Re: [Xen-devel] [Patch v11 3/3] vt-d: fix vt-d Device-TLB flush timeout issue

["Xu, Quan" <quan.xu@xxxxxxxxx>]

On June 23, 2016 12:18 AM, Jan Beulich <JBeulich@xxxxxxxx> wrote:
> >>> On 22.06.16 at 17:54, <quan.xu@xxxxxxxxx> wrote:
> > On June 17, 2016 3:01 PM, Jan Beulich <JBeulich@xxxxxxxx> wrote:
> >> And again I don't understand: ASSERT()s are to verify assumed state.
> >> If
> > static
> >> code analysis resulted in understanding a function is unreachable
> >> when qi_ctrl->qinval_maddr is zero (because qinval ought to have got
> >> disabled if
> > any
> >> of the table setup failed), then adding ASSERT() would (a) document
> >> that and
> >> (b) allow to know quickly if something broke that assumption.
> >
> > other than enable_qinval() -- yes, I need to convert conditionals of
> > qi_ctrl->qinval_maddr into  ASSERT()s..
> > But in enable_qinval(), I am still not quite sure whether I need to
> > convert these conditionals of  qi_ctrl->qinval_maddr into ASSERT()s or
> > not.
> 
> No, I don't think you want to so there - you'd bring the system down in case
> of an actual initialization error. ASSERT()s should only be used on conditions
> controlled entirely by the hypervisor.
> 

Jan, thank you. Now I am clear.

Quan

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