Hi Bhupinder,
My knowledge is limited for this code. So I've just CCed "The REST"
maintainers. Please do CC them in the future.
On 02/21/2017 11:26 AM, Bhupinder Thakur wrote:
Breakup evtchn_send() to allow sending events for a Xen bound channel.
Currently,
there is a check in evtchn_send() i.e. is_consumer_xen() that if the event
channel
is bound to a xen consumer then event generation is not allowed for that
channel.
This check is to disallow a guest from raising an event via this channel.
However,
it should allow Xen to send a event via this channel as it is required for
sending
vpl011 event to the dom0.
This change introduces a new function raw_evtchn_send() which sends the event
without this check. The current evtchn_send() calls this function after doing
the
xen consumer check. Xen uses the raw_evtchm_send() version to send the event
thus
bypassing the check.
Signed-off-by: Bhupinder Thakur <bhupinder.tha...@linaro.org>
---
xen/common/event_channel.c | 49 ++++++++++++++++++++++++++++++++++------------
xen/include/xen/event.h | 6 ++++++
2 files changed, 42 insertions(+), 13 deletions(-)
diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
index 638dc5e..4b039f3 100644
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -27,6 +27,7 @@
#include <xen/keyhandler.h>
#include <xen/event_fifo.h>
#include <asm/current.h>
+#include <xen/domain_page.h>
Why did you include xen/domain_page.h?
#include <public/xen.h>
#include <public/event_channel.h>
@@ -650,25 +651,21 @@ static long evtchn_close(struct domain *d1, int port1,
bool_t guest)
return rc;
}
-int evtchn_send(struct domain *ld, unsigned int lport)
+int raw_evtchn_send(struct domain *ld, unsigned int lport, void *data)
{
struct evtchn *lchn, *rchn;
struct domain *rd;
- int rport, ret = 0;
+ int rport, ret=0;
- if ( !port_is_valid(ld, lport) )
- return -EINVAL;
-
- lchn = evtchn_from_port(ld, lport);
-
- spin_lock(&lchn->lock);
-
- /* Guest cannot send via a Xen-attached event channel. */
- if ( unlikely(consumer_is_xen(lchn)) )
+ if ( !data )
{
- ret = -EINVAL;
- goto out;
+ if ( !port_is_valid(ld, lport) )
+ return -EINVAL;
+ lchn = evtchn_from_port(ld, lport);
+ spin_lock(&lchn->lock);
}
+ else
+ lchn = (struct evtchn *)data;
ret = xsm_evtchn_send(XSM_HOOK, ld, lchn);
if ( ret )
@@ -696,6 +693,32 @@ int evtchn_send(struct domain *ld, unsigned int lport)
}
out:
+ if ( !data )
+ spin_unlock(&lchn->lock);
+
+ return ret;
+}
+
+int evtchn_send(struct domain *ld, unsigned int lport)
+{
+ struct evtchn *lchn;
+ int ret;
+
+ if ( !port_is_valid(ld, lport) )
+ return -EINVAL;
+
+ lchn = evtchn_from_port(ld, lport);
+
+ spin_lock(&lchn->lock);
+
+ if ( unlikely(consumer_is_xen(lchn)) )
+ {
+ printk("evtchn_send failed to send via xen event channel\n");
+ return -EINVAL;
+ }
+
+ ret = raw_evtchn_send(ld, lport, lchn);
+
spin_unlock(&lchn->lock);
return ret;
diff --git a/xen/include/xen/event.h b/xen/include/xen/event.h
index 5008c80..9bd17db 100644
--- a/xen/include/xen/event.h
+++ b/xen/include/xen/event.h
@@ -45,6 +45,12 @@ void send_guest_pirq(struct domain *, const struct pirq *);
/* Send a notification from a given domain's event-channel port. */
int evtchn_send(struct domain *d, unsigned int lport);
+/*
+ * This function is same as evntchn_send() except it does not do xen consumer
check
+ * to allow the events to be sent from xen bound channels.
+ */
+int raw_evtchn_send(struct domain *ld, unsigned int lport, void *data);
+
/* Bind a local event-channel port to the specified VCPU. */
long evtchn_bind_vcpu(unsigned int port, unsigned int vcpu_id);
Cheers,
--
Julien Grall
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel