Mailing List Archive

From: Daniel De Graaf <dgdegra@tycho.nsa.gov>

Without a grant reference, full access to the domain's memory is
required to use the shared page. Add an additional parameter in
xenstore to allow grant mapping to be used.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
---
drivers/input/xen-kbdfront.c | 39 ++++++++++++++++++++++++++++-----------
1 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/drivers/input/xen-kbdfront.c b/drivers/input/xen-kbdfront.c
index 7f85a86..a5c064e 100644
--- a/drivers/input/xen-kbdfront.c
+++ b/drivers/input/xen-kbdfront.c
@@ -11,12 +11,6 @@
* more details.
*/

-/*
- * TODO:
- *
- * Switch to grant tables together with xen-fbfront.c.
- */
-
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
@@ -30,6 +24,8 @@
#include <xen/xen.h>
#include <xen/events.h>
#include <xen/page.h>
+#include <xen/grant_table.h>
+#include <xen/interface/grant_table.h>
#include <xen/interface/io/fbif.h>
#include <xen/interface/io/kbdif.h>
#include <xen/xenbus.h>
@@ -38,6 +34,7 @@ struct xenkbd_info {
struct input_dev *kbd;
struct input_dev *ptr;
struct xenkbd_page *page;
+ int gref;
int irq;
struct xenbus_device *xbdev;
char phys[32];
@@ -122,6 +119,7 @@ static int __devinit xenkbd_probe(struct xenbus_device *dev,
dev_set_drvdata(&dev->dev, info);
info->xbdev = dev;
info->irq = -1;
+ info->gref = -1;
snprintf(info->phys, sizeof(info->phys), "xenbus/%s", dev->nodename);

info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
@@ -218,15 +216,20 @@ static int xenkbd_connect_backend(struct xenbus_device *dev,
int ret, evtchn;
struct xenbus_transaction xbt;

+ ret = gnttab_grant_foreign_access(dev->otherend_id,
+ virt_to_mfn(info->page), 0);
+ if (ret < 0)
+ return ret;
+ info->gref = ret;
+
ret = xenbus_alloc_evtchn(dev, &evtchn);
if (ret)
- return ret;
+ goto error_grant;
ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
0, dev->devicetype, info);
if (ret < 0) {
- xenbus_free_evtchn(dev, evtchn);
xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
- return ret;
+ goto error_evtchan;
}
info->irq = ret;

@@ -234,12 +237,15 @@ static int xenkbd_connect_backend(struct xenbus_device *dev,
ret = xenbus_transaction_start(&xbt);
if (ret) {
xenbus_dev_fatal(dev, ret, "starting transaction");
- return ret;
+ goto error_irqh;
}
ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
virt_to_mfn(info->page));
if (ret)
goto error_xenbus;
+ ret = xenbus_printf(xbt, dev->nodename, "page-gref", "%u", info->gref);
+ if (ret)
+ goto error_xenbus;
ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
evtchn);
if (ret)
@@ -249,7 +255,7 @@ static int xenkbd_connect_backend(struct xenbus_device *dev,
if (ret == -EAGAIN)
goto again;
xenbus_dev_fatal(dev, ret, "completing transaction");
- return ret;
+ goto error_irqh;
}

xenbus_switch_state(dev, XenbusStateInitialised);
@@ -258,6 +264,14 @@ static int xenkbd_connect_backend(struct xenbus_device *dev,
error_xenbus:
xenbus_transaction_end(xbt, 1);
xenbus_dev_fatal(dev, ret, "writing xenstore");
+ error_irqh:
+ unbind_from_irqhandler(info->irq, info);
+ info->irq = -1;
+ error_evtchan:
+ xenbus_free_evtchn(dev, evtchn);
+ error_grant:
+ gnttab_end_foreign_access_ref(info->gref, 0);
+ info->gref = -1;
return ret;
}

@@ -266,6 +280,9 @@ static void xenkbd_disconnect_backend(struct xenkbd_info *info)
if (info->irq >= 0)
unbind_from_irqhandler(info->irq, info);
info->irq = -1;
+ if (info->gref >= 0)
+ gnttab_end_foreign_access_ref(info->gref, 0);
+ info->gref = -1;
}

static void xenkbd_backend_changed(struct xenbus_device *dev,
--
1.7.1


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