[libvirt] [libvirt-perl PATCH] Add virDomainGetIOThreads and virDomainPinIOThread bindings

6 Mar 2015

Test results in the following output:

$ perl examples/iothreadsinfo.pl
Addr 
VMM type: QEMU
...
Domain: {
  ID: 2 'f18iothr'
  UUID: fb9f7826-b5d7-4f74-b962-7181ef3fc9ec
  IOThread: {
    affinity: 0010
    number: 1
  }
  IOThread: {
    affinity: 0001
    number: 2
  }
  IOThread: {
    affinity: 1100
    number: 3
  }
}

Signed-off-by: John Ferlan <jferlan@redhat.com>
---

Figured I'd post these just to have them "ready" once the pinning options
for IOThreads are done being reviewed.  Also running the Perl bindings did
find one issue regarding the already pushed GetIOThreadsInfo with respect
to ReadOnly bit checking (when it shouldn't have been) - a patch to resolve
that has been posted as well.

 Changes                   |  4 ++++
 Virt.xs                   | 43 +++++++++++++++++++++++++++++++++++++++++++
 examples/iothreadsinfo.pl | 36 ++++++++++++++++++++++++++++++++++++
 lib/Sys/Virt/Domain.pm    | 17 +++++++++++++++++
 4 files changed, 100 insertions(+)
 create mode 100644 examples/iothreadsinfo.pl

diff --git a/Changes b/Changes
index b62ee24..f3e2f83 100644
--- a/Changes
+++ b/Changes
@@ -1,5 +1,9 @@
 Revision history for perl module Sys::Virt
 
+1.2.14 2015-03-06
+
+ - Add virDomainGetIOThreads and virDomainPinIOThread API bindings
+
 1.2.14 2015-00-00
 
  - XXX
diff --git a/Virt.xs b/Virt.xs
index f9ec7a4..15d48f7 100644
--- a/Virt.xs
+++ b/Virt.xs
@@ -5014,6 +5014,49 @@ get_emulator_pin_info(dom, flags=0)
       RETVAL
 
 
+void
+get_iothread_info(dom, flags=0)
+      virDomainPtr dom;
+      unsigned int flags;
+ PREINIT:
+      virDomainIOThreadInfoPtr *iothrinfo;
+      int niothreads;
+      int i;
+   PPCODE:
+      if ((niothreads = virDomainGetIOThreadsInfo(dom, &iothrinfo,
+                                                  flags)) < 0)
+          _croak_error();
+
+      EXTEND(SP, niothreads);
+      for (i = 0 ; i < niothreads ; i++) {
+          HV *rec = newHV();
+          (void)hv_store(rec, "number", 6,
+                         newSViv(iothrinfo[i]->iothread_id), 0);
+          (void)hv_store(rec, "affinity", 8,
+                         newSVpvn((char*)iothrinfo[i]->cpumap,
+                                  iothrinfo[i]->cpumaplen), 0);
+          PUSHs(newRV_noinc((SV *)rec));
+      }
+
+      if (iothrinfo)
+          Safefree(iothrinfo);
+
+
+void
+pin_iothread(dom, iothread_id, mask, flags=0)
+     virDomainPtr dom;
+     unsigned int iothread_id;
+     SV *mask;
+     unsigned int flags;
+PREINIT:
+     STRLEN masklen;
+     unsigned char *maps;
+ PPCODE:
+     maps = (unsigned char *)SvPV(mask, masklen);
+     if (virDomainPinVcpuFlags(dom, iothread_id, maps, masklen, flags) < 0)
+         _croak_error();
+
+
 int
 num_of_snapshots(dom, flags=0)
       virDomainPtr dom;
diff --git a/examples/iothreadsinfo.pl b/examples/iothreadsinfo.pl
new file mode 100644
index 0000000..c527e8c
--- /dev/null
+++ b/examples/iothreadsinfo.pl
@@ -0,0 +1,36 @@
+# -*- perl -*-
+use strict;
+use warnings;
+use Sys::Virt;
+
+my $addr = @ARGV ? shift @ARGV : "";
+print "Addr $addr\n";
+my $con = Sys::Virt->new(address => $addr, readonly => 1);
+
+print "VMM type: ", $con->get_type(), "\n";
+
+foreach my $dom (sort { $a->get_id <=> $b->get_id } $con->list_all_domains) {
+    print "Domain: {\n";
+    print "  ID: ", $dom->get_id(), " '" , $dom->get_name(), "'\n";
+    print "  UUID: ", $dom->get_uuid_string(), "\n";
+    my $nodeinfo = $con->get_node_info;
+    my @info = $dom->get_iothread_info(Sys::Virt::Domain::AFFECT_CONFIG);
+
+    foreach my $info (@info) {
+	print "  IOThread: {\n";
+	foreach (sort { $a cmp $b } keys %{$info}) {
+	    if ($_ eq "affinity") {
+		print "    ", $_, ": ";
+		my @mask = split //, $info->{$_};
+		for (my $p = 0 ; $p < $nodeinfo->{cpus} ; $p++) {
+		    print ((ord($mask[$p/8]) & (1 << ($p % 8))) ? 1 : 0);
+		}
+		print "\n";
+	    } else {
+		print "    ", $_, ": ", $info->{$_}, "\n";
+	    }
+	}
+	print "  }\n";
+    }
+    print "}\n";
+}
diff --git a/lib/Sys/Virt/Domain.pm b/lib/Sys/Virt/Domain.pm
index 5c8ef47..062c012 100644
--- a/lib/Sys/Virt/Domain.pm
+++ b/lib/Sys/Virt/Domain.pm
@@ -1216,6 +1216,23 @@ the physical CPUa, 8 cpus per character. To create a suitable
 bitstring, use the C<vec> function with a value of C<1> for the
 C<BITS> parameter.
 
+=item @iothreadinfo = $dom->get_iothread_info($flags=0)
+
+Obtain information about the state of all IOThreads in a running
+guest domain. The returned list will have one element for each IOThread,
+where each elements contains a hash reference. The keys in the hash
+are, C<number> the IOThread number and C<affinity> giving the allowed
+schedular placement. The value for C<affinity> is a
+string representing a bitmask against physical CPUs, 8 cpus per
+character. To extract the bits use the C<unpack> function with
+the C<b*> template.
+
+=item $dom->pin_iothread($iothread, $mask)
+
+Pin the IOThread given by index C<$iothread> to physical CPUs
+given by C<$mask>. The C<$mask> is a string representing a bitmask
+against physical CPUs, 8 cpus per character.
+
 =item my @stats = $dom->get_cpu_stats($startCpu, $numCpus, $flags=0)
 
 Requests the guests host physical CPU usage statistics, starting
-- 
2.1.0

    

John Ferlan

Daniel P. Berrange

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