Re: kvm_buf_set_msrs: Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed.

[Paolo Bonzini <pbonzini@redhat.com>]

On 20/05/20 12:15, Li Feng wrote:
> /root/qemu-master/x86_64-softmmu/qemu-system-x86_64 -enable-kvm
> -device virtio-balloon -cpu
> host,-vmx-exit-nosave-debugctl,-vmx-exit-ack-intr,-vmx-exit-save-pat,-vmx-exit-load-pat,-vmx-exit-save-efer,-vmx-exit-load-efer,-vmx-exit-save-preemption-timer
> -smp 4 -m 2G -drive
> file=/root/html/fedora-10g.img,format=raw,cache=none,aio=native,if=none,id=drive-virtio-disk1
> -device virtio-blk-pci,scsi=off,drive=drive-virtio-disk1,id=virtio-disk1,bootindex=1
> -device virtio-net,netdev=nw1,mac=00:11:22:EE:EE:10 -netdev
> tap,id=nw1,script=no,downscript=no,ifname=tap0 -serial mon:stdio
> -nographic -object
> memory-backend-file,id=mem0,size=2G,mem-path=/dev/hugepages,share=on
> -numa node,memdev=mem0 -vnc 0.0.0.0:100 -machine usb=on,nvdimm -device
> usb-tablet -monitor tcp:0.0.0.0:1234,server,nowait -qmp
> tcp:0.0.0.0:2234,server,nowait -device
> virtio-serial-pci,id=virtio-serial0,max_ports=16 -chardev
> socket,id=channel1,path=/tmp/helloworld1,server,nowait -device
> virtserialport,chardev=channel1,name=com.redhat.rhevm.vdsm1,bus=virtio-serial0.0,id=port1
> 
> The CentOS version(qemu-kvm-ev-2.12.0-33.1.el7) works well on my VM.
> So I guess this is an issue in the upstream master codebase.

I don't know, it's really weird that KVM rejects bit 9.  It should be
fine as long as KVM_SET_CPUID2 is called before kvm_init_msrs (which is
true, it's some 30 lines earlier in kvm_arch_init_vcpu).

Thanks,

Paolo