Issue

Description of problem: CPU flags don't match between QEMU cmdline and Libvirt xml(dumpxml) on some AMD hosts Version-Release number of selected component (if applicable): Test Env: 5.14.0-252.el9.x86_64 qemu-kvm-7.2.0-6.el9.x86_64 libvirt-9.0.0-3.el9.x86_64 Model name: AMD EPYC 7313 16-Core Processor How reproducible: 100% Steps to Reproduce: 1. define one basic xml file cat test.xml <domain type='kvm'> <name>test</name> <memory>1</memory> <os> <type arch='x86_64' machine='q35'>hvm</type> </os> <cpu mode='host-model'/> </domain> 2. start libvirt with above xml configuration. Then check the cpu element by 'virsh dumpxml test' when it's running. <cpu mode='custom' match='exact' check='full'> <model fallback='forbid'>EPYC-Milan</model> <vendor>AMD</vendor> <feature policy='require' name='x2apic'/> <feature policy='require' name='tsc-deadline'/> <feature policy='require' name='hypervisor'/> <feature policy='require' name='tsc_adjust'/> <feature policy='require' name='vaes'/> <feature policy='require' name='vpclmulqdq'/> <feature policy='require' name='spec-ctrl'/> <feature policy='require' name='stibp'/> <feature policy='require' name='arch-capabilities'/> <feature policy='require' name='ssbd'/> <feature policy='require' name='cmp_legacy'/> <feature policy='require' name='virt-ssbd'/> <feature policy='disable' name='lbrv'/> <feature policy='disable' name='tsc-scale'/> <feature policy='disable' name='vmcb-clean'/> <feature policy='disable' name='pause-filter'/> <feature policy='disable' name='pfthreshold'/> <feature policy='disable' name='v-vmsave-vmload'/> <feature policy='disable' name='vgif'/> <feature policy='require' name='rdctl-no'/> <feature policy='require' name='skip-l1dfl-vmentry'/> <feature policy='require' name='mds-no'/> <feature policy='require' name='pschange-mc-no'/> <feature policy='disable' name='svm'/> <feature policy='require' name='topoext'/> <feature policy='disable' name='npt'/> <feature policy='disable' name='nrip-save'/> <feature policy='disable' name='svme-addr-chk'/> </cpu> 3. Check the QEMU cpu command lines with 'ps -aux | grep qemu' -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,virt-ssbd=on,lbrv=on,tsc-scale=on,vmcb-clean=on,pause-filter=on,pfthreshold=on,v-vmsave-vmload=on,vgif=on,rdctl-no=on,skip-l1dfl-vmentry=on,mds-no=on,pschange-mc-no=on Actual results: 1. we can see libvirt disables lots of features but in qemu command line, these features are still 'on'. 2. Boot a separate qemu process with above qemu command line, I can get lots of warnings. /usr/libexec/qemu-kvm -qmp unix:/tmp/mm,server=on,wait=off -M q35 -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,virt-ssbd=on,lbrv=on,tsc-scale=on,vmcb-clean=on,pause-filter=on,pfthreshold=on,v-vmsave-vmload=on,vgif=on,rdctl-no=on,skip-l1dfl-vmentry=on,mds-no=on,pschange-mc-no=on -monitor stdio QEMU 7.2.0 monitor - type 'help' for more information (qemu) qemu-kvm: warning: This feature depends on other features that were not requested: CPUID.8000000AH:EDX.lbrv [bit 1] qemu-kvm: warning: This feature depends on other features that were not requested: CPUID.8000000AH:EDX.tsc-scale [bit 4] qemu-kvm: warning: This feature depends on other features that were not requested: CPUID.8000000AH:EDX.vmcb-clean [bit 5] qemu-kvm: warning: This feature depends on other features that were not requested: CPUID.8000000AH:EDX.pause-filter [bit 10] qemu-kvm: warning: This feature depends on other features that were not requested: CPUID.8000000AH:EDX.pfthreshold [bit 12] qemu-kvm: warning: This feature depends on other features that were not requested: CPUID.8000000AH:EDX.v-vmsave-vmload [bit 15] qemu-kvm: warning: This feature depends on other features that were not requested: CPUID.8000000AH:EDX.vgif [bit 16] VNC server running on ::1:5900 3. Run `query-cpu-model-expansion` with model name `host`, these features all show 'True'. { "execute":"query-cpu-model-expansion","arguments":{"type":"full","model": {"name":"host"} }} Expected results: They should be the same Additional info: Such situation also happens on AMD Rome and AMD Geona,

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