Description of problem:

When booting guest with 512 VCPUs on host with 448 CPUs, there are ACPI table limits warnings.

Version-Release number of selected component (if applicable):

qemu-kvm-5.2.0-5.module+el8.4.0+9775+0937c167.x86_64
kernel-4.18.0-280.el8.dt3.x86_64

How reproducible:

100%
Steps to Reproduce:
1.boot guest with 512 VCPUs on hosts only with 448 cpus:

/usr/libexec/qemu-kvm \
    -name 'avocado-vt-vm1'  \
    -sandbox on  \
    -machine q35,kernel-irqchip=split \
    -device pcie-root-port,id=pcie-root-port-0,multifunction=on,bus=pcie.0,addr=0x1,chassis=1 \
    -device pcie-pci-bridge,id=pcie-pci-bridge-0,addr=0x0,bus=pcie-root-port-0  \
    -nodefaults \
    -device VGA,bus=pcie.0,addr=0x2 \
    -m 128G  \
    -smp 512  \
    -device intel-iommu,intremap=on,eim=on \
    -cpu 'IvyBridge',+kvm_pv_unhalt \
    -chardev socket,nowait,path=/var/tmp/monitor-qmpmonitor1-20201130-083617-UdoMuUZg,server,id=qmp_id_qmpmonitor1  \
    -mon chardev=qmp_id_qmpmonitor1,mode=control \
    -chardev socket,nowait,path=/var/tmp/monitor-catch_monitor-20201130-083617-UdoMuUZg,server,id=qmp_id_catch_monitor  \
    -mon chardev=qmp_id_catch_monitor,mode=control \
    -device pvpanic,ioport=0x505,id=idUR0xIV \
    -chardev socket,nowait,path=/var/tmp/serial-serial0-20201130-083617-UdoMuUZg,server,id=chardev_serial0 \
    -device isa-serial,id=serial0,chardev=chardev_serial0  \
    -chardev socket,id=seabioslog_id_20201130-083617-UdoMuUZg,path=/var/tmp/seabios-20201130-083617-UdoMuUZg,server,nowait \
    -device isa-debugcon,chardev=seabioslog_id_20201130-083617-UdoMuUZg,iobase=0x402 \
    -device pcie-root-port,id=pcie-root-port-1,port=0x1,addr=0x1.0x1,bus=pcie.0,chassis=2 \
    -device qemu-xhci,id=usb1,bus=pcie-root-port-1,addr=0x0 \
    -device usb-tablet,id=usb-tablet1,bus=usb1.0,port=1 \
    -device pcie-root-port,id=pcie-root-port-2,port=0x2,addr=0x1.0x2,bus=pcie.0,chassis=3 \
    -object iothread,id=iothread0 \
    -device virtio-scsi-pci,id=virtio_scsi_pci0,iothread=iothread0,bus=pcie-root-port-2,addr=0x0 \
    -blockdev node-name=file_image1,driver=file,auto-read-only=on,discard=unmap,aio=threads,filename=/home/kvm_autotest_root/images/rhel840-64-virtio-scsi.qcow2,cache.direct=on,cache.no-flush=off \
    -blockdev node-name=drive_image1,driver=qcow2,read-only=off,cache.direct=on,cache.no-flush=off,file=file_image1 \
    -device scsi-hd,id=image1,drive=drive_image1,write-cache=on \
    -device pcie-root-port,id=pcie-root-port-3,port=0x3,addr=0x1.0x3,bus=pcie.0,chassis=4 \
    -device virtio-net-pci,mac=9a:1e:ad:8c:d6:8d,id=idXcapzE,netdev=idDDACLf,bus=pcie-root-port-3,addr=0x0  \
    -netdev tap,id=idDDACLf,vhost=on  \
    -vnc :0  \
    -rtc base=utc,clock=host,driftfix=slew  \
    -boot menu=off,order=cdn,once=c,strict=off \
    -enable-kvm -monitor stdio \
    -device pcie-root-port,id=pcie_extra_root_port_0,multifunction=on,bus=pcie.0,addr=0x3,chassis=5
2.
3.

Actual results:

QEMU 5.2.0 monitor - type 'help' for more information
(qemu) qemu-kvm: warning: ACPI table size 65958 exceeds 65536 bytes, migration may not work
Try removing CPUs, NUMA nodes, memory slots or PCI bridges.qemu-kvm: warning: ACPI table size 66074 exceeds 65536 bytes, migration may not work
Try removing CPUs, NUMA nodes, memory slots or PCI bridges.

Logging in guest and check cpu info:
# grep "processor" /proc/cpuinfo | wc -l
512


If I use pc-q35-rhel8.3.0, the warnings still exist.

Expected results:

No warnings
Additional info: