ovs-numa: Allow leading 0x on pmd-cpu-mask.

pmd-cpu-mask is interpreted as a hex bit mask. So it should be written
with a leading 0x to indicate this. But if this is done, while the value
is interpreted correctly and the PMDs pinned as expected, a confusing
warning message is also issued.

This patch allows but does not require a leading 0x or 0X to be used
without a warning. Existing functionality is not affected. Relevant DPDK
docs also updated.

Signed-off-by: Billy O'Mahony <billy.o.mahony@intel.com>
Tested-by: Kevin Traynor <ktraynor@redhat.com>
Signed-off-by: Daniele Di Proietto <diproiettod@vmware.com>

4 files changed, 22 insertions, 14 deletions

diff --git a/INSTALL.DPDK-ADVANCED.rst b/INSTALL.DPDK-ADVANCED.rst
index 9b2895bf6..1c2437d89 100644
--- a/INSTALL.DPDK-ADVANCED.rst
+++ b/INSTALL.DPDK-ADVANCED.rst
@@ -175,10 +175,11 @@ core shared by two logical cores, run::
 where ``N`` is the logical core number.
 
 In this example, it would show that cores ``1`` and ``21`` share the same
-physical core., thus, the ``pmd-cpu-mask`` can be used to enable these two pmd
-threads running on these two logical cores (one physical core) is::
+physical core. As cores are counted from 0, the ``pmd-cpu-mask`` can be used
+to enable these two pmd threads running on these two logical cores (one
+physical core) is::
 
-    $ ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=100002
+    $ ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=0x200002
 
 Isolate Cores
 ~~~~~~~~~~~~~
@@ -239,7 +240,7 @@ affinitized accordingly.
   By setting a bit in the mask, a pmd thread is created and pinned to the
   corresponding CPU core. e.g. to run a pmd thread on core 2::
 
-      $ ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=4
+      $ ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=0x4
 
   .. note::
     pmd thread on a NUMA node is only created if there is at least one DPDK
@@ -269,7 +270,7 @@ is done automatically.
 A set bit in the mask means a pmd thread is created and pinned to the
 corresponding CPU core. For example, to run pmd threads on core 1 and 2::
 
-    $ ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=6
+    $ ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=0x6
 
 When using dpdk and dpdkvhostuser ports in a bi-directional VM loopback as
 shown below, spreading the workload over 2 or 4 pmd threads shows significant
@@ -436,7 +437,7 @@ guide`_ to create and initialize the database, start ovs-vswitchd and add
    of rx queues at vhost-user interface gets automatically configured after
    virtio device connection and doesn't need manual configuration::
 
-       $ ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=c
+       $ ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=0xC
        $ ovs-vsctl set Interface dpdk0 options:n_rxq=2
        $ ovs-vsctl set Interface dpdk1 options:n_rxq=2
 
diff --git a/INSTALL.DPDK.rst b/INSTALL.DPDK.rst
index c91cc019b..10ccfdf3b 100644
--- a/INSTALL.DPDK.rst
+++ b/INSTALL.DPDK.rst
@@ -223,10 +223,10 @@ NUMA node 0, run::
 
 Similarly, if you wish to better scale the workloads across cores, then
 multiple pmd threads can be created and pinned to CPU cores by explicity
-specifying ``pmd-cpu-mask``. For example, to spawn two pmd threads and pin
-them to cores 1,2, run::
+specifying ``pmd-cpu-mask``. Cores are numbered from 0, so to spawn two pmd
+threads and pin them to cores 1,2, run::
 
-    $ ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=6
+    $ ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=0x6
 
 For details on using ivshmem with DPDK, refer to `the advanced installation
 guide <INSTALL.DPDK-ADVANCED.rst>`__.
diff --git a/lib/ovs-numa.c b/lib/ovs-numa.c
index c8173e0b4..e1e7068a2 100644
--- a/lib/ovs-numa.c
+++ b/lib/ovs-numa.c
@@ -535,6 +535,7 @@ ovs_numa_set_cpu_mask(const char *cmask)
 {
     int core_id = 0;
     int i;
+    int end_idx;
 
     if (!found_numa_and_core) {
         return;
@@ -551,7 +552,13 @@ ovs_numa_set_cpu_mask(const char *cmask)
         return;
     }
 
-    for (i = strlen(cmask) - 1; i >= 0; i--) {
+    /* Ignore leading 0x. */
+    end_idx = 0;
+    if (!strncmp(cmask, "0x", 2) || !strncmp(cmask, "0X", 2)) {
+        end_idx = 2;
+    }
+
+    for (i = strlen(cmask) - 1; i >= end_idx; i--) {
         char hex = toupper((unsigned char)cmask[i]);
         int bin, j;
 
@@ -575,7 +582,7 @@ ovs_numa_set_cpu_mask(const char *cmask)
             if (core_id >= hmap_count(&all_cpu_cores)) {
                 return;
             }
-	}
+        }
     }
 
     /* For unspecified cores, sets 'available' to false.  */
diff --git a/tests/pmd.at b/tests/pmd.at
index 18b29728a..8f05d74b7 100644
--- a/tests/pmd.at
+++ b/tests/pmd.at
@@ -123,7 +123,7 @@ pmd thread numa_id <cleared> core_id <cleared>:
 ])
 
 TMP=$(cat ovs-vswitchd.log | wc -l | tr -d [[:blank:]])
-AT_CHECK([ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=3])
+AT_CHECK([ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=0x3])
 CHECK_PMD_THREADS_CREATED([2], [], [+$TMP])
 
 AT_CHECK([ovs-appctl dpif-netdev/pmd-rxq-show | sed SED_NUMA_CORE_PATTERN], [0], [dnl
@@ -136,7 +136,7 @@ pmd thread numa_id <cleared> core_id <cleared>:
 ])
 
 TMP=$(cat ovs-vswitchd.log | wc -l | tr -d [[:blank:]])
-AT_CHECK([ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=1])
+AT_CHECK([ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=0x1])
 CHECK_PMD_THREADS_CREATED([1], [], [+$TMP])
 
 AT_CHECK([ovs-appctl dpif-netdev/pmd-rxq-show | sed SED_NUMA_CORE_PATTERN], [0], [dnl
@@ -471,7 +471,7 @@ AT_CHECK([ovs-appctl vlog/set dpif:dbg dpif_netdev:dbg])
 
 AT_CHECK([ovs-ofctl add-flow br0 actions=controller])
 
-AT_CHECK([ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=1fe])
+AT_CHECK([ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=0x1fe])
 
 AT_CHECK([ovs-vsctl add-port br0 p1 -- set Interface p1 type=dummy-pmd ofport_request=1 options:n_rxq=4 other_config:pmd-rxq-affinity="0:3,1:7,2:2,3:8"])