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

[Vitaly Kuznetsov <vkuznets@redhat.com>]

"Dr. David Alan Gilbert" <dgilbert@redhat.com> writes:

> * Philippe Mathieu-Daudé (philmd@redhat.com) wrote:
>> Cc'ing David/Paolo in case they have a clue...
>> 
>> On 5/14/20 1:27 PM, Li Feng wrote:
>> > Dear all,
>> > 
>> > I have encountered a weird crash.
>> > I remember before a few days it works well and I rebase my code from upstream.
>> > 
>> > This is the command:
>> > /root/qemu-master/x86_64-softmmu/qemu-system-x86_64 -enable-kvm
>> > -device virtio-balloon -cpu host -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 unix:///tmp/a.socket,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
>> > -qmp tcp:0.0.0.0:2234,server,nowait
>> > qemu-system-x86_64: error: failed to set MSR 0x48f to 0x7fefff00036dfb
>> > qemu-system-x86_64: /root/qemu-master/target/i386/kvm.c:2695:
>> > kvm_buf_set_msrs: Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed.
>
> 48f is MSR_IA32_VMX_TRUE_EXIT_CTLS
> I've not got a note of seeing that one before.
>

If you're not intended to run nested VMs (which would make it 3-level
nesting btw) you can try:

'-cpu host,-vmx'

The strange part is that we don't seem to mangle
MSR_IA32_VMX_TRUE_EXIT_CTLS in QEMU. I bet it has something to do with
VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR in KVM.

>> > This is the commit record:
>> > *   c88f1ffc19 - (origin/master, origin/HEAD) Merge remote-tracking
>> > branch 'remotes/kevin/tags/for-upstream' into staging (3 days ago)
>> > <Peter Maydell>
>> > |\
>> > | * 47e0b38a13 - block: Drop unused .bdrv_has_zero_init_truncate (3
>> > days ago) <Eric Blake>
>> > | * dbc636e791 - vhdx: Rework truncation logic (3 days ago) <Eric Blake>
>> > | * bda4cdcbb9 - parallels: Rework truncation logic (3 days ago) <Eric Blake>
>> > | * be9c9404db - ssh: Support BDRV_REQ_ZERO_WRITE for truncate (3 days
>> > ago) <Eric Blake>
>> > | * fec00559e7 - sheepdog: Support BDRV_REQ_ZERO_WRITE for truncate (3
>> > days ago) <Eric Blake>
>> > | * 2f98910d5b - rbd: Support BDRV_REQ_ZERO_WRITE for truncate (3 days
>> > ago) <Eric Blake>
>> > 
>> > I run this qemu in a VM base on EXSi.
>> > 
>> > Does anyone have the same issue?
>
> cc'ing in Vitaly since he knows VMWare stuff.

I wish it was true :-)

>
> What's your host CPU?
>

And what's your L1 kernel?

-- 
Vitaly