Re: [Qemu-devel] [PATCH] kvm: allow arbitrarily sized mmio ioeventfd

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2012-03-20 13:31, Michael S. Tsirkin wrote:
> We use a 2 byte ioeventfd for virtio memory,
> add support for this.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  hw/ivshmem.c |    8 ++++----
>  kvm-all.c    |   15 ++++++++-------
>  kvm-stub.c   |    2 +-
>  kvm.h        |    3 ++-
>  4 files changed, 15 insertions(+), 13 deletions(-)
> 
> diff --git a/hw/ivshmem.c b/hw/ivshmem.c
> index 5ebf840..f02530c 100644
> --- a/hw/ivshmem.c
> +++ b/hw/ivshmem.c
> @@ -354,8 +354,8 @@ static void close_guest_eventfds(IVShmemState *s, int posn)
>      guest_curr_max = s->peers[posn].nb_eventfds;
>  
>      for (i = 0; i < guest_curr_max; i++) {
> -        kvm_set_ioeventfd_mmio_long(s->peers[posn].eventfds[i],
> -                    s->mmio_addr + DOORBELL, (posn << 16) | i, 0);
> +        kvm_set_ioeventfd_mmio(s->peers[posn].eventfds[i],
> +                    s->mmio_addr + DOORBELL, (posn << 16) | i, 0, 4);
>          close(s->peers[posn].eventfds[i]);
>      }
>  
> @@ -500,8 +500,8 @@ static void ivshmem_read(void *opaque, const uint8_t * buf, int flags)
>      }
>  
>      if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
> -        if (kvm_set_ioeventfd_mmio_long(incoming_fd, s->mmio_addr + DOORBELL,
> -                        (incoming_posn << 16) | guest_max_eventfd, 1) < 0) {
> +        if (kvm_set_ioeventfd_mmio(incoming_fd, s->mmio_addr + DOORBELL,
> +                        (incoming_posn << 16) | guest_max_eventfd, 1, 4) < 0) {
>              fprintf(stderr, "ivshmem: ioeventfd not available\n");
>          }
>      }
> diff --git a/kvm-all.c b/kvm-all.c
> index 42e5e23..bcf0dbe 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -744,10 +744,10 @@ static void kvm_mem_ioeventfd_add(MemoryRegionSection *section,
>  {
>      int r;
>  
> -    assert(match_data && section->size == 4);
> +    assert(match_data && section->size <= 8);

Probably nitpicking, but does it also work with non-power-of-two sizes?

Jan

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