As I'm the addressee of the ping for some reason ... :-) the fix looks good to me but I'm not sure about all the consequences of moving kvm_put_vcpu_events() to an earlier stage. Max, Paolo, please take a look! Eiichi Tsukata <eiichi.tsukata@xxxxxxxxxxx> writes: > Ping. > >> On Nov 8, 2023, at 10:12, Eiichi Tsukata <eiichi.tsukata@xxxxxxxxxxx> wrote: >> >> Hi all, appreciate any comments or feedbacks on the patch. >> >> Thanks, >> Eiichi >> >>> On Nov 1, 2023, at 23:04, Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> wrote: >>> >>> Eiichi Tsukata <eiichi.tsukata@xxxxxxxxxxx> writes: >>> >>>> FYI: The EINVAL in vmx_set_nested_state() is caused by the following condition: >>>> * vcpu->arch.hflags == 0 >>>> * kvm_state->hdr.vmx.smm.flags == KVM_STATE_NESTED_SMM_VMXON >>> >>> This is a weird state indeed, >>> >>> 'vcpu->arch.hflags == 0' means we're not in SMM and not in guest mode >>> but kvm_state->hdr.vmx.smm.flags == KVM_STATE_NESTED_SMM_VMXON is a >>> reflection of vmx->nested.smm.vmxon (see >>> vmx_get_nested_state()). vmx->nested.smm.vmxon gets set (conditioally) >>> in vmx_enter_smm() and gets cleared in vmx_leave_smm() which means the >>> vCPU must be in SMM to have it set. >>> >>> In case the vCPU is in SMM upon migration, HF_SMM_MASK must be set from >>> kvm_vcpu_ioctl_x86_set_vcpu_events() -> kvm_smm_changed() but QEMU's >>> kvm_put_vcpu_events() calls kvm_put_nested_state() _before_ >>> kvm_put_vcpu_events(). This can explain "vcpu->arch.hflags == 0". >>> >>> Paolo, Max, any idea how this is supposed to work? >>> >>> -- >>> Vitaly >>> >> > -- Vitaly
