vulkan: fix coopmat2 flash attention for non-contiguous inputs (llama/11281)

Add code similar to mul_mm_cm2 to force alignment of strides, to avoid
a performance regression.

Add noncontiguous FA tests in test-backend-ops.

Fixes #11268.

ggml/src/ggml-vulkan/ggml-vulkan.cpp

@@ -386,10 +386,13 @@ struct vk_flash_attn_push_constants {
     uint32_t nev3;
     uint32_t nem1;
 
+    uint32_t nb01;
     uint32_t nb02;
     uint32_t nb03;
+    uint32_t nb11;
     uint32_t nb12;
     uint32_t nb13;
+    uint32_t nb21;
     uint32_t nb22;
     uint32_t nb23;
     uint32_t nb31;
@@ -4809,7 +4812,14 @@ static void ggml_vk_flash_attn(ggml_backend_vk_context * ctx, vk_context& subctx
     }
     assert(pipelines);
 
-    bool aligned = (KV % pipelines[1]->align) == 0;
+    const uint32_t q_stride = (uint32_t)(nbq1 / ggml_type_size(q->type));
+    const uint32_t k_stride = (uint32_t)(nbk1 / ggml_type_size(k->type));
+    const uint32_t v_stride = (uint32_t)(nbv1 / ggml_type_size(v->type));
+
+    bool aligned = (KV % pipelines[1]->align) == 0 &&
+                   // the "aligned" shader variant will forcibly align strides, for performance
+                   (q_stride & 7) == 0 && (k_stride & 7) == 0 && (v_stride & 7) == 0;
+
     vk_pipeline pipeline = pipelines[aligned];
     assert(pipeline);
 
@@ -4845,15 +4855,15 @@ static void ggml_vk_flash_attn(ggml_backend_vk_context * ctx, vk_context& subctx
 
     if (ctx->device->uma) {
         ggml_vk_host_get(ctx->device, q->data, d_Q, q_buf_offset);
-        ggml_vk_host_get(ctx->device, k->data, d_K, q_buf_offset);
-        ggml_vk_host_get(ctx->device, v->data, d_V, q_buf_offset);
-        ggml_vk_host_get(ctx->device, dst->data, d_D, q_buf_offset);
+        ggml_vk_host_get(ctx->device, k->data, d_K, k_buf_offset);
+        ggml_vk_host_get(ctx->device, v->data, d_V, v_buf_offset);
+        ggml_vk_host_get(ctx->device, dst->data, d_D, d_buf_offset);
         Q_uma = d_Q != nullptr;
         K_uma = d_K != nullptr;
         V_uma = d_V != nullptr;
         D_uma = d_D != nullptr;
         if (mask) {
-            ggml_vk_host_get(ctx->device, mask->data, d_M, q_buf_offset);
+            ggml_vk_host_get(ctx->device, mask->data, d_M, m_buf_offset);
             M_uma = d_M != nullptr;
         }
     }
@@ -4891,7 +4901,18 @@ static void ggml_vk_flash_attn(ggml_backend_vk_context * ctx, vk_context& subctx
         }
     }
 
-    const vk_flash_attn_push_constants pc = { N, KV, (uint32_t)ne1, (uint32_t)ne2, (uint32_t)ne3, (uint32_t)neq2, (uint32_t)neq3, (uint32_t)nek2, (uint32_t)nek3, (uint32_t)nev2, (uint32_t)nev3, nem1, (uint32_t)nbq2, (uint32_t)nbq3, (uint32_t)nbk2, (uint32_t)nbk3, (uint32_t)nbv2, (uint32_t)nbv3, nbm1, scale, max_bias, logit_softcap, mask != nullptr, n_head_log2, m0, m1 };
+    const vk_flash_attn_push_constants pc = { N, KV,
+                                              (uint32_t)ne1, (uint32_t)ne2, (uint32_t)ne3,
+                                              (uint32_t)neq2, (uint32_t)neq3,
+                                              (uint32_t)nek2, (uint32_t)nek3,
+                                              (uint32_t)nev2, (uint32_t)nev3,
+                                              nem1,
+                                              q_stride, (uint32_t)nbq2, (uint32_t)nbq3,
+                                              k_stride, (uint32_t)nbk2, (uint32_t)nbk3,
+                                              v_stride, (uint32_t)nbv2, (uint32_t)nbv3,
+                                              nbm1,
+                                              scale, max_bias, logit_softcap,
+                                              mask != nullptr, n_head_log2, m0, m1 };
     ggml_vk_dispatch_pipeline(ctx, subctx, pipeline,
                                 {
                                     vk_subbuffer{d_Q, q_buf_offset, VK_WHOLE_SIZE},
@@ -8668,6 +8689,7 @@ static void ggml_vk_check_results_1(ggml_tensor * tensor) {
     ggml_tensor * src0 = tensor->src[0];
     ggml_tensor * src1 = tensor->src[1];
     ggml_tensor * src2 = tensor->src[2];
+    ggml_tensor * src3 = tensor->src[3];
 
     void * tensor_data = tensor->data;
 
@@ -8730,6 +8752,9 @@ static void ggml_vk_check_results_1(ggml_tensor * tensor) {
                         if (src2 != nullptr) {
                             std::cerr << "src2=" << src2 << " src2->name=" << src2->name << " op=" << ggml_op_name(src2->op) << " type=" << ggml_type_name(src2->type) << " ne0=" << src2->ne[0] << " nb0=" << src2->nb[0] << " ne1=" << src2->ne[1] << " nb1=" << src2->nb[1] << " ne2=" << src2->ne[2] << " nb2=" << src2->nb[2] << " ne3=" << src2->ne[3] << " nb3=" << src2->nb[3] << " offset=" << src2->view_offs << std::endl;
                         }
+                        if (src3 != nullptr) {
+                            std::cerr << "src3=" << src3 << " src3->name=" << src3->name << " op=" << ggml_op_name(src3->op) << " type=" << ggml_type_name(src3->type) << " ne0=" << src3->ne[0] << " nb0=" << src3->nb[0] << " ne1=" << src3->ne[1] << " nb1=" << src3->nb[1] << " ne2=" << src3->ne[2] << " nb2=" << src3->nb[2] << " ne3=" << src3->ne[3] << " nb3=" << src3->nb[3] << " offset=" << src3->view_offs << std::endl;
+                        }
                         std::cerr << "First error: result=" << first_error_result << " correct=" << first_error_correct  << " i3=" << first_error[3] << " i2=" << first_error[2] << " i1=" << first_error[1] << " i0=" << first_error[0] << std::endl;
                         std::cerr << std::endl << "Result:" << std::endl;
                         ggml_vk_print_tensor_area(tensor, tensor_data, i0, i1, i2, i3);
@@ -8774,6 +8799,9 @@ static void ggml_vk_check_results_1(ggml_tensor * tensor) {
         if (src2 != nullptr) {
             std::cerr << "src2=" << src2 << " op=" << ggml_op_name(src2->op) << " type=" << ggml_type_name(src2->type) << " ne0=" << src2->ne[0] << " nb0=" << src2->nb[0] << " ne1=" << src2->ne[1] << " nb1=" << src2->nb[1] << " ne2=" << src2->ne[2] << " nb2=" << src2->nb[2] << " ne3=" << src2->ne[3] << " nb3=" << src2->nb[3] << " offset=" << src2->view_offs << std::endl;
         }
+        if (src3 != nullptr) {
+            std::cerr << "src3=" << src3 << " op=" << ggml_op_name(src3->op) << " type=" << ggml_type_name(src3->type) << " ne0=" << src3->ne[0] << " nb0=" << src3->nb[0] << " ne1=" << src3->ne[1] << " nb1=" << src3->nb[1] << " ne2=" << src3->ne[2] << " nb2=" << src3->nb[2] << " ne3=" << src3->ne[3] << " nb3=" << src3->nb[3] << " offset=" << src3->view_offs << std::endl;
+        }
         std::cerr << "First error: result=" << first_error_result << " correct=" << first_error_correct  << " i3=" << first_error[3] << " i2=" << first_error[2] << " i1=" << first_error[1] << " i0=" << first_error[0] << std::endl;
         std::cerr << std::endl << "Result:" << std::endl;
         ggml_vk_print_tensor_area(tensor, tensor_data, 5, 5, 0, 0);
@@ -8796,6 +8824,9 @@ static void ggml_vk_check_results_1(ggml_tensor * tensor) {
         if (src2 != nullptr) {
             std::cerr << "src2=" << src2 << " op=" << ggml_op_name(src2->op) << " type=" << ggml_type_name(src2->type) << " ne0=" << src2->ne[0] << " nb0=" << src2->nb[0] << " ne1=" << src2->ne[1] << " nb1=" << src2->nb[1] << " ne2=" << src2->ne[2] << " nb2=" << src2->nb[2] << " ne3=" << src2->ne[3] << " nb3=" << src2->nb[3] << " offset=" << src2->view_offs << std::endl;
         }
+        if (src3 != nullptr) {
+            std::cerr << "src3=" << src3 << " op=" << ggml_op_name(src3->op) << " type=" << ggml_type_name(src3->type) << " ne0=" << src3->ne[0] << " nb0=" << src3->nb[0] << " ne1=" << src3->ne[1] << " nb1=" << src3->nb[1] << " ne2=" << src3->ne[2] << " nb2=" << src3->nb[2] << " ne3=" << src3->ne[3] << " nb3=" << src3->nb[3] << " offset=" << src3->view_offs << std::endl;
+        }
         std::cerr << "First error: result=" << first_error_result << " correct=" << first_error_correct  << " i3=" << first_error[3] << " i2=" << first_error[2] << " i1=" << first_error[1] << " i0=" << first_error[0] << std::endl;
         std::cerr << std::endl << "Result:" << std::endl;
         ggml_vk_print_tensor_area(tensor, tensor_data, first_error[0], first_error[1], first_error[2], first_error[3]);

ggml/src/ggml-vulkan/vulkan-shaders/flash_attn_cm2.comp

@@ -42,10 +42,13 @@ layout (push_constant) uniform parameter {
     uint32_t nev3;
     uint32_t nem1;
 
+    uint32_t nb01;
     uint32_t nb02;
     uint32_t nb03;
+    uint32_t nb11;
     uint32_t nb12;
     uint32_t nb13;
+    uint32_t nb21;
     uint32_t nb22;
     uint32_t nb23;
     uint32_t nb31;
@@ -146,6 +149,23 @@ void main() {
     tensorLayoutK = setTensorLayoutDimensionNV(tensorLayoutK, KV, D);
     tensorLayoutV = setTensorLayoutDimensionNV(tensorLayoutV, KV, D);
 
+    // nb?1 are already divided by the type size and are in units of elements
+    uint32_t q_stride = p.nb01;
+    uint32_t k_stride = p.nb11;
+    uint32_t v_stride = p.nb21;
+    // hint to the compiler that strides are aligned for the aligned variant of the shader
+    if (Clamp != gl_CooperativeMatrixClampModeConstantNV)
+    {
+        q_stride &= ~7;
+#if !defined(BLOCK_SIZE)
+        k_stride &= ~7;
+        v_stride &= ~7;
+#endif
+    }
+    tensorLayoutQ = setTensorLayoutStrideNV(tensorLayoutQ, q_stride, 1);
+    tensorLayoutK = setTensorLayoutStrideNV(tensorLayoutK, k_stride, 1);
+    tensorLayoutV = setTensorLayoutStrideNV(tensorLayoutV, v_stride, 1);
+
     coopmat<Q_TYPE, gl_ScopeWorkgroup, Br, D, gl_MatrixUseA> Q;
     coopmat<float16_t, gl_ScopeWorkgroup, Br, D, gl_MatrixUseA> Qf16;