From 13d689792e6f5c724d9bc4ac6e4014095c1efc94 Mon Sep 17 00:00:00 2001 From: Stefan Reiter Date: Thu, 18 Jun 2020 16:36:54 +0200 Subject: [PATCH 1/1] fix #2794: allow legacy IGD passthrough Legacy IGD passthrough requires address 00:1f.0 to not be assigned to anything on QEMU startup (currently it's assigned to bridge pci.2). Changing this in general would break live-migration, so introduce a new hostpci parameter "legacy-igd", which if set to 1 will move that bridge to be nested under bridge 1. This is safe because: * Bridge 1 is unconditionally created on i440fx, so nesting is ok * Defaults are not changed, i.e. PCI layout only changes when the new parameter is specified manually * hostpci forbids migration anyway Additionally, the PT device has to be assigned address 00:02.0 in the guest as well, which is usually used for VGA assignment. Luckily, IGD PT requires vga=none, so that is not an issue either. See https://git.qemu.org/?p=qemu.git;a=blob;f=docs/igd-assign.txt Signed-off-by: Stefan Reiter --- PVE/QemuServer.pm | 10 ++++++++-- PVE/QemuServer/PCI.pm | 45 +++++++++++++++++++++++++++++++++++++------ 2 files changed, 47 insertions(+), 8 deletions(-) diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm index 1c08222..1abe64b 100644 --- a/PVE/QemuServer.pm +++ b/PVE/QemuServer.pm @@ -3102,7 +3102,7 @@ sub config_to_command { } # host pci device passthrough - my ($kvm_off, $gpu_passthrough) = PVE::QemuServer::PCI::print_hostpci_devices( + my ($kvm_off, $gpu_passthrough, $legacy_igd) = PVE::QemuServer::PCI::print_hostpci_devices( $conf, $devices, $winversion, $q35, $bridges, $arch, $machine_type); # usb devices @@ -3458,7 +3458,13 @@ sub config_to_command { for my $k (sort {$b cmp $a} keys %$bridges) { next if $q35 && $k < 4; # q35.cfg already includes bridges up to 3 - $pciaddr = print_pci_addr("pci.$k", undef, $arch, $machine_type); + + my $k_name = $k; + if ($k == 2 && $legacy_igd) { + $k_name = "$k-igd"; + } + $pciaddr = print_pci_addr("pci.$k_name", undef, $arch, $machine_type); + my $devstr = "pci-bridge,id=pci.$k,chassis_nr=$k$pciaddr"; if ($q35) { # add after -readconfig pve-q35.cfg diff --git a/PVE/QemuServer/PCI.pm b/PVE/QemuServer/PCI.pm index 39f9970..e835f39 100644 --- a/PVE/QemuServer/PCI.pm +++ b/PVE/QemuServer/PCI.pm @@ -55,6 +55,14 @@ EODESCR optional => 1, default => 0, }, + 'legacy-igd' => { + type => 'boolean', + description => "Pass this device in legacy IGD mode (allows required" + . " 1f.0 PCI bridge and assigns correct address)." + . " Requires i440fx machine type and VGA set to 'none'.", + optional => 1, + default => 0, + }, 'mdev' => { type => 'string', format_description => 'string', @@ -89,7 +97,8 @@ sub get_pci_addr_map { $pci_addr_map = { piix3 => { bus => 0, addr => 1, conflict_ok => qw(ehci) }, ehci => { bus => 0, addr => 1, conflict_ok => qw(piix3) }, # instead of piix3 on arm - vga => { bus => 0, addr => 2 }, + vga => { bus => 0, addr => 2, conflict_ok => qw(legacy-igd) }, + 'legacy-igd' => { bus => 0, addr => 2, conflict_ok => qw(vga) }, # legacy-igd requires vga=none balloon0 => { bus => 0, addr => 3 }, watchdog => { bus => 0, addr => 4 }, scsihw0 => { bus => 0, addr => 5, conflict_ok => qw(pci.3) }, @@ -149,6 +158,7 @@ sub get_pci_addr_map { 'xhci' => { bus => 1, addr => 27 }, 'pci.4' => { bus => 1, addr => 28 }, 'rng0' => { bus => 1, addr => 29 }, + 'pci.2-igd' => { bus => 1, addr => 30 }, # replaces pci.2 in case a legacy IGD device is passed through 'virtio6' => { bus => 2, addr => 1 }, 'virtio7' => { bus => 2, addr => 2 }, 'virtio8' => { bus => 2, addr => 3 }, @@ -351,6 +361,7 @@ sub print_hostpci_devices { my $kvm_off = 0; my $gpu_passthrough = 0; + my $legacy_igd = 0; for (my $i = 0; $i < $MAX_HOSTPCI_DEVICES; $i++) { my $id = "hostpci$i"; @@ -372,7 +383,32 @@ sub print_hostpci_devices { $pciaddr = print_pcie_addr($id); } } else { - $pciaddr = print_pci_addr($id, $bridges, $arch, $machine_type); + my $pci_name = $d->{'legacy-igd'} ? 'legacy-igd' : $id; + $pciaddr = print_pci_addr($pci_name, $bridges, $arch, $machine_type); + } + + my $pcidevices = $d->{pciid}; + my $multifunction = 1 if @$pcidevices > 1; + + if ($d->{'legacy-igd'}) { + die "only one device can be assigned in legacy-igd mode\n" + if $legacy_igd; + $legacy_igd = 1; + + die "legacy IGD assignment requires VGA mode to be 'none'\n" + if !defined($conf->{'vga'}) || $conf->{'vga'} ne 'none'; + die "legacy IGD assignment requires rombar to be enabled\n" + if defined($d->{rombar}) && !$d->{rombar}; + die "legacy IGD assignment is not compatible with x-vga\n" + if $d->{'x-vga'}; + die "legacy IGD assignment is not compatible with mdev\n" + if $d->{mdev}; + die "legacy IGD assignment is not compatible with q35\n" + if $q35; + die "legacy IGD assignment is not compatible with multifunction devices\n" + if $multifunction; + die "legacy IGD assignment only works for devices on host bus 00:02.0\n" + if $pcidevices->[0]->{id} !~ m/02\.0$/; } my $xvga = ''; @@ -383,9 +419,6 @@ sub print_hostpci_devices { $gpu_passthrough = 1; } - my $pcidevices = $d->{pciid}; - my $multifunction = 1 if @$pcidevices > 1; - my $sysfspath; if ($d->{mdev} && scalar(@$pcidevices) == 1) { my $pci_id = $pcidevices->[0]->{id}; @@ -420,7 +453,7 @@ sub print_hostpci_devices { } } - return ($kvm_off, $gpu_passthrough); + return ($kvm_off, $gpu_passthrough, $legacy_igd); } 1; -- 2.39.2