Vk: expose and implement KHR_portability_subset.

doc/snippets/MagnumVk.cpp

@@ -311,6 +311,26 @@ info.setEnabledFeatures(properties.features() & // mask away unsupported ones
 /* [Device-creation-check-supported] */
 }
 
+{
+Vk::Instance instance;
+/* [Device-creation-portability-subset] */
+Vk::DeviceProperties properties = DOXYGEN_IGNORE(Vk::pickDevice(instance));
+Vk::Device device{instance, Vk::DeviceCreateInfo{properties}
+    /* enable triangle fans only if actually supported */
+    .setEnabledFeatures(properties.features() & Vk::DeviceFeature::TriangleFans)
+    DOXYGEN_IGNORE()
+};
+
+DOXYGEN_IGNORE()
+
+if(device.enabledFeatures() & Vk::DeviceFeature::TriangleFans) {
+    // draw a triangle fan mesh
+} else {
+    // indexed draw fallback
+}
+/* [Device-creation-portability-subset] */
+}
+
 {
 Vk::Instance instance;
 VkQueryPool pool{};

doc/vulkan-mapping.dox

@@ -571,6 +571,8 @@ Vulkan structure                        | Matching API
 @type_vk{PhysicalDeviceMultiviewFeatures} @m_class{m-label m-flat m-success} **KHR, 1.1** | @ref DeviceFeatures
 @type_vk{PhysicalDeviceMultiviewProperties} @m_class{m-label m-flat m-success} **KHR, 1.1** | |
 @type_vk{PhysicalDevicePointClippingProperties} @m_class{m-label m-flat m-success} **KHR, 1.1** | |
+@type_vk{PhysicalDevicePortabilitySubsetFeaturesKHR} @m_class{m-label m-flat m-warning} **KHR** | @ref DeviceFeatures
+@type_vk{PhysicalDevicePortabilitySubsetPropertiesKHR} @m_class{m-label m-flat m-warning} **KHR** | |
 @type_vk{PhysicalDeviceProperties}, \n @type_vk{PhysicalDeviceProperties2}  @m_class{m-label m-flat m-success} **KHR, 1.1** | @ref DeviceProperties
 @type_vk{PhysicalDeviceProtectedMemoryFeatures} @m_class{m-label m-flat m-success} **1.1** | @ref DeviceFeatures
 @type_vk{PhysicalDeviceProtectedMemoryProperties} @m_class{m-label m-flat m-success} **1.1** | |

doc/vulkan-support.dox

@@ -123,6 +123,7 @@ Extension                                           | Status
 @vk_extension{EXT,vertex_attribute_divisor}         | |
 @vk_extension{EXT,index_type_uint8}                 | @ref Vk::vkIndexType() only
 @vk_extension{KHR,acceleration_structure}           | |
+@vk_extension{KHR,portability_subset}               | done except properties
 @vk_extension{KHR,deferred_host_operations}         | |
 @vk_extension{KHR,pipeline_library}                 | |
 @vk_extension{KHR,ray_tracing_pipeline}             | |

src/Magnum/Vk/Device.cpp

@@ -86,6 +86,15 @@ struct DeviceCreateInfo::State {
     VkPhysicalDeviceFeatures2 features2{};
     Implementation::DeviceFeatures features{};
     DeviceFeatures enabledFeatures;
+    /* Some features are treated as implicitly enabled. Currently this includes
+       KHR_portability_subset features on devices that *don't* advertise the
+       extension, in the future it might be for example features unique to
+       Vulkan1[12]Features (which isn't present in the pNext chain), for which
+       the corresponding extension got enabled and thus implicitly enabled
+       those. For all those is common that those don't get explicitly marked as
+       enabled on device creation and are also not listed among enabled
+       features in the startup log. */
+    DeviceFeatures implicitFeatures;
     void* firstEnabledFeature{};
     /* Used for checking if the device enables extensions required by features */
     #ifndef CORRADE_NO_ASSERT
@@ -165,6 +174,22 @@ DeviceCreateInfo::DeviceCreateInfo(DeviceProperties& deviceProperties, const Ext
             if(extensionProperties->isSupported<Extensions::KHR::create_renderpass2>())
                 addEnabledExtensions<Extensions::KHR::create_renderpass2>();
         }
+
+        /* Enable the KHR_portability_subset extension, which *has to be*
+           enabled when available. Not enabling any of its features though,
+           that responsibility lies on the user. */
+        if(extensionProperties->isSupported<Extensions::KHR::portability_subset>()) {
+            addEnabledExtensions<Extensions::KHR::portability_subset>();
+
+        /* Otherwise, if KHR_portability_subset is not supported, mark its
+           features as *implicitly* supported -- those don't get explicitly
+           enabled and are also not listed in the list of enabled features in
+           the startup log */
+        /** @todo wrap this under a NoImplicitFeatures flag? it doesn't actually
+            *do* anything though */
+        } else {
+            _state->implicitFeatures = Implementation::deviceFeaturesPortabilitySubset();
+        }
     }
 
     /* Conservatively populate the device properties.
@@ -308,8 +333,14 @@ template<class T> void structureConnectIfUsed(Containers::Reference<const void*>
 
 }
 
-DeviceCreateInfo& DeviceCreateInfo::setEnabledFeatures(const DeviceFeatures& features) & {
-    /* Remember the features to pass them to Device later */
+DeviceCreateInfo& DeviceCreateInfo::setEnabledFeatures(const DeviceFeatures& features_) & {
+    /* Filter out implicit features as those are treated as being present even
+       if not explicitly enabled (such as KHR_portability_subset on devices
+       that *don't* advertise the extension */
+    const DeviceFeatures features = features_ & ~_state->implicitFeatures;
+
+    /* Remember the features to pass them to Device later. This gets combined
+       with implicitFeatures again for Device::enabledFeatures(). */
     _state->enabledFeatures = features;
 
     /* Clear any existing pointers to the feature structure chain. This needs
@@ -346,6 +377,7 @@ DeviceCreateInfo& DeviceCreateInfo::setEnabledFeatures(const DeviceFeatures& fea
             _state->features.accelerationStructure,
             _state->features.samplerYcbcrConversion,
             _state->features.descriptorIndexing,
+            _state->features.portabilitySubset,
             _state->features.shaderSubgroupExtendedTypes,
             _state->features._8BitStorage,
             _state->features.shaderAtomicInt64,
@@ -451,6 +483,8 @@ DeviceCreateInfo& DeviceCreateInfo::setEnabledFeatures(const DeviceFeatures& fea
         _state->features.samplerYcbcrConversion, VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SAMPLER_YCBCR_CONVERSION_FEATURES);
     structureConnectIfUsed(next, _state->firstEnabledFeature,
         _state->features.descriptorIndexing, VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DESCRIPTOR_INDEXING_FEATURES);
+    structureConnectIfUsed(next, _state->firstEnabledFeature,
+        _state->features.portabilitySubset, VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PORTABILITY_SUBSET_FEATURES_KHR);
     structureConnectIfUsed(next, _state->firstEnabledFeature,
         _state->features.shaderSubgroupExtendedTypes, VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_SUBGROUP_EXTENDED_TYPES_FEATURES);
     structureConnectIfUsed(next, _state->firstEnabledFeature,
@@ -652,7 +686,10 @@ Result Device::tryCreateInternal(Instance& instance, const DeviceCreateInfo& inf
     const Version version = info._state->version != Version::None ?
         info._state->version : _properties->version();
 
-    /* Print all enabled extensions if we're not told to be quiet */
+    /* Print all enabled extensions and features if we're not told to be quiet.
+       The implicit features (such as KHR_portability_subset features on
+       devices that *don't* advertise the extension) are not listed here but
+       are added to Device::enabledFeatures() below. */
     if(!info._state->quietLog) {
         Debug{} << "Device:" << _properties->name();
         Debug{} << "Device version:" << version;
@@ -678,7 +715,7 @@ Result Device::tryCreateInternal(Instance& instance, const DeviceCreateInfo& inf
     }
 
     initializeExtensions<const char*>({info->ppEnabledExtensionNames, info->enabledExtensionCount});
-    initialize(instance, version, info._state->enabledFeatures);
+    initialize(instance, version, info._state->enabledFeatures | info._state->implicitFeatures);
 
     #ifndef CORRADE_NO_ASSERT
     /* This is a dumb O(n^2) search but in an assert that's completely fine */

src/Magnum/Vk/Device.h

@@ -115,6 +115,33 @@ explicitly enabled.
 With both @ref Instance and @ref Device created, you can proceed to setting up
 a @ref CommandPool.
 
+@subsection Vk-Device-portability-subset Vulkan portability subset
+
+To simplify porting to platforms with the Portability Subset, Magnum implicitly
+enables the @vk_extension{KHR,portability_subset} extension on all devices that
+advertise it, as required by the spec, so you don't need to handle that part.
+This behavior can be disabled with
+@ref DeviceCreateInfo::Flag::NoImplicitExtensions.
+
+For portability-related @ref DeviceFeatures, on conformant Vulkan
+implementations (which don't advertise @vk_extension{KHR,portability_subset})
+these are all implicitly marked as supported in @ref DeviceProperties::features()
+and then implicitly marked as enabled in @ref Device::enabledFeatures(),
+independently of whether you enable them or not. On devices having only the
+Portability Subset, the supported features are listed in
+@ref DeviceProperties::features() but you're expected to manually enable them
+on device creation --- that part is *not done implicitly* by the engine.
+
+A workflow that supports both conformant and Portability Subset devices with a
+single code path is outlined in the following snippet --- on device creation
+you request features that you want (which is a no-op on conformant
+implementations), and at runtime you query those features in appropriate cases
+(which will be always @cpp true @ce on conformant implementations). As with
+other features, all APIs that require a particular Portability Subset feature
+are marked as such and also listed among others at @ref requires-vk-feature.
+
+@snippet MagnumVk.cpp Device-creation-portability-subset
+
 @see @ref vulkan-wrapping-optimizing-properties
 
 @section Vk-Device-command-line Command-line options

src/Magnum/Vk/DeviceCreateInfo.h

@@ -69,6 +69,12 @@ class MAGNUM_VK_EXPORT DeviceCreateInfo {
              * @vk_extension{KHR,get_memory_requirements2} to provide a broader
              * functionality. If you want to have a complete control over what
              * gets enabled, set this flag.
+             *
+             * This flag also affects enabling of
+             * @vk_extension{KHR,portability_subset},which is *required* to be
+             * enabled by the spec on any device that advertises it, and
+             * behavior of related @ref DeviceFeatures. See
+             * @ref Vk-Device-portability-subset for details.
              */
             NoImplicitExtensions = 1u << 31
         };
@@ -234,6 +240,8 @@ class MAGNUM_VK_EXPORT DeviceCreateInfo {
          *      (Vulkan 1.1, @vk_extension{KHR,sampler_ycbcr_conversion})
          * -    @type_vk_keyword{PhysicalDeviceDescriptorIndexingFeatures}
          *      (Vulkan 1.2, @vk_extension{EXT,descriptor_indexing})
+         * -    @type_vk_keyword{PhysicalDevicePortabilitySubsetFeaturesKHR}
+         *      (@vk_extension{KHR,portability_subset})
          * -    @type_vk_keyword{PhysicalDeviceShaderSubgroupExtendedTypesFeatures}
          *      (Vulkan 1.2, @vk_extension{KHR,shader_subgroup_extended_types})
          * -    @type_vk_keyword{PhysicalDevice8BitStorageFeatures} (Vulkan

src/Magnum/Vk/DeviceFeatures.h

@@ -880,6 +880,121 @@ enum class DeviceFeature: UnsignedShort {
      */
     RuntimeDescriptorArray,
 
+    /* VkPhysicalDevicePortabilitySubsetFeaturesKHR, #164 */
+
+    /**
+     * Whether constant alpha as source or destination blend color is
+     * supported.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    ConstantAlphaColorBlendFactors,
+
+    /**
+     * Whether synchronization using events is supported.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    Events,
+
+    /**
+     * Whether an @ref ImageView can be created with a format containing
+     * different number of components or a different number of bits in each
+     * component than the format of the underlying @ref Image.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    ImageViewFormatReinterpretation,
+
+    /**
+     * Whether remapping format components in an @ref ImageView is supported.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    ImageViewFormatSwizzle,
+
+    /**
+     * Whether a 2D view can be created on a 3D @ref Image can be created.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    ImageView2DOn3DImage,
+
+    /**
+     * Whether multisample 2D array @ref Image can be created.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    MultisampleArrayImage,
+
+    /**
+     * Whether descriptors with comparison samplers can be updated.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    MutableComparisonSamplers,
+
+    /**
+     * Whether rasterization using a point polygon mode is supported.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    PointPolygons,
+
+    /**
+     * Whether setting a mipmap LOD bias when creating a sampler is supported.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    SamplerMipLodBias,
+
+    /**
+     * Whether separate front and back stencil test reference values are
+     * supported.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    SeparateStencilMaskRef,
+
+    /**
+     * Whether interpolation at centroid, offset and sample is supported.
+     * Depends on @ref DeviceFeature::SampleRateShading.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    ShaderSampleRateInterpolationFunctions,
+
+    /**
+     * Whether isoline output from a tessellation shader stage is supported.
+     * Depends on @ref DeviceFeature::TessellationShader.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    TessellationIsolines,
+
+    /**
+     * Whether point output from a tessellation shader stage is supported.
+     * Depends on @ref DeviceFeature::TessellationShader.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    TessellationPointMode,
+
+    /**
+     * Whether triangle fan mesh primitives are supported.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    TriangleFans,
+
+    /**
+     * Whether accessing a vertex input attribute beyond the stride of
+     * corresponding vertex input binding is supported.
+     * @requires_vk_extension Extension @vk_extension{KHR,portability_subset},
+     *      see @ref Vk-Device-portability-subset for details.
+     */
+    VertexAttributeAccessBeyondStride,
+
     /* VkPhysicalDeviceShaderSubgroupExtendedTypesFeatures, #176 */
 
     /**

src/Magnum/Vk/DeviceProperties.cpp

@@ -309,6 +309,10 @@ const DeviceFeatures& DeviceProperties::features() {
             Implementation::structureConnect(next, features.samplerYcbcrConversion, VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SAMPLER_YCBCR_CONVERSION_FEATURES);
         if(isOrVersionSupportedInternal<Extensions::EXT::descriptor_indexing>())
             Implementation::structureConnect(next, features.descriptorIndexing, VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DESCRIPTOR_INDEXING_FEATURES);
+        /* See below as well -- the features are implicitly marked as supported
+           if the KHR_portability_subset extension is *not* present */
+        if(isOrVersionSupportedInternal<Extensions::KHR::portability_subset>())
+            Implementation::structureConnect(next, features.portabilitySubset, VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PORTABILITY_SUBSET_FEATURES_KHR);
         if(isOrVersionSupportedInternal<Extensions::KHR::shader_subgroup_extended_types>())
             Implementation::structureConnect(next, features.shaderSubgroupExtendedTypes, VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_SUBGROUP_EXTENDED_TYPES_FEATURES);
         if(isOrVersionSupportedInternal<Extensions::KHR::_8bit_storage>())
@@ -351,6 +355,11 @@ const DeviceFeatures& DeviceProperties::features() {
         #undef _c
         #undef _cver
         #undef _cext
+
+        /* If the KHR_portability_subset extension is not present, its features
+           are marked as being implicitly supported */
+        if(!isOrVersionSupportedInternal<Extensions::KHR::portability_subset>())
+            _state->features |= Implementation::deviceFeaturesPortabilitySubset();
     }
 
     return _state->features;

src/Magnum/Vk/DeviceProperties.h

@@ -451,6 +451,9 @@ class MAGNUM_VK_EXPORT DeviceProperties {
          * -    If Vulkan 1.2 or the @vk_extension{EXT,descriptor_indexing}
          *      extension is supported by the device, the `pNext` chain
          *      contains @type_vk_keyword{PhysicalDeviceDescriptorIndexingFeatures}
+         * -    If the @vk_extension{KHR,portability_subset} extension is
+         *      supported by the device, the `pNext` chain contains
+         *      @type_vk_keyword{PhysicalDevicePortabilitySubsetFeaturesKHR}
          * -    If Vulkan 1.2 or the @vk_extension{KHR,shader_subgroup_extended_types}
          *      extension is supported by the device, the `pNext` chain
          *      contains @type_vk_keyword{PhysicalDeviceShaderSubgroupExtendedTypesFeatures}
@@ -493,6 +496,11 @@ class MAGNUM_VK_EXPORT DeviceProperties {
          *      the device, the `pNext` chain contains
          *      @type_vk_keyword{PhysicalDeviceRayQueryFeaturesKHR}
          *
+         * If the @vk_extension{KHR,portability_subset} is *not* supported by
+         * the device, all features related to it are implicitly marked as
+         * supported to simplify portability-aware logic. See
+         * @ref Vk-Device-portability-subset for details.
+         *
          * @see @ref Device::enabledFeatures(),
          *      @fn_vk_keyword{GetPhysicalDeviceFeatures2},
          *      @fn_vk_keyword{GetPhysicalDeviceFeatures},

src/Magnum/Vk/Extensions.cpp

@@ -75,6 +75,7 @@ constexpr Extension DeviceExtensions[] {
     Extensions::KHR::acceleration_structure{},
     Extensions::KHR::deferred_host_operations{},
     Extensions::KHR::pipeline_library{},
+    Extensions::KHR::portability_subset{},
     Extensions::KHR::ray_query{},
     Extensions::KHR::ray_tracing_pipeline{},
 };

src/Magnum/Vk/Extensions.h

@@ -149,24 +149,25 @@ namespace EXT {
     _extension(50, KHR,acceleration_structure,              Vk11, None) // #151
     _extension(51, KHR,sampler_ycbcr_conversion,            Vk10, Vk11) // #157
     _extension(52, KHR,bind_memory2,                        Vk10, Vk11) // #158
-    _extension(53, KHR,maintenance3,                        Vk10, Vk11) // #169
-    _extension(54, KHR,draw_indirect_count,                 Vk10, Vk12) // #170
-    _extension(55, KHR,shader_subgroup_extended_types,      Vk11, Vk12) // #176
-   _extension_(56, KHR,8bit_storage,_8bit_storage,          Vk10, Vk12) // #178
-    _extension(57, KHR,shader_atomic_int64,                 Vk10, Vk12) // #181
-    _extension(58, KHR,driver_properties,                   Vk10, Vk12) // #197
-    _extension(59, KHR,shader_float_controls,               Vk10, Vk12) // #198
-    _extension(60, KHR,depth_stencil_resolve,               Vk10, Vk12) // #200
-    _extension(61, KHR,timeline_semaphore,                  Vk10, Vk12) // #208
-    _extension(62, KHR,vulkan_memory_model,                 Vk10, Vk12) // #212
-    _extension(63, KHR,spirv_1_4,                           Vk11, Vk12) // #237
-    _extension(64, KHR,separate_depth_stencil_layouts,      Vk10, Vk12) // #242
-    _extension(65, KHR,uniform_buffer_standard_layout,      Vk10, Vk12) // #254
-    _extension(66, KHR,buffer_device_address,               Vk10, Vk12) // #258
-    _extension(67, KHR,deferred_host_operations,            Vk10, None) // #259
-    _extension(68, KHR,pipeline_library,                    Vk10, None) // #291
-    _extension(69, KHR,ray_tracing_pipeline,                Vk11, None) // #348
-    _extension(70, KHR,ray_query,                           Vk11, None) // #349
+    _extension(53, KHR,portability_subset,                  Vk10, None) // #164
+    _extension(54, KHR,maintenance3,                        Vk10, Vk11) // #169
+    _extension(55, KHR,draw_indirect_count,                 Vk10, Vk12) // #170
+    _extension(56, KHR,shader_subgroup_extended_types,      Vk11, Vk12) // #176
+   _extension_(57, KHR,8bit_storage,_8bit_storage,          Vk10, Vk12) // #178
+    _extension(58, KHR,shader_atomic_int64,                 Vk10, Vk12) // #181
+    _extension(59, KHR,driver_properties,                   Vk10, Vk12) // #197
+    _extension(60, KHR,shader_float_controls,               Vk10, Vk12) // #198
+    _extension(61, KHR,depth_stencil_resolve,               Vk10, Vk12) // #200
+    _extension(62, KHR,timeline_semaphore,                  Vk10, Vk12) // #208
+    _extension(63, KHR,vulkan_memory_model,                 Vk10, Vk12) // #212
+    _extension(64, KHR,spirv_1_4,                           Vk11, Vk12) // #237
+    _extension(65, KHR,separate_depth_stencil_layouts,      Vk10, Vk12) // #242
+    _extension(66, KHR,uniform_buffer_standard_layout,      Vk10, Vk12) // #254
+    _extension(67, KHR,buffer_device_address,               Vk10, Vk12) // #258
+    _extension(68, KHR,deferred_host_operations,            Vk10, None) // #259
+    _extension(69, KHR,pipeline_library,                    Vk10, None) // #291
+    _extension(70, KHR,ray_tracing_pipeline,                Vk11, None) // #348
+    _extension(71, KHR,ray_query,                           Vk11, None) // #349
 }
 #undef _extension
 

src/Magnum/Vk/Implementation/DeviceFeatures.h

@@ -47,6 +47,7 @@ struct DeviceFeatures {
     VkPhysicalDeviceAccelerationStructureFeaturesKHR accelerationStructure;
     VkPhysicalDeviceSamplerYcbcrConversionFeatures samplerYcbcrConversion;
     VkPhysicalDeviceDescriptorIndexingFeatures descriptorIndexing;
+    VkPhysicalDevicePortabilitySubsetFeaturesKHR portabilitySubset;
     VkPhysicalDeviceShaderSubgroupExtendedTypesFeatures shaderSubgroupExtendedTypes;
     VkPhysicalDevice8BitStorageFeatures _8BitStorage;
     VkPhysicalDeviceShaderAtomicInt64Features shaderAtomicInt64;
@@ -63,6 +64,25 @@ struct DeviceFeatures {
     VkPhysicalDeviceRayQueryFeaturesKHR rayQuery;
 };
 
+constexpr Vk::DeviceFeatures deviceFeaturesPortabilitySubset() {
+    return
+        DeviceFeature::ConstantAlphaColorBlendFactors|
+        DeviceFeature::Events|
+        DeviceFeature::ImageViewFormatReinterpretation|
+        DeviceFeature::ImageViewFormatSwizzle|
+        DeviceFeature::ImageView2DOn3DImage|
+        DeviceFeature::MultisampleArrayImage|
+        DeviceFeature::MutableComparisonSamplers|
+        DeviceFeature::PointPolygons|
+        DeviceFeature::SamplerMipLodBias|
+        DeviceFeature::SeparateStencilMaskRef|
+        DeviceFeature::ShaderSampleRateInterpolationFunctions|
+        DeviceFeature::TessellationIsolines|
+        DeviceFeature::TessellationPointMode|
+        DeviceFeature::TriangleFans|
+        DeviceFeature::VertexAttributeAccessBeyondStride;
+}
+
 }}}
 
 #endif

src/Magnum/Vk/Implementation/deviceFeatureMapping.hpp

@@ -155,6 +155,24 @@ _ce(DescriptorBindingVariableDescriptorCount, descriptorBindingVariableDescripto
 _ce(RuntimeDescriptorArray, runtimeDescriptorArray)
 #undef _ce
 
+#define _ce(value, field) _cext(value, field, portabilitySubset, KHR::portability_subset)
+_ce(ConstantAlphaColorBlendFactors, constantAlphaColorBlendFactors)
+_ce(Events, events)
+_ce(ImageViewFormatReinterpretation, imageViewFormatReinterpretation)
+_ce(ImageViewFormatSwizzle, imageViewFormatSwizzle)
+_ce(ImageView2DOn3DImage, imageView2DOn3DImage)
+_ce(MultisampleArrayImage, multisampleArrayImage)
+_ce(MutableComparisonSamplers, mutableComparisonSamplers)
+_ce(PointPolygons, pointPolygons)
+_ce(SamplerMipLodBias, samplerMipLodBias)
+_ce(SeparateStencilMaskRef, separateStencilMaskRef)
+_ce(ShaderSampleRateInterpolationFunctions, shaderSampleRateInterpolationFunctions)
+_ce(TessellationIsolines, tessellationIsolines)
+_ce(TessellationPointMode, tessellationPointMode)
+_ce(TriangleFans, triangleFans)
+_ce(VertexAttributeAccessBeyondStride, vertexAttributeAccessBeyondStride)
+#undef _ce
+
 _cext(ShaderSubgroupExtendedTypes, shaderSubgroupExtendedTypes, shaderSubgroupExtendedTypes, KHR::shader_subgroup_extended_types)
 
 #define _ce(value, field) _cext(value, field, _8BitStorage, KHR::_8bit_storage)

src/Magnum/Vk/Test/DevicePropertiesVkTest.cpp

@@ -44,6 +44,9 @@
 #include "Magnum/Vk/Version.h"
 #include "Magnum/Vk/VulkanTester.h"
 
+#include "Magnum/Vk/Implementation/DeviceFeatures.h"
+    /* for deviceFeaturesPortabilitySubset() */
+
 namespace Magnum { namespace Vk { namespace Test { namespace {
 
 struct DevicePropertiesVkTest: VulkanTester {
@@ -66,6 +69,8 @@ struct DevicePropertiesVkTest: VulkanTester {
     void driverProperties();
 
     void features();
+    void featuresNoPortability();
+    void featuresPortability();
     void featureExpectedSupported();
     void featureExpectedUnsupported();
 
@@ -118,6 +123,8 @@ DevicePropertiesVkTest::DevicePropertiesVkTest(): VulkanTester{NoCreate} {
               &DevicePropertiesVkTest::driverProperties,
 
               &DevicePropertiesVkTest::features,
+              &DevicePropertiesVkTest::featuresNoPortability,
+              &DevicePropertiesVkTest::featuresPortability,
               &DevicePropertiesVkTest::featureExpectedSupported,
               &DevicePropertiesVkTest::featureExpectedUnsupported,
 
@@ -254,6 +261,34 @@ void DevicePropertiesVkTest::features() {
     }
 }
 
+void DevicePropertiesVkTest::featuresNoPortability() {
+    Containers::Optional<DeviceProperties> device = tryPickDevice(instance());
+    CORRADE_VERIFY(device);
+
+    if(device->enumerateExtensionProperties().isSupported<Extensions::KHR::portability_subset>())
+        CORRADE_SKIP("KHR_portability_subset supported, can't test");
+
+    /* All features should be marked as supported */
+    CORRADE_COMPARE_AS(device->features(), Implementation::deviceFeaturesPortabilitySubset(),
+        TestSuite::Compare::GreaterOrEqual);
+}
+
+void DevicePropertiesVkTest::featuresPortability() {
+    Containers::Optional<DeviceProperties> device = tryPickDevice(instance());
+    CORRADE_VERIFY(device);
+
+    if(!device->enumerateExtensionProperties().isSupported<Extensions::KHR::portability_subset>())
+        CORRADE_SKIP("KHR_portability_subset not supported, can't test");
+
+    Debug{} << "Supported portability subset:" << (device->features() & Implementation::deviceFeaturesPortabilitySubset());
+
+    /* Not all features should be marked as supported */
+    CORRADE_VERIFY((device->features() & Implementation::deviceFeaturesPortabilitySubset()) != Implementation::deviceFeaturesPortabilitySubset());
+
+    /* But there should be at least one */
+    CORRADE_VERIFY(device->features() & Implementation::deviceFeaturesPortabilitySubset());
+}
+
 void DevicePropertiesVkTest::featureExpectedSupported() {
     Containers::Optional<DeviceProperties> device = tryPickDevice(instance());
     CORRADE_VERIFY(device);

src/Magnum/Vk/Test/DeviceVkTest.cpp

@@ -43,6 +43,9 @@
 #include "Magnum/Vk/Version.h"
 #include "Magnum/Vk/VulkanTester.h"
 
+#include "Magnum/Vk/Implementation/DeviceFeatures.h"
+    /* for deviceFeaturesPortabilitySubset() */
+
 #include "MagnumExternal/Vulkan/flextVkGlobal.h"
 
 namespace Magnum { namespace Vk { namespace Test { namespace {
@@ -80,6 +83,10 @@ struct DeviceVkTest: VulkanTester {
     void constructFeatureWithoutExtension();
     void constructNoQueue();
 
+    void constructNoPortability();
+    void constructNoPortabilityEnablePortabilityFeatures();
+    void constructPortability();
+
     void tryCreateAlreadyCreated();
     void tryCreateUnknownExtension();
 
@@ -178,6 +185,10 @@ DeviceVkTest::DeviceVkTest(): VulkanTester{NoCreate} {
               &DeviceVkTest::constructFeatureWithoutExtension,
               &DeviceVkTest::constructNoQueue,
 
+              &DeviceVkTest::constructNoPortability,
+              &DeviceVkTest::constructNoPortabilityEnablePortabilityFeatures,
+              &DeviceVkTest::constructPortability,
+
               &DeviceVkTest::tryCreateAlreadyCreated,
               &DeviceVkTest::tryCreateUnknownExtension,
 
@@ -631,8 +642,10 @@ void DeviceVkTest::constructFeatures() {
         .setEnabledFeatures(DeviceFeature::RobustBufferAccess)};
     CORRADE_VERIFY(device.handle());
 
-    /* Features should be reported as enabled */
-    CORRADE_COMPARE(device.enabledFeatures(), DeviceFeature::RobustBufferAccess);
+    /* Features should be reported as enabled. Exclude portability subset
+       features that get implicitly marked as enabled on devices w/o
+       KHR_portability_subset. */
+    CORRADE_COMPARE(device.enabledFeatures() & ~Implementation::deviceFeaturesPortabilitySubset(), DeviceFeature::RobustBufferAccess);
 }
 
 void DeviceVkTest::constructFeaturesFromExtensions() {
@@ -652,8 +665,10 @@ void DeviceVkTest::constructFeaturesFromExtensions() {
         .setEnabledFeatures(DeviceFeature::RobustBufferAccess|DeviceFeature::SamplerYcbcrConversion)};
     CORRADE_VERIFY(device.handle());
 
-    /* Features should be reported as enabled */
-    CORRADE_COMPARE(device.enabledFeatures(), DeviceFeature::RobustBufferAccess|DeviceFeature::SamplerYcbcrConversion);
+    /* Features should be reported as enabled. Exclude portability subset
+       features that get implicitly marked as enabled on devices w/o
+       KHR_portability_subset. */
+    CORRADE_COMPARE(device.enabledFeatures() & ~Implementation::deviceFeaturesPortabilitySubset(), DeviceFeature::RobustBufferAccess|DeviceFeature::SamplerYcbcrConversion);
 }
 
 void DeviceVkTest::constructDeviceCreateInfoConstReference() {
@@ -923,6 +938,73 @@ void DeviceVkTest::constructNoQueue() {
     CORRADE_COMPARE(out.str(), "Vk::Device::tryCreate(): needs at least one queue\n");
 }
 
+void DeviceVkTest::constructNoPortability() {
+    DeviceProperties properties = pickDevice(instance());
+
+    if(properties.enumerateExtensionProperties().isSupported<Extensions::KHR::portability_subset>())
+        CORRADE_SKIP("KHR_portability_subset supported, can't test");
+
+    Queue queue{NoCreate};
+    Device device{instance(), DeviceCreateInfo{properties}
+        .addQueues(0, {0.0f}, {queue})
+    };
+
+    /* The extension shouldn't be registered as enabled */
+    CORRADE_VERIFY(!device.isExtensionEnabled<Extensions::KHR::portability_subset>());
+
+    /* All features should be marked as enabled */
+    CORRADE_COMPARE_AS(device.enabledFeatures(), Implementation::deviceFeaturesPortabilitySubset(),
+        TestSuite::Compare::GreaterOrEqual);
+}
+
+void DeviceVkTest::constructNoPortabilityEnablePortabilityFeatures() {
+    DeviceProperties properties = pickDevice(instance());
+
+    if(properties.enumerateExtensionProperties().isSupported<Extensions::KHR::portability_subset>())
+        CORRADE_SKIP("KHR_portability_subset supported, can't test");
+
+    Device device{NoCreate};
+
+    /* Explicitly enabling portability subset features shouldn't do anything
+       when the portability extension isn't present */
+    Queue queue{NoCreate};
+    CORRADE_COMPARE(device.tryCreate(instance(), DeviceCreateInfo{properties}
+        .addQueues(0, {0.0f}, {queue})
+        .setEnabledFeatures(Implementation::deviceFeaturesPortabilitySubset())
+    ), Result::Success);
+
+    /* All features should be marked as enabled */
+    CORRADE_COMPARE_AS(device.enabledFeatures(), Implementation::deviceFeaturesPortabilitySubset(),
+        TestSuite::Compare::GreaterOrEqual);
+}
+
+void DeviceVkTest::constructPortability() {
+    DeviceProperties properties = pickDevice(instance());
+
+    if(!properties.enumerateExtensionProperties().isSupported<Extensions::KHR::portability_subset>())
+        CORRADE_SKIP("KHR_portability_subset not supported, can't test");
+
+    /* (Same as in DevicePropertiesVkTest.) Not all features should be marked
+       as supported... */
+    CORRADE_VERIFY((properties.features() & Implementation::deviceFeaturesPortabilitySubset()) != Implementation::deviceFeaturesPortabilitySubset());
+
+    /* ... but there should be at least one feature */
+    CORRADE_VERIFY(properties.features() &
+Implementation::deviceFeaturesPortabilitySubset());
+
+    Queue queue{NoCreate};
+    Device device{instance(), DeviceCreateInfo{properties}
+        .addQueues(0, {0.0f}, {queue})
+        .setEnabledFeatures(properties.features() &
+Implementation::deviceFeaturesPortabilitySubset())
+    };
+
+    /* All requested features should be marked as enabled */
+    CORRADE_COMPARE_AS(device.enabledFeatures(), properties.features() &
+Implementation::deviceFeaturesPortabilitySubset(),
+        TestSuite::Compare::GreaterOrEqual);
+}
+
 void DeviceVkTest::tryCreateAlreadyCreated() {
     #ifdef CORRADE_NO_ASSERT
     CORRADE_SKIP("CORRADE_NO_ASSERT defined, can't test assertions");

src/MagnumExternal/Vulkan/extensions.txt

@@ -65,6 +65,7 @@ extension EXT_vertex_attribute_divisor          optional
 extension EXT_index_type_uint8                  optional
 extension IMG_format_pvrtc                      optional
 extension KHR_acceleration_structure            optional
+extension KHR_portability_subset                optional
 extension KHR_deferred_host_operations          optional
 extension KHR_pipeline_library                  optional
 extension KHR_ray_tracing_pipeline              optional

src/MagnumExternal/Vulkan/flextVk.h

@@ -274,6 +274,11 @@ extern "C" {
 #define VK_KHR_ACCELERATION_STRUCTURE_SPEC_VERSION 11
 #define VK_KHR_ACCELERATION_STRUCTURE_EXTENSION_NAME "VK_KHR_acceleration_structure"
 
+/* VK_KHR_portability_subset */
+
+#define VK_KHR_PORTABILITY_SUBSET_SPEC_VERSION 1
+#define VK_KHR_PORTABILITY_SUBSET_EXTENSION_NAME "VK_KHR_portability_subset"
+
 /* VK_KHR_pipeline_library */
 
 #define VK_KHR_PIPELINE_LIBRARY_SPEC_VERSION 1
@@ -1555,6 +1560,8 @@ typedef enum {
     VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_ACCELERATION_STRUCTURE_PROPERTIES_KHR = 1000150014,
     VK_STRUCTURE_TYPE_ACCELERATION_STRUCTURE_CREATE_INFO_KHR = 1000150017,
     VK_STRUCTURE_TYPE_ACCELERATION_STRUCTURE_BUILD_SIZES_INFO_KHR = 1000150020,
+    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PORTABILITY_SUBSET_FEATURES_KHR = 1000163000,
+    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PORTABILITY_SUBSET_PROPERTIES_KHR = 1000163001,
     VK_STRUCTURE_TYPE_PIPELINE_LIBRARY_CREATE_INFO_KHR = 1000290000,
     VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FLOAT_CONTROLS_PROPERTIES_KHR = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FLOAT_CONTROLS_PROPERTIES,
     VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_RAY_TRACING_PIPELINE_FEATURES_KHR = 1000347000,
@@ -4721,6 +4728,32 @@ typedef struct VkCopyMemoryToAccelerationStructureInfoKHR {
     VkCopyAccelerationStructureModeKHR                     mode;
 } VkCopyMemoryToAccelerationStructureInfoKHR;
 
+typedef struct VkPhysicalDevicePortabilitySubsetFeaturesKHR {
+    VkStructureType sType;
+    void*        pNext;
+    VkBool32                           constantAlphaColorBlendFactors;
+    VkBool32                           events;
+    VkBool32                           imageViewFormatReinterpretation;
+    VkBool32                           imageViewFormatSwizzle;
+    VkBool32                           imageView2DOn3DImage;
+    VkBool32                           multisampleArrayImage;
+    VkBool32                           mutableComparisonSamplers;
+    VkBool32                           pointPolygons;
+    VkBool32                           samplerMipLodBias;
+    VkBool32                           separateStencilMaskRef;
+    VkBool32                           shaderSampleRateInterpolationFunctions;
+    VkBool32                           tessellationIsolines;
+    VkBool32                           tessellationPointMode;
+    VkBool32                           triangleFans;
+    VkBool32                           vertexAttributeAccessBeyondStride;
+} VkPhysicalDevicePortabilitySubsetFeaturesKHR;
+
+typedef struct VkPhysicalDevicePortabilitySubsetPropertiesKHR {
+    VkStructureType sType;
+    void*        pNext;
+    uint32_t                           minVertexInputBindingStrideAlignment;
+} VkPhysicalDevicePortabilitySubsetPropertiesKHR;
+
 typedef struct VkAccelerationStructureBuildSizesInfoKHR {
     VkStructureType sType;
     const void*        pNext;