[pve-devel] [PATCH] memory hotplug patch v4

Alexandre Derumier aderumier at odiso.com
Wed Aug 27 06:13:46 CEST 2014


From: Stefan Priebe <s.priebe at profihost.ag>

This patch allow to hotplug|define pc dimm devices memory

Minimum size is 128M
Maximum devices is 255

(tested under debian and windows).

vmid.conf
---------
dimm0: size=128
dimm1: size=512
dimm255: size=1024
memory: 1024
maxmemory: 8192

total running memory is : memory + dimmX.

dimmX devices are not seen by os at start, so need to have "memory" enough big to load kernel

hotplug
----
qm set <vmid> -dimm0 128

unplug (not yet implemented in qemu)
------
qm set <vmid> -delete dimm0

linux guest
-----------
-acpi hotplug module should be loaded in guest
-need a recent kernel. (tested with 3.10)

can be enable automaticly, adding:

/lib/udev/rules.d/80-hotplug-cpu-mem.rules
SUBSYSTEM=="cpu", ACTION=="add", TEST=="online", ATTR{online}=="0", \
 ATTR{online}="1"

SUBSYSTEM=="memory", ACTION=="add", TEST=="state", ATTR{state}=="offline", \
 ATTR{state}="online"

windows guest
-------------
works out of the box:

- windows 2012 standard
- windows 2008 enterprise/datacenter

Signed-off-by: Stefan Priebe <s.priebe at profihost.ag>
Signed-off-by: Alexandre Derumier <aderumier at odiso.com>
---
 PVE/API2/Qemu.pm  |    8 ++++
 PVE/QemuServer.pm |  105 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 112 insertions(+), 1 deletion(-)

diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
index 985a9f8..084e4d7 100644
--- a/PVE/API2/Qemu.pm
+++ b/PVE/API2/Qemu.pm
@@ -727,6 +727,10 @@ my $vmconfig_delete_option = sub {
     } else {
         die "error hot-unplug $opt $unplugwarning" if !PVE::QemuServer::vm_deviceunplug($vmid, $conf, $opt);
     }
+    if ($opt =~ m/^dimm(\d+)$/) { #dimms
+
+	PVE::QemuServer::qemu_memory_unplug($vmid, $conf, $opt);
+    }
 
     if ($isDisk) {
 	my $drive = PVE::QemuServer::parse_drive($opt, $conf->{$opt});
@@ -997,6 +1001,10 @@ my $update_vm_api  = sub {
 		    &$vmconfig_update_net($rpcenv, $authuser, $conf, $storecfg, $vmid,
 					  $opt, $param->{$opt});
 
+		} elsif ($opt =~ m/^dimm(\d+)$/) { #dimms
+
+		    PVE::QemuServer::qemu_memory_hotplug($vmid, $conf, $opt, $param->{$opt});
+
 		} else {
 
 		    if($opt eq 'tablet' && $param->{$opt} == 1){
diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index 49356f2..1dbf76e 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -307,6 +307,12 @@ EODESC
 	minimum => 1,
 	default => 1,
     },
+    maxmemory => {
+	optional => 1,
+	type => 'integer',
+	description => "Maximum memory for hotplug.",
+	minimum => 1,
+    },
     acpi => {
 	optional => 1,
 	type => 'boolean',
@@ -477,6 +483,7 @@ my $MAX_UNUSED_DISKS = 8;
 my $MAX_HOSTPCI_DEVICES = 4;
 my $MAX_SERIAL_PORTS = 4;
 my $MAX_PARALLEL_PORTS = 3;
+my $MAX_DIMMS = 255;
 
 my $nic_model_list = ['rtl8139', 'ne2k_pci', 'e1000',  'pcnet',  'virtio',
 		      'ne2k_isa', 'i82551', 'i82557b', 'i82559er', 'vmxnet3'];
@@ -514,6 +521,20 @@ for (my $i = 0; $i < $MAX_NETS; $i++)  {
     $confdesc->{"net$i"} = $netdesc;
 }
 
+my $dimmdesc = {
+    optional => 1,
+    type => 'string',
+    typetext => "size=<BYTES>,
+    description => <<EODESCR,
+Later / Hotplugged memory DIMM modules
+EODESCR
+};
+PVE::JSONSchema::register_standard_option("pve-qm-dimm", $dimmdesc);
+
+for (my $i = 0; $i < $MAX_DIMMS; $i++)  {
+    $confdesc->{"dimm$i"} = $dimmdesc;
+}
+
 my $drivename_hash;
 
 my $idedesc = {
@@ -2780,7 +2801,27 @@ sub config_to_command {
 	push @$devices, '-device', print_drivedevice_full($storecfg, $conf, $vmid, $drive, $bridges);
     });
 
-    push @$cmd, '-m', $conf->{memory} || $defaults->{memory};
+    my $memory = $conf->{memory} || $defaults->{memory};
+    my $totalmemory = $memory;
+    for (my $i = 0; $i < $MAX_DIMMS; $i++)  {
+	next if !exists $conf->{"dimm$i"};
+	$conf->{"dimm$i"} =~ m/size=(\d+)/ or next;
+	my $dimmsize = $1;
+	die "dimm size should be a multiple of 128!\n" if ($dimmsize % 128 != 0);
+
+	push @$cmd, "-object" , "memory-backend-ram,id=mem$i,size=".int(${dimmsize}*1024*1024);
+	push @$cmd, "-device", "pc-dimm,id=dimm$i,memdev=mem$i";
+	$totalmemory += $dimmsize;
+    }
+
+    if ($conf->{maxmemory}) {
+        die "Total memory is bigger than maxmemory\n" if $totalmemory > $conf->{maxmemory};
+	push @$cmd, '-m', "size=".$memory.",slots=$MAX_DIMMS,maxmem=".$conf->{maxmemory}."M";
+	push @$cmd, "-numa", "node" if ($conf->{ostype} && $conf->{ostype} =~ m/^w/);
+
+    } else {
+	push @$cmd, '-m', $memory;
+    }
 
     for (my $i = 0; $i < $MAX_NETS; $i++) {
          next if !$conf->{"net$i"};
@@ -3138,6 +3179,68 @@ sub qemu_cpu_hotplug {
     }
 }
 
+sub qemu_memory_hotplug {
+    my ($vmid, $conf, $dimm, $size) = @_;
+
+    return if !check_running($vmid);
+ 
+    die "maxmemory is not defined" if !$conf->{maxmemory};
+
+    die "dimm already exist" if $conf->{$dimm};
+
+    die "dimm size should be a multiple of 128!\n" if ($size % 128 != 0);
+
+    my $defaults = load_defaults();
+    my $memory = $conf->{memory} || $defaults->{memory};
+    my $totalmemory = $memory;
+    for (my $i = 0; $i < $MAX_DIMMS; $i++)  {
+        next if !exists $conf->{"dimm$i"};
+        $conf->{"dimm$i"} =~ m/size=(\d+)/ or next;
+        my $dimmsize = $1;
+        $totalmemory += $dimmsize;
+    }
+    $totalmemory += $size;
+
+    die "you cannot add more memory than maxmemory!\n" if $totalmemory > $conf->{'maxmemory'};
+
+    eval {
+	# size is in BYTES
+	vm_mon_cmd($vmid, "object-add", 'qom-type' => "memory-backend-ram", id => "mem$dimm", props => { size => int($size*1024*1024) } )
+    };
+    my $err = $@;
+
+    $conf->{"$dimm"} = "size=$size";
+
+    # slot is consumed even on failure and also if device_add fails
+    update_config_nolock($vmid, $conf, 1);
+
+    if (!$err) {
+	eval {
+	    vm_mon_cmd($vmid, "device_add", driver => "pc-dimm", id => "$dimm", memdev => "mem$dimm");
+
+	};
+	$err = $@;
+    }
+
+    die "Memory hot add failed!: $err\n" if $err;
+}
+
+sub qemu_memory_unplug {
+    my ($vmid, $conf, $dimm) = @_;
+
+    return if !check_running($vmid);
+
+    die "memory unplug is not yet implemented";
+
+    eval {
+	vm_mon_cmd($vmid, "device_del", id => $dimm);
+    };
+    if($@){
+	die "error unplug dimm device $dimm";
+    }
+
+}
+
 sub qemu_block_set_io_throttle {
     my ($vmid, $deviceid, $bps, $bps_rd, $bps_wr, $iops, $iops_rd, $iops_wr) = @_;
 
-- 
1.7.10.4



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