diff options
| author | Ricardo Koller <ricarkol@google.com> | 2023-04-26 20:23:24 +0300 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2023-05-16 20:39:18 +0300 |
| commit | 8f5a3eb7513fc4deae511ce91af1c2c23874a8a7 (patch) | |
| tree | 9e9b9dc3c3f9634856d41fd0e129e0798e5f8752 /arch/arm64/include/asm/kvm_pgtable.h | |
| parent | 2f440b72e852be428540579b5813ba2b8236578d (diff) | |
| download | linux-8f5a3eb7513fc4deae511ce91af1c2c23874a8a7.tar.xz | |
KVM: arm64: Add kvm_pgtable_stage2_split()
Add a new stage2 function, kvm_pgtable_stage2_split(), for splitting a
range of huge pages. This will be used for eager-splitting huge pages
into PAGE_SIZE pages. The goal is to avoid having to split huge pages
on write-protection faults, and instead use this function to do it
ahead of time for large ranges (e.g., all guest memory in 1G chunks at
a time).
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/20230426172330.1439644-7-ricarkol@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64/include/asm/kvm_pgtable.h')
| -rw-r--r-- | arch/arm64/include/asm/kvm_pgtable.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index cbc6971e2cb4..850d65f705fa 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -672,6 +672,25 @@ bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr); int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size); /** + * kvm_pgtable_stage2_split() - Split a range of huge pages into leaf PTEs pointing + * to PAGE_SIZE guest pages. + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). + * @addr: Intermediate physical address from which to split. + * @size: Size of the range. + * @mc: Cache of pre-allocated and zeroed memory from which to allocate + * page-table pages. + * + * The function tries to split any level 1 or 2 entry that overlaps + * with the input range (given by @addr and @size). + * + * Return: 0 on success, negative error code on failure. Note that + * kvm_pgtable_stage2_split() is best effort: it tries to break as many + * blocks in the input range as allowed by @mc_capacity. + */ +int kvm_pgtable_stage2_split(struct kvm_pgtable *pgt, u64 addr, u64 size, + struct kvm_mmu_memory_cache *mc); + +/** * 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. |