On 2013-12-17 14:25, Paolo Bonzini wrote: > Il 16/12/2013 10:32, Jan Kiszka ha scritto: >> As long as we do not expose all the VMX related states to user space, >> there is no way to properly reset a VCPU when VMX is enabled. Emulate >> this for now by catching host-side clearings of the feature control MSR. >> This allows to reboot a VM while it is running some hypervisor code. >> >> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> >> --- >> >> Better ideas? Or continue to leave it as it is? > > The final vmx_vcpu_reset is the only really ugly part, but it is > _really_ ugly... Can you modify QEMU to restore MSRs first, and reduce > vmx_reset_nested to just > > if (is_guest_mode(vcpu)) > nested_vmx_vmexit(vcpu); > > free_nested(vmx); > > ? Well, I could make setting of MSR_IA32_FEATURE_CONTROL to 0 an official "clear VMX" interface. Then QEMU would have to issue this MSR set request before doing any other CPU state manipulation. Is that what you have in mind? Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
