From e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb Mon Sep 17 00:00:00 2001 From: Yang Zhang Date: Fri, 28 Aug 2015 09:58:54 +0800 Subject: Add qemu 2.4.0 Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5 Signed-off-by: Yang Zhang --- qemu/hw/char/xen_console.c | 305 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 305 insertions(+) create mode 100644 qemu/hw/char/xen_console.c (limited to 'qemu/hw/char/xen_console.c') diff --git a/qemu/hw/char/xen_console.c b/qemu/hw/char/xen_console.c new file mode 100644 index 000000000..eb7f450ab --- /dev/null +++ b/qemu/hw/char/xen_console.c @@ -0,0 +1,305 @@ +/* + * Copyright (C) International Business Machines Corp., 2005 + * Author(s): Anthony Liguori + * + * 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 . + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "hw/hw.h" +#include "sysemu/char.h" +#include "hw/xen/xen_backend.h" + +#include + +struct buffer { + uint8_t *data; + size_t consumed; + size_t size; + size_t capacity; + size_t max_capacity; +}; + +struct XenConsole { + struct XenDevice xendev; /* must be first */ + struct buffer buffer; + char console[XEN_BUFSIZE]; + int ring_ref; + void *sring; + CharDriverState *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_be_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_be_send_notify(&con->xendev); +} + +static void xencons_send(struct XenConsole *con) +{ + ssize_t len, size; + + size = con->buffer.size - con->buffer.consumed; + if (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_be_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_be_printf(&con->xendev, 1, "backlog is gone\n"); + } + } +} + +/* -------------------------------------------------------------------- */ + +static int con_init(struct XenDevice *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_be_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) { + con->chr = serial_hds[con->xendev.dev]; + } else { + snprintf(label, sizeof(label), "xencons%d", con->xendev.dev); + con->chr = qemu_chr_new(label, output, NULL); + } + + xenstore_store_pv_console_info(con->xendev.dev, con->chr); + +out: + g_free(type); + return ret; +} + +static int con_initialise(struct XenDevice *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) { + con->sring = xc_map_foreign_range(xen_xc, con->xendev.dom, + XC_PAGE_SIZE, + PROT_READ|PROT_WRITE, + con->ring_ref); + } else { + con->sring = xc_gnttab_map_grant_ref(xendev->gnttabdev, con->xendev.dom, + con->ring_ref, + PROT_READ|PROT_WRITE); + } + if (!con->sring) + return -1; + + xen_be_bind_evtchn(&con->xendev); + if (con->chr) { + if (qemu_chr_fe_claim(con->chr) == 0) { + qemu_chr_add_handlers(con->chr, xencons_can_receive, + xencons_receive, NULL, con); + } else { + xen_be_printf(xendev, 0, + "xen_console_init error chardev %s already used\n", + con->chr->label); + con->chr = NULL; + } + } + + xen_be_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 XenDevice *xendev) +{ + struct XenConsole *con = container_of(xendev, struct XenConsole, xendev); + + if (!xendev->dev) { + return; + } + if (con->chr) { + qemu_chr_add_handlers(con->chr, NULL, NULL, NULL, NULL); + qemu_chr_fe_release(con->chr); + } + xen_be_unbind_evtchn(&con->xendev); + + if (con->sring) { + if (!xendev->gnttabdev) { + munmap(con->sring, XC_PAGE_SIZE); + } else { + xc_gnttab_munmap(xendev->gnttabdev, con->sring, 1); + } + con->sring = NULL; + } +} + +static void con_event(struct XenDevice *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, +}; -- cgit 1.2.3-korg