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

[Amos Kong]

----- Original Message -----
> We use a 2 byte ioeventfd for virtio memory,
> add support for this.
> 
> Signed-off-by: Michael S. Tsirkin <address@hidden>

Reviewed-by: Amos Kong <address@hidden>

> ---
>  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);
>  
> -    r = kvm_set_ioeventfd_mmio_long(fd,
> section->offset_within_address_space,
> -                                    data, true);
> +    r = kvm_set_ioeventfd_mmio(fd,
> section->offset_within_address_space,
> +                               data, true, section->size);
>      if (r < 0) {
>          abort();
>      }
> @@ -758,8 +758,8 @@ static void
> kvm_mem_ioeventfd_del(MemoryRegionSection *section,
>  {
>      int r;
>  
> -    r = kvm_set_ioeventfd_mmio_long(fd,
> section->offset_within_address_space,
> -                                    data, false);
> +    r = kvm_set_ioeventfd_mmio(fd,
> section->offset_within_address_space,
> +                               data, false, section->size);
>      if (r < 0) {
>          abort();
>      }
> @@ -1639,14 +1639,15 @@ int kvm_set_signal_mask(CPUArchState *env,
> const sigset_t *sigset)
>      return r;
>  }
>  
> -int kvm_set_ioeventfd_mmio_long(int fd, uint32_t addr, uint32_t val,
> bool assign)
> +int kvm_set_ioeventfd_mmio(int fd, uint32_t addr, uint32_t val, bool
> assign,
> +                           uint32_t size)
>  {
>      int ret;
>      struct kvm_ioeventfd iofd;
>  
>      iofd.datamatch = val;
>      iofd.addr = addr;
> -    iofd.len = 4;
> +    iofd.len = size;
>      iofd.flags = KVM_IOEVENTFD_FLAG_DATAMATCH;
>      iofd.fd = fd;
>  
> diff --git a/kvm-stub.c b/kvm-stub.c
> index 69a1228..0d426db 100644
> --- a/kvm-stub.c
> +++ b/kvm-stub.c
> @@ -120,7 +120,7 @@ int kvm_set_ioeventfd_pio_word(int fd, uint16_t
> addr, uint16_t val, bool assign)
>      return -ENOSYS;
>  }
>  
> -int kvm_set_ioeventfd_mmio_long(int fd, uint32_t adr, uint32_t val,
> bool assign)
> +int kvm_set_ioeventfd_mmio(int fd, uint32_t adr, uint32_t val, bool
> assign, uint32_t len)
>  {
>      return -ENOSYS;
>  }
> diff --git a/kvm.h b/kvm.h
> index 330f17b..9bdbdb0 100644
> --- a/kvm.h
> +++ b/kvm.h
> @@ -210,7 +210,8 @@ int kvm_physical_memory_addr_from_host(KVMState
> *s, void *ram_addr,
>  #endif
>  
>  #endif
> -int kvm_set_ioeventfd_mmio_long(int fd, uint32_t adr, uint32_t val,
> bool assign);
> +int kvm_set_ioeventfd_mmio(int fd, uint32_t adr, uint32_t val, bool
> assign,
> +                           uint32_t size);
>  
>  int kvm_set_ioeventfd_pio_word(int fd, uint16_t adr, uint16_t val,
>  bool assign);
>  #endif
> --
> 1.7.9.111.gf3fb0
> 
>