[Qemu-devel] [V2 02/25] [virtio-9p] Change all pdu handlers to coroutines.

["Venkateswararao Jujjuri (JV)" <jvrao@linux.vnet.ibm.com>]

This patch changes the top level handlers to coroutines and sets the base.
It will be followed up with series of patches to convert all filesystem
calls to threaded coroutines pushing all blocking clals in VirtFS out
of vcpu threads.

Signed-off-by: Venkateswararao Jujjuri "<jvrao@linux.vnet.ibm.com>
---
 hw/9pfs/virtio-9p-coth.h |    1 +
 hw/9pfs/virtio-9p.c      |  139 +++++++++++++++++++++++++++++++---------------
 hw/9pfs/virtio-9p.h      |    4 +-
 3 files changed, 99 insertions(+), 45 deletions(-)

diff --git a/hw/9pfs/virtio-9p-coth.h b/hw/9pfs/virtio-9p-coth.h
index 8445d29..9388f9b 100644
--- a/hw/9pfs/virtio-9p-coth.h
+++ b/hw/9pfs/virtio-9p-coth.h
@@ -17,6 +17,7 @@
 
 #include "qemu-thread.h"
 #include "qemu-coroutine.h"
+#include "virtio-9p.h"
 #include <glib.h>
 
 typedef struct V9fsThPool {
diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index ec97b10..15bfea7 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -19,6 +19,7 @@
 #include "fsdev/qemu-fsdev.h"
 #include "virtio-9p-debug.h"
 #include "virtio-9p-xattr.h"
+#include "virtio-9p-coth.h"
 
 int debug_9p_pdu;
 
@@ -1192,8 +1193,10 @@ static void v9fs_fix_path(V9fsString *dst, V9fsString *src, int len)
     v9fs_string_free(&str);
 }
 
-static void v9fs_version(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_version(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     V9fsString version;
     size_t offset = 7;
 
@@ -1211,10 +1214,13 @@ static void v9fs_version(V9fsState *s, V9fsPDU *pdu)
     complete_pdu(s, pdu, offset);
 
     v9fs_string_free(&version);
+    return;
 }
 
-static void v9fs_attach(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_attach(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid, afid, n_uname;
     V9fsString uname, aname;
     V9fsFidState *fidp;
@@ -1269,8 +1275,10 @@ out:
     qemu_free(vs);
 }
 
-static void v9fs_stat(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_stat(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     V9fsStatState *vs;
     ssize_t err = 0;
@@ -1316,8 +1324,10 @@ out:
     qemu_free(vs);
 }
 
-static void v9fs_getattr(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_getattr(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     V9fsStatStateDotl *vs;
     ssize_t err = 0;
@@ -1465,8 +1475,10 @@ out:
     qemu_free(vs);
 }
 
-static void v9fs_setattr(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_setattr(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     V9fsSetattrState *vs;
     int err = 0;
@@ -1579,8 +1591,10 @@ out:
     v9fs_walk_complete(s, vs, err);
 }
 
-static void v9fs_walk(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_walk(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid, newfid;
     V9fsWalkState *vs;
     int err = 0;
@@ -1751,8 +1765,10 @@ out:
     qemu_free(vs);
 }
 
-static void v9fs_open(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_open(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     V9fsOpenState *vs;
     ssize_t err = 0;
@@ -1836,8 +1852,10 @@ out:
     v9fs_post_lcreate(s, vs, err);
 }
 
-static void v9fs_lcreate(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_lcreate(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t dfid, flags, mode;
     gid_t gid;
     V9fsLcreateState *vs;
@@ -1883,8 +1901,10 @@ static void v9fs_post_do_fsync(V9fsState *s, V9fsPDU *pdu, int err)
     complete_pdu(s, pdu, err);
 }
 
-static void v9fs_fsync(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_fsync(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     size_t offset = 7;
     V9fsFidState *fidp;
@@ -1902,8 +1922,10 @@ static void v9fs_fsync(V9fsState *s, V9fsPDU *pdu)
     v9fs_post_do_fsync(s, pdu, err);
 }
 
-static void v9fs_clunk(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_clunk(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     size_t offset = 7;
     int err;
@@ -2068,8 +2090,10 @@ static void v9fs_xattr_read(V9fsState *s, V9fsReadState *vs)
     qemu_free(vs);
 }
 
-static void v9fs_read(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_read(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     V9fsReadState *vs;
     ssize_t err = 0;
@@ -2207,8 +2231,10 @@ static void v9fs_readdir_post_setdir(V9fsState *s, V9fsReadDirState *vs)
     return;
 }
 
-static void v9fs_readdir(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_readdir(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     V9fsReadDirState *vs;
     ssize_t err = 0;
@@ -2240,7 +2266,6 @@ static void v9fs_readdir(V9fsState *s, V9fsPDU *pdu)
 out:
     complete_pdu(s, pdu, err);
     qemu_free(vs);
-    return;
 }
 
 static void v9fs_write_post_pwritev(V9fsState *s, V9fsWriteState *vs,
@@ -2319,8 +2344,10 @@ out:
     qemu_free(vs);
 }
 
-static void v9fs_write(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_write(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     V9fsWriteState *vs;
     ssize_t err;
@@ -2553,8 +2580,10 @@ out:
     v9fs_post_create(s, vs, err);
 }
 
-static void v9fs_create(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_create(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     V9fsCreateState *vs;
     int err = 0;
@@ -2615,8 +2644,10 @@ out:
     v9fs_post_symlink(s, vs, err);
 }
 
-static void v9fs_symlink(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_symlink(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t dfid;
     V9fsSymlinkState *vs;
     int err = 0;
@@ -2651,14 +2682,19 @@ out:
     qemu_free(vs);
 }
 
-static void v9fs_flush(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_flush(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     /* A nop call with no return */
     complete_pdu(s, pdu, 7);
+    return;
 }
 
-static void v9fs_link(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_link(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t dfid, oldfid;
     V9fsFidState *dfidp, *oldfidp;
     V9fsString name, fullname;
@@ -2710,8 +2746,10 @@ static void v9fs_remove_post_remove(V9fsState *s, V9fsRemoveState *vs,
     qemu_free(vs);
 }
 
-static void v9fs_remove(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_remove(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     V9fsRemoveState *vs;
     int err = 0;
@@ -2877,8 +2915,10 @@ out:
     qemu_free(vs);
 }
 
-static void v9fs_rename(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_rename(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     V9fsRenameState *vs;
     ssize_t err = 0;
@@ -3002,8 +3042,10 @@ out:
     qemu_free(vs);
 }
 
-static void v9fs_wstat(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_wstat(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     V9fsWstatState *vs;
     int err = 0;
@@ -3087,8 +3129,10 @@ out:
     qemu_free(vs);
 }
 
-static void v9fs_statfs(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_statfs(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     V9fsStatfsState *vs;
     ssize_t err = 0;
 
@@ -3113,6 +3157,7 @@ static void v9fs_statfs(V9fsState *s, V9fsPDU *pdu)
 out:
     complete_pdu(s, vs->pdu, err);
     qemu_free(vs);
+    return;
 }
 
 static void v9fs_mknod_post_lstat(V9fsState *s, V9fsMkState *vs, int err)
@@ -3149,8 +3194,10 @@ out:
     qemu_free(vs);
 }
 
-static void v9fs_mknod(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_mknod(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     V9fsMkState *vs;
     int err = 0;
@@ -3195,8 +3242,10 @@ out:
  * So when a TLOCK request comes, always return success
  */
 
-static void v9fs_lock(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_lock(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid, err = 0;
     V9fsLockState *vs;
 
@@ -3240,8 +3289,10 @@ out:
  * handling is done by client's VFS layer.
  */
 
-static void v9fs_getlock(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_getlock(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid, err = 0;
     V9fsGetlockState *vs;
 
@@ -3309,8 +3360,10 @@ out:
     qemu_free(vs);
 }
 
-static void v9fs_mkdir(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_mkdir(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     V9fsMkState *vs;
     int err = 0;
@@ -3433,8 +3486,10 @@ out:
     qemu_free(vs);
 }
 
-static void v9fs_xattrwalk(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_xattrwalk(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     ssize_t err = 0;
     V9fsXattrState *vs;
     int32_t fid, newfid;
@@ -3487,8 +3542,10 @@ out:
     qemu_free(vs);
 }
 
-static void v9fs_xattrcreate(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_xattrcreate(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int flags;
     int32_t fid;
     ssize_t err = 0;
@@ -3541,8 +3598,10 @@ out:
     qemu_free(vs);
 }
 
-static void v9fs_readlink(V9fsState *s, V9fsPDU *pdu)
+static void v9fs_readlink(void *opaque)
 {
+    V9fsPDU *pdu = opaque;
+    V9fsState *s = pdu->s;
     int32_t fid;
     V9fsReadLinkState *vs;
     int err = 0;
@@ -3569,9 +3628,7 @@ out:
     qemu_free(vs);
 }
 
-typedef void (pdu_handler_t)(V9fsState *s, V9fsPDU *pdu);
-
-static pdu_handler_t *pdu_handlers[] = {
+static CoroutineEntry *pdu_co_handlers[] = {
     [P9_TREADDIR] = v9fs_readdir,
     [P9_TSTATFS] = v9fs_statfs,
     [P9_TGETATTR] = v9fs_getattr,
@@ -3608,18 +3665,14 @@ static pdu_handler_t *pdu_handlers[] = {
 
 static void submit_pdu(V9fsState *s, V9fsPDU *pdu)
 {
-    pdu_handler_t *handler;
-
+    Coroutine *co;
     if (debug_9p_pdu) {
         pprint_pdu(pdu);
     }
-
-    BUG_ON(pdu->id >= ARRAY_SIZE(pdu_handlers));
-
-    handler = pdu_handlers[pdu->id];
-    BUG_ON(handler == NULL);
-
-    handler(s, pdu);
+    BUG_ON(pdu->id >= ARRAY_SIZE(pdu_co_handlers));
+    BUG_ON(pdu_co_handlers[pdu->id] == NULL);
+    co = qemu_coroutine_create(pdu_co_handlers[pdu->id]);
+    qemu_coroutine_enter(co, pdu);
 }
 
 void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq)
@@ -3631,7 +3684,7 @@ void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq)
     while ((pdu = alloc_pdu(s)) &&
             (len = virtqueue_pop(vq, &pdu->elem)) != 0) {
         uint8_t *ptr;
-
+        pdu->s = s;
         BUG_ON(pdu->elem.out_num == 0 || pdu->elem.in_num == 0);
         BUG_ON(pdu->elem.out_sg[0].iov_len < 7);
 
@@ -3640,9 +3693,7 @@ void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq)
         memcpy(&pdu->size, ptr, 4);
         pdu->id = ptr[4];
         memcpy(&pdu->tag, ptr + 5, 2);
-
         submit_pdu(s, pdu);
     }
-
     free_pdu(s, pdu);
 }
diff --git a/hw/9pfs/virtio-9p.h b/hw/9pfs/virtio-9p.h
index 2bfbe62..fb1e465 100644
--- a/hw/9pfs/virtio-9p.h
+++ b/hw/9pfs/virtio-9p.h
@@ -5,7 +5,7 @@
 #include <dirent.h>
 #include <sys/time.h>
 #include <utime.h>
-
+#include "hw/virtio.h"
 #include "fsdev/file-op-9p.h"
 
 /* The feature bitmap for virtio 9P */
@@ -114,6 +114,7 @@ static inline const char *rpath(FsContext *ctx, const char *path, char *buffer)
 #define P9_IOHDRSZ 24
 
 typedef struct V9fsPDU V9fsPDU;
+struct V9fsState;
 
 struct V9fsPDU
 {
@@ -121,6 +122,7 @@ struct V9fsPDU
     uint16_t tag;
     uint8_t id;
     VirtQueueElement elem;
+    struct V9fsState *s;
     QLIST_ENTRY(V9fsPDU) next;
 };
 
-- 
1.7.1