[GPU] PagedAttention improvements and fixes (openvinotoolkit#29248)

### Details:
- Extended IncreasePositionIdsPrecision to support Matmul followed by
Reshape, improving accuracy for large context sizes
 - Added support for sliding window size PA parameter
- Fixed PA caching: added missing scale and fixed PA primitive
descriptor comparator

src/plugins/intel_gpu/include/intel_gpu/primitives/paged_attention.hpp

@@ -30,7 +30,18 @@ struct paged_attention : public primitive_base<paged_attention> {
     }
 
     bool operator==(const primitive& rhs) const override {
-        return compare_common_params(rhs);
+        if (!compare_common_params(rhs))
+            return false;
+
+        auto rhs_casted = downcast<const paged_attention>(rhs);
+
+        return head_size == rhs_casted.head_size &&
+               heads_num == rhs_casted.heads_num &&
+               kv_heads_num == rhs_casted.kv_heads_num &&
+               sliding_window == rhs_casted.sliding_window &&
+               has_alibi == rhs_casted.has_alibi &&
+               has_rotated_blocks == rhs_casted.has_rotated_blocks &&
+               scale_val.value_or(1.0f) == rhs_casted.scale_val.value_or(1.0f);
     }
 
     void save(BinaryOutputBuffer& ob) const override {
@@ -40,6 +51,14 @@ struct paged_attention : public primitive_base<paged_attention> {
         ob << kv_heads_num;
         ob << has_alibi;
         ob << has_rotated_blocks;
+        ob << sliding_window;
+
+        if (scale_val.has_value()) {
+            ob << true;
+            ob << scale_val.value();
+        } else {
+            ob << false;
+        }
     }
 
     void load(BinaryInputBuffer& ib) override {
@@ -49,12 +68,24 @@ struct paged_attention : public primitive_base<paged_attention> {
         ib >> kv_heads_num;
         ib >> has_alibi;
         ib >> has_rotated_blocks;
+        ib >> sliding_window;
+
+        bool has_scale;
+        ib >> has_scale;
+        if (has_scale) {
+            float scale = 1.0f;
+            ib >> scale;
+            scale_val = scale;
+        } else {
+            scale_val = std::optional<float>();
+        }
     }
 
     std::optional<float> scale_val{};
     size_t head_size = 0;
     size_t heads_num = 0;
     size_t kv_heads_num = 0;
+    size_t sliding_window = 0;
     bool has_alibi = false;
     bool has_rotated_blocks = false;
 };

src/plugins/intel_gpu/src/graph/impls/ocl/paged_attention.cpp

@@ -665,6 +665,7 @@ struct paged_attention_impl : multi_stage_primitive<paged_attention> {
         config.is_causal = true;
         config.is_paged_attention = true;
         config.paged_attention_block_size = static_cast<int64_t>(paged_attention::block_size);
+        config.paged_attention_sliding_window = desc->sliding_window;
 
         if (desc->scale_val.has_value()) {
             config.has_const_scale_val = true;

src/plugins/intel_gpu/src/kernel_selector/cl_kernels/pa_sdpa_opt.cl

@@ -197,7 +197,11 @@ KERNEL(pa_sdpa_opt)(
             qk_acc += alibi_slopes[head_num_idx] * alibi_val;
 #endif
 
+#if SLIDING_WINDOW_SIZE != 0
+            if (token_idx >= seq_len || (seq_len > SLIDING_WINDOW_SIZE && token_idx < (seq_len - SLIDING_WINDOW_SIZE)))
+#else
             if (token_idx >= seq_len)
+#endif
                 qk_acc = SOFTMAX_ACCUMULATOR_VAL_MIN;
 
             qk_max = SOFTMAX_ACCUMULATOR_MAX_FUNC(qk_max, TO_SOFTMAX_ACCUMULATOR_TYPE(qk_acc));

src/plugins/intel_gpu/src/kernel_selector/cl_kernels/sdpa_opt.cl

@@ -784,7 +784,12 @@ inline MASK_VECTOR_TYPE FUNC(load_attn_mask)(OPTIONAL_SHAPE_INFO_ARG
         }
     } else {
         for (uint i = 0; i < SUBGROUP_SIZE; i++) {
+#if defined(IS_PAGED_ATTENTION) && SLIDING_WINDOW_SIZE != 0
+            if ((source_seq_idx + i > target_seq_idx) ||
+                (target_seq_idx >= SLIDING_WINDOW_SIZE && source_seq_idx + i < target_seq_idx - SLIDING_WINDOW_SIZE))
+#else
             if (source_seq_idx + i > target_seq_idx)
+#endif
                 mask_vec[i] = NAN;
         }
     }
@@ -1167,7 +1172,11 @@ MAKE_VECTOR_TYPE(INPUT0_TYPE, TARGET_SEQ_LEN_BLOCK_SIZE) qk_acc = INPUT0_VAL_ZER
                 unroll_for (uint i = 0; i < TARGET_SEQ_LEN_BLOCK_SIZE; i++) {
 #if IS_CAUSAL
                 // casual mask: valid only if m >= n
+#if defined(IS_PAGED_ATTENTION) && SLIDING_WINDOW_SIZE != 0
+                if ((seq_len + i <= target_seq_idx + sglid) && (target_seq_idx + sglid < SLIDING_WINDOW_SIZE || seq_len + i >= target_seq_idx + sglid - SLIDING_WINDOW_SIZE)) {
+#else
                 if (seq_len + i <= target_seq_idx + sglid) {
+#endif
 #endif  // IS_CAUSAL
 #if !APPLY_SCALES_TO_QUERY
 #if HAS_SCALE_INPUT

src/plugins/intel_gpu/src/kernel_selector/kernels/sdpa/pa_sdpa_kernel_opt.cpp

@@ -206,6 +206,7 @@ JitConstants PagedAttentionSDPAKernelOpt::GetJitConstants(const pa_sdpa_params&
     jit.AddConstant(MakeJitConstant("SEQ_LEN_PARTITION_SIZE", seq_len_partition_size));
     jit.AddConstant(MakeJitConstant("PAGED_ATTENTION_BLOCK_SIZE", paged_attention_block_size));
     jit.AddConstant(MakeJitConstant("SUBGROUP_SIZE", subgroup_size));
+    jit.AddConstant(MakeJitConstant("SLIDING_WINDOW_SIZE", config.paged_attention_sliding_window));
 
     if (config.broadcast_axis != -1) {
         jit.AddConstant(MakeJitConstant("BROADCAST_GROUP_SIZE", config.group_size));

src/plugins/intel_gpu/src/kernel_selector/kernels/sdpa/sdpa_kernel_base.h

@@ -95,6 +95,7 @@ struct sdpa_configuration {
 
     // Paged Attention configuration
     bool is_paged_attention = false;
+    size_t paged_attention_sliding_window = 0;
     int64_t paged_attention_aligned_seq_len = -1;
     int64_t paged_attention_block_size = 0;
     int64_t paged_attention_max_len = 0;

src/plugins/intel_gpu/src/kernel_selector/kernels/sdpa/sdpa_kernel_opt.cpp

@@ -186,6 +186,7 @@ JitConstants SDPAKernelOpt::GetJitConstants(const sdpa_params& params, size_t ke
     jit.AddConstant(MakeJitConstant("SG_SCALE_FACTOR", get_sg_number_scale_factor(params, config.head_size, kernel_idx)));
 
     if (params.conf.is_paged_attention) {
+        jit.AddConstant(MakeJitConstant("SLIDING_WINDOW_SIZE", params.conf.paged_attention_sliding_window));
         if (params.conf.has_alibi_input) {
             jit.AddConstant(MakeJitConstant("HAS_ALIBI", 1));
         }

src/plugins/intel_gpu/src/plugin/ops/paged_attention.cpp

@@ -52,6 +52,7 @@ static void CreatePagedAttentionExtensionOp(ProgramBuilder& p, const std::shared
     prim.heads_num = heads_num;
 
     const size_t scale_idx = 9;
+    const size_t sliding_window_idx = 10;
     const size_t alibi_idx = 11;
 
     std::shared_ptr<ov::op::v0::Constant> scale_const = ov::as_type_ptr<ov::op::v0::Constant>(op->get_input_node_shared_ptr(scale_idx));
@@ -62,6 +63,12 @@ static void CreatePagedAttentionExtensionOp(ProgramBuilder& p, const std::shared
         prim.scale_val = std::optional<float>();
     }
 
+    std::shared_ptr<ov::op::v0::Constant> sliding_windows_const = ov::as_type_ptr<ov::op::v0::Constant>(op->get_input_node_shared_ptr(sliding_window_idx));
+    if (sliding_windows_const) {
+        OPENVINO_ASSERT(ov::shape_size(sliding_windows_const->get_output_shape(0)) == 1);
+        prim.sliding_window = sliding_windows_const->cast_vector<size_t>()[0];
+    }
+
     std::shared_ptr<ov::op::v0::Constant> alibi_const = ov::as_type_ptr<ov::op::v0::Constant>(op->get_input_node_shared_ptr(alibi_idx));
     OPENVINO_ASSERT(alibi_const != nullptr);
     prim.has_alibi = ov::shape_size(alibi_const->get_output_shape(0)) > 0;

src/plugins/intel_gpu/src/plugin/transformations/increase_position_ids_precision.cpp

@@ -31,7 +31,8 @@ IncreasePositionIdsPrecision::IncreasePositionIdsPrecision() {
 
     auto gemm_or_matmul = wrap_type<ov::intel_gpu::op::Gemm, ov::op::v0::MatMul>();
     auto transpose_m = wrap_type<ov::op::v1::Transpose>({gemm_or_matmul, any_input()});
-    auto concat_input = std::make_shared<Or>(OutputVector{gemm_or_matmul, transpose_m});
+    auto reshape_m = wrap_type<ov::op::v1::Reshape>({gemm_or_matmul, any_input()});
+    auto concat_input = std::make_shared<Or>(OutputVector{gemm_or_matmul, transpose_m, reshape_m});
     auto concat = wrap_type<ov::op::v0::Concat>({concat_input, concat_input});
     auto sin = wrap_type<ov::op::v0::Sin>({concat});
     auto cos = wrap_type<ov::op::v0::Cos>({concat});

src/plugins/intel_gpu/tests/unit/transformations/increase_position_ids_precision_test.cpp

@@ -176,3 +176,53 @@ TEST_F(TransformationTestsF, IncreasePositionIdsMatmulWithoutUnsqueeze) {
     }
     comparator.enable(FunctionsComparator::CmpValues::ATTRIBUTES);
 }
+
+TEST_F(TransformationTestsF, IncreasePositionIdsReshapeAfterMatmul) {
+    {
+        auto input = std::make_shared<ov::op::v0::Parameter>(ov::element::i64, ov::PartialShape{ -1, -1 });
+        auto input_convert = std::make_shared<ov::op::v0::Convert>(input, ov::element::i32);
+        auto input_unsqueeze = std::make_shared<ov::op::v0::Unsqueeze>(input_convert, std::make_shared<ov::op::v0::Constant>(ov::element::i64, ov::Shape{1}, std::vector<int64_t>{1}));
+        auto input_convert_fp = std::make_shared<ov::op::v0::Convert>(input_unsqueeze, ov::element::f16);
+        auto rotary_embd_const = std::make_shared<ov::op::v0::Constant>(ov::element::f16, ov::Shape{1, 64, 1});
+        auto reshape_dims = std::make_shared<ov::op::v0::Parameter>(ov::element::i64, ov::PartialShape{3});
+
+        auto matmul = std::make_shared<ov::op::v0::MatMul>(input_convert_fp, rotary_embd_const);
+        auto reshape = std::make_shared<ov::op::v1::Reshape>(matmul, reshape_dims, true);
+        auto concat = std::make_shared<ov::op::v0::Concat>(ov::OutputVector{reshape, reshape}, 2);
+
+        auto cos = std::make_shared<ov::op::v0::Cos>(concat);
+        auto sin = std::make_shared<ov::op::v0::Sin>(concat);
+
+        auto rope_input = std::make_shared<ov::op::v0::Parameter>(ov::element::f16, ov::PartialShape::dynamic(4));
+        auto rope = std::make_shared<ov::op::internal::RoPE>(ov::OutputVector{rope_input, cos, sin}, ov::op::internal::RoPE::Config());
+
+        model = std::make_shared<ov::Model>(ov::NodeVector{ rope }, ov::ParameterVector{ input, rope_input, reshape_dims });
+        manager.register_pass<IncreasePositionIdsPrecision>();
+    }
+    {
+        auto input = std::make_shared<ov::op::v0::Parameter>(ov::element::i64, ov::PartialShape{ -1, -1 });
+        auto input_convert = std::make_shared<ov::op::v0::Convert>(input, ov::element::i32);
+        auto input_unsqueeze = std::make_shared<ov::op::v0::Unsqueeze>(input_convert, std::make_shared<ov::op::v0::Constant>(ov::element::i64, ov::Shape{1}, std::vector<int64_t>{1}));
+        auto rotary_embd_const = std::make_shared<ov::op::v0::Constant>(ov::element::f16, ov::Shape{1, 64, 1});
+        auto reshape_dims = std::make_shared<ov::op::v0::Parameter>(ov::element::i64, ov::PartialShape{3});
+
+        auto input_convert_f32 = std::make_shared<ov::op::v0::Convert>(input_unsqueeze, ov::element::f32);
+        auto rotary_embd_const_convert_f32 = std::make_shared<ov::op::v0::Convert>(rotary_embd_const, ov::element::f32);
+
+        auto matmul = std::make_shared<ov::op::v0::MatMul>(input_convert_f32, rotary_embd_const_convert_f32);
+        auto reshape = std::make_shared<ov::op::v1::Reshape>(matmul, reshape_dims, true);
+        auto concat = std::make_shared<ov::op::v0::Concat>(ov::OutputVector{reshape, reshape}, 2);
+
+        auto cos = std::make_shared<ov::op::v0::Cos>(concat);
+        auto sin = std::make_shared<ov::op::v0::Sin>(concat);
+
+        auto cos_convert = std::make_shared<ov::op::v0::Convert>(cos, ov::element::f16);
+        auto sin_convert = std::make_shared<ov::op::v0::Convert>(sin, ov::element::f16);
+
+        auto rope_input = std::make_shared<ov::op::v0::Parameter>(ov::element::f16, ov::PartialShape::dynamic(4));
+        auto rope = std::make_shared<ov::op::internal::RoPE>(ov::OutputVector{rope_input, cos_convert, sin_convert}, ov::op::internal::RoPE::Config());
+
+        model_ref = std::make_shared<ov::Model>(ov::NodeVector{ rope }, ov::ParameterVector{ input, rope_input, reshape_dims });
+    }
+    comparator.enable(FunctionsComparator::CmpValues::ATTRIBUTES);
+}