Hypervisor Data Types for Address Spaces and Memory Pages

The hypervisor architecture defines the following independent address spaces:

System physical addresses (SPAs)

SPAs define the physical address space of the underlying hardware as seen by the CPUs. There is only one system physical address space per computer.

Guest physical addresses (GPAs)

GPAs define the guest operating system's view of physical memory. GPAs can be mapped to underlying SPAs. There is one guest physical address space per partition.

Guest virtual addresses (GVAs)

GVAs are used within the guest operating system when it enables address translation and provides a valid guest page table.

The size of all three of these address spaces can be up to 264 bytes. The following types are therefore defined:

typedef UINT64 HV_SPA;
typedef UINT64 HV_GPA;
typedef UINT64 HV_GVA;

Many hypervisor interfaces act on pages of memory instead of on single bytes. The minimum page size is architecture-dependent. For x64 operating systems, the minimum page size is defined as 4 KB. The following types are defined for hypervisor pages of memory:

#define X64_PAGE_SIZE 0x1000
#define HV_X64_MAX_PAGE_NUMBER (MAXUINT64/X64_PAGE_SIZE)
#define HV_PAGE_SIZE    X64_PAGE_SIZE
#define HV_LARGE_PAGE_SIZE X64_LARGE_PAGE_SIZE
#define HV_PAGE_MASK (HV_PAGE_SIZE - 1)

typedef UINT64 HV_SPA_PAGE_NUMBER;
typedef UINT64 HV_GPA_PAGE_NUMBER;
typedef UINT64 HV_GVA_PAGE_NUMBER;

typedef HV_GPA_PAGE_NUMBER *PHV_GPA_PAGE_NUMBER;

To convert an HV_SPA to an HV_SPA_PAGE_NUMBER, divide by HV_PAGE_SIZE.

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Build date: 11/16/2013