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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2020 Google LLC
* Author: Will Deacon <[email protected]>
*/
#ifndef __ARM64_KVM_PGTABLE_H__
#define __ARM64_KVM_PGTABLE_H__
#include <linux/bits.h>
#include <linux/kvm_host.h>
#include <linux/types.h>
#define KVM_PGTABLE_MAX_LEVELS 4U
static inline u64 kvm_get_parange(u64 mmfr0)
{
u64 parange = cpuid_feature_extract_unsigned_field(mmfr0,
ID_AA64MMFR0_PARANGE_SHIFT);
if (parange > ID_AA64MMFR0_PARANGE_MAX)
parange = ID_AA64MMFR0_PARANGE_MAX;
return parange;
}
typedef u64 kvm_pte_t;
/**
* struct kvm_pgtable_mm_ops - Memory management callbacks.
* @zalloc_page: Allocate a single zeroed memory page. The @arg parameter
* can be used by the walker to pass a memcache. The
* initial refcount of the page is 1.
* @zalloc_pages_exact: Allocate an exact number of zeroed memory pages. The
* @size parameter is in bytes, and is rounded-up to the
* next page boundary. The resulting allocation is
* physically contiguous.
* @free_pages_exact: Free an exact number of memory pages previously
* allocated by zalloc_pages_exact.
* @get_page: Increment the refcount on a page.
* @put_page: Decrement the refcount on a page. When the refcount
* reaches 0 the page is automatically freed.
* @page_count: Return the refcount of a page.
* @phys_to_virt: Convert a physical address into a virtual address mapped
* in the current context.
* @virt_to_phys: Convert a virtual address mapped in the current context
* into a physical address.
*/
struct kvm_pgtable_mm_ops {
void* (*zalloc_page)(void *arg);
void* (*zalloc_pages_exact)(size_t size);
void (*free_pages_exact)(void *addr, size_t size);
void (*get_page)(void *addr);
void (*put_page)(void *addr);
int (*page_count)(void *addr);
void* (*phys_to_virt)(phys_addr_t phys);
phys_addr_t (*virt_to_phys)(void *addr);
};
/**
* enum kvm_pgtable_stage2_flags - Stage-2 page-table flags.
* @KVM_PGTABLE_S2_NOFWB: Don't enforce Normal-WB even if the CPUs have
* ARM64_HAS_STAGE2_FWB.
* @KVM_PGTABLE_S2_IDMAP: Only use identity mappings.
*/
enum kvm_pgtable_stage2_flags {
KVM_PGTABLE_S2_NOFWB = BIT(0),
KVM_PGTABLE_S2_IDMAP = BIT(1),
};
/**
* struct kvm_pgtable - KVM page-table.
* @ia_bits: Maximum input address size, in bits.
* @start_level: Level at which the page-table walk starts.
* @pgd: Pointer to the first top-level entry of the page-table.
* @mm_ops: Memory management callbacks.
* @mmu: Stage-2 KVM MMU struct. Unused for stage-1 page-tables.
*/
struct kvm_pgtable {
u32 ia_bits;
u32 start_level;
kvm_pte_t *pgd;
struct kvm_pgtable_mm_ops *mm_ops;
/* Stage-2 only */
struct kvm_s2_mmu *mmu;
enum kvm_pgtable_stage2_flags flags;
};
/**
* enum kvm_pgtable_prot - Page-table permissions and attributes.
* @KVM_PGTABLE_PROT_X: Execute permission.
* @KVM_PGTABLE_PROT_W: Write permission.
* @KVM_PGTABLE_PROT_R: Read permission.
* @KVM_PGTABLE_PROT_DEVICE: Device attributes.
*/
enum kvm_pgtable_prot {
KVM_PGTABLE_PROT_X = BIT(0),
KVM_PGTABLE_PROT_W = BIT(1),
KVM_PGTABLE_PROT_R = BIT(2),
KVM_PGTABLE_PROT_DEVICE = BIT(3),
};
#define PAGE_HYP (KVM_PGTABLE_PROT_R | KVM_PGTABLE_PROT_W)
#define PAGE_HYP_EXEC (KVM_PGTABLE_PROT_R | KVM_PGTABLE_PROT_X)
#define PAGE_HYP_RO (KVM_PGTABLE_PROT_R)
#define PAGE_HYP_DEVICE (PAGE_HYP | KVM_PGTABLE_PROT_DEVICE)
/**
* struct kvm_mem_range - Range of Intermediate Physical Addresses
* @start: Start of the range.
* @end: End of the range.
*/
struct kvm_mem_range {
u64 start;
u64 end;
};
/**
* enum kvm_pgtable_walk_flags - Flags to control a depth-first page-table walk.
* @KVM_PGTABLE_WALK_LEAF: Visit leaf entries, including invalid
* entries.
* @KVM_PGTABLE_WALK_TABLE_PRE: Visit table entries before their
* children.
* @KVM_PGTABLE_WALK_TABLE_POST: Visit table entries after their
* children.
*/
enum kvm_pgtable_walk_flags {
KVM_PGTABLE_WALK_LEAF = BIT(0),
KVM_PGTABLE_WALK_TABLE_PRE = BIT(1),
KVM_PGTABLE_WALK_TABLE_POST = BIT(2),
};
typedef int (*kvm_pgtable_visitor_fn_t)(u64 addr, u64 end, u32 level,
kvm_pte_t *ptep,
enum kvm_pgtable_walk_flags flag,
void * const arg);
/**
* struct kvm_pgtable_walker - Hook into a page-table walk.
* @cb: Callback function to invoke during the walk.
* @arg: Argument passed to the callback function.
* @flags: Bitwise-OR of flags to identify the entry types on which to
* invoke the callback function.
*/
struct kvm_pgtable_walker {
const kvm_pgtable_visitor_fn_t cb;
void * const arg;
const enum kvm_pgtable_walk_flags flags;
};
/**
* kvm_pgtable_hyp_init() - Initialise a hypervisor stage-1 page-table.
* @pgt: Uninitialised page-table structure to initialise.
* @va_bits: Maximum virtual address bits.
* @mm_ops: Memory management callbacks.
*
* Return: 0 on success, negative error code on failure.
*/
int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits,
struct kvm_pgtable_mm_ops *mm_ops);
/**
* kvm_pgtable_hyp_destroy() - Destroy an unused hypervisor stage-1 page-table.
* @pgt: Page-table structure initialised by kvm_pgtable_hyp_init().
*
* The page-table is assumed to be unreachable by any hardware walkers prior
* to freeing and therefore no TLB invalidation is performed.
*/
void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt);
/**
* kvm_pgtable_hyp_map() - Install a mapping in a hypervisor stage-1 page-table.
* @pgt: Page-table structure initialised by kvm_pgtable_hyp_init().
* @addr: Virtual address at which to place the mapping.
* @size: Size of the mapping.
* @phys: Physical address of the memory to map.
* @prot: Permissions and attributes for the mapping.
*
* The offset of @addr within a page is ignored, @size is rounded-up to
* the next page boundary and @phys is rounded-down to the previous page
* boundary.
*
* If device attributes are not explicitly requested in @prot, then the
* mapping will be normal, cacheable. Attempts to install a new mapping
* for a virtual address that is already mapped will be rejected with an
* error and a WARN().
*
* Return: 0 on success, negative error code on failure.
*/
int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,
enum kvm_pgtable_prot prot);
/**
* kvm_get_vtcr() - Helper to construct VTCR_EL2
* @mmfr0: Sanitized value of SYS_ID_AA64MMFR0_EL1 register.
* @mmfr1: Sanitized value of SYS_ID_AA64MMFR1_EL1 register.
* @phys_shfit: Value to set in VTCR_EL2.T0SZ.
*
* The VTCR value is common across all the physical CPUs on the system.
* We use system wide sanitised values to fill in different fields,
* except for Hardware Management of Access Flags. HA Flag is set
* unconditionally on all CPUs, as it is safe to run with or without
* the feature and the bit is RES0 on CPUs that don't support it.
*
* Return: VTCR_EL2 value
*/
u64 kvm_get_vtcr(u64 mmfr0, u64 mmfr1, u32 phys_shift);
/**
* kvm_pgtable_stage2_init_flags() - Initialise a guest stage-2 page-table.
* @pgt: Uninitialised page-table structure to initialise.
* @arch: Arch-specific KVM structure representing the guest virtual
* machine.
* @mm_ops: Memory management callbacks.
* @flags: Stage-2 configuration flags.
*
* Return: 0 on success, negative error code on failure.
*/
int kvm_pgtable_stage2_init_flags(struct kvm_pgtable *pgt, struct kvm_arch *arch,
struct kvm_pgtable_mm_ops *mm_ops,
enum kvm_pgtable_stage2_flags flags);
#define kvm_pgtable_stage2_init(pgt, arch, mm_ops) \
kvm_pgtable_stage2_init_flags(pgt, arch, mm_ops, 0)
/**
* kvm_pgtable_stage2_destroy() - Destroy an unused guest stage-2 page-table.
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*().
*
* The page-table is assumed to be unreachable by any hardware walkers prior
* to freeing and therefore no TLB invalidation is performed.
*/
void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt);
/**
* kvm_pgtable_stage2_map() - Install a mapping in a guest stage-2 page-table.
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*().
* @addr: Intermediate physical address at which to place the mapping.
* @size: Size of the mapping.
* @phys: Physical address of the memory to map.
* @prot: Permissions and attributes for the mapping.
* @mc: Cache of pre-allocated and zeroed memory from which to allocate
* page-table pages.
*
* The offset of @addr within a page is ignored, @size is rounded-up to
* the next page boundary and @phys is rounded-down to the previous page
* boundary.
*
* If device attributes are not explicitly requested in @prot, then the
* mapping will be normal, cacheable.
*
* Note that the update of a valid leaf PTE in this function will be aborted,
* if it's trying to recreate the exact same mapping or only change the access
* permissions. Instead, the vCPU will exit one more time from guest if still
* needed and then go through the path of relaxing permissions.
*
* Note that this function will both coalesce existing table entries and split
* existing block mappings, relying on page-faults to fault back areas outside
* of the new mapping lazily.
*
* Return: 0 on success, negative error code on failure.
*/
int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,
u64 phys, enum kvm_pgtable_prot prot,
void *mc);
/**
* kvm_pgtable_stage2_set_owner() - Unmap and annotate pages in the IPA space to
* track ownership.
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*().
* @addr: Base intermediate physical address to annotate.
* @size: Size of the annotated range.
* @mc: Cache of pre-allocated and zeroed memory from which to allocate
* page-table pages.
* @owner_id: Unique identifier for the owner of the page.
*
* By default, all page-tables are owned by identifier 0. This function can be
* used to mark portions of the IPA space as owned by other entities. When a
* stage 2 is used with identity-mappings, these annotations allow to use the
* page-table data structure as a simple rmap.
*
* Return: 0 on success, negative error code on failure.
*/
int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size,
void *mc, u8 owner_id);
/**
* kvm_pgtable_stage2_unmap() - Remove a mapping from a guest stage-2 page-table.
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*().
* @addr: Intermediate physical address from which to remove the mapping.
* @size: Size of the mapping.
*
* The offset of @addr within a page is ignored and @size is rounded-up to
* the next page boundary.
*
* TLB invalidation is performed for each page-table entry cleared during the
* unmapping operation and the reference count for the page-table page
* containing the cleared entry is decremented, with unreferenced pages being
* freed. Unmapping a cacheable page will ensure that it is clean to the PoC if
* FWB is not supported by the CPU.
*
* Return: 0 on success, negative error code on failure.
*/
int kvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size);
/**
* kvm_pgtable_stage2_wrprotect() - Write-protect guest stage-2 address range
* without TLB invalidation.
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*().
* @addr: Intermediate physical address from which to write-protect,
* @size: Size of the range.
*
* The offset of @addr within a page is ignored and @size is rounded-up to
* the next page boundary.
*
* Note that it is the caller's responsibility to invalidate the TLB after
* calling this function to ensure that the updated permissions are visible
* to the CPUs.
*
* Return: 0 on success, negative error code on failure.
*/
int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size);
/**
* kvm_pgtable_stage2_mkyoung() - Set the access flag in a page-table entry.
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*().
* @addr: Intermediate physical address to identify the page-table entry.
*
* The offset of @addr within a page is ignored.
*
* If there is a valid, leaf page-table entry used to translate @addr, then
* set the access flag in that entry.
*
* Return: The old page-table entry prior to setting the flag, 0 on failure.
*/
kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr);
/**
* kvm_pgtable_stage2_mkold() - Clear the access flag in a page-table entry.
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*().
* @addr: Intermediate physical address to identify the page-table entry.
*
* The offset of @addr within a page is ignored.
*
* If there is a valid, leaf page-table entry used to translate @addr, then
* clear the access flag in that entry.
*
* Note that it is the caller's responsibility to invalidate the TLB after
* calling this function to ensure that the updated permissions are visible
* to the CPUs.
*
* Return: The old page-table entry prior to clearing the flag, 0 on failure.
*/
kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr);
/**
* kvm_pgtable_stage2_relax_perms() - Relax the permissions enforced by a
* page-table entry.
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*().
* @addr: Intermediate physical address to identify the page-table entry.
* @prot: Additional permissions to grant for the mapping.
*
* The offset of @addr within a page is ignored.
*
* If there is a valid, leaf page-table entry used to translate @addr, then
* relax the permissions in that entry according to the read, write and
* execute permissions specified by @prot. No permissions are removed, and
* TLB invalidation is performed after updating the entry.
*
* Return: 0 on success, negative error code on failure.
*/
int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr,
enum kvm_pgtable_prot prot);
/**
* kvm_pgtable_stage2_is_young() - Test whether a page-table entry has the
* access flag set.
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*().
* @addr: Intermediate physical address to identify the page-table entry.
*
* The offset of @addr within a page is ignored.
*
* Return: True if the page-table entry has the access flag set, false otherwise.
*/
bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr);
/**
* kvm_pgtable_stage2_flush_range() - Clean and invalidate data cache to Point
* of Coherency for guest stage-2 address
* range.
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*().
* @addr: Intermediate physical address from which to flush.
* @size: Size of the range.
*
* The offset of @addr within a page is ignored and @size is rounded-up to
* the next page boundary.
*
* Return: 0 on success, negative error code on failure.
*/
int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size);
/**
* kvm_pgtable_walk() - Walk a page-table.
* @pgt: Page-table structure initialised by kvm_pgtable_*_init().
* @addr: Input address for the start of the walk.
* @size: Size of the range to walk.
* @walker: Walker callback description.
*
* The offset of @addr within a page is ignored and @size is rounded-up to
* the next page boundary.
*
* The walker will walk the page-table entries corresponding to the input
* address range specified, visiting entries according to the walker flags.
* Invalid entries are treated as leaf entries. Leaf entries are reloaded
* after invoking the walker callback, allowing the walker to descend into
* a newly installed table.
*
* Returning a negative error code from the walker callback function will
* terminate the walk immediately with the same error code.
*
* Return: 0 on success, negative error code on failure.
*/
int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size,
struct kvm_pgtable_walker *walker);
/**
* kvm_pgtable_stage2_find_range() - Find a range of Intermediate Physical
* Addresses with compatible permission
* attributes.
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*().
* @addr: Address that must be covered by the range.
* @prot: Protection attributes that the range must be compatible with.
* @range: Range structure used to limit the search space at call time and
* that will hold the result.
*
* The offset of @addr within a page is ignored. An IPA is compatible with @prot
* iff its corresponding stage-2 page-table entry has default ownership and, if
* valid, is mapped with protection attributes identical to @prot.
*
* Return: 0 on success, negative error code on failure.
*/
int kvm_pgtable_stage2_find_range(struct kvm_pgtable *pgt, u64 addr,
enum kvm_pgtable_prot prot,
struct kvm_mem_range *range);
#endif /* __ARM64_KVM_PGTABLE_H__ */
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