implement PVE Version addition for QEMU machine

With our QEMU 4.1.1 package we can pass a additional internal version
to QEMU's machine, it will be split out there and ignored, but
returned on a QMP 'query-machines' call.

This allows us to use it for increasing the granularity with which we
can roll-out HW layout changes/additions for VMs. Until now we
required a machine version bump, happening normally every major
release of QEMU, with seldom, for us irrelevant, exceptions.
This often delays rolling out a feature, which would break
live-migration, by several months. That can now be avoided, the new
"pve-version" component of the machine can be bumped at will, and
thus we are much more flexible.

That versions orders after the ($major, $minor) version components
from an stable release - it can thus also be reset on the next
release.

The implementation extends the qemu-machine REGEX, remembers
"pve-version" when doing a "query-machines" and integrates support
into the min_version and extract_version helpers.

We start out with a version of 1.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
Reviewed-by: Stefan Reiter <s.reiter@proxmox.com>

PVE/QemuServer.pm

@@ -93,7 +93,7 @@ PVE::JSONSchema::register_standard_option('pve-qm-image-format', {
 PVE::JSONSchema::register_standard_option('pve-qemu-machine', {
 	description => "Specifies the Qemu machine type.",
 	type => 'string',
-	pattern => '(pc|pc(-i440fx)?-\d+(\.\d+)+(\.pxe)?|q35|pc-q35-\d+(\.\d+)+(\.pxe)?|virt(?:-\d+(\.\d+)+)?)',
+	pattern => '(pc|pc(-i440fx)?-\d+(\.\d+)+(\+pve\d+)?(\.pxe)?|q35|pc-q35-\d+(\.\d+)+(\+pve\d+)?(\.pxe)?|virt(?:-\d+(\.\d+)+)?(\+pve\d+)?)',
 	maxLength => 40,
 	optional => 1,
 });
@@ -1875,7 +1875,7 @@ sub print_drivedevice_full {
 	    }
 
 	    # for compatibility only, we prefer scsi-hd (#2408, #2355, #2380)
-	    my $version = PVE::QemuServer::Machine::extract_version($machine_type) // kvm_user_version();
+	    my $version = PVE::QemuServer::Machine::extract_version($machine_type, kvm_user_version());
 	    if ($path =~ m/^iscsi\:\/\// &&
 	       !min_version($version, 4, 1)) {
 		$devicetype = 'generic';
@@ -3361,13 +3361,14 @@ my $default_machines = {
 };
 
 sub get_vm_machine {
-    my ($conf, $forcemachine, $arch) = @_;
+    my ($conf, $forcemachine, $arch, $add_pve_version) = @_;
 
     my $machine = $forcemachine || $conf->{machine};
 
-    if (!$machine) {
+    if (!$machine || $machine =~ m/^(?:pc|q35|virt)$/) {
 	$arch //= 'x86_64';
 	$machine ||= $default_machines->{$arch};
+	$machine .= "+pve$PVE::QemuServer::Machine::PVE_MACHINE_VERSION" if $add_pve_version;
     }
 
     return $machine;
@@ -3469,8 +3470,10 @@ sub config_to_command {
     my $kvm_binary = get_command_for_arch($arch);
     my $kvmver = kvm_user_version($kvm_binary);
 
-    my $machine_type = get_vm_machine($conf, $forcemachine, $arch);
-    my $machine_version = PVE::QemuServer::Machine::extract_version($machine_type) // $kvmver;
+    my $add_pve_version = min_version($kvmver, 4, 1);
+
+    my $machine_type = get_vm_machine($conf, $forcemachine, $arch, $add_pve_version);
+    my $machine_version = PVE::QemuServer::Machine::extract_version($machine_type, $kvmver);
     $kvm //= 1 if is_native($arch);
 
     if ($kvm) {
@@ -7049,7 +7052,7 @@ sub qemu_use_old_bios_files {
         $machine_type = $1;
         $use_old_bios_files = 1;
     } else {
-	my $version = PVE::QemuServer::Machine::extract_version($machine_type) // kvm_user_version();
+	my $version = PVE::QemuServer::Machine::extract_version($machine_type, kvm_user_version());
         # Note: kvm version < 2.4 use non-efi pxe files, and have problems when we
         # load new efi bios files on migration. So this hack is required to allow
         # live migration from qemu-2.2 to qemu-2.4, which is sometimes used when

PVE/QemuServer/Helpers.pm

@@ -103,10 +103,10 @@ sub vm_running_locally {
 }
 
 sub min_version {
-    my ($verstr, $version_major, $version_minor) = @_;
+    my ($verstr, $major, $minor, $pve) = @_;
 
-    if ($verstr =~ m/^(\d+)\.(\d+)/) {
-	return 1 if version_cmp($1, $version_major, $2, $version_minor) >= 0;
+    if ($verstr =~ m/^(\d+)\.(\d+)(?:\.(\d+))?(?:\+pve(\d+))?/) {
+	return 1 if version_cmp($1, $major, $2, $minor, $4, $pve) >= 0;
 	return 0;
     }
 

PVE/QemuServer/Machine.pm

@@ -6,6 +6,10 @@ use warnings;
 use PVE::QemuServer::Helpers;
 use PVE::QemuServer::Monitor;
 
+# Bump this for VM HW layout changes during a release (where the QEMU machine
+# version stays the same)
+our $PVE_MACHINE_VERSION = 1;
+
 sub machine_type_is_q35 {
     my ($conf) = @_;
 
@@ -18,31 +22,43 @@ sub get_current_qemu_machine {
 
     my $res = PVE::QemuServer::Monitor::mon_cmd($vmid, 'query-machines');
 
-    my ($current, $default);
+    my ($current, $pve_version, $default);
     foreach my $e (@$res) {
 	$default = $e->{name} if $e->{'is-default'};
 	$current = $e->{name} if $e->{'is-current'};
+	$pve_version = $e->{'pve-version'} if $e->{'pve-version'};
     }
 
+    $current .= "+$pve_version" if $current && $pve_version;
+
     # fallback to the default machine if current is not supported by qemu
     return $current || $default || 'pc';
 }
 
+# returns a string with major.minor+pve<VERSION>, patch version-part is ignored
+# as it's seldom ressembling a real QEMU machine type, so it would be '0' 99% of
+# the time anyway.. This explicitly separates pveversion from the machine.
 sub extract_version {
-    my ($machine_type) = @_;
+    my ($machine_type, $kvmversion) = @_;
 
-    if ($machine_type && $machine_type =~ m/^((?:pc(-i440fx|-q35)?|virt)-(\d+)\.(\d+))/) {
-	return "$3.$4";
+    if (defined($machine_type) && $machine_type =~ m/^(?:pc(?:-i440fx|-q35)?|virt)-(\d+)\.(\d+)(?:\.(\d+))?(\+pve\d+)?/) {
+	my $versionstr = "$1.$2";
+	$versionstr .= $4 if $4;
+	return $versionstr;
+    } elsif (defined($kvmversion)) {
+	if ($kvmversion =~ m/^(\d+)\.(\d+)/) {
+	    return "$1.$2+pve$PVE_MACHINE_VERSION";
+	}
     }
 
     return undef;
 }
 
 sub machine_version {
-    my ($machine_type, $version_major, $version_minor) = @_;
+    my ($machine_type, $major, $minor, $pve) = @_;
 
     return PVE::QemuServer::Helpers::min_version(
-	extract_version($machine_type), $version_major, $version_minor);
+	extract_version($machine_type), $major, $minor, $pve);
 }
 
 # dies if a) VM not running or not exisiting b) Version query failed

test/cfg2cmd/i440fx-win10-hostpci.conf.cmd

@@ -33,5 +33,5 @@
   -netdev 'type=tap,id=net0,ifname=tap8006i0,script=/var/lib/qemu-server/pve-bridge,downscript=/var/lib/qemu-server/pve-bridgedown,vhost=on' \
   -device 'virtio-net-pci,mac=2E:01:68:F9:9C:87,netdev=net0,bus=pci.0,addr=0x12,id=net0,bootindex=300' \
   -rtc 'driftfix=slew,base=localtime' \
-  -machine 'type=pc' \
+  -machine 'type=pc+pve1' \
   -global 'kvm-pit.lost_tick_policy=discard'

test/cfg2cmd/minimal-defaults.conf.cmd

@@ -21,4 +21,4 @@
   -device 'VGA,id=vga,bus=pci.0,addr=0x2' \
   -device 'virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3' \
   -iscsi 'initiator-name=iqn.1993-08.org.debian:01:aabbccddeeff' \
-  -machine 'type=pc'
+  -machine 'type=pc+pve1'

test/cfg2cmd/q35-linux-hostpci.conf.cmd

@@ -36,4 +36,4 @@
   -iscsi 'initiator-name=iqn.1993-08.org.debian:01:aabbccddeeff' \
   -netdev 'type=tap,id=net0,ifname=tap8006i0,script=/var/lib/qemu-server/pve-bridge,downscript=/var/lib/qemu-server/pve-bridgedown,vhost=on' \
   -device 'virtio-net-pci,mac=2E:01:68:F9:9C:87,netdev=net0,bus=pci.0,addr=0x12,id=net0,bootindex=300' \
-  -machine 'type=q35'
+  -machine 'type=q35+pve1'

test/cfg2cmd/q35-win10-hostpci.conf.cmd

@@ -34,5 +34,5 @@
   -netdev 'type=tap,id=net0,ifname=tap8006i0,script=/var/lib/qemu-server/pve-bridge,downscript=/var/lib/qemu-server/pve-bridgedown,vhost=on' \
   -device 'virtio-net-pci,mac=2E:01:68:F9:9C:87,netdev=net0,bus=pci.0,addr=0x12,id=net0,bootindex=300' \
   -rtc 'driftfix=slew,base=localtime' \
-  -machine 'type=q35' \
+  -machine 'type=q35+pve1' \
   -global 'kvm-pit.lost_tick_policy=discard'

test/cfg2cmd/spice-linux-4.1.conf.cmd

@@ -27,4 +27,4 @@
   -iscsi 'initiator-name=iqn.1993-08.org.debian:01:aabbccddeeff' \
   -netdev 'type=tap,id=net0,ifname=tap8006i0,script=/var/lib/qemu-server/pve-bridge,downscript=/var/lib/qemu-server/pve-bridgedown,vhost=on' \
   -device 'virtio-net-pci,mac=A2:C0:43:67:08:A1,netdev=net0,bus=pci.0,addr=0x12,id=net0,bootindex=300' \
-  -machine 'type=pc'
+  -machine 'type=pc+pve1'