Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> writes: > Wanpeng Li <kernellwp@xxxxxxxxx> writes: > >> Hi Vitaly, >> 2018-05-16 23:21 GMT+08:00 Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>: >>> Changes since v3 [Radim Krcmar]: >>> - PATCH2 fixing 'HV_GENERIC_SET_SPARCE_4K' typo added. >>> - PATCH5 introducing kvm_make_vcpus_request_mask() API added. >>> - Fix undefined behavior for hv->vp_index >= 64. >>> - Merge kvm_hv_flush_tlb() and kvm_hv_flush_tlb_ex() >>> - For -ex case preload all banks with a single kvm_read_guest(). >>> >>> Description: >>> >>> This is both a new feature and a bugfix. >>> >>> Bugfix description: >>> >>> It was found that Windows 2016 guests on KVM crash when they have > 64 >>> vCPUs, non-flat topology (>1 core/thread per socket; in case it has >64 >>> sockets Windows just ignores vCPUs above 64) and Hyper-V enlightenments >> >> We try the below command line, the Windows 2016 guest successfully to >> login and there are 80 vCPUs can be observed in the guest w/o the >> patchset, why you mentioned the crash and ignore? >> >> /usr/local/bin/qemu-system-x86_64 -machine pc-i440fx-rhel7.3.0 -m >> 8192 -smp 80,sockets=2,cores=40,threads=1 -device >> ide-drive,bus=ide.0,drive=test -drive >> id=test,if=none,file=/instanceimage/359b18ab-05bb-460d-9b53-89505bca68ed/359b18ab-05bb-460d-9b53-89505bca68ed_vda_1.qcow2 >> -net nic,model=virtio -net user -monitor stdio -usb -usbdevice tablet >> --enable-kvm --cpu host -vnc 0.0.0.0:2 > > Crash happens when you manifest yourself as Hyper-V, you can do this by > adding any 'hv-*' feature (e.g. try '-cpu host,hv_vpindex'). Oh, and the 'ignore' happens when you pass more than 64 sockets (somthing like "-smp 128,sockets=128,cores=1,threads=1") -- and this happens regardless of Hyper-V enlightenments. But I guess it's just because Windows doesn't support more than 64 sockets. -- Vitaly
