Package org.lwjgl.vulkan

Class NVExternalMemoryRdma

java.lang.Object
org.lwjgl.vulkan.NVExternalMemoryRdma
public class NVExternalMemoryRdma extends Object
This extension adds support for allocating memory which can be used for remote direct memory access (RDMA) from other devices.
Examples

 VkPhysicalDeviceMemoryBudgetPropertiesEXT memoryBudgetProperties = { VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MEMORY_BUDGET_PROPERTIES_EXT };
 VkPhysicalDeviceMemoryProperties2 memoryProperties2 = { VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MEMORY_PROPERTIES_2, &memoryBudgetProperties };
 vkGetPhysicalDeviceMemoryProperties2(physicalDevice, &memoryProperties2);
 uint32_t heapIndex = (uint32_t)-1;
 for (uint32_t memoryType = 0; memoryType < memoryProperties2.memoryProperties.memoryTypeCount; memoryType++) {
     if (memoryProperties2.memoryProperties.memoryTypes[memoryType].propertyFlags & VK_MEMORY_PROPERTY_RDMA_CAPABLE_BIT_NV) {
         heapIndex = memoryProperties2.memoryProperties.memoryTypes[memoryType].heapIndex;
         break;
     }
 }
 if ((heapIndex == (uint32_t)-1) ||
     (memoryBudgetProperties.heapBudget[heapIndex] < size)) {
     return;
 }
 
 VkPhysicalDeviceExternalBufferInfo externalBufferInfo = { VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_EXTERNAL_BUFFER_INFO };
 externalBufferInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;
 externalBufferInfo.handleType = VK_EXTERNAL_MEMORY_HANDLE_TYPE_RDMA_ADDRESS_BIT_NV;
 
 VkExternalBufferProperties externalBufferProperties = { VK_STRUCTURE_TYPE_EXTERNAL_BUFFER_PROPERTIES };
 vkGetPhysicalDeviceExternalBufferProperties(physicalDevice, &externalBufferInfo, &externalBufferProperties);
 
 if (!(externalBufferProperties.externalMemoryProperties.externalMemoryFeatures & VK_EXTERNAL_MEMORY_FEATURE_EXPORTABLE_BIT)) {
     return;
 }
 
 VkExternalMemoryBufferCreateInfo externalMemoryBufferCreateInfo = { VK_STRUCTURE_TYPE_EXTERNAL_MEMORY_BUFFER_CREATE_INFO };
 externalMemoryBufferCreateInfo.handleTypes = VK_EXTERNAL_MEMORY_HANDLE_TYPE_RDMA_ADDRESS_BIT_NV;
 
 VkBufferCreateInfo bufferCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO, &externalMemoryBufferCreateInfo };
 bufferCreateInfo.size = size;
 bufferCreateInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;
 
 VkMemoryRequirements mem_reqs;
 vkCreateBuffer(device, &bufferCreateInfo, NULL, &buffer);
 vkGetBufferMemoryRequirements(device, buffer, &mem_reqs);
 
 VkExportMemoryAllocateInfo exportMemoryAllocateInfo = { VK_STRUCTURE_TYPE_EXPORT_MEMORY_ALLOCATE_INFO };
 exportMemoryAllocateInfo.handleTypes = VK_EXTERNAL_MEMORY_HANDLE_TYPE_RDMA_ADDRESS_BIT_NV;
 
 // Find memory type index
 uint32_t i = 0;
 for (; i < VK_MAX_MEMORY_TYPES; i++) {
     if ((mem_reqs.memoryTypeBits & (1 << i)) &&
         (memoryProperties.memoryTypes[i].propertyFlags & VK_MEMORY_PROPERTY_RDMA_CAPABLE_BIT_NV)) {
         break;
     }
 }
 
 VkMemoryAllocateInfo memAllocInfo = { VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO, &exportMemoryAllocateInfo };
 memAllocInfo.allocationSize = mem_reqs.size;
 memAllocInfo.memoryTypeIndex = i;
 
 vkAllocateMemory(device, &memAllocInfo, NULL, &mem);
 vkBindBufferMemory(device, buffer, mem, 0);
 
 VkMemoryGetRemoteAddressInfoNV getMemoryRemoteAddressInfo = { VK_STRUCTURE_TYPE_MEMORY_GET_REMOTE_ADDRESS_INFO_NV };
 getMemoryRemoteAddressInfo.memory = mem;
 getMemoryRemoteAddressInfo.handleType = VK_EXTERNAL_MEMORY_HANDLE_TYPE_RDMA_ADDRESS_BIT_NV;
 
 VkRemoteAddressNV rdmaAddress;
 vkGetMemoryRemoteAddressNV(device, &getMemoryRemoteAddressInfo, &rdmaAddress);
 // address returned in 'rdmaAddress' can be used by external devices to initiate RDMA transfers
Name String
VK_NV_external_memory_rdma
Extension Type
Device extension
Registered Extension Number
372
Revision
1
Extension and Version Dependencies
VK_KHR_external_memory or Version 1.1
Contact
Other Extension Metadata
Last Modified Date
2021-04-19
IP Status
No known IP claims.
Contributors
  • Carsten Rohde, NVIDIA

  • Field Details

  • Method Details

    • nvkGetMemoryRemoteAddressNV

      public static int nvkGetMemoryRemoteAddressNV(org.lwjgl.vulkan.VkDevice device, long pMemoryGetRemoteAddressInfo, long pAddress)
      Unsafe version of: GetMemoryRemoteAddressNV

    • vkGetMemoryRemoteAddressNV

      public static int vkGetMemoryRemoteAddressNV(org.lwjgl.vulkan.VkDevice device, VkMemoryGetRemoteAddressInfoNV pMemoryGetRemoteAddressInfo, org.lwjgl.PointerBuffer pAddress)
      Get an address for a memory object accessible by remote devices.
      C Specification

      To export an address representing the payload of a Vulkan device memory object accessible by remote devices, call:

      
 VkResult vkGetMemoryRemoteAddressNV(
     VkDevice                                    device,
     const VkMemoryGetRemoteAddressInfoNV*       pMemoryGetRemoteAddressInfo,
     VkRemoteAddressNV*                          pAddress);
      Description

      More communication may be required between the kernel-mode drivers of the devices involved. This information is out of scope of this documentation and should be requested from the vendors of the devices.

      Valid Usage (Implicit)
      • device must be a valid VkDevice handle
      • pMemoryGetRemoteAddressInfo must be a valid pointer to a valid VkMemoryGetRemoteAddressInfoNV structure
      • pAddress must be a valid pointer to a VkRemoteAddressNV value
      Return Codes
      On success, this command returns
      On failure, this command returns
      See Also

      VkMemoryGetRemoteAddressInfoNV

      Parameters:
      device - the logical device that created the device memory being exported.
      pMemoryGetRemoteAddressInfo - a pointer to a VkMemoryGetRemoteAddressInfoNV structure containing parameters of the export operation.
      pAddress - a pointer to a VkRemoteAddressNV value in which an address representing the payload of the device memory object is returned.