diff options
| author | Ricardo Koller <ricarkol@google.com> | 2023-04-26 20:23:23 +0300 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2023-05-16 20:39:18 +0300 |
| commit | 2f440b72e852be428540579b5813ba2b8236578d (patch) | |
| tree | c4be44262abb5c8da28ca42115b6ae7e885693d4 /arch/arm64/kvm/arm.c | |
| parent | 26f457142d7ee2da20a5b701862230e4961423d9 (diff) | |
| download | linux-2f440b72e852be428540579b5813ba2b8236578d.tar.xz | |
KVM: arm64: Add KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE
Add a capability for userspace to specify the eager split chunk size.
The chunk size specifies how many pages to break at a time, using a
single allocation. Bigger the chunk size, more pages need to be
allocated ahead of time.
Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/20230426172330.1439644-6-ricarkol@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64/kvm/arm.c')
| -rw-r--r-- | arch/arm64/kvm/arm.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 14391826241c..c605626801c4 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -65,6 +65,7 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) { int r; + u64 new_cap; if (cap->flags) return -EINVAL; @@ -89,6 +90,24 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, r = 0; set_bit(KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED, &kvm->arch.flags); break; + case KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE: + new_cap = cap->args[0]; + + mutex_lock(&kvm->slots_lock); + /* + * To keep things simple, allow changing the chunk + * size only when no memory slots have been created. + */ + if (!kvm_are_all_memslots_empty(kvm)) { + r = -EINVAL; + } else if (new_cap && !kvm_is_block_size_supported(new_cap)) { + r = -EINVAL; + } else { + r = 0; + kvm->arch.mmu.split_page_chunk_size = new_cap; + } + mutex_unlock(&kvm->slots_lock); + break; default: r = -EINVAL; break; @@ -302,6 +321,15 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_ARM_PTRAUTH_GENERIC: r = system_has_full_ptr_auth(); break; + case KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE: + if (kvm) + r = kvm->arch.mmu.split_page_chunk_size; + else + r = KVM_ARM_EAGER_SPLIT_CHUNK_SIZE_DEFAULT; + break; + case KVM_CAP_ARM_SUPPORTED_BLOCK_SIZES: + r = kvm_supported_block_sizes(); + break; default: r = 0; } |