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[virtio-9p] Add infrastructure to support glib threads and coroutines.

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This patch is originally made by Arun Bharadwaj for glib support.
Later Harsh Prateek Bora added coroutines support.
This version implemented with suggestions from
Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>.

Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com>
Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri "<jvrao@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
This commit is contained in:
Venkateswararao Jujjuri (JV) 2011-04-23 18:40:22 -07:00 committed by Aneesh Kumar K.V
parent 4b76a481ee
commit 39c0564e00
4 changed files with 167 additions and 2 deletions
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2
Makefile.objs
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@ -305,8 +305,10 @@ hw-obj-$(CONFIG_SOUND) += $(sound-obj-y)
9pfs-nested-$(CONFIG_VIRTFS) = virtio-9p.o virtio-9p-debug.o
9pfs-nested-$(CONFIG_VIRTFS) += virtio-9p-local.o virtio-9p-xattr.o
9pfs-nested-$(CONFIG_VIRTFS) += virtio-9p-xattr-user.o virtio-9p-posix-acl.o
9pfs-nested-$(CONFIG_VIRTFS) += virtio-9p-coth.o
hw-obj-$(CONFIG_REALLY_VIRTFS) += $(addprefix 9pfs/, $(9pfs-nested-y))
$(addprefix 9pfs/, $(9pfs-nested-y)): QEMU_CFLAGS+=$(GLIB_CFLAGS)
######################################################################

102
hw/9pfs/virtio-9p-coth.c Normal file
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@ -0,0 +1,102 @@
/*
* Virtio 9p backend
*
* Copyright IBM, Corp. 2010
*
* Authors:
* Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
* Venkateswararao Jujjuri(JV) <jvrao@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include "qemu-char.h"
#include "fsdev/qemu-fsdev.h"
#include "qemu-thread.h"
#include "qemu-coroutine.h"
#include "virtio-9p-coth.h"
/* v9fs glib thread pool */
static V9fsThPool v9fs_pool;
void co_run_in_worker_bh(void *opaque)
{
Coroutine *co = opaque;
g_thread_pool_push(v9fs_pool.pool, co, NULL);
}
static void v9fs_qemu_process_req_done(void *arg)
{
char byte;
ssize_t len;
Coroutine *co;
do {
len = read(v9fs_pool.rfd, &byte, sizeof(byte));
} while (len == -1 && errno == EINTR);
while ((co = g_async_queue_try_pop(v9fs_pool.completed)) != NULL) {
qemu_coroutine_enter(co, NULL);
}
}
static void v9fs_thread_routine(gpointer data, gpointer user_data)
{
ssize_t len;
char byte = 0;
Coroutine *co = data;
qemu_coroutine_enter(co, NULL);
g_async_queue_push(v9fs_pool.completed, co);
do {
len = write(v9fs_pool.wfd, &byte, sizeof(byte));
} while (len == -1 && errno == EINTR);
}
int v9fs_init_worker_threads(void)
{
int ret = 0;
int notifier_fds[2];
V9fsThPool *p = &v9fs_pool;
sigset_t set, oldset;
sigfillset(&set);
/* Leave signal handling to the iothread. */
pthread_sigmask(SIG_SETMASK, &set, &oldset);
/* init thread system if not already initialized */
if (!g_thread_get_initialized()) {
g_thread_init(NULL);
}
if (qemu_pipe(notifier_fds) == -1) {
ret = -1;
goto err_out;
}
p->pool = g_thread_pool_new(v9fs_thread_routine, p, -1, FALSE, NULL);
if (!p->pool) {
ret = -1;
goto err_out;
}
p->completed = g_async_queue_new();
if (!p->completed) {
/*
* We are going to terminate.
* So don't worry about cleanup
*/
ret = -1;
goto err_out;
}
p->rfd = notifier_fds[0];
p->wfd = notifier_fds[1];
fcntl(p->rfd, F_SETFL, O_NONBLOCK);
fcntl(p->wfd, F_SETFL, O_NONBLOCK);
qemu_set_fd_handler(p->rfd, v9fs_qemu_process_req_done, NULL, NULL);
err_out:
pthread_sigmask(SIG_SETMASK, &oldset, NULL);
return ret;
}

58
hw/9pfs/virtio-9p-coth.h Normal file
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@ -0,0 +1,58 @@
/*
* Virtio 9p backend
*
* Copyright IBM, Corp. 2010
*
* Authors:
* Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
* Venkateswararao Jujjuri(JV) <jvrao@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#ifndef _QEMU_VIRTIO_9P_COTH_H
#define _QEMU_VIRTIO_9P_COTH_H
#include "qemu-thread.h"
#include "qemu-coroutine.h"
#include <glib.h>
typedef struct V9fsThPool {
int rfd;
int wfd;
GThreadPool *pool;
GAsyncQueue *completed;
} V9fsThPool;
/*
* we want to use bottom half because we want to make sure the below
* sequence of events.
*
* 1. Yield the coroutine in the QEMU thread.
* 2. Submit the coroutine to a worker thread.
* 3. Enter the coroutine in the worker thread.
* we cannot swap step 1 and 2, because that would imply worker thread
* can enter coroutine while step1 is still running
*/
#define v9fs_co_run_in_worker(code_block) \
do { \
QEMUBH *co_bh; \
co_bh = qemu_bh_new(co_run_in_worker_bh, \
qemu_coroutine_self()); \
qemu_bh_schedule(co_bh); \
/* \
* yeild in qemu thread and re-enter back \
* in glib worker thread \
*/ \
qemu_coroutine_yield(); \
qemu_bh_delete(co_bh); \
code_block; \
/* re-enter back to qemu thread */ \
qemu_coroutine_yield(); \
} while (0)
extern void co_run_in_worker_bh(void *);
extern int v9fs_init_worker_threads(void);
#endif

7
hw/9pfs/virtio-9p-device.c
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@ -18,6 +18,7 @@
#include "virtio-9p.h"
#include "fsdev/qemu-fsdev.h"
#include "virtio-9p-xattr.h"
#include "virtio-9p-coth.h"
static uint32_t virtio_9p_get_features(VirtIODevice *vdev, uint32_t features)
{
@ -50,13 +51,11 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf)
struct stat stat;
FsTypeEntry *fse;
s = (V9fsState *)virtio_common_init("virtio-9p",
VIRTIO_ID_9P,
sizeof(struct virtio_9p_config)+
MAX_TAG_LEN,
sizeof(V9fsState));
/* initialize pdu allocator */
QLIST_INIT(&s->free_list);
for (i = 0; i < (MAX_REQ - 1); i++) {
@ -132,6 +131,10 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf)
s->tag_len;
s->vdev.get_config = virtio_9p_get_config;
if (v9fs_init_worker_threads() < 0) {
fprintf(stderr, "worker thread initialization failed\n");
exit(1);
}
return &s->vdev;
}