Quoting Fabian Grünbichler from the bug report: > Intel ships some CPUs where the CPU address width and the IOMMU > address width are different, which requires setting that option to > properly support huge pages and/or VFIO: > > https://bugzilla.kernel.org/show_bug.cgi?id=220057 > https://lore.kernel.org/all/20250502224035.3183451-1-alex.william...@redhat.com/t > https://lore.kernel.org/qemu-devel/20250130134346.1754143-1-...@redhat.com/
This likely also gives users a way forward with a regression reported in the community forum: https://forum.proxmox.com/threads/169586/ Signed-off-by: Fiona Ebner <f.eb...@proxmox.com> --- src/PVE/QemuServer/CPUConfig.pm | 31 +++++++++++++------ .../q35-viommu-intel-guest-phys-bits.conf | 2 ++ .../q35-viommu-intel-guest-phys-bits.conf.cmd | 25 +++++++++++++++ 3 files changed, 48 insertions(+), 10 deletions(-) create mode 100644 src/test/cfg2cmd/q35-viommu-intel-guest-phys-bits.conf create mode 100644 src/test/cfg2cmd/q35-viommu-intel-guest-phys-bits.conf.cmd diff --git a/src/PVE/QemuServer/CPUConfig.pm b/src/PVE/QemuServer/CPUConfig.pm index 1c7c12fc..786a99d8 100644 --- a/src/PVE/QemuServer/CPUConfig.pm +++ b/src/PVE/QemuServer/CPUConfig.pm @@ -223,6 +223,13 @@ my $cpu_fmt = { pattern => qr/$cpu_flag_any_re(;$cpu_flag_any_re)*/, optional => 1, }, + 'guest-phys-bits' => { + type => 'integer', + minimum => 32, # see target/i386/cpu.c in QEMU + maximum => 64, + description => "Number of physical address bits available to the guest.", + optional => 1, + }, 'phys-bits' => { type => 'string', format => 'pve-phys-bits', @@ -680,18 +687,22 @@ sub get_cpu_options { $pve_forced_flags, ); - my $phys_bits = ''; - foreach my $conf ($custom_cpu, $cpu) { - next if !defined($conf); - my $conf_val = $conf->{'phys-bits'}; - next if !$conf_val; - if ($conf_val eq 'host') { - $phys_bits = ",host-phys-bits=true"; - } else { - $phys_bits = ",phys-bits=$conf_val"; + for my $phys_bits_opt (qw(guest-phys-bits phys-bits)) { + my $phys_bits = ''; + foreach my $conf ($custom_cpu, $cpu) { + next if !defined($conf); + my $conf_val = $conf->{$phys_bits_opt}; + next if !$conf_val; + if ($conf_val eq 'host') { + die "unexpected value 'host' for guest-phys-bits" + if $phys_bits_opt eq 'guest-phys-bits'; + $phys_bits = ",host-phys-bits=true"; + } else { + $phys_bits = ",${phys_bits_opt}=${conf_val}"; + } } + $cpu_str .= $phys_bits; } - $cpu_str .= $phys_bits; return ('-cpu', $cpu_str); } diff --git a/src/test/cfg2cmd/q35-viommu-intel-guest-phys-bits.conf b/src/test/cfg2cmd/q35-viommu-intel-guest-phys-bits.conf new file mode 100644 index 00000000..7decb63e --- /dev/null +++ b/src/test/cfg2cmd/q35-viommu-intel-guest-phys-bits.conf @@ -0,0 +1,2 @@ +machine: q35,viommu=intel +cpu: host,guest-phys-bits=39 diff --git a/src/test/cfg2cmd/q35-viommu-intel-guest-phys-bits.conf.cmd b/src/test/cfg2cmd/q35-viommu-intel-guest-phys-bits.conf.cmd new file mode 100644 index 00000000..b24baeb0 --- /dev/null +++ b/src/test/cfg2cmd/q35-viommu-intel-guest-phys-bits.conf.cmd @@ -0,0 +1,25 @@ +/usr/bin/kvm \ + -id 8006 \ + -name 'vm8006,debug-threads=on' \ + -no-shutdown \ + -chardev 'socket,id=qmp,path=/var/run/qemu-server/8006.qmp,server=on,wait=off' \ + -mon 'chardev=qmp,mode=control' \ + -chardev 'socket,id=qmp-event,path=/var/run/qmeventd.sock,reconnect-ms=5000' \ + -mon 'chardev=qmp-event,mode=control' \ + -pidfile /var/run/qemu-server/8006.pid \ + -daemonize \ + -smp '1,sockets=1,cores=1,maxcpus=1' \ + -nodefaults \ + -boot 'menu=on,strict=on,reboot-timeout=1000,splash=/usr/share/qemu-server/bootsplash.jpg' \ + -vnc 'unix:/var/run/qemu-server/8006.vnc,password=on' \ + -cpu 'host,+kvm_pv_eoi,+kvm_pv_unhalt,guest-phys-bits=39' \ + -m 512 \ + -global 'ICH9-LPC.disable_s3=1' \ + -global 'ICH9-LPC.disable_s4=1' \ + -device 'intel-iommu,intremap=on,caching-mode=on' \ + -readconfig /usr/share/qemu-server/pve-q35-4.0.cfg \ + -device 'usb-tablet,id=tablet,bus=ehci.0,port=1' \ + -device 'VGA,id=vga,bus=pcie.0,addr=0x1' \ + -device 'virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3,free-page-reporting=on' \ + -iscsi 'initiator-name=iqn.1993-08.org.debian:01:aabbccddeeff' \ + -machine 'type=q35+pve0,kernel-irqchip=split' -- 2.47.2 _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
