[Qemu-devel] Re: [PATCH 4/6] provide in-kernel i8259 chip

[Juan Quintela <quintela@redhat.com>]

Glauber Costa <glommer@redhat.com> wrote:
> This patch provides kvm with an in-kernel i8259 chip. We are currently not enabling it.
> The code is heavily based on what's in qemu-kvm.git.
>
> Signed-off-by: Glauber Costa <glommer@redhat.com>
> ---
>  hw/i8259.c |  103 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  hw/pc.h    |    1 +
>  kvm-all.c  |   24 ++++++++++++++
>  kvm.h      |    2 +
>  4 files changed, 130 insertions(+), 0 deletions(-)
>
> diff --git a/hw/i8259.c b/hw/i8259.c
> index 3de22e3..31524f5 100644
> --- a/hw/i8259.c
> +++ b/hw/i8259.c
> @@ -26,6 +26,7 @@
>  #include "isa.h"
>  #include "monitor.h"
>  #include "qemu-timer.h"
> +#include "kvm.h"
>  
>  /* debug PIC */
>  //#define DEBUG_PIC
> @@ -446,9 +447,77 @@ static uint32_t elcr_ioport_read(void *opaque, uint32_t addr1)
>      return s->elcr;
>  }
>  
> +static int kvm_kernel_pic_load_from_user(void *opaque)
> +{
> +#if defined(TARGET_I386)
> +    PicState *s = (void *)opaque;
> +    struct kvm_irqchip chip;
> +    struct kvm_pic_state *kpic;

It miss:
   if (!kvm_enabled() && !kvm_irqchip_enabled()) {
      return 0;
   }

Or similar logic, otherwise kvm_set_irqchip() is called when kvm_irqchip
is not enabled.  Same for save_to_user.

> +    chip.chip_id = (&s->pics_state->pics[0] == s) ?
> +                   KVM_IRQCHIP_PIC_MASTER :
> +                   KVM_IRQCHIP_PIC_SLAVE;
> +    kpic = &chip.chip.pic;
> +
> +    kpic->last_irr = s->last_irr;
> +    kpic->irr = s->irr;
> +    kpic->imr = s->imr;
> +    kpic->isr = s->isr;
> +    kpic->priority_add = s->priority_add;
> +    kpic->irq_base = s->irq_base;
> +    kpic->read_reg_select = s->read_reg_select;
> +    kpic->poll = s->poll;
> +    kpic->special_mask = s->special_mask;
> +    kpic->init_state = s->init_state;
> +    kpic->auto_eoi = s->auto_eoi;
> +    kpic->rotate_on_auto_eoi = s->rotate_on_auto_eoi;
> +    kpic->special_fully_nested_mode = s->special_fully_nested_mode;
> +    kpic->init4 = s->init4;
> +    kpic->elcr = s->elcr;
> +    kpic->elcr_mask = s->elcr_mask;
> +
> +    kvm_set_irqchip(&chip);
> +#endif
> +    return 0;
> +}
....
>  static const VMStateDescription vmstate_pic = {
>      .name = "i8259",
>      .version_id = 1,
> +    .pre_save = kvm_kernel_pic_save_to_user,
> +    .post_load = kvm_kernel_pic_load_from_user,

Let the three version_id fields together, please.


> +#if defined(KVM_CAP_IRQCHIP) && defined(TARGET_I386)
> +static void kvm_i8259_set_irq(void *opaque, int irq, int level)
> +{
> +    int pic_ret;
> +    if (kvm_set_irq(irq, level, &pic_ret)) {
> +        if (pic_ret != 0)
> +            apic_set_irq_delivered();
> +        return;
> +    }
> +}
> +
> +static void kvm_pic_init1(int io_addr, PicState *s)
> +{
> +    vmstate_register(io_addr, &vmstate_pic, s);
> +    qemu_register_reset(pic_reset, s);
> +}
> +
> +qemu_irq *kvm_i8259_init(qemu_irq parent_irq)
> +{
> +    PicState2 *s;
> +
> +    s = qemu_mallocz(sizeof(PicState2));
> +
> +    kvm_pic_init1(0x20, &s->pics[0]);
> +    kvm_pic_init1(0xa0, &s->pics[1]);
> +    s->parent_irq = parent_irq;
> +    s->pics[0].pics_state = s;
> +    s->pics[1].pics_state = s;
> +    isa_pic = s;
> +    return qemu_allocate_irqs(kvm_i8259_set_irq, s, 24);
> +}
> +#endif

I think everything would be nicer if this three functions where merged
with the _non_ kvm ones with a kvm_enable() test.  They only differ in
2-3 lines.

Later, Juan.