[Qemu-devel] [RFC][PATCH 02/15] virtproxy: qemu-vp, standalone daemon skeleton

[Michael Roth <mdroth@linux.vnet.ibm.com>]

Daemon to be run in guest, or on host in standalone mode.
(re-)implements some qemu utility functions used by core virtproxy.c
code via wrapper functions. For built-in virtproxy code we will define
these wrapper functions in terms of qemu's built-in implementations.

Main logic will come in a later patch.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 qemu-vp.c |  151 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 151 insertions(+), 0 deletions(-)
 create mode 100644 qemu-vp.c

diff --git a/qemu-vp.c b/qemu-vp.c
new file mode 100644
index 0000000..5075cdc
--- /dev/null
+++ b/qemu-vp.c
@@ -0,0 +1,151 @@
+/*
+ * virt-proxy - host/guest communication daemon
+ *
+ * Copyright IBM Corp. 2010
+ *
+ * Authors:
+ *  Michael Roth      <mdroth@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "virtproxy.h"
+
+/* mirror qemu I/O-related code for standalone daemon */
+typedef struct IOHandlerRecord {
+    int fd;
+    IOCanReadHandler *fd_read_poll;
+    IOHandler *fd_read;
+    IOHandler *fd_write;
+    int deleted;
+    void *opaque;
+    /* temporary data */
+    struct pollfd *ufd;
+    QLIST_ENTRY(IOHandlerRecord) next;
+} IOHandlerRecord;
+
+static QLIST_HEAD(, IOHandlerRecord) io_handlers =
+    QLIST_HEAD_INITIALIZER(io_handlers);
+
+int vp_set_fd_handler2(int fd,
+                         IOCanReadHandler *fd_read_poll,
+                         IOHandler *fd_read,
+                         IOHandler *fd_write,
+                         void *opaque)
+{
+    IOHandlerRecord *ioh;
+
+    if (!fd_read && !fd_write) {
+        QLIST_FOREACH(ioh, &io_handlers, next) {
+            if (ioh->fd == fd) {
+                ioh->deleted = 1;
+                break;
+            }
+        }
+    } else {
+        QLIST_FOREACH(ioh, &io_handlers, next) {
+            if (ioh->fd == fd)
+                goto found;
+        }
+        ioh = qemu_mallocz(sizeof(IOHandlerRecord));
+        QLIST_INSERT_HEAD(&io_handlers, ioh, next);
+    found:
+        ioh->fd = fd;
+        ioh->fd_read_poll = fd_read_poll;
+        ioh->fd_read = fd_read;
+        ioh->fd_write = fd_write;
+        ioh->opaque = opaque;
+        ioh->deleted = 0;
+    }
+    return 0;
+}
+
+int vp_set_fd_handler(int fd,
+                        IOHandler *fd_read,
+                        IOHandler *fd_write,
+                        void *opaque)
+{
+    return vp_set_fd_handler2(fd, NULL, fd_read, fd_write, opaque);
+}
+
+int vp_send_all(int fd, const void *buf, int len1)
+{
+    int ret, len;
+
+    len = len1;
+    while (len > 0) {
+        ret = write(fd, buf, len);
+        if (ret < 0) {
+            if (errno != EINTR && errno != EAGAIN) {
+                warn("write() failed");
+                return -1;
+            }
+        } else if (ret == 0) {
+            break;
+        } else {
+            buf += ret;
+            len -= ret;
+        }
+    }
+    return len1 - len;
+}
+
+static void main_loop_wait(int nonblocking)
+{
+    IOHandlerRecord *ioh;
+    fd_set rfds, wfds, xfds;
+    int ret, nfds;
+    struct timeval tv;
+    int timeout = 1000;
+
+    if (nonblocking) {
+        timeout = 0;
+    }
+
+    /* poll any events */
+    nfds = -1;
+    FD_ZERO(&rfds);
+    FD_ZERO(&wfds);
+    FD_ZERO(&xfds);
+    QLIST_FOREACH(ioh, &io_handlers, next) {
+        if (ioh->deleted)
+            continue;
+        if (ioh->fd_read &&
+            (!ioh->fd_read_poll ||
+             ioh->fd_read_poll(ioh->opaque) != 0)) {
+            FD_SET(ioh->fd, &rfds);
+            if (ioh->fd > nfds)
+                nfds = ioh->fd;
+        }
+        if (ioh->fd_write) {
+            FD_SET(ioh->fd, &wfds);
+            if (ioh->fd > nfds)
+                nfds = ioh->fd;
+        }
+    }
+
+    tv.tv_sec = timeout / 1000;
+    tv.tv_usec = (timeout % 1000) * 1000;
+
+    ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv);
+
+    if (ret > 0) {
+        IOHandlerRecord *pioh;
+
+        QLIST_FOREACH_SAFE(ioh, &io_handlers, next, pioh) {
+            if (ioh->deleted) {
+                QLIST_REMOVE(ioh, next);
+                qemu_free(ioh);
+                continue;
+            }
+            if (ioh->fd_read && FD_ISSET(ioh->fd, &rfds)) {
+                ioh->fd_read(ioh->opaque);
+            }
+            if (ioh->fd_write && FD_ISSET(ioh->fd, &wfds)) {
+                ioh->fd_write(ioh->opaque);
+            }
+        }
+    }
+}
-- 
1.7.0.4