Re: [Qemu-devel] [PATCH] virtio dataplane: adapt dataplane for virtio Version 1

[Pierre Morel <pmorel@linux.vnet.ibm.com>]

On 08/26/2015 01:29 PM, Greg Kurz wrote:
> On Tue, 25 Aug 2015 12:33:30 +0200
> Pierre Morel <pmorel@linux.vnet.ibm.com> wrote:
>
>> Let dataplane allocate different region for the desc/avail/used
>> ring regions.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
>> ---
> Great ! It works !
>
> Since we end up with 3 blocks of code that are identical save the ring
> region name, we can simplify further with a macro. I have pasted a
> patch below. You may fold it directly into your patch if people agree,
>
> In any case, you have:
>
> Acked-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
> Tested-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
>
> Merci Pierre !
>
> --
> Greg
It saves a lot of LOCs, thanks, (and also for review and test)
I apply the patch and send a v2

Pierre

>>   hw/virtio/dataplane/vring.c         |   54 ++++++++++++++++++++++++++++------
>>   include/hw/virtio/dataplane/vring.h |    4 ++-
>>   2 files changed, 47 insertions(+), 11 deletions(-)
>>
>> diff --git a/hw/virtio/dataplane/vring.c b/hw/virtio/dataplane/vring.c
>> index 07fd69c..49d783b 100644
>> --- a/hw/virtio/dataplane/vring.c
>> +++ b/hw/virtio/dataplane/vring.c
>> @@ -67,22 +67,46 @@ static void vring_unmap(void *buffer, bool is_write)
>>   /* Map the guest's vring to host memory */
>>   bool vring_setup(Vring *vring, VirtIODevice *vdev, int n)
>>   {
>> -    hwaddr vring_addr = virtio_queue_get_ring_addr(vdev, n);
>> -    hwaddr vring_size = virtio_queue_get_ring_size(vdev, n);
>> +    hwaddr vring_addr;
>> +    hwaddr vring_size;
>>       void *vring_ptr;
>> +    struct vring *vr = &vring->vr;
>>
>>       vring->broken = false;
>> +    vr->num = virtio_queue_get_num(vdev, n);
>>
>> -    vring_ptr = vring_map(&vring->mr, vring_addr, vring_size, true);
>> +    vring_addr = virtio_queue_get_desc_addr(vdev, n);
>> +    vring_size = virtio_queue_get_desc_size(vdev, n);
>> +    vring_ptr = vring_map(&vring->mr_desc, vring_addr, vring_size, true);
>>       if (!vring_ptr) {
>> -        error_report("Failed to map vring "
>> -                     "addr %#" HWADDR_PRIx " size %" HWADDR_PRIu,
>> -                     vring_addr, vring_size);
>> -        vring->broken = true;
>> -        return false;
>> +        error_report("Failed to map vring desc "
>> +                 "addr %#" HWADDR_PRIx " size %" HWADDR_PRIu,
>> +                 vring_addr, vring_size);
>> +        goto out_err_desc;
>>       }
>> +    vr->desc = vring_ptr;
>>
>> -    vring_init(&vring->vr, virtio_queue_get_num(vdev, n), vring_ptr, 4096);
>> +    vring_addr = virtio_queue_get_avail_addr(vdev, n);
>> +    vring_size = virtio_queue_get_avail_size(vdev, n);
>> +    vring_ptr = vring_map(&vring->mr_avail, vring_addr, vring_size, true);
>> +    if (!vring_ptr) {
>> +        error_report("Failed to map vring avail "
>> +                 "addr %#" HWADDR_PRIx " size %" HWADDR_PRIu,
>> +                 vring_addr, vring_size);
>> +        goto out_err_avail;
>> +    }
>> +    vr->avail = vring_ptr;
>> +
>> +    vring_addr = virtio_queue_get_used_addr(vdev, n);
>> +    vring_size = virtio_queue_get_used_size(vdev, n);
>> +    vring_ptr = vring_map(&vring->mr_used, vring_addr, vring_size, true);
>> +    if (!vring_ptr) {
>> +        error_report("Failed to map vring used "
>> +                 "addr %#" HWADDR_PRIx " size %" HWADDR_PRIu,
>> +                 vring_addr, vring_size);
>> +        goto out_err_used;
>> +    }
>> +    vr->used = vring_ptr;
>>
>>       vring->last_avail_idx = virtio_queue_get_last_avail_idx(vdev, n);
>>       vring->last_used_idx = vring_get_used_idx(vdev, vring);
>> @@ -92,6 +116,14 @@ bool vring_setup(Vring *vring, VirtIODevice *vdev, int n)
>>       trace_vring_setup(virtio_queue_get_ring_addr(vdev, n),
>>                         vring->vr.desc, vring->vr.avail, vring->vr.used);
>>       return true;
>> +
>> +out_err_used:
>> +    memory_region_unref(vring->mr_avail);
>> +out_err_avail:
>> +    memory_region_unref(vring->mr_desc);
>> +out_err_desc:
>> +    vring->broken = true;
>> +    return false;
>>   }
>>
>>   void vring_teardown(Vring *vring, VirtIODevice *vdev, int n)
>> @@ -99,7 +131,9 @@ void vring_teardown(Vring *vring, VirtIODevice *vdev, int n)
>>       virtio_queue_set_last_avail_idx(vdev, n, vring->last_avail_idx);
>>       virtio_queue_invalidate_signalled_used(vdev, n);
>>
>> -    memory_region_unref(vring->mr);
>> +    memory_region_unref(vring->mr_desc);
>> +    memory_region_unref(vring->mr_avail);
>> +    memory_region_unref(vring->mr_used);
>>   }
>>
>>   /* Disable guest->host notifies */
>> diff --git a/include/hw/virtio/dataplane/vring.h b/include/hw/virtio/dataplane/vring.h
>> index 8d97db9..a596e4c 100644
>> --- a/include/hw/virtio/dataplane/vring.h
>> +++ b/include/hw/virtio/dataplane/vring.h
>> @@ -22,7 +22,9 @@
>>   #include "hw/virtio/virtio.h"
>>
>>   typedef struct {
>> -    MemoryRegion *mr;               /* memory region containing the vring */
>> +    MemoryRegion *mr_desc;          /* memory region for the vring desc */
>> +    MemoryRegion *mr_avail;         /* memory region for the vring avail */
>> +    MemoryRegion *mr_used;          /* memory region for the vring used */
>>       struct vring vr;                /* virtqueue vring mapped to host memory */
>>       uint16_t last_avail_idx;        /* last processed avail ring index */
>>       uint16_t last_used_idx;         /* last processed used ring index */
> --- a/hw/virtio/dataplane/vring.c
> +++ b/hw/virtio/dataplane/vring.c
> @@ -64,49 +64,34 @@ static void vring_unmap(void *buffer, bool is_write)
>       memory_region_unref(mr);
>   }
>
> +#define MAP_VRING_DESCRIPTOR(d) {                                       \
> +        hwaddr addr;                                                    \
> +        hwaddr size;                                                    \
> +        void *ptr;                                                      \
> +                                                                        \
> +        addr = virtio_queue_get_##d##_addr(vdev, n);                    \
> +        size = virtio_queue_get_##d## _size(vdev, n);                   \
> +        ptr = vring_map(&vring->mr_##d, addr, size, true);              \
> +        if (!ptr) {                                                     \
> +            error_report("Failed to map vring "#d" "                    \
> +                         "addr %#" HWADDR_PRIx " size %" HWADDR_PRIu,   \
> +                         addr, size);                                   \
> +            goto out_err_##d;                                           \
> +        }                                                               \
> +        vr->d = ptr;                                                    \
> +    }
> +
>   /* Map the guest's vring to host memory */
>   bool vring_setup(Vring *vring, VirtIODevice *vdev, int n)
>   {
> -    hwaddr vring_addr;
> -    hwaddr vring_size;
> -    void *vring_ptr;
>       struct vring *vr = &vring->vr;
>
>       vring->broken = false;
>       vr->num = virtio_queue_get_num(vdev, n);
>
> -    vring_addr = virtio_queue_get_desc_addr(vdev, n);
> -    vring_size = virtio_queue_get_desc_size(vdev, n);
> -    vring_ptr = vring_map(&vring->mr_desc, vring_addr, vring_size, true);
> -    if (!vring_ptr) {
> -        error_report("Failed to map vring desc "
> -                 "addr %#" HWADDR_PRIx " size %" HWADDR_PRIu,
> -                 vring_addr, vring_size);
> -        goto out_err_desc;
> -    }
> -    vr->desc = vring_ptr;
> -
> -    vring_addr = virtio_queue_get_avail_addr(vdev, n);
> -    vring_size = virtio_queue_get_avail_size(vdev, n);
> -    vring_ptr = vring_map(&vring->mr_avail, vring_addr, vring_size, true);
> -    if (!vring_ptr) {
> -        error_report("Failed to map vring avail "
> -                 "addr %#" HWADDR_PRIx " size %" HWADDR_PRIu,
> -                 vring_addr, vring_size);
> -        goto out_err_avail;
> -    }
> -    vr->avail = vring_ptr;
> -
> -    vring_addr = virtio_queue_get_used_addr(vdev, n);
> -    vring_size = virtio_queue_get_used_size(vdev, n);
> -    vring_ptr = vring_map(&vring->mr_used, vring_addr, vring_size, true);
> -    if (!vring_ptr) {
> -        error_report("Failed to map vring used "
> -                 "addr %#" HWADDR_PRIx " size %" HWADDR_PRIu,
> -                 vring_addr, vring_size);
> -        goto out_err_used;
> -    }
> -    vr->used = vring_ptr;
> +    MAP_VRING_DESCRIPTOR(desc);
> +    MAP_VRING_DESCRIPTOR(avail);
> +    MAP_VRING_DESCRIPTOR(used);
>
>       vring->last_avail_idx = virtio_queue_get_last_avail_idx(vdev, n);
>       vring->last_used_idx = vring_get_used_idx(vdev, vring);
>
>
>