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authorSheng Yang <sheng@linux.intel.com>2010-07-01 15:00:50 +0800
committerAvi Kivity <avi@redhat.com>2010-08-01 10:47:29 +0300
commit95c87e2b4460a488ec7ce42f273893e410ab385a (patch)
tree4b9375cfcdd0cbfafe15a094d39057848ac748c3 /virt
parentfef093bec0364ff5e6fd488cd81637f6bb3a2d0d (diff)
downloadkernel-95c87e2b4460a488ec7ce42f273893e410ab385a.tar.gz
KVM: Fix IOMMU memslot reference warning
This patch fixes the following warning. =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- include/linux/kvm_host.h:259 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 no locks held by qemu-system-x86/29679. stack backtrace: Pid: 29679, comm: qemu-system-x86 Not tainted 2.6.35-rc3+ #200 Call Trace: [<ffffffff810a224e>] lockdep_rcu_dereference+0xa8/0xb1 [<ffffffffa018a06f>] kvm_iommu_unmap_memslots+0xc9/0xde [kvm] [<ffffffffa018a0c4>] kvm_iommu_unmap_guest+0x40/0x4e [kvm] [<ffffffffa018f772>] kvm_arch_destroy_vm+0x1a/0x186 [kvm] [<ffffffffa01800d0>] kvm_put_kvm+0x110/0x167 [kvm] [<ffffffffa0180ecc>] kvm_vcpu_release+0x18/0x1c [kvm] [<ffffffff81156f5d>] fput+0x22a/0x3a0 [<ffffffff81152288>] filp_close+0xb4/0xcd [<ffffffff8106599f>] put_files_struct+0x1b7/0x36b [<ffffffff81065830>] ? put_files_struct+0x48/0x36b [<ffffffff8131ee59>] ? do_raw_spin_unlock+0x118/0x160 [<ffffffff81065bc0>] exit_files+0x6d/0x75 [<ffffffff81068348>] do_exit+0x47d/0xc60 [<ffffffff8177e7b5>] ? _raw_spin_unlock_irq+0x30/0x36 [<ffffffff81068bfa>] do_group_exit+0xcf/0x134 [<ffffffff81080790>] get_signal_to_deliver+0x732/0x81d [<ffffffff81095996>] ? cpu_clock+0x4e/0x60 [<ffffffff81002082>] do_notify_resume+0x117/0xc43 [<ffffffff810a2fa3>] ? trace_hardirqs_on+0xd/0xf [<ffffffff81080d79>] ? sys_rt_sigtimedwait+0x2b5/0x3bf [<ffffffff8177d9f2>] ? trace_hardirqs_off_thunk+0x3a/0x3c [<ffffffff81003221>] ? sysret_signal+0x5/0x3d [<ffffffff8100343b>] int_signal+0x12/0x17 Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/iommu.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c
index 673c88a8efe9..779559552ce7 100644
--- a/virt/kvm/iommu.c
+++ b/virt/kvm/iommu.c
@@ -126,9 +126,10 @@ unmap_pages:
static int kvm_iommu_map_memslots(struct kvm *kvm)
{
- int i, r = 0;
+ int i, idx, r = 0;
struct kvm_memslots *slots;
+ idx = srcu_read_lock(&kvm->srcu);
slots = kvm_memslots(kvm);
for (i = 0; i < slots->nmemslots; i++) {
@@ -136,6 +137,7 @@ static int kvm_iommu_map_memslots(struct kvm *kvm)
if (r)
break;
}
+ srcu_read_unlock(&kvm->srcu, idx);
return r;
}
@@ -285,15 +287,17 @@ static void kvm_iommu_put_pages(struct kvm *kvm,
static int kvm_iommu_unmap_memslots(struct kvm *kvm)
{
- int i;
+ int i, idx;
struct kvm_memslots *slots;
+ idx = srcu_read_lock(&kvm->srcu);
slots = kvm_memslots(kvm);
for (i = 0; i < slots->nmemslots; i++) {
kvm_iommu_put_pages(kvm, slots->memslots[i].base_gfn,
slots->memslots[i].npages);
}
+ srcu_read_unlock(&kvm->srcu, idx);
return 0;
}