Re: [Xen-devel] [PATCH 4 of 5] evtchn delivery on HVM

[Jeremy Fitzhardinge <jeremy@xxxxxxxx>]

On 03/10/2010 07:47 AM, Stefano Stabellini wrote:
> Hi all,
> this patch sets the callback to receive evtchns from Xen, using the
> callback vector delivery mechanism.
>    
Please see my comments on Sheng's version of this patch and his updates, 
specifically regarding the xen_hvm_domain() tests in xen_evtchn_do_upcall().
Thanks,
    J

> Signed-off-by: Stefano Stabellini<stefano.stabellini@xxxxxxxxxxxxx>
> Signed-off-by: Sheng Yang<sheng@xxxxxxxxxxxxxxx>
>
> ---
>
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index 6292cc6..72e8546 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -34,8 +34,11 @@
>   #include<xen/interface/vcpu.h>
>   #include<xen/interface/memory.h>
>   #include<xen/interface/hvm/hvm_op.h>
> +#include<xen/interface/hvm/params.h>
>   #include<xen/features.h>
>   #include<xen/page.h>
> +#include<xen/hvm.h>
> +#include<xen/events.h>
>   #include<xen/hvc-console.h>
>
>   #include<asm/paravirt.h>
> @@ -1267,9 +1270,25 @@ static void __init init_pv_clocksource(void)
>         xen_register_clocksource();
>   }
>
> +static int set_callback_via(uint64_t via)
> +{
> +       struct xen_hvm_param a;
> +
> +       a.domid = DOMID_SELF;
> +       a.index = HVM_PARAM_CALLBACK_IRQ;
> +       a.value = via;
> +       return HYPERVISOR_hvm_op(HVMOP_set_param,&a);
> +}
> +
> +void do_hvm_pv_evtchn_intr(void)
> +{
> +       xen_evtchn_do_upcall(get_irq_regs());
> +}
> +
>   void __init xen_guest_init(void)
>   {
>         int r;
> +       uint64_t callback_via;
>
>         r = init_hvm_pv_info();
>         if (r<  0)
> @@ -1277,5 +1296,14 @@ void __init xen_guest_init(void)
>
>         init_shared_info();
>         init_pv_clocksource();
> +
> +       callback_via = HVM_CALLBACK_VECTOR(GENERIC_INTERRUPT_VECTOR);
> +       set_callback_via(callback_via);
> +       generic_interrupt_extension = do_hvm_pv_evtchn_intr;
> +
> +       have_vcpu_info_placement = 0;
> +       x86_init.irqs.intr_init = xen_init_IRQ;
> +       pv_time_ops = xen_time_ops;
> +       machine_ops = xen_machine_ops;
>   }
>
> diff --git a/drivers/xen/events.c b/drivers/xen/events.c
> index 2f57276..ef25a53 100644
> --- a/drivers/xen/events.c
> +++ b/drivers/xen/events.c
> @@ -621,9 +621,10 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
>         struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
>         unsigned count;
>
> -       exit_idle();
> -       irq_enter();
> -
> +       if (!xen_hvm_domain()) {
> +               exit_idle();
> +               irq_enter();
> +       }
>         do {
>                 unsigned long pending_words;
>
> @@ -659,8 +660,10 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
>         } while(count != 1);
>
>   out:
> -       irq_exit();
> -       set_irq_regs(old_regs);
> +       if (!xen_hvm_domain()) {
> +               irq_exit();
> +               set_irq_regs(old_regs);
> +       }
>
>         put_cpu();
>   }
> @@ -939,5 +942,8 @@ void __init xen_init_IRQ(void)
>         for (i = 0; i<  NR_EVENT_CHANNELS; i++)
>                 mask_evtchn(i);
>
> -       irq_ctx_init(smp_processor_id());
> +       if (xen_hvm_domain())
> +               native_init_IRQ();
> +       else
> +               irq_ctx_init(smp_processor_id());
>   }
> diff --git a/include/xen/events.h b/include/xen/events.h
> index e68d59a..b0d3b3c 100644
> --- a/include/xen/events.h
> +++ b/include/xen/events.h
> @@ -56,4 +56,6 @@ void xen_poll_irq(int irq);
>   /* Determine the IRQ which is bound to an event channel */
>   unsigned irq_from_evtchn(unsigned int evtchn);
>
> +void xen_evtchn_do_upcall(struct pt_regs *regs);
> +
>   #endif        /* _XEN_EVENTS_H */
> diff --git a/include/xen/hvm.h b/include/xen/hvm.h
> index c2a55f6..35c9c11 100644
> --- a/include/xen/hvm.h
> +++ b/include/xen/hvm.h
> @@ -3,6 +3,7 @@
>   #define XEN_HVM_H__
>
>   #include<xen/interface/hvm/params.h>
> +#include<asm/xen/hypercall.h>
>
>   static inline unsigned long hvm_get_parameter(int idx)
>   {
> @@ -20,4 +21,9 @@ static inline unsigned long hvm_get_parameter(int idx)
>          return xhv.value;
>   }
>
> +#define HVM_CALLBACK_VIA_TYPE_VECTOR 0x2
> +#define HVM_CALLBACK_VIA_TYPE_SHIFT 56
> +#define HVM_CALLBACK_VECTOR(x) (((uint64_t)HVM_CALLBACK_VIA_TYPE_VECTOR)<<\
> +                               HVM_CALLBACK_VIA_TYPE_SHIFT | (x))
> +
>   #endif /* XEN_HVM_H__ */
>
> _______________________________________________
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> http://lists.xensource.com/xen-devel
>
>    

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