Re: [Xen-devel] [PATCH v4 1/6] VMX: Statically assign two PI hooks

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 21.09.16 at 04:37, <feng.wu@xxxxxxxxx> wrote:
> PI hooks: vmx_pi_switch_from() and vmx_pi_switch_to() are
> needed even when any previously assigned device is detached
> from the domain. Since 'SN' bit is also used to control the
> CPU side PI and we change the state of SN bit in these two
> functions, then evaluate this bit in vmx_deliver_posted_intr()
> when trying to deliver the interrupt in posted way via software.
> The problem is if we deassign the hooks while the vCPU is runnable
> in the runqueue with 'SN' set, all the furture notificaton event
> will be suppressed. This patch makes these two hooks statically
> assigned.

So if only SN left set is a problem, why do you need to also keep
vmx_pi_switch_from in place? It's vmx_pi_switch_to() which clears
the bit, and vmx_deliver_posted_intr() doesn't actively change it.

Jan


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