On Tue, Sep 1, 2009 at 2:18 PM, Marcelo Tosatti<mtosatti@xxxxxxxxxx> wrote: > On Tue, Sep 01, 2009 at 02:14:17PM +0200, Mohammed Gamal wrote: >> On Tue, Sep 1, 2009 at 1:48 PM, Marcelo Tosatti<mtosatti@xxxxxxxxxx> wrote: >> > On Tue, Sep 01, 2009 at 12:48:18PM +0200, Mohammed Gamal wrote: >> >> - Change returned handle_invalid_guest_state() to return relevant exit codes >> >> - Move triggering the emulation from vmx_vcpu_run() to vmx_handle_exit() >> >> - Return to userspace instead of repeatedly trying to emulate instructions that have already failed >> >> >> >> Signed-off-by: Mohammed Gamal <m.gamal005@xxxxxxxxx> >> > >> > Mohammed, >> > >> > The handle_invalid_guest_state loop is potentially problematic. It would >> > be more appropriate to use the __vcpu_run loop. >> > >> > Can't you set vmx->emulation_required depending on the result >> > of one call to emulate_instruction and get rid of the while >> > (!guest_state_valid(vcpu)) loop? >> > >> >> Invalid state emulation is VMX-specfic, while the __vcpu_run loop is >> independent of the virtualization extension (defined in x86.c), no? >> AMD SVM can comforably run hosts in big-real mode and thus it doesn't >> have the notion of a guest going to an invalid state because of mode >> switching, so I don't think it'd be a good idea to move emulation into >> a generic layer. Please correct me if I am wrong > > Right. But all i am asking is to emulate one instruction at a > time in handle_invalid_guest_state, instead of looping until > guest_state_valid(vcpu). > > So you get rid of schedule(), the check for signal_pending, etc. But we'll still need to enter the guest when it's in a valid state, so we need to move that loop somewhere, and now that we still have a loop we'll also still need to do the pending signals and scheduling checks, no? I'd appreciate any suggestions you have to alleviate this. > > -- 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
