[PATCH 5/5] tools/kvm/9p: Simplify the handler

Aneesh Kumar K.V
2011-06-18T17:49:23Z

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
tools/kvm/include/net/9p/9p.h | 1 -
tools/kvm/virtio/9p.c | 261 +++++++++++++++++++++++------------------
2 files changed, 147 insertions(+), 115 deletions(-)

diff --git a/tools/kvm/include/net/9p/9p.h b/tools/kvm/include/net/9p/9p.h
index cc11592..61ecff3 100644
--- 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 ef2fbaf..f2b9299 100644
--- a/tools/kvm/virtio/9p.c
+++ b/tools/kvm/virtio/9p.c
@@ -67,6 +67,15 @@ 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)
@@ -184,12 +193,12 @@ 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);
@@ -197,35 +206,35 @@ 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;
@@ -239,28 +248,29 @@ 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);

@@ -280,21 +290,22 @@ 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) {
@@ -306,7 +317,8 @@ 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;
@@ -323,22 +335,23 @@ 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++)
@@ -355,7 +368,7 @@ 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;
}
@@ -400,14 +413,14 @@ 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;

@@ -429,29 +442,30 @@ 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;
@@ -459,19 +473,20 @@ 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);
@@ -497,17 +512,17 @@ 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);
@@ -517,39 +532,32 @@ 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,
@@ -565,30 +573,55 @@ 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;
}

--
1.7.4.1