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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [v3 2/5] Qemu-Xen-vTPM: Xen frontend driver infrastructure
This patch adds infrastructure for xen front drivers living in qemu,
so drivers don't need to implement common stuff on their own. It's
mostly xenbus management stuff: some functions to access XenStore,
setting up XenStore watches, callbacks on device discovery and state
changes, and handle event channel between the virtual machines.
Call xen_fe_register() function to register XenDevOps, and make sure,
XenDevOps's flags is DEVOPS_FLAG_FE, which is flag bit to point out
the XenDevOps is Xen frontend.
--Changes in v3:
-New xen_frontend.c file
-Move xenbus_switch_state() to xen_frontend.c
-Move xen_stubdom_be() to xenstore_fe_read_be_str()
-Move *_stubdom_*() to *_fe_*()
Signed-off-by: Quan Xu <quan.xu@xxxxxxxxx>
---
hw/xen/Makefile.objs | 2 +-
hw/xen/xen_backend.c | 11 +-
hw/xen/xen_frontend.c | 323 +++++++++++++++++++++++++++++++++++++++++++
include/hw/xen/xen_backend.h | 14 ++
4 files changed, 348 insertions(+), 2 deletions(-)
create mode 100644 hw/xen/xen_frontend.c
diff --git a/hw/xen/Makefile.objs b/hw/xen/Makefile.objs
index a0ca0aa..b0bb065 100644
--- a/hw/xen/Makefile.objs
+++ b/hw/xen/Makefile.objs
@@ -1,5 +1,5 @@
# xen backend driver support
-common-obj-$(CONFIG_XEN_BACKEND) += xen_backend.o xen_devconfig.o
+common-obj-$(CONFIG_XEN_BACKEND) += xen_backend.o xen_devconfig.o
xen_frontend.o
obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen-host-pci-device.o
obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen_pt.o xen_pt_config_init.o xen_pt_msi.o
diff --git a/hw/xen/xen_backend.c b/hw/xen/xen_backend.c
index b2cb22b..ad6e324 100644
--- a/hw/xen/xen_backend.c
+++ b/hw/xen/xen_backend.c
@@ -275,7 +275,7 @@ static struct XenDevice *xen_be_get_xendev(const char
*type, int dom, int dev,
/*
* release xen backend device.
*/
-static struct XenDevice *xen_be_del_xendev(int dom, int dev)
+struct XenDevice *xen_be_del_xendev(int dom, int dev)
{
struct XenDevice *xendev, *xnext;
@@ -681,6 +681,10 @@ static void xenstore_update(void *unused)
if (sscanf(vec[XS_WATCH_TOKEN], "fe:%" PRIxPTR, &ptr) == 1) {
xenstore_update_fe(vec[XS_WATCH_PATH], (void*)ptr);
}
+ if (sscanf(vec[XS_WATCH_TOKEN], "stub:%" PRIxPTR ":%d:%" PRIxPTR,
+ &type, &dom, &ops) == 3) {
+ xenstore_fe_update(vec[XS_WATCH_PATH], (void *)type, dom, (void *)ops);
+ }
cleanup:
free(vec);
@@ -808,3 +812,8 @@ void xen_be_printf(struct XenDevice *xendev, int msg_level,
const char *fmt, ...
}
qemu_log_flush();
}
+
+void xen_qtail_insert_xendev(struct XenDevice *xendev)
+{
+ QTAILQ_INSERT_TAIL(&xendevs, xendev, next);
+}
diff --git a/hw/xen/xen_frontend.c b/hw/xen/xen_frontend.c
new file mode 100644
index 0000000..07ffc5c
--- /dev/null
+++ b/hw/xen/xen_frontend.c
@@ -0,0 +1,323 @@
+/*
+ * Xen frontend driver infrastructure
+ *
+ * Copyright (c) 2014 Intel Corporation
+ * Authors:
+ * Quan Xu <quan.xu@xxxxxxxxx>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/signal.h>
+
+#include "hw/hw.h"
+#include "sysemu/char.h"
+#include "qemu/log.h"
+#include "hw/xen/xen_backend.h"
+#include <xen/grant_table.h>
+
+/* private */
+static int debug;
+
+/* ------------------------------------------------------------- */
+/*Get backend with fe type|domid, try to write the backend-id when
+ *create virtual machine.
+ *
+ *[XenStore]
+ *
+ *Dom.ID = ""
+ * device
+ * vtpm = ""
+ * 0 = ""
+ * backend-id = "ID"
+ *[..]
+ */
+
+char *xenstore_fe_read_be_str(const char *type, int dom, int dev)
+{
+ char *val, *domu;
+ char path[XEN_BUFSIZE];
+ unsigned int len, ival;
+
+ /*fe path*/
+ domu = xs_get_domain_path(xenstore, dom);
+ snprintf(path, sizeof(path), "%s/device/%s/%d/backend-id",
+ domu, type, dev);
+ g_free(domu);
+
+ val = xs_read(xenstore, 0, path, &len);
+ if (!val || 1 != sscanf(val, "%d", &ival)) {
+ g_free(val);
+ return NULL;
+ }
+ g_free(val);
+
+ /*be path*/
+ domu = xs_get_domain_path(xenstore, ival);
+
+ return domu;
+}
+
+/*make sure, initialize the 'xendev->fe' in xendev->ops->init() or
+ * xendev->ops->initialize()
+ */
+int xenbus_switch_state(struct XenDevice *xendev, enum xenbus_state xbus)
+{
+ xs_transaction_t xbt = XBT_NULL;
+
+ if (xendev->fe_state == xbus) {
+ return 0;
+ }
+
+ xendev->fe_state = xbus;
+ if (xendev->fe == NULL) {
+ xen_be_printf(NULL, 0, "xendev->fe is NULL\n");
+ return -1;
+ }
+
+retry_transaction:
+ xbt = xs_transaction_start(xenstore);
+ if (xbt == XBT_NULL) {
+ goto abort_transaction;
+ }
+
+ if (xenstore_write_int(xendev->fe, "state", xbus)) {
+ goto abort_transaction;
+ }
+
+ if (!xs_transaction_end(xenstore, xbt, 0)) {
+ if (errno == EAGAIN) {
+ goto retry_transaction;
+ }
+ }
+
+ return 0;
+
+abort_transaction:
+ xs_transaction_end(xenstore, xbt, 1);
+ return -1;
+}
+
+void xenstore_fe_update(char *watch, char *type, int dom, struct XenDevOps
*ops)
+{
+ struct XenDevice *xendev;
+ char path[XEN_BUFSIZE];
+ char *ptr, *bepath;
+ unsigned int len, dev;
+
+ if (!(ops->flags & DEVOPS_FLAG_FE)) {
+ return;
+ }
+
+ len = snprintf(path, sizeof(path), "backend/%s/%d", type, dom);
+ ptr = strstr(watch, path);
+ if (ptr == NULL) {
+ return;
+ }
+
+ if (sscanf(ptr+len, "/%u/%255s", &dev, path) != 2) {
+ strcpy(path, "");
+ if (sscanf(ptr+len, "/%u", &dev) != 1) {
+ dev = -1;
+ }
+ }
+
+ if (dev == -1) {
+ return;
+ }
+
+ xendev = xen_fe_get_xendev(type, dom, dev, ops);
+ if (xendev != NULL) {
+ bepath = xs_read(xenstore, 0, xendev->be, &len);
+ /*bepath is NULL, indicates that the backend is not running,
+ *delete it.
+ */
+ if (bepath == NULL) {
+ xen_be_del_xendev(dom, dev);
+ } else {
+ free(bepath);
+ if (xendev->ops->backend_changed) {
+ xendev->ops->backend_changed(xendev, path);
+ }
+ }
+ }
+}
+
+/*
+ * get xen fe device, allocate a new one if it doesn't exist.
+ */
+struct XenDevice *xen_fe_get_xendev(const char *type, int dom, int dev,
+ struct XenDevOps *ops)
+{
+ struct XenDevice *xendev;
+ char *stub;
+
+ xendev = xen_be_find_xendev(type, dom, dev);
+ if (xendev) {
+ return xendev;
+ }
+
+ /* init new xendev */
+ xendev = g_malloc0(ops->size);
+ xendev->type = type;
+ xendev->dom = dom;
+ xendev->dev = dev;
+ xendev->ops = ops;
+
+ /*return if the ops->flags is not DEVOPS_FLAG_FE*/
+ if (!(ops->flags & DEVOPS_FLAG_FE)) {
+ return NULL;
+ }
+
+ stub = xenstore_fe_read_be_str(xendev->type, xendev->dom, xendev->dev);
+ snprintf(xendev->be, sizeof(xendev->be), "%s/backend/%s/%d/%d",
+ stub, xendev->type, xendev->dom, xendev->dev);
+ g_free(stub);
+ snprintf(xendev->name, sizeof(xendev->name), "%s-%d",
+ xendev->type, xendev->dev);
+
+ xendev->debug = debug;
+ xendev->local_port = -1;
+
+ xendev->evtchndev = xen_xc_evtchn_open(NULL, 0);
+ if (xendev->evtchndev == XC_HANDLER_INITIAL_VALUE) {
+ xen_be_printf(NULL, 0, "can't open evtchn device\n");
+ g_free(xendev);
+ return NULL;
+ }
+ fcntl(xc_evtchn_fd(xendev->evtchndev), F_SETFD, FD_CLOEXEC);
+
+ if (ops->flags & DEVOPS_FLAG_NEED_GNTDEV) {
+ xendev->gnttabdev = xen_xc_gnttab_open(NULL, 0);
+ if (xendev->gnttabdev == XC_HANDLER_INITIAL_VALUE) {
+ xen_be_printf(NULL, 0, "can't open gnttab device\n");
+ xc_evtchn_close(xendev->evtchndev);
+ g_free(xendev);
+ return NULL;
+ }
+ } else {
+ xendev->gnttabdev = XC_HANDLER_INITIAL_VALUE;
+ }
+
+ xen_qtail_insert_xendev(xendev);
+
+ if (xendev->ops->alloc) {
+ xendev->ops->alloc(xendev);
+ }
+
+ return xendev;
+}
+
+/* simplify QEMU side, a thread is running in Xen backend, which will
+ * connect frontend when the frontend is initialised. Call these initialised
+ * functions.
+ */
+
+static int xen_fe_check(struct XenDevice *xendev, uint32_t domid,
+ int handle)
+{
+ int rc = 0;
+
+ if (xendev->ops->init) {
+ rc = xendev->ops->init(xendev);
+ }
+
+ if (rc != 0) {
+ xen_be_printf(xendev, 0, "xendev %s init error\n",
+ xendev->name);
+ goto err;
+ }
+
+ if (xendev->ops->initialise) {
+ rc = xendev->ops->initialise(xendev);
+ }
+
+ if (rc != 0) {
+ xen_be_printf(xendev, 0, "xendev %s initialise error\n",
+ xendev->name);
+ goto err;
+ }
+
+ if (xendev->ops->connected) {
+ xendev->ops->connected(xendev);
+ }
+
+ return rc;
+
+err:
+ xen_be_del_xendev(domid, handle);
+ return -1;
+}
+
+static int xenstore_fe_scan(const char *type, uint32_t domid,
+ struct XenDevOps *ops)
+{
+ struct XenDevice *xendev;
+ char path[XEN_BUFSIZE], token[XEN_BUFSIZE];
+ char *domu;
+ unsigned int cdev, j;
+ char **dev = NULL;
+
+ /*Xen frontend : /local/domain/ID */
+ domu = xs_get_domain_path(xenstore, domid);
+ snprintf(path, sizeof(path), "%s/device/%s",
+ domu, type);
+ free(domu);
+ dev = xs_directory(xenstore, 0, path, &cdev);
+ if (dev == NULL) {
+ return 0;
+ }
+
+ for (j = 0; j < cdev; j++) {
+ xendev = xen_fe_get_xendev(type, domid, atoi(dev[j]), ops);
+ if (xendev == NULL) {
+ xen_be_printf(xendev, 0, "xendev is NULL.\n");
+ continue;
+ }
+
+ /* simplify QEMU side, a thread is running in Xen backend, which will
+ * connect frontend when the frontend is initialised.
+ */
+ if (xen_fe_check(xendev, domid, atoi(dev[j])) < 0) {
+ xen_be_printf(xendev, 0, "xendev fe_check error.\n");
+ continue;
+ }
+
+ /*setup watch*/
+ snprintf(token, sizeof(token), "stub:%p:%d:%p",
+ type, domid, xendev->ops);
+ if (!xs_watch(xenstore, xendev->be, token)) {
+ xen_be_printf(xendev, 0, "xs_watch failed.\n");
+ continue;
+ }
+ }
+
+ free(dev);
+ return 0;
+}
+
+int xen_fe_register(const char *type, struct XenDevOps *ops)
+{
+ return xenstore_fe_scan(type, xen_domid, ops);
+}
diff --git a/include/hw/xen/xen_backend.h b/include/hw/xen/xen_backend.h
index 3b4125e..06e202f 100644
--- a/include/hw/xen/xen_backend.h
+++ b/include/hw/xen/xen_backend.h
@@ -15,6 +15,8 @@ struct XenDevice;
#define DEVOPS_FLAG_NEED_GNTDEV 1
/* don't expect frontend doing correct state transitions (aka console quirk) */
#define DEVOPS_FLAG_IGNORE_STATE 2
+/*dev is frontend device*/
+#define DEVOPS_FLAG_FE 4
struct XenDevOps {
size_t size;
@@ -80,6 +82,8 @@ int xenstore_read_fe_uint64(struct XenDevice *xendev, const
char *node, uint64_t
const char *xenbus_strstate(enum xenbus_state state);
struct XenDevice *xen_be_find_xendev(const char *type, int dom, int dev);
void xen_be_check_state(struct XenDevice *xendev);
+struct XenDevice *xen_be_del_xendev(int dom, int dev);
+void xen_qtail_insert_xendev(struct XenDevice *xendev);
/* xen backend driver bits */
int xen_be_init(void);
@@ -91,6 +95,16 @@ int xen_be_send_notify(struct XenDevice *xendev);
void xen_be_printf(struct XenDevice *xendev, int msg_level, const char *fmt,
...)
GCC_FMT_ATTR(3, 4);
+/*Xen frontend driver*/
+int xen_fe_register(const char *type, struct XenDevOps *ops);
+int xen_be_alloc_unbound(struct XenDevice *xendev, int dom, int remote_dom);
+char *xenstore_fe_read_be_str(const char *type, int dom, int dev);
+int xenbus_switch_state(struct XenDevice *xendev, enum xenbus_state xbus);
+struct XenDevice *xen_fe_get_xendev(const char *type, int dom, int dev,
+ struct XenDevOps *ops);
+void xenstore_fe_update(char *watch, char *type, int dom,
+ struct XenDevOps *ops);
+
/* actual backend drivers */
extern struct XenDevOps xen_console_ops; /* xen_console.c */
extern struct XenDevOps xen_kbdmouse_ops; /* xen_framebuffer.c */
--
1.8.3.2
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