diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 7 | ||||
| -rw-r--r-- | arch/riscv/kvm/mmu.c | 13 |
2 files changed, 15 insertions, 5 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index b5493a7f8f22..d78eda7ee23a 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3047,7 +3047,7 @@ Kernel parameters Default is 0 (don't ignore, but inject #GP) kvm.eager_page_split= - [KVM,X86] Controls whether or not KVM will try to + [KVM,X86,RISCV] Controls whether or not KVM will try to proactively split all huge pages during dirty logging. Eager page splitting reduces interruptions to vCPU execution by eliminating the write-protection faults @@ -3067,7 +3067,10 @@ Kernel parameters the KVM_CLEAR_DIRTY ioctl, and only for the pages being cleared. - Eager page splitting is only supported when kvm.tdp_mmu=Y. + On x86, eager page splitting is only supported when + kvm.tdp_mmu=Y. + + On RISCV, eager page splitting is supported by default. Default is Y (on). diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c index 9ae10f5b2984..154f3afaf1c9 100644 --- a/arch/riscv/kvm/mmu.c +++ b/arch/riscv/kvm/mmu.c @@ -16,6 +16,9 @@ #include <asm/kvm_mmu.h> #include <asm/kvm_nacl.h> +static bool __read_mostly eager_page_split = true; +module_param(eager_page_split, bool, 0644); + static void mmu_wp_memory_region(struct kvm *kvm, int slot) { struct kvm_memslots *slots = kvm_memslots(kvm); @@ -168,8 +171,10 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, kvm_riscv_gstage_wp_range(&gstage, start, end); - if (kvm_dirty_log_manual_protect_and_init_set(kvm)) - mmu_split_huge_pages(&gstage, start, end); + if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { + if (READ_ONCE(eager_page_split)) + mmu_split_huge_pages(&gstage, start, end); + } /* * Remote TLB flush is not needed here since callers of @@ -244,7 +249,9 @@ void kvm_arch_commit_memory_region(struct kvm *kvm, if (kvm_dirty_log_manual_protect_and_init_set(kvm)) return; mmu_wp_memory_region(kvm, new->id); - mmu_split_memory_region(kvm, new->id); + + if (READ_ONCE(eager_page_split)) + mmu_split_memory_region(kvm, new->id); } } |