        }
 
        *outlen = VIRTIO_P9_HDR_LEN + sizeof(u32) + rread->count;
-       set_p9msg_hdr(outmsg, *outlen, P9_RREAD, msg->tag);
+       set_p9msg_hdr(inmsg, *outlen, P9_RREAD, outmsg->tag);
 
        return true;
 }
 
-static bool virtio_p9_stat(struct p9_dev *p9dev, struct p9_msg *msg,
-                          u32 len, struct iovec *iov,
-                          int outiovcnt, int iniovcnt, u32 *outlen)
+static bool virtio_p9_stat(struct p9_dev *p9dev,
+                          struct p9_pdu *pdu, u32 *outlen)
 {
-       struct p9_msg *outmsg = iov[0].iov_base;
-       struct p9_tstat *tstat = (struct p9_tstat *)msg->msg;
-       struct p9_rstat *rstat = (struct p9_rstat *)(outmsg->msg + sizeof(u16));
+       u32 ret;
        struct stat st;
+       struct p9_msg *inmsg  = pdu->in_iov[0].iov_base;
+       struct p9_msg *outmsg = pdu->out_iov[0].iov_base;
+       struct p9_tstat *tstat = (struct p9_tstat *)outmsg->msg;
+       struct p9_rstat *rstat = (struct p9_rstat *)(inmsg->msg + sizeof(u16));
        struct p9_fid *fid = &p9dev->fids[tstat->fid];
-       u32 ret;
 
        if (lstat(fid->abs_path, &st) < 0)
                return false;
@@ -460,19 +474,20 @@ static bool virtio_p9_stat(struct p9_dev *p9dev, struct p9_msg *msg,
        ret = virtio_p9_fill_stat(p9dev, fid->path, &st, rstat);
 
        *outlen = VIRTIO_P9_HDR_LEN + ret + sizeof(u16);
-       set_p9msg_hdr(outmsg, *outlen, P9_RSTAT, msg->tag);
+       set_p9msg_hdr(inmsg, *outlen, P9_RSTAT, outmsg->tag);
        return true;
 }
 
-static bool virtio_p9_wstat(struct p9_dev *p9dev, struct p9_msg *msg,
-                           u32 len, struct iovec *iov,
-                           int outiovcnt, int iniovcnt, u32 *outlen)
+static bool virtio_p9_wstat(struct p9_dev *p9dev,
+                           struct p9_pdu *pdu, u32 *outlen)
 {
-       struct p9_msg *outmsg = iov[0].iov_base;
-       struct p9_twstat *twstat = (struct p9_twstat *)msg->msg;
+       int res = 0;
        struct p9_str *str;
+       struct p9_msg *inmsg  = pdu->in_iov[0].iov_base;
+       struct p9_msg *outmsg = pdu->out_iov[0].iov_base;
+       struct p9_twstat *twstat = (struct p9_twstat *)outmsg->msg;
        struct p9_fid *fid = &p9dev->fids[twstat->fid];
-       int res = 0;
+
 
        if (twstat->stat.length != -1UL)
                res = ftruncate(fid->fd, twstat->stat.length);
@@ -498,17 +513,17 @@ static bool virtio_p9_wstat(struct p9_dev *p9dev, struct p9_msg *msg,
        }
 
        *outlen = VIRTIO_P9_HDR_LEN;
-       set_p9msg_hdr(outmsg, *outlen, P9_RWSTAT, msg->tag);
+       set_p9msg_hdr(inmsg, *outlen, P9_RWSTAT, outmsg->tag);
 
        return res == 0;
 }
 
-static bool virtio_p9_remove(struct p9_dev *p9dev, struct p9_msg *msg,
-                            u32 len, struct iovec *iov,
-                            int outiovcnt, int iniovcnt, u32 *outlen)
+static bool virtio_p9_remove(struct p9_dev *p9dev,
+                            struct p9_pdu *pdu, u32 *outlen)
 {
-       struct p9_msg *outmsg = iov[0].iov_base;
-       struct p9_tremove *tremove = (struct p9_tremove *)msg->msg;
+       struct p9_msg *inmsg  = pdu->in_iov[0].iov_base;
+       struct p9_msg *outmsg = pdu->out_iov[0].iov_base;
+       struct p9_tremove *tremove = (struct p9_tremove *)outmsg->msg;
        struct p9_fid *fid = &p9dev->fids[tremove->fid];
 
        close_fid(p9dev, tremove->fid);
@@ -518,39 +533,32 @@ static bool virtio_p9_remove(struct p9_dev *p9dev, struct p9_msg *msg,
                unlink(fid->abs_path);
 
        *outlen = VIRTIO_P9_HDR_LEN;
-       set_p9msg_hdr(outmsg, *outlen, P9_RREMOVE, msg->tag);
+       set_p9msg_hdr(inmsg, *outlen, P9_RREMOVE, outmsg->tag);
        return true;
 }
 
-static bool virtio_p9_write(struct p9_dev *p9dev, struct p9_msg *msg,
-                           u32 len, struct iovec *iov,
-                           int outiovcnt, int iniovcnt, u32 *outlen)
+static bool virtio_p9_write(struct p9_dev *p9dev,
+                           struct p9_pdu *pdu, u32 *outlen)
 {
-       struct p9_msg *outmsg;
-       struct p9_rwrite *rwrite;
-       struct p9_twrite *twrite = (struct p9_twrite *)msg->msg;
+       struct p9_msg *inmsg  = pdu->in_iov[0].iov_base;
+       struct p9_msg *outmsg = pdu->out_iov[0].iov_base;
+       struct p9_twrite *twrite = (struct p9_twrite *)outmsg->msg;
+       struct p9_rwrite *rwrite = (struct p9_rwrite *)inmsg->msg;
        struct p9_fid *fid = &p9dev->fids[twrite->fid];
 
-       if (outiovcnt == 1) {
-               outmsg = iov[0].iov_base;
-               rwrite = (struct p9_rwrite *)outmsg->msg;
-               rwrite->count = pwrite(fid->fd, &twrite->data,
-                                      twrite->count, twrite->offset);
-       } else {
-               outmsg = iov[2].iov_base;
-               rwrite = (struct p9_rwrite *)outmsg->msg;
-               rwrite->count = pwrite(fid->fd, iov[1].iov_base,
-                                      twrite->count, twrite->offset);
-       }
+
+       pdu->out_iov[0].iov_base += (sizeof(*outmsg) + sizeof(*twrite));
+       pdu->out_iov[0].iov_len -= (sizeof(*outmsg) + sizeof(*twrite));
+       rwrite->count = pwritev(fid->fd, pdu->out_iov,
+                               pdu->out_iov_cnt, twrite->offset);
        *outlen = VIRTIO_P9_HDR_LEN + sizeof(u32);
-       set_p9msg_hdr(outmsg, *outlen, P9_RWRITE, msg->tag);
+       set_p9msg_hdr(inmsg, *outlen, P9_RWRITE, outmsg->tag);
 
        return true;
 }
 
-typedef bool p9_handler(struct p9_dev *p9dev, struct p9_msg *msg,
-                       u32 len, struct iovec *iov,
-                       int outiovcnt, int iniovcnt, u32 *outlen);
+typedef bool p9_handler(struct p9_dev *p9dev,
+                       struct p9_pdu *pdu, u32 *outlen);
 
 static p9_handler *virtio_9p_handler [] = {
        [P9_TVERSION] = virtio_p9_version,
@@ -566,30 +574,55 @@ static p9_handler *virtio_9p_handler [] = {
        [P9_TWRITE]   = virtio_p9_write,
 };
 
+static struct p9_pdu *virtio_p9_pdu_init(struct kvm *kvm, struct virt_queue *vq)
+{
+       struct p9_pdu *pdu = calloc(1, sizeof(*pdu));
+       if (!pdu)
+               return NULL;
+
+       pdu->queue_head  = virt_queue__get_inout_iov(kvm, vq, pdu->in_iov,
+                                                    pdu->out_iov,
+                                                    &pdu->in_iov_cnt,
+                                                    &pdu->out_iov_cnt);
+       return pdu;
+}
+
+static u8 virtio_p9_get_cmd(struct p9_pdu *pdu)
+{
+       struct p9_msg *msg;
+       /*
+        * we can peek directly into pdu for a u8
+        * value. The host endianess won't be an issue
+        */
+       msg = pdu->out_iov[0].iov_base;
+       return msg->cmd;
+}
+
 static bool virtio_p9_do_io_request(struct kvm *kvm, struct p9_dev_job *job)
 {
+       u8 cmd;
        u32 len = 0;
-       u16 out, in, head;
-       struct p9_msg *msg;
        p9_handler *handler;
-       struct virt_queue *vq;
        struct p9_dev *p9dev;
-       struct iovec iov[VIRTQUEUE_NUM];
+       struct virt_queue *vq;
+       struct p9_pdu *p9pdu;
 
        vq = job->vq;
        p9dev = job->p9dev;
-       head  = virt_queue__get_iov(vq, iov, &out, &in, kvm);
-       msg   = iov[0].iov_base;
 
-       if (msg->cmd >= ARRAY_SIZE(virtio_9p_handler) ||
-           !virtio_9p_handler[msg->cmd]) {
-               printf("Unsupported P9 message type: %u\n", msg->cmd);
+       p9pdu = virtio_p9_pdu_init(kvm, vq);
+       cmd = virtio_p9_get_cmd(p9pdu);
+
+       if (cmd >= ARRAY_SIZE(virtio_9p_handler) ||
+           !virtio_9p_handler[cmd]) {
+               printf("Unsupported P9 message type: %u\n", cmd);
 
        } else {
-               handler = virtio_9p_handler[msg->cmd];
-               handler(p9dev, msg, iov[0].iov_len, iov+1, out, in, &len);
+               handler = virtio_9p_handler[cmd];
+               handler(p9dev, p9pdu, &len);
        }
-       virt_queue__set_used_elem(vq, head, len);
+       virt_queue__set_used_elem(vq, p9pdu->queue_head, len);
+       free(p9pdu);
        return true;
 }