KVM: fix rcu usage in init_rmode_* functions (40dcaa9f) · Commits · 戴 / test

fix: [ 3494.671786] stack backtrace: [ 3494.671789] Pid: 10527, comm: qemu-system-x86 Not tainted 2.6.38-rc6+ #23 [ 3494.671790] Call Trace: [ 3494.671796] [] ? lockdep_rcu_dereference+0x9d/0xa5 [ 3494.671826] [] ? kvm_memslots+0x6b/0x73 [kvm] [ 3494.671834] [] ? gfn_to_memslot+0x16/0x4f [kvm] [ 3494.671843] [] ? gfn_to_hva+0x16/0x27 [kvm] [ 3494.671851] [] ? kvm_write_guest_page+0x31/0x83 [kvm] [ 3494.671861] [] ? kvm_clear_guest_page+0x1a/0x1c [kvm] [ 3494.671867] [] ? vmx_set_tss_addr+0x83/0x122 [kvm_intel] and: [ 8328.789599] stack backtrace: [ 8328.789601] Pid: 18736, comm: qemu-system-x86 Not tainted 2.6.38-rc6+ #23 [ 8328.789603] Call Trace: [ 8328.789609] [] ? lockdep_rcu_dereference+0x9d/0xa5 [ 8328.789621] [] ? kvm_memslots+0x6b/0x73 [kvm] [ 8328.789628] [] ? gfn_to_memslot+0x16/0x4f [kvm] [ 8328.789635] [] ? gfn_to_hva+0x16/0x27 [kvm] [ 8328.789643] [] ? kvm_write_guest_page+0x31/0x83 [kvm] [ 8328.789699] [] ? kvm_clear_guest_page+0x1a/0x1c [kvm] [ 8328.789713] [] ? vmx_create_vcpu+0x316/0x3c8 [kvm_intel] Signed-off-by:

Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by:

Avi Kivity <avi@redhat.com>

arch/x86/kvm/vmx.c

+8 −4

Original line number	Original line	Diff line number	Diff line
	@@ -2397,11 +2397,12 @@ static bool guest_state_valid(struct kvm_vcpu *vcpu)

	static int init_rmode_tss(struct kvm *kvm)		static int init_rmode_tss(struct kvm *kvm)
	{		{
	gfn_t fn = rmode_tss_base(kvm) >> PAGE_SHIFT;		gfn_t fn;
	u16 data = 0;		u16 data = 0;
	int ret = 0;		int r, idx, ret = 0;
	int r;

			idx = srcu_read_lock(&kvm->srcu);
			fn = rmode_tss_base(kvm) >> PAGE_SHIFT;
	r = kvm_clear_guest_page(kvm, fn, 0, PAGE_SIZE);		r = kvm_clear_guest_page(kvm, fn, 0, PAGE_SIZE);
	if (r < 0)		if (r < 0)
	goto out;		goto out;
	@@ -2425,12 +2426,13 @@ static int init_rmode_tss(struct kvm *kvm)

	ret = 1;		ret = 1;
	out:		out:
			srcu_read_unlock(&kvm->srcu, idx);
	return ret;		return ret;
	}		}

	static int init_rmode_identity_map(struct kvm *kvm)		static int init_rmode_identity_map(struct kvm *kvm)
	{		{
	int i, r, ret;		int i, idx, r, ret;
	pfn_t identity_map_pfn;		pfn_t identity_map_pfn;
	u32 tmp;		u32 tmp;

	@@ -2445,6 +2447,7 @@ static int init_rmode_identity_map(struct kvm *kvm)
	return 1;		return 1;
	ret = 0;		ret = 0;
	identity_map_pfn = kvm->arch.ept_identity_map_addr >> PAGE_SHIFT;		identity_map_pfn = kvm->arch.ept_identity_map_addr >> PAGE_SHIFT;
			idx = srcu_read_lock(&kvm->srcu);
	r = kvm_clear_guest_page(kvm, identity_map_pfn, 0, PAGE_SIZE);		r = kvm_clear_guest_page(kvm, identity_map_pfn, 0, PAGE_SIZE);
	if (r < 0)		if (r < 0)
	goto out;		goto out;
	@@ -2460,6 +2463,7 @@ static int init_rmode_identity_map(struct kvm *kvm)
	kvm->arch.ept_identity_pagetable_done = true;		kvm->arch.ept_identity_pagetable_done = true;
	ret = 1;		ret = 1;
	out:		out:
			srcu_read_unlock(&kvm->srcu, idx);
	return ret;		return ret;
	}		}

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