[pve-devel] [PATCH qemu-server 1/2] add virtio-mem support
Alexandre Derumier
aderumier at odiso.com
Mon Mar 7 12:36:00 CET 2022
This patch add virtio-mem support, through a new maxmemory option.
a 4GB static memory is needed for DMA+boot memory, as this memory
is almost always un-unpluggeable.
1 virtio-mem pci device is setup for each numa node on pci.4 bridge
virtio-mem use a fixed blocksize with 32k max blocksize,
so blocksize is computed from the maxmemory/32000 with a minimum of
2MB to map THP.
(lower blocksize = more chance to unplug memory).
Signed-off-by: Alexandre Derumier <aderumier at odiso.com>
---
PVE/QemuServer.pm | 9 ++-
PVE/QemuServer/Memory.pm | 130 ++++++++++++++++++++++++++++++---------
PVE/QemuServer/PCI.pm | 8 +++
3 files changed, 118 insertions(+), 29 deletions(-)
diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index bb44e58..a52ca95 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -340,6 +340,13 @@ my $confdesc = {
maximum => 262144,
default => 'cgroup v1: 1024, cgroup v2: 100',
},
+ maxmemory => {
+ optional => 1,
+ type => 'integer',
+ description => "Max hotpluggable virtio-mem memory",
+ minimum => 4096,
+ default => undef,
+ },
memory => {
optional => 1,
type => 'integer',
@@ -3758,7 +3765,7 @@ sub config_to_command {
push @$cmd, get_cpu_options($conf, $arch, $kvm, $kvm_off, $machine_version, $winversion, $gpu_passthrough);
}
- PVE::QemuServer::Memory::config($conf, $vmid, $sockets, $cores, $defaults, $hotplug_features, $cmd);
+ PVE::QemuServer::Memory::config($conf, $vmid, $sockets, $cores, $defaults, $hotplug_features, $cmd, $devices, $bridges, $arch, $machine_type);
push @$cmd, '-S' if $conf->{freeze};
diff --git a/PVE/QemuServer/Memory.pm b/PVE/QemuServer/Memory.pm
index a41f5ae..9b7c33c 100644
--- a/PVE/QemuServer/Memory.pm
+++ b/PVE/QemuServer/Memory.pm
@@ -8,11 +8,48 @@ use PVE::Exception qw(raise raise_param_exc);
use PVE::QemuServer;
use PVE::QemuServer::Monitor qw(mon_cmd);
+use PVE::QemuServer::PCI qw(print_pci_addr);
my $MAX_NUMA = 8;
my $MAX_MEM = 4194304;
my $STATICMEM = 1024;
+my $compute_static_mem = sub {
+ my ($conf, $defaults) = @_;
+
+ my $sockets = 1;
+ $sockets = $conf->{smp} if $conf->{smp}; # old style - no longer iused
+ $sockets = $conf->{sockets} if $conf->{sockets};
+ my $hotplug_features = PVE::QemuServer::parse_hotplug_features(defined($conf->{hotplug}) ? $conf->{hotplug} : '1');
+
+ my $static_memory = 0;
+
+ if ($hotplug_features->{memory} || $conf->{maxmemory}) {
+ $static_memory = $STATICMEM;
+ $static_memory = $static_memory * $sockets if ($conf->{hugepages} && $conf->{hugepages} == 1024);
+ $static_memory = 4096 if $conf->{maxmemory};
+ } else {
+ $static_memory = $conf->{memory} || $defaults->{memory};
+ }
+
+ return $static_memory;
+};
+
+my $compute_virtiomem_block_size = sub {
+ my ($conf, $static_memory) = @_;
+
+ my $maxmemory = $conf->{maxmemory};
+ return undef if !$maxmemory;
+
+ #virtiomem can map 32000 block size. try to use lowerst blocksize, lower = more chance to unplug memory.
+ my $blocksize = ($maxmemory - $static_memory) / 32000;
+ #round next power of 2
+ $blocksize = 2**(int(log($blocksize)/log(2))+1);
+ #2MB is the minimum to be aligned with THP
+ $blocksize = 2 if $blocksize < 2;
+ return $blocksize;
+};
+
sub get_numa_node_list {
my ($conf) = @_;
my @numa_map;
@@ -104,6 +141,8 @@ sub foreach_reverse_dimm {
}
}
+
+
sub qemu_memory_hotplug {
my ($vmid, $conf, $defaults, $opt, $value) = @_;
@@ -116,13 +155,45 @@ sub qemu_memory_hotplug {
$value = $defaults->{memory} if !$value;
return $value if $value == $memory;
- my $static_memory = $STATICMEM;
- $static_memory = $static_memory * $sockets if ($conf->{hugepages} && $conf->{hugepages} == 1024);
+ my $static_memory = &$compute_static_mem($conf, $defaults);
+ my $maxmemory = $conf->{maxmemory} || $MAX_MEM;
die "memory can't be lower than $static_memory MB" if $value < $static_memory;
- die "you cannot add more memory than $MAX_MEM MB!\n" if $memory > $MAX_MEM;
+ die "you cannot add more memory than $maxmemory MB!\n" if $value > $maxmemory;
+
+ if ($conf->{maxmemory}) {
+
+ my $requested_size = ($value - $static_memory) / $sockets * 1024 * 1024;
- if($value > $memory) {
+ my $totalsize = $static_memory;
+ my $err = undef;
+
+ for (my $i = 0; $i < $sockets; $i++) {
+
+ my $id = "virtiomem$i";
+ my $retry = 0;
+ mon_cmd($vmid, 'qom-set', path => "/machine/peripheral/$id", property => "requested-size", value => int($requested_size));
+
+ my $size = 0;
+ while (1) {
+ sleep 1;
+ $size = mon_cmd($vmid, 'qom-get', path => "/machine/peripheral/$id", property => "size");
+ $err = 1 if $retry > 5;
+ last if $size eq $requested_size || $retry > 5;
+ $retry++;
+ }
+ $totalsize += ($size / 1024 / 1024 );
+ }
+
+ #update conf after each succesful module unplug
+ if($err) {
+ $conf->{memory} = $totalsize;
+ PVE::QemuConfig->write_config($vmid, $conf);
+ raise_param_exc({ 'memory' => "error modify virtio memory" }) if $err;
+ }
+ return $totalsize;
+
+ } elsif($value > $memory) {
my $numa_hostmap;
@@ -217,32 +288,27 @@ sub qemu_dimm_list {
}
sub config {
- my ($conf, $vmid, $sockets, $cores, $defaults, $hotplug_features, $cmd) = @_;
+ my ($conf, $vmid, $sockets, $cores, $defaults, $hotplug_features, $cmd, $devices, $bridges, $arch, $machine_type) = @_;
my $memory = $conf->{memory} || $defaults->{memory};
- my $static_memory = 0;
+ my $static_memory = &$compute_static_mem($conf, $defaults);
+
+ if ($hotplug_features->{memory} || $conf->{maxmemory}) {
+
+ my $maxmemory = $conf->{maxmemory} || $MAX_MEM;
- if ($hotplug_features->{memory}) {
die "NUMA needs to be enabled for memory hotplug\n" if !$conf->{numa};
- die "Total memory is bigger than ${MAX_MEM}MB\n" if $memory > $MAX_MEM;
+ die "Total memory is bigger than ${maxmemory}MB\n" if $memory > $maxmemory;
for (my $i = 0; $i < $MAX_NUMA; $i++) {
die "cannot enable memory hotplugging with custom NUMA topology\n"
if $conf->{"numa$i"};
}
-
- my $sockets = 1;
- $sockets = $conf->{sockets} if $conf->{sockets};
-
- $static_memory = $STATICMEM;
- $static_memory = $static_memory * $sockets if ($conf->{hugepages} && $conf->{hugepages} == 1024);
-
die "minimum memory must be ${static_memory}MB\n" if($memory < $static_memory);
- push @$cmd, '-m', "size=${static_memory},slots=255,maxmem=${MAX_MEM}M";
-
+ my $cmdstr = "size=${static_memory},maxmem=${maxmemory}M";
+ $cmdstr .= ",slots=255" if !$conf->{maxmemory};
+ push @$cmd, '-m', $cmdstr;
} else {
-
- $static_memory = $memory;
push @$cmd, '-m', $static_memory;
}
@@ -309,7 +375,21 @@ sub config {
}
}
- if ($hotplug_features->{memory}) {
+ if ($conf->{maxmemory}) {
+ my $node_maxmem = ($conf->{maxmemory} - $static_memory) / $sockets;
+ my $node_mem = ($memory - $static_memory) / $sockets;
+ my $blocksize = &$compute_virtiomem_block_size($conf, $static_memory);
+
+ for (my $i = 0; $i < $sockets; $i++) {
+
+ my $id = "virtiomem$i";
+ my $pciaddr = print_pci_addr($id, $bridges, $arch, $machine_type);
+
+ my $mem_object = print_mem_object($conf, "mem-$id", $node_maxmem);
+ push @$cmd, "-object" , $mem_object;
+ push @$devices, "-device", "virtio-mem-pci,block-size=${blocksize}M,requested-size=${node_mem}M,id=$id,memdev=mem-$id,node=$i$pciaddr";
+ }
+ } elsif ($hotplug_features->{memory}) {
foreach_dimm($conf, $vmid, $memory, $sockets, sub {
my ($conf, $vmid, $name, $dimm_size, $numanode, $current_size, $memory) = @_;
@@ -435,20 +515,14 @@ sub hugepages_topology {
my $defaults = PVE::QemuServer::load_defaults();
my $memory = $conf->{memory} || $defaults->{memory};
- my $static_memory = 0;
+ my $static_memory = &$compute_static_mem($conf, $defaults);
+
my $sockets = 1;
$sockets = $conf->{smp} if $conf->{smp}; # old style - no longer iused
$sockets = $conf->{sockets} if $conf->{sockets};
my $numa_custom_topology = undef;
my $hotplug_features = PVE::QemuServer::parse_hotplug_features(defined($conf->{hotplug}) ? $conf->{hotplug} : '1');
- if ($hotplug_features->{memory}) {
- $static_memory = $STATICMEM;
- $static_memory = $static_memory * $sockets if ($conf->{hugepages} && $conf->{hugepages} == 1024);
- } else {
- $static_memory = $memory;
- }
-
#custom numa topology
for (my $i = 0; $i < $MAX_NUMA; $i++) {
next if !$conf->{"numa$i"};
diff --git a/PVE/QemuServer/PCI.pm b/PVE/QemuServer/PCI.pm
index 70987d8..0172555 100644
--- a/PVE/QemuServer/PCI.pm
+++ b/PVE/QemuServer/PCI.pm
@@ -249,6 +249,14 @@ sub get_pci_addr_map {
'scsihw2' => { bus => 4, addr => 1 },
'scsihw3' => { bus => 4, addr => 2 },
'scsihw4' => { bus => 4, addr => 3 },
+ 'virtiomem0' => { bus => 4, addr => 4 },
+ 'virtiomem1' => { bus => 4, addr => 5 },
+ 'virtiomem2' => { bus => 4, addr => 6 },
+ 'virtiomem3' => { bus => 4, addr => 7 },
+ 'virtiomem4' => { bus => 4, addr => 8 },
+ 'virtiomem5' => { bus => 4, addr => 9 },
+ 'virtiomem6' => { bus => 4, addr => 10 },
+ 'virtiomem7' => { bus => 4, addr => 11 },
} if !defined($pci_addr_map);
return $pci_addr_map;
}
--
2.30.2
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