KVM: use the correct RCU API for PROVE_RCU=y
The RCU/SRCU API have already changed for proving RCU usage.
I got the following dmesg when PROVE_RCU=y because we used incorrect API.
This patch coverts rcu_deference() to srcu_dereference() or family API.
===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
arch/x86/kvm/mmu.c:3020 invoked rcu_dereference_check() without protection!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 0
2 locks held by qemu-system-x86/8550:
#0: (&kvm->slots_lock){+.+.+.}, at: [<ffffffffa011a6ac>] kvm_set_memory_region+0x29/0x50 [kvm]
#1: (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa012262d>] kvm_arch_commit_memory_region+0xa6/0xe2 [kvm]
stack backtrace:
Pid: 8550, comm: qemu-system-x86 Not tainted 2.6.34-rc4-tip-01028-g939eab1 #27
Call Trace:
[<ffffffff8106c59e>] lockdep_rcu_dereference+0xaa/0xb3
[<ffffffffa012f6c1>] kvm_mmu_calculate_mmu_pages+0x44/0x7d [kvm]
[<ffffffffa012263e>] kvm_arch_commit_memory_region+0xb7/0xe2 [kvm]
[<ffffffffa011a5d7>] __kvm_set_memory_region+0x636/0x6e2 [kvm]
[<ffffffffa011a6ba>] kvm_set_memory_region+0x37/0x50 [kvm]
[<ffffffffa015e956>] vmx_set_tss_addr+0x46/0x5a [kvm_intel]
[<ffffffffa0126592>] kvm_arch_vm_ioctl+0x17a/0xcf8 [kvm]
[<ffffffff810a8692>] ? unlock_page+0x27/0x2c
[<ffffffff810bf879>] ? __do_fault+0x3a9/0x3e1
[<ffffffffa011b12f>] kvm_vm_ioctl+0x364/0x38d [kvm]
[<ffffffff81060cfa>] ? up_read+0x23/0x3d
[<ffffffff810f3587>] vfs_ioctl+0x32/0xa6
[<ffffffff810f3b19>] do_vfs_ioctl+0x495/0x4db
[<ffffffff810e6b2f>] ? fget_light+0xc2/0x241
[<ffffffff810e416c>] ? do_sys_open+0x104/0x116
[<ffffffff81382d6d>] ? retint_swapgs+0xe/0x13
[<ffffffff810f3ba6>] sys_ioctl+0x47/0x6a
[<ffffffff810021db>] system_call_fastpath+0x16/0x1b
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c
index 80fd3ad..37ca71e 100644
--- a/virt/kvm/iommu.c
+++ b/virt/kvm/iommu.c
@@ -78,7 +78,7 @@
int i, r = 0;
struct kvm_memslots *slots;
- slots = rcu_dereference(kvm->memslots);
+ slots = kvm_memslots(kvm);
for (i = 0; i < slots->nmemslots; i++) {
r = kvm_iommu_map_pages(kvm, &slots->memslots[i]);
@@ -217,7 +217,7 @@
int i;
struct kvm_memslots *slots;
- slots = rcu_dereference(kvm->memslots);
+ slots = kvm_memslots(kvm);
for (i = 0; i < slots->nmemslots; i++) {
kvm_iommu_put_pages(kvm, slots->memslots[i].base_gfn,
