From 40dcaa9f69fa303ddcb5ea65baf4efefed3aec4b Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Wed, 9 Mar 2011 15:41:04 +0800 Subject: [PATCH] KVM: fix rcu usage in init_rmode_* functions 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 Signed-off-by: Avi Kivity --- arch/x86/kvm/vmx.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 3febb763cb7f..d8475a26add6 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2397,11 +2397,12 @@ static bool guest_state_valid(struct kvm_vcpu *vcpu) static int init_rmode_tss(struct kvm *kvm) { - gfn_t fn = rmode_tss_base(kvm) >> PAGE_SHIFT; + gfn_t fn; u16 data = 0; - int ret = 0; - int r; + int r, idx, ret = 0; + idx = srcu_read_lock(&kvm->srcu); + fn = rmode_tss_base(kvm) >> PAGE_SHIFT; r = kvm_clear_guest_page(kvm, fn, 0, PAGE_SIZE); if (r < 0) goto out; @@ -2425,12 +2426,13 @@ static int init_rmode_tss(struct kvm *kvm) ret = 1; out: + srcu_read_unlock(&kvm->srcu, idx); return ret; } static int init_rmode_identity_map(struct kvm *kvm) { - int i, r, ret; + int i, idx, r, ret; pfn_t identity_map_pfn; u32 tmp; @@ -2445,6 +2447,7 @@ static int init_rmode_identity_map(struct kvm *kvm) return 1; ret = 0; 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); if (r < 0) goto out; @@ -2460,6 +2463,7 @@ static int init_rmode_identity_map(struct kvm *kvm) kvm->arch.ept_identity_pagetable_done = true; ret = 1; out: + srcu_read_unlock(&kvm->srcu, idx); return ret; } -- 2.39.5