On 20.09.2021 19:25, Andrew Cooper wrote:
> 1) vpic_ack_pending_irq() calls vlapic_accept_pic_intr() twice, once in the
> TRACE_2D() instantiation and once "for real". Make the call only once.
>
> 2) vlapic_accept_pic_intr() similarly calls __vlapic_accept_pic_intr() twice,
> although this is more complicated to disentangle.
>
> v cannot be NULL because it has already been dereferenced in the function,
> causing the ternary expression to always call __vlapic_accept_pic_intr().
> However, the return expression of the function takes care to skip the call
> if this vCPU isn't the PIC target. As __vlapic_accept_pic_intr() is far
> from trivial, make the TRACE_2D() semantics match the return semantics by
> only calling __vlapic_accept_pic_intr() when the vCPU is the PIC target.
>
> 3) hpet_set_timer() duplicates calls to hpet_tick_to_ns(). Pull the logic out
> which simplifies both the TRACE and create_periodic_time() calls.
>
> 4) lapic_rearm() makes multiple calls to vlapic_lvtt_period(). Pull it out
> into a local variable.
>
> vlapic_accept_pic_intr() is called on every VMEntry, so this is a reduction in
> VMEntry complexity across the board.
>
> Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com>
> --- a/xen/arch/x86/hvm/vpic.c
> +++ b/xen/arch/x86/hvm/vpic.c
> @@ -512,14 +512,15 @@ void vpic_irq_negative_edge(struct domain *d, int irq)
>
> int vpic_ack_pending_irq(struct vcpu *v)
> {
> - int irq;
> + int irq, accept;
Strictly speaking "accept" wants to be bool, and ...
> struct hvm_hw_vpic *vpic = &v->domain->arch.hvm.vpic[0];
>
> ASSERT(has_vpic(v->domain));
>
> - TRACE_2D(TRC_HVM_EMUL_PIC_PEND_IRQ_CALL, vlapic_accept_pic_intr(v),
> - vpic->int_output);
> - if ( !vlapic_accept_pic_intr(v) || !vpic->int_output )
> + accept = vlapic_accept_pic_intr(v);
... vlapic_accept_pic_intr() would eventually also want to be
converted to return bool.
Jan
