@@ -1860,7 +1860,6 @@ static int kvmppc_vcpu_run_pr(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
static int kvm_vm_ioctl_get_dirty_log_pr(struct kvm *kvm,
struct kvm_dirty_log *log)
{
- struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
struct kvm_vcpu *vcpu;
ulong ga, ga_end;
@@ -1870,15 +1869,12 @@ static int kvm_vm_ioctl_get_dirty_log_pr(struct kvm *kvm,
mutex_lock(&kvm->slots_lock);
- r = kvm_get_dirty_log(kvm, log, &is_dirty);
+ r = kvm_get_dirty_log(kvm, log, &is_dirty, &memslot);
if (r)
goto out;
/* If nothing is dirty, don't bother messing with page tables. */
if (is_dirty) {
- slots = kvm_memslots(kvm);
- memslot = id_to_memslot(slots, log->slot);
-
ga = memslot->base_gfn << PAGE_SHIFT;
ga_end = ga + (memslot->npages << PAGE_SHIFT);
@@ -613,9 +613,8 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
{
int r;
unsigned long n;
- struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
- int is_dirty = 0;
+ int is_dirty;
if (kvm_is_ucontrol(kvm))
return -EINVAL;
@@ -626,14 +625,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
if (log->slot >= KVM_USER_MEM_SLOTS)
goto out;
- slots = kvm_memslots(kvm);
- memslot = id_to_memslot(slots, log->slot);
- r = -ENOENT;
- if (!memslot->dirty_bitmap)
- goto out;
-
- kvm_arch_sync_dirty_log(kvm, memslot);
- r = kvm_get_dirty_log(kvm, log, &is_dirty);
+ r = kvm_get_dirty_log(kvm, log, &is_dirty, &memslot);
if (r)
goto out;
@@ -809,7 +809,7 @@ void kvm_arch_dirty_log_tlb_flush(struct kvm *kvm,
#else /* !CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */
int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log);
int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log,
- int *is_dirty);
+ int *is_dirty, struct kvm_memory_slot **memslot);
#endif
int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
@@ -1136,31 +1136,42 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
}
#ifndef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
-int kvm_get_dirty_log(struct kvm *kvm,
- struct kvm_dirty_log *log, int *is_dirty)
+/**
+ * kvm_get_dirty_log - get a snapshot of dirty pages
+ * @kvm: pointer to kvm instance
+ * @log: slot id and address to which we copy the log
+ * @is_dirty: set to '1' if any dirty pages were found
+ * @memslot: set to the associated memslot, always valid on success
+ */
+int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log,
+ int *is_dirty, struct kvm_memory_slot **memslot)
{
struct kvm_memslots *slots;
- struct kvm_memory_slot *memslot;
int i, as_id, id;
unsigned long n;
unsigned long any = 0;
+ *memslot = NULL;
+ *is_dirty = 0;
+
as_id = log->slot >> 16;
id = (u16)log->slot;
if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
return -EINVAL;
slots = __kvm_memslots(kvm, as_id);
- memslot = id_to_memslot(slots, id);
- if (!memslot->dirty_bitmap)
+ *memslot = id_to_memslot(slots, id);
+ if (!(*memslot)->dirty_bitmap)
return -ENOENT;
- n = kvm_dirty_bitmap_bytes(memslot);
+ kvm_arch_sync_dirty_log(kvm, *memslot);
+
+ n = kvm_dirty_bitmap_bytes(*memslot);
for (i = 0; !any && i < n/sizeof(long); ++i)
- any = memslot->dirty_bitmap[i];
+ any = (*memslot)->dirty_bitmap[i];
- if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
+ if (copy_to_user(log->dirty_bitmap, (*memslot)->dirty_bitmap, n))
return -EFAULT;
if (any)
Rework kvm_get_dirty_log() so that it "returns" the associated memslot on success. A future patch will rework memslot handling such that id_to_memslot() can return NULL, returning the memslot makes it more obvious that the validity of the memslot has been verified, i.e. precludes the need to add validity checks in the arch code that are technically unnecessary. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- arch/powerpc/kvm/book3s_pr.c | 6 +----- arch/s390/kvm/kvm-s390.c | 12 ++---------- include/linux/kvm_host.h | 2 +- virt/kvm/kvm_main.c | 27 +++++++++++++++++++-------- 4 files changed, 23 insertions(+), 24 deletions(-)