Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 244 insertions, 0 deletions

diff --git a/chardev/char-win.c b/chardev/char-win.c
new file mode 100644
index 000000000..d4fb44c4d
--- /dev/null
+++ b/chardev/char-win.c
@@ -0,0 +1,244 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/main-loop.h"
+#include "qemu/module.h"
+#include "qapi/error.h"
+#include "chardev/char-win.h"
+
+static void win_chr_read(Chardev *chr, DWORD len)
+{
+    WinChardev *s = WIN_CHARDEV(chr);
+    int max_size = qemu_chr_be_can_write(chr);
+    int ret, err;
+    uint8_t buf[CHR_READ_BUF_LEN];
+    DWORD size;
+
+    if (len > max_size) {
+        len = max_size;
+    }
+    if (len == 0) {
+        return;
+    }
+
+    ZeroMemory(&s->orecv, sizeof(s->orecv));
+    s->orecv.hEvent = s->hrecv;
+    ret = ReadFile(s->file, buf, len, &size, &s->orecv);
+    if (!ret) {
+        err = GetLastError();
+        if (err == ERROR_IO_PENDING) {
+            ret = GetOverlappedResult(s->file, &s->orecv, &size, TRUE);
+        }
+    }
+
+    if (size > 0) {
+        qemu_chr_be_write(chr, buf, size);
+    }
+}
+
+static int win_chr_serial_poll(void *opaque)
+{
+    Chardev *chr = CHARDEV(opaque);
+    WinChardev *s = WIN_CHARDEV(opaque);
+    COMSTAT status;
+    DWORD comerr;
+
+    ClearCommError(s->file, &comerr, &status);
+    if (status.cbInQue > 0) {
+        win_chr_read(chr, status.cbInQue);
+        return 1;
+    }
+    return 0;
+}
+
+int win_chr_serial_init(Chardev *chr, const char *filename, Error **errp)
+{
+    WinChardev *s = WIN_CHARDEV(chr);
+    COMMCONFIG comcfg;
+    COMMTIMEOUTS cto = { 0, 0, 0, 0, 0};
+    COMSTAT comstat;
+    DWORD size;
+    DWORD err;
+
+    s->hsend = CreateEvent(NULL, TRUE, FALSE, NULL);
+    if (!s->hsend) {
+        error_setg(errp, "Failed CreateEvent");
+        goto fail;
+    }
+    s->hrecv = CreateEvent(NULL, TRUE, FALSE, NULL);
+    if (!s->hrecv) {
+        error_setg(errp, "Failed CreateEvent");
+        goto fail;
+    }
+
+    s->file = CreateFile(filename, GENERIC_READ | GENERIC_WRITE, 0, NULL,
+                      OPEN_EXISTING, FILE_FLAG_OVERLAPPED, 0);
+    if (s->file == INVALID_HANDLE_VALUE) {
+        error_setg_win32(errp, GetLastError(), "Failed CreateFile");
+        s->file = NULL;
+        goto fail;
+    }
+
+    if (!SetupComm(s->file, NRECVBUF, NSENDBUF)) {
+        error_setg(errp, "Failed SetupComm");
+        goto fail;
+    }
+
+    ZeroMemory(&comcfg, sizeof(COMMCONFIG));
+    size = sizeof(COMMCONFIG);
+    GetDefaultCommConfig(filename, &comcfg, &size);
+    comcfg.dcb.DCBlength = sizeof(DCB);
+    CommConfigDialog(filename, NULL, &comcfg);
+
+    if (!SetCommState(s->file, &comcfg.dcb)) {
+        error_setg(errp, "Failed SetCommState");
+        goto fail;
+    }
+
+    if (!SetCommMask(s->file, EV_ERR)) {
+        error_setg(errp, "Failed SetCommMask");
+        goto fail;
+    }
+
+    cto.ReadIntervalTimeout = MAXDWORD;
+    if (!SetCommTimeouts(s->file, &cto)) {
+        error_setg(errp, "Failed SetCommTimeouts");
+        goto fail;
+    }
+
+    if (!ClearCommError(s->file, &err, &comstat)) {
+        error_setg(errp, "Failed ClearCommError");
+        goto fail;
+    }
+    qemu_add_polling_cb(win_chr_serial_poll, chr);
+    return 0;
+
+ fail:
+    return -1;
+}
+
+int win_chr_pipe_poll(void *opaque)
+{
+    Chardev *chr = CHARDEV(opaque);
+    WinChardev *s = WIN_CHARDEV(opaque);
+    DWORD size;
+
+    PeekNamedPipe(s->file, NULL, 0, NULL, &size, NULL);
+    if (size > 0) {
+        win_chr_read(chr, size);
+        return 1;
+    }
+    return 0;
+}
+
+/* Called with chr_write_lock held.  */
+static int win_chr_write(Chardev *chr, const uint8_t *buf, int len1)
+{
+    WinChardev *s = WIN_CHARDEV(chr);
+    DWORD len, ret, size, err;
+
+    len = len1;
+    ZeroMemory(&s->osend, sizeof(s->osend));
+    s->osend.hEvent = s->hsend;
+    while (len > 0) {
+        if (s->hsend) {
+            ret = WriteFile(s->file, buf, len, &size, &s->osend);
+        } else {
+            ret = WriteFile(s->file, buf, len, &size, NULL);
+        }
+        if (!ret) {
+            err = GetLastError();
+            if (err == ERROR_IO_PENDING) {
+                ret = GetOverlappedResult(s->file, &s->osend, &size, TRUE);
+                if (ret) {
+                    buf += size;
+                    len -= size;
+                } else {
+                    break;
+                }
+            } else {
+                break;
+            }
+        } else {
+            buf += size;
+            len -= size;
+        }
+    }
+    return len1 - len;
+}
+
+static void char_win_finalize(Object *obj)
+{
+    Chardev *chr = CHARDEV(obj);
+    WinChardev *s = WIN_CHARDEV(chr);
+
+    if (s->hsend) {
+        CloseHandle(s->hsend);
+    }
+    if (s->hrecv) {
+        CloseHandle(s->hrecv);
+    }
+    if (!s->keep_open && s->file) {
+        CloseHandle(s->file);
+    }
+    if (s->fpipe) {
+        qemu_del_polling_cb(win_chr_pipe_poll, chr);
+    } else {
+        qemu_del_polling_cb(win_chr_serial_poll, chr);
+    }
+
+    qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
+}
+
+void win_chr_set_file(Chardev *chr, HANDLE file, bool keep_open)
+{
+    WinChardev *s = WIN_CHARDEV(chr);
+
+    s->keep_open = keep_open;
+    s->file = file;
+}
+
+static void char_win_class_init(ObjectClass *oc, void *data)
+{
+    ChardevClass *cc = CHARDEV_CLASS(oc);
+
+    cc->chr_write = win_chr_write;
+}
+
+static const TypeInfo char_win_type_info = {
+    .name = TYPE_CHARDEV_WIN,
+    .parent = TYPE_CHARDEV,
+    .instance_size = sizeof(WinChardev),
+    .instance_finalize = char_win_finalize,
+    .class_init = char_win_class_init,
+    .abstract = true,
+};
+
+static void register_types(void)
+{
+    type_register_static(&char_win_type_info);
+}
+
+type_init(register_types);