Commit 90d83dc3 authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Avi Kivity
Browse files

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: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 9beeaa2d

arch/ia64/kvm/kvm-ia64.c

+1 −1
Original line number Diff line number Diff line
@@ -1381,7 +1381,7 @@ static void kvm_release_vm_pages(struct kvm *kvm) 
	int i, j;

	unsigned long base_gfn;



	slots = rcu_dereference(kvm->memslots);

	slots = kvm_memslots(kvm);

	for (i = 0; i < slots->nmemslots; i++) {

		memslot = &slots->memslots[i];

		base_gfn = memslot->base_gfn;

arch/s390/kvm/kvm-s390.h

+1 −1
Original line number Diff line number Diff line
@@ -72,7 +72,7 @@ static inline void kvm_s390_vcpu_set_mem(struct kvm_vcpu *vcpu) 
	struct kvm_memslots *memslots;



	idx = srcu_read_lock(&vcpu->kvm->srcu);

	memslots = rcu_dereference(vcpu->kvm->memslots);

	memslots = kvm_memslots(vcpu->kvm);



	mem = &memslots->memslots[0];

arch/x86/kvm/mmu.c

+4 −3
Original line number Diff line number Diff line
@@ -787,7 +787,7 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, 
	int retval = 0;

	struct kvm_memslots *slots;



	slots = rcu_dereference(kvm->memslots);

	slots = kvm_memslots(kvm);



	for (i = 0; i < slots->nmemslots; i++) {

		struct kvm_memory_slot *memslot = &slots->memslots[i];
@@ -3016,7 +3016,8 @@ unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm) 
	unsigned int  nr_pages = 0;

	struct kvm_memslots *slots;



	slots = rcu_dereference(kvm->memslots);

	slots = kvm_memslots(kvm);



	for (i = 0; i < slots->nmemslots; i++)

		nr_pages += slots->memslots[i].npages;
@@ -3292,7 +3293,7 @@ static int count_rmaps(struct kvm_vcpu *vcpu) 
	int i, j, k, idx;



	idx = srcu_read_lock(&kvm->srcu);

	slots = rcu_dereference(kvm->memslots);

	slots = kvm_memslots(kvm);

	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {

		struct kvm_memory_slot *m = &slots->memslots[i];

		struct kvm_rmap_desc *d;

arch/x86/kvm/vmx.c

+1 −1
Original line number Diff line number Diff line
@@ -1558,7 +1558,7 @@ static gva_t rmode_tss_base(struct kvm *kvm) 
		struct kvm_memslots *slots;

		gfn_t base_gfn;



		slots = rcu_dereference(kvm->memslots);

		slots = kvm_memslots(kvm);

		base_gfn = kvm->memslots->memslots[0].base_gfn +

				 kvm->memslots->memslots[0].npages - 3;

		return base_gfn << PAGE_SHIFT;

arch/x86/kvm/x86.c

+2 −2
Original line number Diff line number Diff line
@@ -2497,7 +2497,7 @@ gfn_t unalias_gfn_instantiation(struct kvm *kvm, gfn_t gfn) 
	struct kvm_mem_alias *alias;

	struct kvm_mem_aliases *aliases;



	aliases = rcu_dereference(kvm->arch.aliases);

	aliases = kvm_aliases(kvm);



	for (i = 0; i < aliases->naliases; ++i) {

		alias = &aliases->aliases[i];
@@ -2516,7 +2516,7 @@ gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn) 
	struct kvm_mem_alias *alias;

	struct kvm_mem_aliases *aliases;



	aliases = rcu_dereference(kvm->arch.aliases);

	aliases = kvm_aliases(kvm);



	for (i = 0; i < aliases->naliases; ++i) {

		alias = &aliases->aliases[i];