diff options
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 40 |
1 files changed, 30 insertions, 10 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index c8b5694..dc5f245 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1037,27 +1037,47 @@ static int __rmap_write_protect(struct kvm *kvm, unsigned long *rmapp, int level return write_protected; } -int kvm_mmu_rmap_write_protect(struct kvm *kvm, u64 gfn, - struct kvm_memory_slot *slot) +/** + * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages + * @kvm: kvm instance + * @slot: slot to protect + * @gfn_offset: start of the BITS_PER_LONG pages we care about + * @mask: indicates which pages we should protect + * + * Used when we do not need to care about huge page mappings: e.g. during dirty + * logging we do not have any such mappings. + */ +void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, + struct kvm_memory_slot *slot, + gfn_t gfn_offset, unsigned long mask) { unsigned long *rmapp; - int i, write_protected = 0; - for (i = PT_PAGE_TABLE_LEVEL; - i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) { - rmapp = __gfn_to_rmap(gfn, i, slot); - write_protected |= __rmap_write_protect(kvm, rmapp, i); - } + while (mask) { + rmapp = &slot->rmap[gfn_offset + __ffs(mask)]; + __rmap_write_protect(kvm, rmapp, PT_PAGE_TABLE_LEVEL); - return write_protected; + /* clear the first set bit */ + mask &= mask - 1; + } } static int rmap_write_protect(struct kvm *kvm, u64 gfn) { struct kvm_memory_slot *slot; + unsigned long *rmapp; + int i; + int write_protected = 0; slot = gfn_to_memslot(kvm, gfn); - return kvm_mmu_rmap_write_protect(kvm, gfn, slot); + + for (i = PT_PAGE_TABLE_LEVEL; + i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) { + rmapp = __gfn_to_rmap(gfn, i, slot); + write_protected |= __rmap_write_protect(kvm, rmapp, i); + } + + return write_protected; } static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, |