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authorJan Kiszka <jan.kiszka@web.de>2009-04-13 11:59:32 +0200
committerAvi Kivity <avi@redhat.com>2009-04-22 13:52:09 +0300
commit4cd481f68dde99ac416003b825c835f71e364393 (patch)
treeee30cd2e24534285cdb2b4315e7d441c9689ea99
parentbf47a760f66add7870fba33ab50f58b550d6bbd1 (diff)
KVM: Fix overlapping check for memory slots
When checking for overlapping slots on registration of a new one, kvm currently also considers zero-length (ie. deleted) slots and rejects requests incorrectly. This finally denies user space from joining slots. Fix the check by skipping deleted slots and advertise this via a KVM_CAP_JOIN_MEMORY_REGIONS_WORKS. Cc: stable@kernel.org Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
-rw-r--r--include/linux/kvm.h2
-rw-r--r--virt/kvm/kvm_main.c3
2 files changed, 4 insertions, 1 deletions
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 311a073afe8a..8cc137911b34 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -409,6 +409,8 @@ struct kvm_trace_rec {
#ifdef __KVM_HAVE_DEVICE_ASSIGNMENT
#define KVM_CAP_DEVICE_DEASSIGNMENT 27
#endif
+/* Another bug in KVM_SET_USER_MEMORY_REGION fixed: */
+#define KVM_CAP_JOIN_MEMORY_REGIONS_WORKS 30
#ifdef KVM_CAP_IRQ_ROUTING
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 28d693a1ee8f..1ecbe2391c8b 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -961,7 +961,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
struct kvm_memory_slot *s = &kvm->memslots[i];
- if (s == memslot)
+ if (s == memslot || !s->npages)
continue;
if (!((base_gfn + npages <= s->base_gfn) ||
(base_gfn >= s->base_gfn + s->npages)))
@@ -1983,6 +1983,7 @@ static long kvm_dev_ioctl_check_extension_generic(long arg)
switch (arg) {
case KVM_CAP_USER_MEMORY:
case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
+ case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
return 1;
#ifdef CONFIG_HAVE_KVM_IRQCHIP
case KVM_CAP_IRQ_ROUTING: