[v2,4/8] livepatch: Fix documentation of timeout

Commit Message

Ross Lagerwall Dec. 14, 2016, 7:51 a.m. UTC

The hypervisor expects the timeout from the hypercall to be in
nanoseconds, so document this correctly. Also correctly document
what happens when timeout is set to zero.

Signed-off-by: Ross Lagerwall <[e-mail]>
---
 docs/misc/livepatch.markdown  | 13 +++++++------
 tools/libxc/include/xenctrl.h |  2 +-
 xen/common/livepatch.c        |  4 ++--
 xen/include/public/sysctl.h   |  5 +++--
 4 files changed, 13 insertions(+), 11 deletions(-)

Comments

Wei Liu Dec. 14, 2016, 7:54 a.m. UTC | #1

On Wed, Dec 14, 2016 at 07:51:56AM +0000, Ross Lagerwall wrote:
> The hypervisor expects the timeout from the hypercall to be in
> nanoseconds, so document this correctly. Also correctly document
> what happens when timeout is set to zero.
> 
> Signed-off-by: Ross Lagerwall <[e-mail]>

Acked-by: Wei Liu <[e-mail]>

Patch

diff --git a/docs/misc/livepatch.markdown b/docs/misc/livepatch.markdown
index 8f0559f..54a6b85 100644
--- a/docs/misc/livepatch.markdown
+++ b/docs/misc/livepatch.markdown
@@ -689,9 +689,9 @@  The caller provides:
   payload. If the operation takes more time than the upper bound of time
   the `rc` in `xen_livepatch_status' retrieved via **XEN_SYSCTL_LIVEPATCH_GET**
   will be -XEN_EBUSY.
- * `time` the upper bound of time (ms) the cmd should take. Zero means infinite.
-   If within the time the operation does not succeed the operation would go in
-   error state.
+ * `time` the upper bound of time (ns) the cmd should take. Zero means to use
+   the hypervisor default. If within the time the operation does not succeed
+   the operation would go in error state.
  * `pad` - *MUST* be zero.
 
 The return value will be zero unless the provided fields are incorrect.
@@ -706,9 +706,10 @@  The structure is as follow:
 struct xen_sysctl_livepatch_action {  
     xen_livepatch_name_t name;              /* IN, name of the patch. */  
     uint32_t cmd;                           /* IN: LIVEPATCH_ACTION_* */  
-    uint32_t time;                          /* IN: Zero if no timeout. */   
-                                            /* Or upper bound of time (ms) */   
-                                            /* for operation to take. */  
+    uint32_t time;                          /* IN: If zero then uses */
+                                            /* hypervisor default. */
+                                            /* Or upper bound of time (ns) */
+                                            /* for operation to take. */
 };  
 
 </pre>
diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index 2c83544..4ab0f57 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -2703,7 +2703,7 @@  int xc_livepatch_list(xc_interface *xch, unsigned int max, unsigned int start,
  * The operations are asynchronous and the hypervisor may take a while
  * to complete them. The `timeout` offers an option to expire the
  * operation if it could not be completed within the specified time
- * (in ms). Value of 0 means let hypervisor decide the best timeout.
+ * (in ns). Value of 0 means let hypervisor decide the best timeout.
  */
 int xc_livepatch_apply(xc_interface *xch, char *name, uint32_t timeout);
 int xc_livepatch_revert(xc_interface *xch, char *name, uint32_t timeout);
diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c
index fc8ef99..246e673 100644
--- a/xen/common/livepatch.c
+++ b/xen/common/livepatch.c
@@ -1227,8 +1227,8 @@  static int schedule_work(struct payload *data, uint32_t cmd, uint32_t timeout)
     livepatch_work.data = data;
     livepatch_work.timeout = timeout ?: MILLISECS(30);
 
-    dprintk(XENLOG_DEBUG, LIVEPATCH "%s: timeout is %"PRI_stime"ms\n",
-            data->name, livepatch_work.timeout / MILLISECS(1));
+    dprintk(XENLOG_DEBUG, LIVEPATCH "%s: timeout is %"PRIu32"ns\n",
+            data->name, livepatch_work.timeout);
 
     atomic_set(&livepatch_work.semaphore, -1);
 
diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h
index 28ac56c..00f5e77 100644
--- a/xen/include/public/sysctl.h
+++ b/xen/include/public/sysctl.h
@@ -1067,8 +1067,9 @@  struct xen_sysctl_livepatch_action {
 #define LIVEPATCH_ACTION_APPLY        3
 #define LIVEPATCH_ACTION_REPLACE      4
     uint32_t cmd;                           /* IN: LIVEPATCH_ACTION_*. */
-    uint32_t timeout;                       /* IN: Zero if no timeout. */
-                                            /* Or upper bound of time (ms) */
+    uint32_t timeout;                       /* IN: If zero then uses */
+                                            /* hypervisor default. */
+                                            /* Or upper bound of time (ns) */
                                             /* for operation to take. */
 };
 typedef struct xen_sysctl_livepatch_action xen_sysctl_livepatch_action_t;