vkr: wrap vkr_ring_layout offset+size as memory_region struct

Tracking offset+size together for each ring control variable makes extra
upcoming layout validation simpler.

Signed-off-by: Ryan Neph <ryanneph@google.com>
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>

src/venus/vkr_ring.c

@@ -68,7 +68,7 @@ vkr_ring_create(const struct vkr_ring_layout *layout,
       return NULL;
 
 #define ring_attach_shared(member)                                                       \
-   ring->shared.member = (void *)((uint8_t *)shared + layout->member##_offset)
+   ring->shared.member = (void *)((uint8_t *)shared + layout->member.offset)
    ring_attach_shared(head);
    ring_attach_shared(tail);
    ring_attach_shared(status);
@@ -76,10 +76,10 @@ vkr_ring_create(const struct vkr_ring_layout *layout,
    ring_attach_shared(extra);
 #undef ring_attach_shared
 
-   assert(layout->buffer_size && util_is_power_of_two(layout->buffer_size));
+   assert(layout->buffer.size && util_is_power_of_two(layout->buffer.size));
-   ring->buffer_size = layout->buffer_size;
+   ring->buffer_size = layout->buffer.size;
-   ring->buffer_mask = layout->buffer_size - 1;
+   ring->buffer_mask = layout->buffer.size - 1;
-   ring->extra_size = layout->extra_size;
+   ring->extra_size = layout->extra.size;
 
    /* we will manage head and status, and we expect them to be 0 initially */
    if (*ring->shared.head || *ring->shared.status) {

src/venus/vkr_ring.h

@@ -10,17 +10,18 @@
 
 struct virgl_context;
 
+struct memory_region {
+   size_t offset;
+   size_t size;
+};
+
 /* the layout of a ring in a virgl_resource */
 struct vkr_ring_layout {
-   size_t head_offset;
+   struct memory_region head;
-   size_t tail_offset;
+   struct memory_region tail;
-   size_t status_offset;
+   struct memory_region status;
-
+   struct memory_region buffer;
-   size_t buffer_offset;
+   struct memory_region extra;
-   size_t buffer_size;
-
-   size_t extra_offset;
-   size_t extra_size;
 };
 
 static_assert(ATOMIC_INT_LOCK_FREE == 2 && sizeof(atomic_uint) == 4,

src/venus/vkr_transport.c

@@ -155,19 +155,19 @@ lookup_ring(struct vkr_context *ctx, uint64_t ring_id)
 static bool
 validate_ring_layout(const struct vkr_ring_layout *layout, size_t buf_size)
 {
-   if (layout->head_offset > buf_size || layout->tail_offset > buf_size ||
+   if (layout->head.offset > buf_size || layout->tail.offset > buf_size ||
-       layout->status_offset > buf_size || layout->buffer_offset > buf_size ||
+       layout->status.offset > buf_size || layout->buffer.offset > buf_size ||
-       layout->extra_offset > buf_size)
+       layout->extra.offset > buf_size)
       return false;
 
-   if (sizeof(uint32_t) > buf_size - layout->head_offset ||
+   if (sizeof(uint32_t) > buf_size - layout->head.offset ||
-       sizeof(uint32_t) > buf_size - layout->tail_offset ||
+       sizeof(uint32_t) > buf_size - layout->tail.offset ||
-       sizeof(uint32_t) > buf_size - layout->status_offset ||
+       sizeof(uint32_t) > buf_size - layout->status.offset ||
-       layout->buffer_size > buf_size - layout->buffer_offset ||
+       layout->buffer.size > buf_size - layout->buffer.offset ||
-       layout->extra_size > buf_size - layout->extra_offset)
+       layout->extra.size > buf_size - layout->extra.offset)
       return false;
 
-   if (!layout->buffer_size || !util_is_power_of_two(layout->buffer_size))
+   if (!layout->buffer.size || !util_is_power_of_two(layout->buffer.size))
       return false;
 
    return true;
@@ -207,13 +207,11 @@ vkr_dispatch_vkCreateRingMESA(struct vn_dispatch_context *dispatch,
    size = info->size;
 
    const struct vkr_ring_layout layout = {
-      .head_offset = info->headOffset,
+      .head = {info->headOffset, sizeof(uint32_t)},
-      .tail_offset = info->tailOffset,
+      .tail = {info->tailOffset, sizeof(uint32_t)},
-      .status_offset = info->statusOffset,
+      .status = {info->statusOffset, sizeof(uint32_t)},
-      .buffer_offset = info->bufferOffset,
+      .buffer = {info->bufferOffset, info->bufferSize},
-      .buffer_size = info->bufferSize,
+      .extra = {info->extraOffset, info->extraSize},
-      .extra_offset = info->extraOffset,
-      .extra_size = info->extraSize,
    };
 
    if (!validate_ring_layout(&layout, size)) {