Re: [Xen-devel] [V10 PATCH 19/23] PVH xen: vmcs related changes

[Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>]

On Tue, 20 Aug 2013 15:27:12 +0100
George Dunlap <george.dunlap@xxxxxxxxxxxxx> wrote:

> On 08/19/2013 11:21 PM, Mukesh Rathor wrote:
> > On Mon, 19 Aug 2013 17:00:53 +0100
> > George Dunlap <George.Dunlap@xxxxxxxxxxxxx> wrote:
> >
> >> On Wed, Jul 24, 2013 at 2:59 AM, Mukesh Rathor
> >> <mukesh.rathor@xxxxxxxxxx> wrote:
> >>> @@ -1294,6 +1534,9 @@ void vmx_do_resume(struct vcpu *v)
> >>>           hvm_asid_flush_vcpu(v);
> >>>       }
> >>>
> >>> +    if ( is_pvh_vcpu(v) )
> >>> +        reset_stack_and_jump(vmx_asm_do_vmentry);
> >>> +
> >>
> >> This skips the debugger stuff, but also skips hvm_do_resume().
> >> hvm_do_resume() has timer and ioreq stuff that's not needed for
> >> PVH, but it also has code to "Inject a pending hw/sw trap".  Might
> >> that code not be needed?
> >
> > We inject exceptions directly for PVH, like in vmxit_int3() if the
> > exception doesn't belong to supported debugger, we inject it into
> > the guest. PVH supports gdbsx debugger, but not the external
> > debugger which seems to set the vector to be injected (for
> > HVMOP_inject_trap).
> 
> But the HVM VMX code does exactly the same thing for int3.  When is
> this code triggered in the HVM case, and why is it not necessary for
> the PVH case?

Like implied above, for HVMOP_inject_trap which I believe is some external
debugger which sets the vector to be injected.

-M


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel