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| author | Alex Williamson <alex.williamson@redhat.com> | 2012-12-21 15:20:16 (GMT) |
|---|---|---|
| committer | Gleb Natapov <gleb@redhat.com> | 2012-12-23 08:17:38 (GMT) |
| commit | 116c14c0191f3378e6567af296529ac287e85aa2 (patch) | |
| tree | 98b6f582d2d2f83da21918a95bfea48f1d37d84e | |
| parent | 871a069db9f29938071b3d214cb964980071ffbf (diff) | |
| download | linux-116c14c0191f3378e6567af296529ac287e85aa2.tar.xz | |
kvm: Fix memory slot generation updates
Previous patch "kvm: Minor memory slot optimization" (b7f69c555ca43)
overlooked the generation field of the memory slots. Re-using the
original memory slots left us with with two slightly different memory
slots with the same generation. To fix this, make update_memslots()
take a new parameter to specify the last generation. This also makes
generation management more explicit to avoid such problems in the future.
Reported-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
| -rw-r--r-- | include/linux/kvm_host.h | 3 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 9 |
2 files changed, 7 insertions, 5 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 32fdc45..cbe0d68 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -428,7 +428,8 @@ void kvm_exit(void); void kvm_get_kvm(struct kvm *kvm); void kvm_put_kvm(struct kvm *kvm); -void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new); +void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new, + u64 last_generation); static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm) { diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index bd31096..14cbae8 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -672,7 +672,8 @@ static void sort_memslots(struct kvm_memslots *slots) slots->id_to_index[slots->memslots[i].id] = i; } -void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new) +void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new, + u64 last_generation) { if (new) { int id = new->id; @@ -684,7 +685,7 @@ void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new) sort_memslots(slots); } - slots->generation++; + slots->generation = last_generation + 1; } static int check_memory_region_flags(struct kvm_userspace_memory_region *mem) @@ -819,7 +820,7 @@ int __kvm_set_memory_region(struct kvm *kvm, slot = id_to_memslot(slots, mem->slot); slot->flags |= KVM_MEMSLOT_INVALID; - update_memslots(slots, NULL); + update_memslots(slots, NULL, kvm->memslots->generation); old_memslots = kvm->memslots; rcu_assign_pointer(kvm->memslots, slots); @@ -867,7 +868,7 @@ int __kvm_set_memory_region(struct kvm *kvm, memset(&new.arch, 0, sizeof(new.arch)); } - update_memslots(slots, &new); + update_memslots(slots, &new, kvm->memslots->generation); old_memslots = kvm->memslots; rcu_assign_pointer(kvm->memslots, slots); synchronize_srcu_expedited(&kvm->srcu); |