From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from [222.73.24.84] (helo=song.cn.fujitsu.com) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TgA1j-0002zV-G9 for kexec@lists.infradead.org; Wed, 05 Dec 2012 08:08:20 +0000 Message-ID: <50BF0076.10205@cn.fujitsu.com> Date: Wed, 05 Dec 2012 16:06:14 +0800 From: Zhang Yanfei MIME-Version: 1.0 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> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Marcelo Tosatti , Gleb Natapov , "Eric W. Biederman" Cc: "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "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(); } -- 1.7.1 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec