This is a bug.
Test Environment:
Repro Steps:
1. Boot up guest using: -cpu Cascadelake-Server
[root@clx-2s2 yexin]# qemu-system-x86_64 -accel kvm -drive if=virtio,id=hd,file=/home/yexin/rhel7u6.qcow2,format=qcow2 -m 4096 -smp 4 -cpu Cascadelake-Server -serial stdio
char device redirected to /dev/pts/3 (label serial0)
qemu-system-x86_64: warning: host doesn't support requested feature: CPUID.07H:ECX [bit 4]
2. To check CPU ID related to features[FEAT_7_0_EDX] :CPUID_7_0_EDX_ARCH_CAPABILITIES
Expected Result: Both host and guest's CPUID.07H EDX bit 29 should be 1.
Actual Result:
Host's cpuid: 0x00000007 0x00: eax=0x00000000 ebx=0xd39ffffb ecx=0x00000818 edx=0xbc000000 (EDX bit 29=1)
Guest's cpuid : 0x00000007 0x00: eax=0x00000000 ebx=0xd19f0fb9 ecx=0x00000818 edx=0x84000000 (EDX bit 29=0)
Target Release: 19.10
This is a bug.
Test Environment:
Repro Steps:
1. Boot up guest using: -cpu Cascadelake-Server
[root@clx-2s2 yexin]# qemu-system-x86_64 -accel kvm -drive if=virtio, id=hd,file= /home/yexin/ rhel7u6. qcow2,format= qcow2 -m 4096 -smp 4 -cpu Cascadelake-Server -serial stdio
char device redirected to /dev/pts/3 (label serial0)
qemu-system-x86_64: warning: host doesn't support requested feature: CPUID.07H:ECX [bit 4]
qemu-system-x86_64: warning: host doesn't support requested feature: CPUID.07H:ECX [bit 4]
qemu-system-x86_64: warning: host doesn't support requested feature: CPUID.07H:ECX [bit 4]
qemu-system-x86_64: warning: host doesn't support requested feature: CPUID.07H:ECX [bit 4]
2. To check CPU ID related to features[ FEAT_7_ 0_EDX] :CPUID_ 7_0_EDX_ ARCH_CAPABILITI ES
Expected Result: Both host and guest's CPUID.07H EDX bit 29 should be 1.
Actual Result:
Host's cpuid: 0x00000007 0x00: eax=0x00000000 ebx=0xd39ffffb ecx=0x00000818 edx=0xbc000000 (EDX bit 29=1)
Guest's cpuid : 0x00000007 0x00: eax=0x00000000 ebx=0xd19f0fb9 ecx=0x00000818 edx=0x84000000 (EDX bit 29=0)
Target Release: 19.10