From patchwork Wed Dec 5 08:06:14 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yanfei Zhang X-Patchwork-Id: 1840521 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 54DE040B17 for ; Wed, 5 Dec 2012 08:08:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752097Ab2LEIIQ (ORCPT ); Wed, 5 Dec 2012 03:08:16 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:20204 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751648Ab2LEIIM (ORCPT ); Wed, 5 Dec 2012 03:08:12 -0500 X-IronPort-AV: E=Sophos;i="4.83,376,1352044800"; d="scan'208";a="6337526" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 05 Dec 2012 16:06:23 +0800 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id qB588Rje007146; Wed, 5 Dec 2012 16:08:27 +0800 Received: from [10.167.226.121] ([10.167.226.121]) by fnstmail02.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.3) with ESMTP id 2012120516073240-250200 ; Wed, 5 Dec 2012 16:07:32 +0800 Message-ID: <50BF0076.10205@cn.fujitsu.com> Date: Wed, 05 Dec 2012 16:06:14 +0800 From: Zhang Yanfei User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.8) Gecko/20121012 Thunderbird/10.0.8 MIME-Version: 1.0 To: Marcelo Tosatti , Gleb Natapov , "Eric W. Biederman" CC: "kexec@lists.infradead.org" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v10 2/2] KVM-INTEL: provide the vmclear function and a bitmap to support VMCLEAR in kdump References: <50BEFEBA.6070602@cn.fujitsu.com> In-Reply-To: <50BEFEBA.6070602@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/12/05 16:07:32, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/12/05 16:07:32, Serialize complete at 2012/12/05 16:07:32 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The vmclear function will be assigned to the callback function pointer when loading kvm-intel module. And the bitmap indicates whether we should do VMCLEAR operation in kdump. The bits in the bitmap are set/unset according to different conditions. Signed-off-by: Zhang Yanfei --- arch/x86/kvm/vmx.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 67 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index f858159..2d5226a 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -42,6 +42,7 @@ #include #include #include +#include #include "trace.h" @@ -992,6 +993,46 @@ static void vmcs_load(struct vmcs *vmcs) vmcs, phys_addr); } +#ifdef CONFIG_KEXEC +/* + * This bitmap is used to indicate whether the vmclear + * operation is enabled on all cpus. All disabled by + * default. + */ +static cpumask_t crash_vmclear_enabled_bitmap = CPU_MASK_NONE; + +static inline void crash_enable_local_vmclear(int cpu) +{ + cpumask_set_cpu(cpu, &crash_vmclear_enabled_bitmap); +} + +static inline void crash_disable_local_vmclear(int cpu) +{ + cpumask_clear_cpu(cpu, &crash_vmclear_enabled_bitmap); +} + +static inline int crash_local_vmclear_enabled(int cpu) +{ + return cpumask_test_cpu(cpu, &crash_vmclear_enabled_bitmap); +} + +static void crash_vmclear_local_loaded_vmcss(void) +{ + int cpu = raw_smp_processor_id(); + struct loaded_vmcs *v; + + if (!crash_local_vmclear_enabled(cpu)) + return; + + list_for_each_entry(v, &per_cpu(loaded_vmcss_on_cpu, cpu), + loaded_vmcss_on_cpu_link) + vmcs_clear(v->vmcs); +} +#else +static inline void crash_enable_local_vmclear(int cpu) { } +static inline void crash_disable_local_vmclear(int cpu) { } +#endif /* CONFIG_KEXEC */ + static void __loaded_vmcs_clear(void *arg) { struct loaded_vmcs *loaded_vmcs = arg; @@ -1001,8 +1042,10 @@ static void __loaded_vmcs_clear(void *arg) return; /* vcpu migration can race with cpu offline */ if (per_cpu(current_vmcs, cpu) == loaded_vmcs->vmcs) per_cpu(current_vmcs, cpu) = NULL; + crash_disable_local_vmclear(cpu); list_del(&loaded_vmcs->loaded_vmcss_on_cpu_link); loaded_vmcs_init(loaded_vmcs); + crash_enable_local_vmclear(cpu); } static void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs) @@ -1535,8 +1578,10 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu) kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu); local_irq_disable(); + crash_disable_local_vmclear(cpu); list_add(&vmx->loaded_vmcs->loaded_vmcss_on_cpu_link, &per_cpu(loaded_vmcss_on_cpu, cpu)); + crash_enable_local_vmclear(cpu); local_irq_enable(); /* @@ -2341,6 +2386,18 @@ static int hardware_enable(void *garbage) return -EBUSY; INIT_LIST_HEAD(&per_cpu(loaded_vmcss_on_cpu, cpu)); + + /* + * Now we can enable the vmclear operation in kdump + * since the loaded_vmcss_on_cpu list on this cpu + * has been initialized. + * + * Though the cpu is not in VMX operation now, there + * is no problem to enable the vmclear operation + * for the loaded_vmcss_on_cpu list is empty! + */ + crash_enable_local_vmclear(cpu); + rdmsrl(MSR_IA32_FEATURE_CONTROL, old); test_bits = FEATURE_CONTROL_LOCKED; @@ -7367,6 +7424,11 @@ static int __init vmx_init(void) if (r) goto out3; +#ifdef CONFIG_KEXEC + rcu_assign_pointer(crash_vmclear_loaded_vmcss, + crash_vmclear_local_loaded_vmcss); +#endif + vmx_disable_intercept_for_msr(MSR_FS_BASE, false); vmx_disable_intercept_for_msr(MSR_GS_BASE, false); vmx_disable_intercept_for_msr(MSR_KERNEL_GS_BASE, true); @@ -7404,6 +7466,11 @@ static void __exit vmx_exit(void) free_page((unsigned long)vmx_io_bitmap_b); free_page((unsigned long)vmx_io_bitmap_a); +#ifdef CONFIG_KEXEC + rcu_assign_pointer(crash_vmclear_loaded_vmcss, NULL); + synchronize_rcu(); +#endif + kvm_exit(); }