Based on an analysis of the HyperV firmwares (Gen1 and Gen2) it seems like the SCONTROL is not being set to the ENABLED state as like we have thought. Also from a test done by Vitaly Kuznetsov, running a nested HyperV it was concluded that the first access to the SCONTROL MSR with a read resulted with the value of 0x1, aka HV_SYNIC_CONTROL_ENABLE. It's important to note that this diverges from the value states in the HyperV TLFS of 0. Signed-off-by: Jon Doron <arilou@xxxxxxxxx> --- arch/x86/kvm/hyperv.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index af9cdb426dd2..814d3aee5cef 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -900,6 +900,7 @@ int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages) kvm_request_apicv_update(vcpu->kvm, false, APICV_INHIBIT_REASON_HYPERV); synic->active = true; synic->dont_zero_synic_pages = dont_zero_synic_pages; + synic->control = HV_SYNIC_CONTROL_ENABLE; return 0; } -- 2.24.1
