Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752702Ab3FWNsK (ORCPT ); Sun, 23 Jun 2013 09:48:10 -0400 Received: from e23smtp07.au.ibm.com ([202.81.31.140]:46939 "EHLO e23smtp07.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751738Ab3FWNsG (ORCPT ); Sun, 23 Jun 2013 09:48:06 -0400 From: "Srivatsa S. Bhat" Subject: [PATCH 29/45] kvm/vmx: Use get/put_online_cpus_atomic() to prevent CPU offline To: tglx@linutronix.de, peterz@infradead.org, tj@kernel.org, oleg@redhat.com, paulmck@linux.vnet.ibm.com, rusty@rustcorp.com.au, mingo@kernel.org, akpm@linux-foundation.org, namhyung@kernel.org, walken@google.com, vincent.guittot@linaro.org, laijs@cn.fujitsu.com Cc: rostedt@goodmis.org, wangyun@linux.vnet.ibm.com, xiaoguangrong@linux.vnet.ibm.com, sbw@mit.edu, fweisbec@gmail.com, zhong@linux.vnet.ibm.com, nikunj@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, linux-pm@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Gleb Natapov , Paolo Bonzini , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, kvm@vger.kernel.org Date: Sun, 23 Jun 2013 19:14:27 +0530 Message-ID: <20130623134423.19094.90107.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130623133642.19094.16038.stgit@srivatsabhat.in.ibm.com> References: <20130623133642.19094.16038.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13062313-0260-0000-0000-0000033402C3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2441 Lines: 83 Once stop_machine() is gone from the CPU offline path, we won't be able to depend on disabling preemption to prevent CPUs from going offline from under us. Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going offline, while invoking from atomic context. Cc: Gleb Natapov Cc: Paolo Bonzini Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: x86@kernel.org Cc: kvm@vger.kernel.org Signed-off-by: Srivatsa S. Bhat --- arch/x86/kvm/vmx.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 260a919..4e1e966 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -7164,12 +7165,12 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) if (!vmm_exclusive) kvm_cpu_vmxoff(); - cpu = get_cpu(); + cpu = get_online_cpus_atomic(); vmx_vcpu_load(&vmx->vcpu, cpu); vmx->vcpu.cpu = cpu; err = vmx_vcpu_setup(vmx); vmx_vcpu_put(&vmx->vcpu); - put_cpu(); + put_online_cpus_atomic(); if (err) goto free_vmcs; if (vm_need_virtualize_apic_accesses(kvm)) { @@ -7706,12 +7707,12 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) vmx->nested.vmcs01_tsc_offset = vmcs_read64(TSC_OFFSET); - cpu = get_cpu(); + cpu = get_online_cpus_atomic(); vmx->loaded_vmcs = vmcs02; vmx_vcpu_put(vcpu); vmx_vcpu_load(vcpu, cpu); vcpu->cpu = cpu; - put_cpu(); + put_online_cpus_atomic(); vmx_segment_cache_clear(vmx); @@ -8023,12 +8024,12 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu) leave_guest_mode(vcpu); prepare_vmcs12(vcpu, vmcs12); - cpu = get_cpu(); + cpu = get_online_cpus_atomic(); vmx->loaded_vmcs = &vmx->vmcs01; vmx_vcpu_put(vcpu); vmx_vcpu_load(vcpu, cpu); vcpu->cpu = cpu; - put_cpu(); + put_online_cpus_atomic(); vmx_segment_cache_clear(vmx); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/