From 82ed36164c8a8ee685ea3fb3c4f741214ac070ca Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Thu, 15 Dec 2011 02:03:22 +0000 Subject: KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras Signed-off-by: Alexander Graf Signed-off-by: Avi Kivity --- arch/powerpc/kvm/book3s_pr.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'arch/powerpc/kvm/book3s_pr.c') diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index 2da670405727..c193625d5289 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -1056,6 +1056,45 @@ out: return ret; } +/* + * Get (and clear) the dirty memory log for a memory slot. + */ +int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, + struct kvm_dirty_log *log) +{ + struct kvm_memory_slot *memslot; + struct kvm_vcpu *vcpu; + ulong ga, ga_end; + int is_dirty = 0; + int r; + unsigned long n; + + mutex_lock(&kvm->slots_lock); + + r = kvm_get_dirty_log(kvm, log, &is_dirty); + if (r) + goto out; + + /* If nothing is dirty, don't bother messing with page tables. */ + if (is_dirty) { + memslot = id_to_memslot(kvm->memslots, log->slot); + + ga = memslot->base_gfn << PAGE_SHIFT; + ga_end = ga + (memslot->npages << PAGE_SHIFT); + + kvm_for_each_vcpu(n, vcpu, kvm) + kvmppc_mmu_pte_pflush(vcpu, ga, ga_end); + + n = kvm_dirty_bitmap_bytes(memslot); + memset(memslot->dirty_bitmap, 0, n); + } + + r = 0; +out: + mutex_unlock(&kvm->slots_lock); + return r; +} + int kvmppc_core_prepare_memory_region(struct kvm *kvm, struct kvm_userspace_memory_region *mem) { -- cgit v1.2.2