[pve-devel] [PATCH 2/2] add memory/dimm hotplug incl. migration support

[Stefan Priebe - Profihost AG]

Am 04.07.2014 10:49, schrieb Alexandre DERUMIER:
> Thanks for the patch, I think it's not too much different in qemu 2.1
> 
> I see in you code :
> my $MAX_DIMMS = 10;
> 
> 
> 
> and
> 
> + push @$cmd, '-m', "size=".$memory.",slots=10,maxmem=".$conf->{maxmemory}."G"; 
> 
> 
> is "slots=10" = max_dimms ? (if yes,we should remove this hardcoded value)

Yes it is. It was just a test to verify it is working at all.

> 
> I wonder if we could set max_dimm= 256 (max supported by acpi),$dimmsize=1G by default.
>
> so like this we can easily hotplug 256G by default.

Why? You could also insert a 4GB module or just a 512MB module.


Stefan

> ----- Mail original ----- 
> 
> De: "Stefan Priebe" <s.priebe at profihost.ag> 
> À: pve-devel at pve.proxmox.com 
> Envoyé: Vendredi 4 Juillet 2014 10:23:45 
> Objet: [pve-devel] [PATCH 2/2] add memory/dimm hotplug incl. migration support 
> 
> 
> Signed-off-by: Stefan Priebe <s.priebe at profihost.ag> 
> --- 
> PVE/API2/Qemu.pm | 3 ++ 
> PVE/QemuServer.pm | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++--- 
> 2 files changed, 96 insertions(+), 4 deletions(-) 
> 
> diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm 
> index 96c9302..11abcd3 100644 
> --- a/PVE/API2/Qemu.pm 
> +++ b/PVE/API2/Qemu.pm 
> @@ -1008,6 +1008,9 @@ my $update_vm_api = sub { 
> if($opt eq 'cores' && $conf->{maxcpus}){ 
> PVE::QemuServer::qemu_cpu_hotplug($vmid, $conf, $param->{$opt}); 
> } 
> + elsif ($opt eq 'memory' && $running){ 
> + PVE::QemuServer::qemu_memory_hotplug($vmid, $conf, $conf_param->{$opt}); 
> + } 
> 
> $conf->{$opt} = $param->{$opt}; 
> PVE::QemuServer::update_config_nolock($vmid, $conf, 1); 
> diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm 
> index b94e976..8913ee8 100644 
> --- a/PVE/QemuServer.pm 
> +++ b/PVE/QemuServer.pm 
> @@ -483,6 +483,7 @@ my $MAX_UNUSED_DISKS = 8; 
> my $MAX_HOSTPCI_DEVICES = 2; 
> my $MAX_SERIAL_PORTS = 4; 
> my $MAX_PARALLEL_PORTS = 3; 
> +my $MAX_DIMMS = 10; 
> 
> my $nic_model_list = ['rtl8139', 'ne2k_pci', 'e1000', 'pcnet', 'virtio', 
> 'ne2k_isa', 'i82551', 'i82557b', 'i82559er', 'vmxnet3']; 
> @@ -520,6 +521,20 @@ for (my $i = 0; $i < $MAX_NETS; $i++) { 
> $confdesc->{"net$i"} = $netdesc; 
> } 
> 
> +my $dimmdesc = { 
> + optional => 1, 
> + type => 'string', 
> + typetext => "size=<BYTES>,start=<startadress>", 
> + 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 $idedesc = { 
> @@ -2769,12 +2784,24 @@ sub config_to_command { 
> push @$devices, '-device', print_drivedevice_full($storecfg, $conf, $vmid, $drive, $bridges); 
> }); 
> 
> - $conf->{memory} ||= $defaults->{memory}; 
> + my $memory = $conf->{memory} || $defaults->{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; 
> + $conf->{"dimm$i"} =~ m/start=(\d+)/ or next; 
> + my $dimmstart = $1; 
> + $memory -= $dimmsize; 
> + push @$cmd, "-object" , "memory-ram,id=mem$i,size=".int(${dimmsize}*1024*1024); 
> + push @$cmd, "-device", "dimm,id=dimm$i,memdev=mem$i,start=$dimmstart"; 
> + } 
> 
> - if ($conf->{maxmemory} && $conf->{maxmemory}*1024 > $conf->{memory}) { 
> - push @$cmd, '-m', "size=".$conf->{memory}.",slots=10,maxmem=".$conf->{maxmemory}."G"; 
> + if ($conf->{maxmemory}) { 
> + die "Memory is bigger than maxmemory\n" if $conf->{memory} > $conf->{maxmemory}*1024; 
> + push @$cmd, '-m', "size=".$memory.",slots=10,maxmem=".$conf->{maxmemory}."G"; 
> } else { 
> - push @$cmd, '-m', $conf->{memory}; 
> + push @$cmd, '-m', $memory; 
> } 
> 
> for (my $i = 0; $i < $MAX_NETS; $i++) { 
> @@ -3133,6 +3160,56 @@ sub qemu_cpu_hotplug { 
> } 
> } 
> 
> +sub qemu_memory_hotplug { 
> + my ($vmid, $conf, $memory) = @_; 
> + 
> + return if !check_running($vmid); 
> + 
> + die "memory hot add is not possible maxmemory config is missing!\n" if !$conf->{maxmemory}; 
> + die "you cannot add more memory than maxmemory!\n" if $memory > $conf->{'maxmemory'}*1024; 
> + 
> + # delta of memory must be a multiple of 1024 
> + my $toadd = $memory - $conf->{memory}; 
> + 
> + die "memory hot remove is not supported!\n" if $toadd <= 0; 
> + 
> + die "memory hot add must be in gb steps!\n" if ($toadd/1024 != int($toadd/1024)); 
> + 
> + # check for free dimms 
> + my $i = 0; 
> + while (defined $conf->{"dimm$i"} && $i < $MAX_DIMMS) {$i++;} 
> + 
> + die "no free dimm slot found!\n" if ($i >= $MAX_DIMMS); 
> + 
> + eval { 
> + # size is in BYTES 
> + vm_mon_cmd($vmid, "object-add", 'qom-type' => "memory-ram", id => "mem$i", props => { size => int($toadd*1024*1024) } ) 
> + }; 
> + my $err = $@; 
> + 
> + $conf->{"dimm$i"} = "size=$toadd"; 
> + 
> + # slot is consumed even on failure and also if device_add fails 
> + update_config_nolock($vmid, $conf, 1); 
> + 
> + if (!$err) { 
> + eval { 
> + vm_mon_cmd($vmid, "device_add", driver => "dimm", id => "dimm$i", memdev => "mem$i"); 
> + 
> + my $cmd = { execute => 'qom-get', arguments => { path => "/machine/peripheral/dimm$i", property => "start" } }; 
> + my $start = vm_qmp_command($vmid, $cmd); 
> + 
> + $conf->{"dimm$i"} .= ",start=$start"; 
> + 
> + # slot is consumed even on failure and also if device_add fails 
> + update_config_nolock($vmid, $conf, 1); 
> + }; 
> + $err = $@; 
> + } 
> + 
> + die "Memory hot add failed!: $err\n" if $err; 
> +} 
> + 
> sub qemu_block_set_io_throttle { 
> my ($vmid, $deviceid, $bps, $bps_rd, $bps_wr, $iops, $iops_rd, $iops_wr) = @_; 
> 
> @@ -3341,6 +3418,18 @@ sub vm_start { 
> # set environment variable useful inside network script 
> $ENV{PVE_MIGRATED_FROM} = $migratedfrom if $migratedfrom; 
> 
> + # fresh VM start ignore DIMMs / delete them 
> + if (!$migratedfrom) { 
> + my $found = 0; 
> + for (my $i = 0; $i < $MAX_DIMMS; $i++) { 
> + next if !exists $conf->{"dimm$i"}; 
> + delete($conf->{"dimm$i"}); 
> + $found = 1; 
> + } 
> + update_config_nolock($vmid, $conf, 1); 
> + $conf = load_config($vmid, $migratedfrom); 
> + } 
> + 
> my ($cmd, $vollist, $spice_port) = config_to_command($storecfg, $vmid, $conf, $defaults, $forcemachine); 
> 
> my $migrate_port = 0; 
>