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    x86/kvm/hyper-v: inject #GP only when invalid SINTx vector is unmasked · 915e6f78
    Vitaly Kuznetsov 提交于
    Hyper-V 2016 on KVM with SynIC enabled doesn't boot with the following
    trace:
    
        kvm_entry:            vcpu 0
        kvm_exit:             reason MSR_WRITE rip 0xfffff8000131c1e5 info 0 0
        kvm_hv_synic_set_msr: vcpu_id 0 msr 0x40000090 data 0x10000 host 0
        kvm_msr:              msr_write 40000090 = 0x10000 (#GP)
        kvm_inj_exception:    #GP (0x0)
    
    KVM acts according to the following statement from TLFS:
    
    "
    11.8.4 SINTx Registers
    ...
    Valid values for vector are 16-255 inclusive. Specifying an invalid
    vector number results in #GP.
    "
    
    However, I checked and genuine Hyper-V doesn't #GP when we write 0x10000
    to SINTx. I checked with Microsoft and they confirmed that if either the
    Masked bit (bit 16) or the Polling bit (bit 18) is set to 1, then they
    ignore the value of Vector. Make KVM act accordingly.
    Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
    Reviewed-by: NRoman Kagan <rkagan@virtuozzo.com>
    Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
    915e6f78
hyperv.c 37.2 KB