Adding upstream version 1:7.2+dfsg.upstream/1%7.2+dfsgupstream

Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>

1 files changed, 298 insertions, 0 deletions

diff --git a/hw/char/xen_console.c b/hw/char/xen_console.c
new file mode 100644
index 00000000..63153dfd
--- /dev/null
+++ b/hw/char/xen_console.c
@@ -0,0 +1,298 @@
+/*
+ *  Copyright (C) International Business Machines  Corp., 2005
+ *  Author(s): Anthony Liguori <aliguori@us.ibm.com>
+ *
+ *  Copyright (C) Red Hat 2007
+ *
+ *  Xen Console
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; under version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include <sys/select.h>
+#include <termios.h>
+
+#include "qapi/error.h"
+#include "sysemu/sysemu.h"
+#include "chardev/char-fe.h"
+#include "hw/xen/xen-legacy-backend.h"
+
+#include "hw/xen/interface/io/console.h"
+
+struct buffer {
+    uint8_t *data;
+    size_t consumed;
+    size_t size;
+    size_t capacity;
+    size_t max_capacity;
+};
+
+struct XenConsole {
+    struct XenLegacyDevice  xendev;  /* must be first */
+    struct buffer     buffer;
+    char              console[XEN_BUFSIZE];
+    int               ring_ref;
+    void              *sring;
+    CharBackend       chr;
+    int               backlog;
+};
+
+static void buffer_append(struct XenConsole *con)
+{
+    struct buffer *buffer = &con->buffer;
+    XENCONS_RING_IDX cons, prod, size;
+    struct xencons_interface *intf = con->sring;
+
+    cons = intf->out_cons;
+    prod = intf->out_prod;
+    xen_mb();
+
+    size = prod - cons;
+    if ((size == 0) || (size > sizeof(intf->out)))
+        return;
+
+    if ((buffer->capacity - buffer->size) < size) {
+        buffer->capacity += (size + 1024);
+        buffer->data = g_realloc(buffer->data, buffer->capacity);
+    }
+
+    while (cons != prod)
+        buffer->data[buffer->size++] = intf->out[
+            MASK_XENCONS_IDX(cons++, intf->out)];
+
+    xen_mb();
+    intf->out_cons = cons;
+    xen_pv_send_notify(&con->xendev);
+
+    if (buffer->max_capacity &&
+        buffer->size > buffer->max_capacity) {
+        /* Discard the middle of the data. */
+
+        size_t over = buffer->size - buffer->max_capacity;
+        uint8_t *maxpos = buffer->data + buffer->max_capacity;
+
+        memmove(maxpos - over, maxpos, over);
+        buffer->data = g_realloc(buffer->data, buffer->max_capacity);
+        buffer->size = buffer->capacity = buffer->max_capacity;
+
+        if (buffer->consumed > buffer->max_capacity - over)
+            buffer->consumed = buffer->max_capacity - over;
+    }
+}
+
+static void buffer_advance(struct buffer *buffer, size_t len)
+{
+    buffer->consumed += len;
+    if (buffer->consumed == buffer->size) {
+        buffer->consumed = 0;
+        buffer->size = 0;
+    }
+}
+
+static int ring_free_bytes(struct XenConsole *con)
+{
+    struct xencons_interface *intf = con->sring;
+    XENCONS_RING_IDX cons, prod, space;
+
+    cons = intf->in_cons;
+    prod = intf->in_prod;
+    xen_mb();
+
+    space = prod - cons;
+    if (space > sizeof(intf->in))
+        return 0; /* ring is screwed: ignore it */
+
+    return (sizeof(intf->in) - space);
+}
+
+static int xencons_can_receive(void *opaque)
+{
+    struct XenConsole *con = opaque;
+    return ring_free_bytes(con);
+}
+
+static void xencons_receive(void *opaque, const uint8_t *buf, int len)
+{
+    struct XenConsole *con = opaque;
+    struct xencons_interface *intf = con->sring;
+    XENCONS_RING_IDX prod;
+    int i, max;
+
+    max = ring_free_bytes(con);
+    /* The can_receive() func limits this, but check again anyway */
+    if (max < len)
+        len = max;
+
+    prod = intf->in_prod;
+    for (i = 0; i < len; i++) {
+        intf->in[MASK_XENCONS_IDX(prod++, intf->in)] =
+            buf[i];
+    }
+    xen_wmb();
+    intf->in_prod = prod;
+    xen_pv_send_notify(&con->xendev);
+}
+
+static void xencons_send(struct XenConsole *con)
+{
+    ssize_t len, size;
+
+    size = con->buffer.size - con->buffer.consumed;
+    if (qemu_chr_fe_backend_connected(&con->chr)) {
+        len = qemu_chr_fe_write(&con->chr,
+                                con->buffer.data + con->buffer.consumed,
+                                size);
+    } else {
+        len = size;
+    }
+    if (len < 1) {
+        if (!con->backlog) {
+            con->backlog = 1;
+            xen_pv_printf(&con->xendev, 1,
+                          "backlog piling up, nobody listening?\n");
+        }
+    } else {
+        buffer_advance(&con->buffer, len);
+        if (con->backlog && len == size) {
+            con->backlog = 0;
+            xen_pv_printf(&con->xendev, 1, "backlog is gone\n");
+        }
+    }
+}
+
+/* -------------------------------------------------------------------- */
+
+static int con_init(struct XenLegacyDevice *xendev)
+{
+    struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
+    char *type, *dom, label[32];
+    int ret = 0;
+    const char *output;
+
+    /* setup */
+    dom = xs_get_domain_path(xenstore, con->xendev.dom);
+    if (!xendev->dev) {
+        snprintf(con->console, sizeof(con->console), "%s/console", dom);
+    } else {
+        snprintf(con->console, sizeof(con->console), "%s/device/console/%d", dom, xendev->dev);
+    }
+    free(dom);
+
+    type = xenstore_read_str(con->console, "type");
+    if (!type || strcmp(type, "ioemu") != 0) {
+        xen_pv_printf(xendev, 1, "not for me (type=%s)\n", type);
+        ret = -1;
+        goto out;
+    }
+
+    output = xenstore_read_str(con->console, "output");
+
+    /* no Xen override, use qemu output device */
+    if (output == NULL) {
+        if (con->xendev.dev) {
+            qemu_chr_fe_init(&con->chr, serial_hd(con->xendev.dev),
+                             &error_abort);
+        }
+    } else {
+        snprintf(label, sizeof(label), "xencons%d", con->xendev.dev);
+        qemu_chr_fe_init(&con->chr,
+                         /*
+                          * FIXME: sure we want to support implicit
+                          * muxed monitors here?
+                          */
+                         qemu_chr_new_mux_mon(label, output, NULL),
+                         &error_abort);
+    }
+
+    xenstore_store_pv_console_info(con->xendev.dev,
+                                   qemu_chr_fe_get_driver(&con->chr));
+
+out:
+    g_free(type);
+    return ret;
+}
+
+static int con_initialise(struct XenLegacyDevice *xendev)
+{
+    struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
+    int limit;
+
+    if (xenstore_read_int(con->console, "ring-ref", &con->ring_ref) == -1)
+        return -1;
+    if (xenstore_read_int(con->console, "port", &con->xendev.remote_port) == -1)
+        return -1;
+    if (xenstore_read_int(con->console, "limit", &limit) == 0)
+        con->buffer.max_capacity = limit;
+
+    if (!xendev->dev) {
+        xen_pfn_t mfn = con->ring_ref;
+        con->sring = xenforeignmemory_map(xen_fmem, con->xendev.dom,
+                                          PROT_READ | PROT_WRITE,
+                                          1, &mfn, NULL);
+    } else {
+        con->sring = xen_be_map_grant_ref(xendev, con->ring_ref,
+                                          PROT_READ | PROT_WRITE);
+    }
+    if (!con->sring)
+        return -1;
+
+    xen_be_bind_evtchn(&con->xendev);
+    qemu_chr_fe_set_handlers(&con->chr, xencons_can_receive,
+                             xencons_receive, NULL, NULL, con, NULL, true);
+
+    xen_pv_printf(xendev, 1,
+                  "ring mfn %d, remote port %d, local port %d, limit %zd\n",
+                  con->ring_ref,
+                  con->xendev.remote_port,
+                  con->xendev.local_port,
+                  con->buffer.max_capacity);
+    return 0;
+}
+
+static void con_disconnect(struct XenLegacyDevice *xendev)
+{
+    struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
+
+    qemu_chr_fe_deinit(&con->chr, false);
+    xen_pv_unbind_evtchn(&con->xendev);
+
+    if (con->sring) {
+        if (!xendev->dev) {
+            xenforeignmemory_unmap(xen_fmem, con->sring, 1);
+        } else {
+            xen_be_unmap_grant_ref(xendev, con->sring);
+        }
+        con->sring = NULL;
+    }
+}
+
+static void con_event(struct XenLegacyDevice *xendev)
+{
+    struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
+
+    buffer_append(con);
+    if (con->buffer.size - con->buffer.consumed)
+        xencons_send(con);
+}
+
+/* -------------------------------------------------------------------- */
+
+struct XenDevOps xen_console_ops = {
+    .size       = sizeof(struct XenConsole),
+    .flags      = DEVOPS_FLAG_IGNORE_STATE|DEVOPS_FLAG_NEED_GNTDEV,
+    .init       = con_init,
+    .initialise = con_initialise,
+    .event      = con_event,
+    .disconnect = con_disconnect,
+};