linux/lib/test_hmm_uapi.h
Alex Sierra 4c2e0f764e lib: add support for device coherent type in test_hmm
Device Coherent type uses device memory that is coherently accesible by
the CPU.  This could be shown as SP (special purpose) memory range at the
BIOS-e820 memory enumeration.  If no SP memory is supported in system,
this could be faked by setting CONFIG_EFI_FAKE_MEMMAP.

Currently, test_hmm only supports two different SP ranges of at least
256MB size. This could be specified in the kernel parameter variable
efi_fake_mem. Ex. Two SP ranges of 1GB starting at 0x100000000 &
0x140000000 physical address. Ex.
efi_fake_mem=1G@0x100000000:0x40000,1G@0x140000000:0x40000

Private and coherent device mirror instances can be created in the same
probed.  This is done by passing the module parameters spm_addr_dev0 &
spm_addr_dev1.  In this case, it will create four instances of
device_mirror.  The first two correspond to private device type, the last
two to coherent type.  Then, they can be easily accessed from user space
through /dev/hmm_mirror<num_device>.  Usually num_device 0 and 1 are for
private, and 2 and 3 for coherent types.  If no module parameters are
passed, two instances of private type device_mirror will be created only.

Link: https://lkml.kernel.org/r/20220715150521.18165-11-alex.sierra@amd.com
Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Alistair Poppple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:29 -07:00

77 lines
2.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
* This is a module to test the HMM (Heterogeneous Memory Management) API
* of the kernel. It allows a userspace program to expose its entire address
* space through the HMM test module device file.
*/
#ifndef _LIB_TEST_HMM_UAPI_H
#define _LIB_TEST_HMM_UAPI_H
#include <linux/types.h>
#include <linux/ioctl.h>
/*
* Structure to pass to the HMM test driver to mimic a device accessing
* system memory and ZONE_DEVICE private memory through device page tables.
*
* @addr: (in) user address the device will read/write
* @ptr: (in) user address where device data is copied to/from
* @npages: (in) number of pages to read/write
* @cpages: (out) number of pages copied
* @faults: (out) number of device page faults seen
*/
struct hmm_dmirror_cmd {
__u64 addr;
__u64 ptr;
__u64 npages;
__u64 cpages;
__u64 faults;
};
/* Expose the address space of the calling process through hmm device file */
#define HMM_DMIRROR_READ _IOWR('H', 0x00, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_WRITE _IOWR('H', 0x01, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_MIGRATE_TO_DEV _IOWR('H', 0x02, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_MIGRATE_TO_SYS _IOWR('H', 0x03, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_SNAPSHOT _IOWR('H', 0x04, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_CHECK_EXCLUSIVE _IOWR('H', 0x06, struct hmm_dmirror_cmd)
/*
* Values returned in hmm_dmirror_cmd.ptr for HMM_DMIRROR_SNAPSHOT.
* HMM_DMIRROR_PROT_ERROR: no valid mirror PTE for this page
* HMM_DMIRROR_PROT_NONE: unpopulated PTE or PTE with no access
* HMM_DMIRROR_PROT_READ: read-only PTE
* HMM_DMIRROR_PROT_WRITE: read/write PTE
* HMM_DMIRROR_PROT_PMD: PMD sized page is fully mapped by same permissions
* HMM_DMIRROR_PROT_PUD: PUD sized page is fully mapped by same permissions
* HMM_DMIRROR_PROT_ZERO: special read-only zero page
* HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL: Migrated device private page on the
* device the ioctl() is made
* HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE: Migrated device private page on some
* other device
* HMM_DMIRROR_PROT_DEV_COHERENT: Migrate device coherent page on the device
* the ioctl() is made
*/
enum {
HMM_DMIRROR_PROT_ERROR = 0xFF,
HMM_DMIRROR_PROT_NONE = 0x00,
HMM_DMIRROR_PROT_READ = 0x01,
HMM_DMIRROR_PROT_WRITE = 0x02,
HMM_DMIRROR_PROT_PMD = 0x04,
HMM_DMIRROR_PROT_PUD = 0x08,
HMM_DMIRROR_PROT_ZERO = 0x10,
HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL = 0x20,
HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE = 0x30,
HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL = 0x40,
HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE = 0x50,
};
enum {
/* 0 is reserved to catch uninitialized type fields */
HMM_DMIRROR_MEMORY_DEVICE_PRIVATE = 1,
HMM_DMIRROR_MEMORY_DEVICE_COHERENT,
};
#endif /* _LIB_TEST_HMM_UAPI_H */