diff options
author | Paul Mackerras <paulus@samba.org> | 2011-12-15 03:03:22 +0100 |
---|---|---|
committer | Avi Kivity <avi@redhat.com> | 2012-03-05 13:52:39 +0100 |
commit | 82ed36164c8a8ee685ea3fb3c4f741214ac070ca (patch) | |
tree | 259f2e7a839d7506d7fbb9a3be6763ad2f5e9fd2 /arch/powerpc/kvm | |
parent | KVM: PPC: Book3S HV: Use the hardware referenced bit for kvm_age_hva (diff) | |
download | linux-82ed36164c8a8ee685ea3fb3c4f741214ac070ca.tar.xz linux-82ed36164c8a8ee685ea3fb3c4f741214ac070ca.zip |
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 <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/powerpc/kvm')
-rw-r--r-- | arch/powerpc/kvm/book3s.c | 39 | ||||
-rw-r--r-- | arch/powerpc/kvm/book3s_64_mmu_hv.c | 69 | ||||
-rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 37 | ||||
-rw-r--r-- | arch/powerpc/kvm/book3s_pr.c | 39 |
4 files changed, 145 insertions, 39 deletions
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index 6bf7e0582c5a..7d54f4ed6d96 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -477,45 +477,6 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu, return 0; } -/* - * 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; -} - void kvmppc_decrementer_func(unsigned long data) { struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data; diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index 926e2b92bdab..783cd3510c93 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -870,6 +870,75 @@ void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte) kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); } +static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp) +{ + struct revmap_entry *rev = kvm->arch.revmap; + unsigned long head, i, j; + unsigned long *hptep; + int ret = 0; + + retry: + lock_rmap(rmapp); + if (*rmapp & KVMPPC_RMAP_CHANGED) { + *rmapp &= ~KVMPPC_RMAP_CHANGED; + ret = 1; + } + if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { + unlock_rmap(rmapp); + return ret; + } + + i = head = *rmapp & KVMPPC_RMAP_INDEX; + do { + hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); + j = rev[i].forw; + + if (!(hptep[1] & HPTE_R_C)) + continue; + + if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { + /* unlock rmap before spinning on the HPTE lock */ + unlock_rmap(rmapp); + while (hptep[0] & HPTE_V_HVLOCK) + cpu_relax(); + goto retry; + } + + /* Now check and modify the HPTE */ + if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_C)) { + /* need to make it temporarily absent to clear C */ + hptep[0] |= HPTE_V_ABSENT; + kvmppc_invalidate_hpte(kvm, hptep, i); + hptep[1] &= ~HPTE_R_C; + eieio(); + hptep[0] = (hptep[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; + rev[i].guest_rpte |= HPTE_R_C; + ret = 1; + } + hptep[0] &= ~HPTE_V_HVLOCK; + } while ((i = j) != head); + + unlock_rmap(rmapp); + return ret; +} + +long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot) +{ + unsigned long i; + unsigned long *rmapp, *map; + + preempt_disable(); + rmapp = memslot->rmap; + map = memslot->dirty_bitmap; + for (i = 0; i < memslot->npages; ++i) { + if (kvm_test_clear_dirty(kvm, rmapp)) + __set_bit_le(i, map); + ++rmapp; + } + preempt_enable(); + return 0; +} + void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa, unsigned long *nb_ret) { diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 86c4191cb75b..0f1ddf0ec032 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1072,6 +1072,43 @@ long kvm_vm_ioctl_allocate_rma(struct kvm *kvm, struct kvm_allocate_rma *ret) return fd; } +/* + * 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; + int r; + unsigned long n; + + mutex_lock(&kvm->slots_lock); + + r = -EINVAL; + if (log->slot >= KVM_MEMORY_SLOTS) + goto out; + + memslot = id_to_memslot(kvm->memslots, log->slot); + r = -ENOENT; + if (!memslot->dirty_bitmap) + goto out; + + n = kvm_dirty_bitmap_bytes(memslot); + memset(memslot->dirty_bitmap, 0, n); + + r = kvmppc_hv_get_dirty_log(kvm, memslot); + if (r) + goto out; + + r = -EFAULT; + if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n)) + goto out; + + r = 0; +out: + mutex_unlock(&kvm->slots_lock); + return r; +} + static unsigned long slb_pgsize_encoding(unsigned long psize) { unsigned long senc = 0; 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) { |