From e6c7d32172f10b68fa9a3be05aa1231352a52171 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Wed, 28 Nov 2012 20:53:15 +0800 Subject: [PATCH] KVM: VMX: fix invalid cpu passed to smp_call_function_single In loaded_vmcs_clear, loaded_vmcs->cpu is the fist parameter passed to smp_call_function_single, if the target cpu is downing (doing cpu hot remove), loaded_vmcs->cpu can become -1 then -1 is passed to smp_call_function_single It can be triggered when vcpu is being destroyed, loaded_vmcs_clear is called in the preemptionable context Signed-off-by: Xiao Guangrong Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/vmx.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index bb18923bf632..4406374e3b6d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1007,9 +1007,11 @@ static void __loaded_vmcs_clear(void *arg) static void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs) { - if (loaded_vmcs->cpu != -1) - smp_call_function_single( - loaded_vmcs->cpu, __loaded_vmcs_clear, loaded_vmcs, 1); + int cpu = loaded_vmcs->cpu; + + if (cpu != -1) + smp_call_function_single(cpu, + __loaded_vmcs_clear, loaded_vmcs, 1); } static inline void vpid_sync_vcpu_single(struct vcpu_vmx *vmx)