/usr/libexec/qemu-kvm \
-name 'avocado-vt-vm1'  \
-sandbox on \
-blockdev '{"node-name": "file_ovmf_code", "driver": "file", "filename": "/usr/share/OVMF/OVMF_CODE.secboot.fd", "auto-read-only": true, "discard": "unmap"}' \
-blockdev '{"node-name": "drive_ovmf_code", "driver": "raw", "read-only": true, "file": "file_ovmf_code"}' \
-blockdev '{"node-name": "file_ovmf_vars", "driver": "file", "filename": "/root/avocado/data/avocado-vt/avocado-vt-vm1_win2019-64-virtio-scsi-ovmf_qcow2_filesystem_VARS.raw", "auto-read-only": true, "discard": "unmap"}' \
-blockdev '{"node-name": "drive_ovmf_vars", "driver": "raw", "read-only": false, "file": "file_ovmf_vars"}' \
-machine q35,pflash0=drive_ovmf_code,pflash1=drive_ovmf_vars,memory-backend=mem-machine_mem \
-device '{"id": "pcie-root-port-0", "driver": "pcie-root-port", "multifunction": true, "bus": "pcie.0", "addr": "0x1", "chassis": 1}' \
-device '{"id": "pcie-pci-bridge-0", "driver": "pcie-pci-bridge", "addr": "0x0", "bus": "pcie-root-port-0"}'  \
-nodefaults \
-device '{"driver": "VGA", "bus": "pcie.0", "addr": "0x2"}' \
-m 8192 \
-object '{"size": 8589934592, "id": "mem-machine_mem", "qom-type": "memory-backend-ram"}'  \
-smp 4,maxcpus=4,cores=2,threads=1,dies=1,sockets=2  \
-cpu 'EPYC-Milan',x2apic=on,tsc-deadline=on,hypervisor=on,tsc-adjust=on,vaes=on,vpclmulqdq=on,spec-ctrl=on,stibp=on,arch-capabilities=on,ssbd=on,cmp-legacy=on,stibp-always-on=on,virt-ssbd=on,amd-psfd=on,lbrv=on,tsc-scale=on,vmcb-clean=on,pause-filter=on,pfthreshold=on,v-vmsave-vmload=on,vgif=on,no-nested-data-bp=on,lfence-always-serializing=on,null-sel-clr-base=on,rdctl-no=on,skip-l1dfl-vmentry=on,mds-no=on,pschange-mc-no=on,erms=off,pku=off,fsrm=off,hv_stimer,hv_synic,hv_vpindex,hv_relaxed,hv_spinlocks=0x1fff,hv_vapic,hv_time,hv_frequencies,hv_runtime,hv_tlbflush,hv_reenlightenment,hv_stimer_direct,hv_ipi,hv-xmm-input,hv_tlbflush_ext,kvm_pv_unhalt=on \
-device '{"id": "pcie-root-port-1", "port": 1, "driver": "pcie-root-port", "addr": "0x1.0x1", "bus": "pcie.0", "chassis": 2}' \
-device '{"driver": "qemu-xhci", "id": "usb1", "bus": "pcie-root-port-1", "addr": "0x0"}' \
-device '{"driver": "usb-tablet", "id": "usb-tablet1", "bus": "usb1.0", "port": "1"}' \
-device '{"id": "pcie-root-port-2", "port": 2, "driver": "pcie-root-port", "addr": "0x1.0x2", "bus": "pcie.0", "chassis": 3}' \
-device '{"id": "virtio_scsi_pci0", "driver": "virtio-scsi-pci", "bus": "pcie-root-port-2", "addr": "0x0"}' \
-blockdev '{"node-name": "file_image1", "driver": "file", "auto-read-only": true, "discard": "unmap", "aio": "threads", "filename": "/home/kvm_autotest_root/images/win2019-64-virtio-scsi-ovmf.qcow2", "cache": {"direct": true, "no-flush": false}}' \
-blockdev '{"node-name": "drive_image1", "driver": "qcow2", "read-only": false, "cache": {"direct": true, "no-flush": false}, "file": "file_image1"}' \
-device '{"driver": "scsi-hd", "id": "image1", "drive": "drive_image1", "write-cache": "on"}' \
-device '{"id": "pcie-root-port-3", "port": 3, "driver": "pcie-root-port", "addr": "0x1.0x3", "bus": "pcie.0", "chassis": 4}' \
-device '{"driver": "virtio-net-pci", "mac": "9a:64:3f:98:cf:a3", "id": "idv8Kcnq", "netdev": "id4f6ZjM", "bus": "pcie-root-port-3", "addr": "0x0", "mq": true, "vectors":1024, "rx_queue_size": 1024, "tx_queue_size":256}' \
-netdev  '{"id": "id4f6ZjM", "type": "tap", "vhost": true, "queues": 2 }' \
-blockdev '{"node-name": "file_cd1", "driver": "file", "auto-read-only": true, "discard": "unmap", "aio": "threads", "filename": "/home/kvm_autotest_root/iso/windows/winutils.iso", "cache": {"direct": true, "no-flush": false}}' \
-blockdev '{"node-name": "drive_cd1", "driver": "raw", "read-only": true, "cache": {"direct": true, "no-flush": false}, "file": "file_cd1"}' \
-device '{"driver": "scsi-cd", "id": "cd1", "drive": "drive_cd1", "write-cache": "on"}'  \
-vnc 0.0.0.0:11  \
-rtc base=localtime,clock=host,driftfix=slew  \
-boot menu=off,order=cdn,once=c,strict=off \
-chardev socket,id=char_vtpm_tpm0,path=/tmp/guest-swtpm.sock   \
-tpmdev emulator,chardev=char_vtpm_tpm0,id=emulator_vtpm_tpm0  \
-device tpm-crb,id=tpm-crb_vtpm_tpm0,tpmdev=emulator_vtpm_tpm0 \
-enable-kvm \
-device '{"id": "pcie_extra_root_port_0", "driver": "pcie-root-port", "multifunction": true, "bus": "pcie.0", "addr": "0x3", "chassis": 5}'

 /usr/libexec/qemu-kvm \
-name 'avocado-vt-vm1'  \
-sandbox on \
-blockdev '{"node-name": "file_ovmf_code", "driver": "file", "filename": "/usr/share/OVMF/OVMF_CODE.secboot.fd", "auto-read-only": true, "discard": "unmap"}' \
-blockdev '{"node-name": "drive_ovmf_code", "driver": "raw", "read-only": true, "file": "file_ovmf_code"}' \
-blockdev '{"node-name": "file_ovmf_vars", "driver": "file", "filename": "/root/avocado/data/avocado-vt/avocado-vt-vm1_win2019-64-virtio-scsi-ovmf_qcow2_filesystem_VARS.raw", "auto-read-only": true, "discard": "unmap"}' \
-blockdev '{"node-name": "drive_ovmf_vars", "driver": "raw", "read-only": false, "file": "file_ovmf_vars"}' \
-machine q35,pflash0=drive_ovmf_code,pflash1=drive_ovmf_vars,memory-backend=mem-machine_mem \
-device '{"id": "pcie-root-port-0", "driver": "pcie-root-port", "multifunction": true, "bus": "pcie.0", "addr": "0x1", "chassis": 1}' \
-device '{"id": "pcie-pci-bridge-0", "driver": "pcie-pci-bridge", "addr": "0x0", "bus": "pcie-root-port-0"}'  \
-nodefaults \
-device '{"driver": "VGA", "bus": "pcie.0", "addr": "0x2"}' \
-m 14336 \
-object '{"size": 15032385536, "id": "mem-machine_mem", "qom-type": "memory-backend-ram"}'  \
-smp 24,maxcpus=24,cores=12,threads=1,dies=1,sockets=2  \
-cpu 'Skylake-Server-IBRS',ss=on,vmx=on,pdcm=on,hypervisor=on,tsc-adjust=on,clflushopt=on,umip=on,pku=on,md-clear=on,stibp=on,flush-l1d=on,arch-capabilities=on,ssbd=on,xsaves=on,ibpb=on,ibrs=on,amd-stibp=on,amd-ssbd=on,rsba=on,skip-l1dfl-vmentry=on,pschange-mc-no=on,gds-no=on,vmx-ins-outs=on,vmx-true-ctls=on,vmx-store-lma=on,vmx-activity-hlt=on,vmx-activity-wait-sipi=on,vmx-vmwrite-vmexit-fields=on,vmx-apicv-xapic=on,vmx-ept=on,vmx-desc-exit=on,vmx-rdtscp-exit=on,vmx-apicv-x2apic=on,vmx-vpid=on,vmx-wbinvd-exit=on,vmx-unrestricted-guest=on,vmx-apicv-register=on,vmx-apicv-vid=on,vmx-rdrand-exit=on,vmx-invpcid-exit=on,vmx-vmfunc=on,vmx-shadow-vmcs=on,vmx-rdseed-exit=on,vmx-pml=on,vmx-xsaves=on,vmx-tsc-scaling=on,vmx-invvpid=on,vmx-invvpid-single-addr=on,vmx-invvpid-all-context=on,vmx-ept-execonly=on,vmx-page-walk-4=on,vmx-ept-2mb=on,vmx-ept-1gb=on,vmx-invept=on,vmx-eptad=on,vmx-invept-single-context=on,vmx-invept-all-context=on,vmx-intr-exit=on,vmx-nmi-exit=on,vmx-vnmi=on,vmx-preemption-timer=on,vmx-posted-intr=on,vmx-vintr-pending=on,vmx-tsc-offset=on,vmx-hlt-exit=on,vmx-invlpg-exit=on,vmx-mwait-exit=on,vmx-rdpmc-exit=on,vmx-rdtsc-exit=on,vmx-cr3-load-noexit=on,vmx-cr3-store-noexit=on,vmx-cr8-load-exit=on,vmx-cr8-store-exit=on,vmx-flexpriority=on,vmx-vnmi-pending=on,vmx-movdr-exit=on,vmx-io-exit=on,vmx-io-bitmap=on,vmx-mtf=on,vmx-msr-bitmap=on,vmx-monitor-exit=on,vmx-pause-exit=on,vmx-secondary-ctls=on,vmx-exit-nosave-debugctl=on,vmx-exit-load-perf-global-ctrl=on,vmx-exit-ack-intr=on,vmx-exit-save-pat=on,vmx-exit-load-pat=on,vmx-exit-save-efer=on,vmx-exit-load-efer=on,vmx-exit-save-preemption-timer=on,vmx-exit-clear-bndcfgs=on,vmx-entry-noload-debugctl=on,vmx-entry-ia32e-mode=on,vmx-entry-load-perf-global-ctrl=on,vmx-entry-load-pat=on,vmx-entry-load-efer=on,vmx-entry-load-bndcfgs=on,vmx-eptp-switching=on,hv_stimer,hv_synic,hv_vpindex,hv_relaxed,hv_spinlocks=0x1fff,hv_vapic,hv_time,hv_frequencies,hv_runtime,hv_tlbflush,hv_reenlightenment,hv_stimer_direct,hv_ipi,hv-xmm-input,hv_tlbflush_ext,kvm_pv_unhalt=on \
-device '{"id": "pcie-root-port-1", "port": 1, "driver": "pcie-root-port", "addr": "0x1.0x1", "bus": "pcie.0", "chassis": 2}' \
-device '{"driver": "qemu-xhci", "id": "usb1", "bus": "pcie-root-port-1", "addr": "0x0"}' \
-device '{"driver": "usb-tablet", "id": "usb-tablet1", "bus": "usb1.0", "port": "1"}' \
-device '{"id": "pcie-root-port-2", "port": 2, "driver": "pcie-root-port", "addr": "0x1.0x2", "bus": "pcie.0", "chassis": 3}' \
-device '{"id": "virtio_scsi_pci0", "driver": "virtio-scsi-pci", "bus": "pcie-root-port-2", "addr": "0x0"}' \
-blockdev '{"node-name": "file_image1", "driver": "file", "auto-read-only": true, "discard": "unmap", "aio": "threads", "filename": "/home/kvm_autotest_root/images/win2019-64-virtio-scsi-ovmf.qcow2", "cache": {"direct": true, "no-flush": false}}' \
-blockdev '{"node-name": "drive_image1", "driver": "qcow2", "read-only": false, "cache": {"direct": true, "no-flush": false}, "file": "file_image1"}' \
-device '{"driver": "scsi-hd", "id": "image1", "drive": "drive_image1", "write-cache": "on"}' \
-device '{"id": "pcie-root-port-3", "port": 3, "driver": "pcie-root-port", "addr": "0x1.0x3", "bus": "pcie.0", "chassis": 4}' \
-device '{"driver": "virtio-net-pci", "mac": "9a:ce:72:8a:fc:eb", "id": "idPdloOb", "netdev": "idt5hMbP", "bus": "pcie-root-port-3", "addr": "0x0" ,  "mq": true, "vectors":1024}' \
-netdev  '{"id": "idt5hMbP", "type": "tap", "vhost": true,  "queues": 2}' \
-blockdev '{"node-name": "file_cd1", "driver": "file", "auto-read-only": true, "discard": "unmap", "aio": "threads", "filename": "/home/kvm_autotest_root/iso/windows/winutils.iso", "cache": {"direct": true, "no-flush": false}}' \
-blockdev '{"node-name": "drive_cd1", "driver": "raw", "read-only": true, "cache": {"direct": true, "no-flush": false}, "file": "file_cd1"}' \
-device '{"driver": "scsi-cd", "id": "cd1", "drive": "drive_cd1", "write-cache": "on"}'  \
-vnc 0.0.0.0:14  \
-rtc base=localtime,clock=host,driftfix=slew  \
-boot menu=off,order=cdn,once=c,strict=off \
-chardev socket,id=char_vtpm_tpm0,path=/tmp/guest-swtpm.sock   \
-tpmdev emulator,chardev=char_vtpm_tpm0,id=emulator_vtpm_tpm0  \
-device tpm-crb,id=tpm-crb_vtpm_tpm0,tpmdev=emulator_vtpm_tpm0 \
-enable-kvm \
-device '{"id": "pcie_extra_root_port_0", "driver": "pcie-root-port", "multifunction": true, "bus": "pcie.0", "addr": "0x3", "chassis": 5}'

import asyncio
import time
import random
import os
import sys

async def handle_echo(reader, writer):
    try:
        while True:
            data = await reader.read(1024)
            if not data:
                break
            await asyncio.sleep(0.2)
    except Exception as e:
        print(f'Error in handle_echo: {str(e)}')
    finally:
        if not writer.is_closing():
                writer.close()
                await writer.wait_closed()

async def main():
    server = await asyncio.start_server(
        handle_echo, '0.0.0.0', int(sys.argv[1]))

    addr = server.sockets[0].getsockname()
    print(f'Serving on {addr}')

    async with server:
        try:
            await server.serve_forever()
        except Exception as e:
            print(f'Error in server: {e}')

asyncio.run(main())

import sys
import socket
import asyncio
import os
import psutil

def is_vms_greater_than_1G():
    pid = os.getpid()

    proc = psutil.Process(pid)

    mem_info = proc.memory_info()

    return mem_info.vms > (1024 * 1024 * 1024)

msg = b"test"

async def tcp_echo_client(id, host, port):
    loop = asyncio.get_running_loop()

    while True:
        try:
            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
            sock.connect((host, port))

            while True:
                if is_vms_greater_than_1G(): #avoid OOM
                    await asyncio.sleep(0.01)
                await loop.sock_sendall(sock, msg)    

        except Exception as e:
            print(f'Exception:{ str(e) }. Reconnecting...')
            sock.close()
            await asyncio.sleep(0.01)

async def main(n, host, port):
    tasks = [tcp_echo_client(i, host, port) for i in range(n)]
    await asyncio.gather(*tasks)

n = int(sys.argv[1]) if len(sys.argv) > 1 else 1
host = sys.argv[2] if len(sys.argv) > 2 else 'localhost'
port = int(sys.argv[3]) if len(sys.argv) > 3 else 8000

asyncio.run(main(n, host, port))