* [PATCH v5 0/2] x86: vmclear vmcss on all cpus when doing kdump if necessary
@ 2012-11-21 2:21 Zhang Yanfei
2012-11-21 2:23 ` [PATCH v5 1/2] x86/kexec: VMCLEAR vmcss on all cpus " Zhang Yanfei
2012-11-21 2:26 ` [PATCH v5 2/2] KVM-INTEL: add a notifier and a bitmap to support VMCLEAR in kdump Zhang Yanfei
0 siblings, 2 replies; 6+ messages in thread
From: Zhang Yanfei @ 2012-11-21 2:21 UTC (permalink / raw)
To: x86, kexec, Marcelo Tosatti, Gleb Natapov; +Cc: linux-kernel, kvm
Currently, kdump just makes all the logical processors leave VMX operation by
executing VMXOFF instruction, so any VMCSs active on the logical processors may
be corrupted. But, sometimes, we need the VMCSs to debug guest images contained
in the host vmcore. To prevent the corruption, we should VMCLEAR the VMCSs before
executing the VMXOFF instruction.
The patch set provides a way to VMCLEAR vmcss related to guests on all cpus before
executing the VMXOFF when doing kdump. This is used to ensure the VMCSs in the
vmcore updated and non-corrupted.
Changelog from v4 to v5:
1. use an atomic notifier instead of function call, so
have all the vmclear codes in vmx.c.
Changelog from v3 to v4:
1. add a new percpu variable vmclear_skipped to skip
vmclear in kdump in some conditions.
Changelog from v2 to v3:
1. remove unnecessary conditions in function
cpu_emergency_clear_loaded_vmcss as Marcelo suggested.
Changelog from v1 to v2:
1. remove the sysctl and clear VMCSs unconditionally.
Zhang Yanfei (2):
x86/kexec: VMCLEAR vmcss on all cpus if necessary
KVM-INTEL: add a notifier and a bitmap to support VMCLEAR in kdump
arch/x86/include/asm/kexec.h | 2 +
arch/x86/kernel/crash.c | 25 ++++++++++++
arch/x86/kvm/vmx.c | 85 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 112 insertions(+), 0 deletions(-)
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v5 1/2] x86/kexec: VMCLEAR vmcss on all cpus if necessary
2012-11-21 2:21 [PATCH v5 0/2] x86: vmclear vmcss on all cpus when doing kdump if necessary Zhang Yanfei
@ 2012-11-21 2:23 ` Zhang Yanfei
2012-11-21 10:33 ` Gleb Natapov
2012-11-21 2:26 ` [PATCH v5 2/2] KVM-INTEL: add a notifier and a bitmap to support VMCLEAR in kdump Zhang Yanfei
1 sibling, 1 reply; 6+ messages in thread
From: Zhang Yanfei @ 2012-11-21 2:23 UTC (permalink / raw)
To: x86, kexec, Marcelo Tosatti, Gleb Natapov; +Cc: linux-kernel, kvm
This patch adds an atomic notifier list named crash_notifier_list.
When loading kvm-intel module, a notifier will be registered in
the list to enable vmcss loaded on all cpus to be VMCLEAR'd if
needed.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
---
arch/x86/include/asm/kexec.h | 2 ++
arch/x86/kernel/crash.c | 25 +++++++++++++++++++++++++
2 files changed, 27 insertions(+), 0 deletions(-)
diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
index 317ff17..5e22b00 100644
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -163,6 +163,8 @@ struct kimage_arch {
};
#endif
+extern struct atomic_notifier_head crash_notifier_list;
+
#endif /* __ASSEMBLY__ */
#endif /* _ASM_X86_KEXEC_H */
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 13ad899..0f3d5b4 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -16,6 +16,8 @@
#include <linux/delay.h>
#include <linux/elf.h>
#include <linux/elfcore.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
#include <asm/processor.h>
#include <asm/hardirq.h>
@@ -30,6 +32,19 @@
int in_crash_kexec;
+/*
+ * The list is used to VMCLEAR vmcss loaded on all
+ * cpus. And when loading kvm_intel module, the
+ * vmclear function will be registered in the list.
+ */
+ATOMIC_NOTIFIER_HEAD(crash_notifier_list);
+EXPORT_SYMBOL_GPL(crash_notifier_list);
+
+static inline void cpu_emergency_vmclear_loaded_vmcss(void)
+{
+ atomic_notifier_call_chain(&crash_notifier_list, 0, NULL);
+}
+
#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
static void kdump_nmi_callback(int cpu, struct pt_regs *regs)
@@ -46,6 +61,11 @@ static void kdump_nmi_callback(int cpu, struct pt_regs *regs)
#endif
crash_save_cpu(regs, cpu);
+ /*
+ * VMCLEAR vmcss loaded on all cpus if needed.
+ */
+ cpu_emergency_vmclear_loaded_vmcss();
+
/* Disable VMX or SVM if needed.
*
* We need to disable virtualization on all CPUs.
@@ -88,6 +108,11 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
kdump_nmi_shootdown_cpus();
+ /*
+ * VMCLEAR vmcss loaded on this cpu if needed.
+ */
+ cpu_emergency_vmclear_loaded_vmcss();
+
/* Booting kdump kernel with VMX or SVM enabled won't work,
* because (among other limitations) we can't disable paging
* with the virt flags.
--
1.7.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v5 2/2] KVM-INTEL: add a notifier and a bitmap to support VMCLEAR in kdump
2012-11-21 2:21 [PATCH v5 0/2] x86: vmclear vmcss on all cpus when doing kdump if necessary Zhang Yanfei
2012-11-21 2:23 ` [PATCH v5 1/2] x86/kexec: VMCLEAR vmcss on all cpus " Zhang Yanfei
@ 2012-11-21 2:26 ` Zhang Yanfei
2012-11-21 10:36 ` Gleb Natapov
1 sibling, 1 reply; 6+ messages in thread
From: Zhang Yanfei @ 2012-11-21 2:26 UTC (permalink / raw)
To: x86, kexec, Marcelo Tosatti, Gleb Natapov; +Cc: linux-kernel, kvm
The notifier will be registered in crash_notifier_list 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 <zhangyanfei@cn.fujitsu.com>
---
arch/x86/kvm/vmx.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 85 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 4ff0ab9..3bbdd75 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -41,6 +41,7 @@
#include <asm/i387.h>
#include <asm/xcr.h>
#include <asm/perf_event.h>
+#include <asm/kexec.h>
#include "trace.h"
@@ -963,6 +964,30 @@ 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);
+}
+#endif
+
static void __loaded_vmcs_clear(void *arg)
{
struct loaded_vmcs *loaded_vmcs = arg;
@@ -972,8 +997,14 @@ 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;
+#ifdef CONFIG_KEXEC
+ crash_disable_local_vmclear(cpu);
+#endif
list_del(&loaded_vmcs->loaded_vmcss_on_cpu_link);
loaded_vmcs_init(loaded_vmcs);
+#ifdef CONFIG_KEXEC
+ crash_enable_local_vmclear(cpu);
+#endif
}
static void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs)
@@ -1491,8 +1522,14 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
local_irq_disable();
+#ifdef CONFIG_KEXEC
+ crash_disable_local_vmclear(cpu);
+#endif
list_add(&vmx->loaded_vmcs->loaded_vmcss_on_cpu_link,
&per_cpu(loaded_vmcss_on_cpu, cpu));
+#ifdef CONFIG_KEXEC
+ crash_enable_local_vmclear(cpu);
+#endif
local_irq_enable();
/*
@@ -2302,6 +2339,20 @@ static int hardware_enable(void *garbage)
return -EBUSY;
INIT_LIST_HEAD(&per_cpu(loaded_vmcss_on_cpu, cpu));
+
+#ifdef CONFIG_KEXEC
+ /*
+ * 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);
+#endif
+
rdmsrl(MSR_IA32_FEATURE_CONTROL, old);
test_bits = FEATURE_CONTROL_LOCKED;
@@ -2335,6 +2386,22 @@ static void vmclear_local_loaded_vmcss(void)
__loaded_vmcs_clear(v);
}
+#ifdef CONFIG_KEXEC
+static int crash_vmclear_local_loaded_vmcss(struct notifier_block *this,
+ unsigned long val, void *ptr)
+{
+ int cpu = raw_smp_processor_id();
+
+ if (crash_local_vmclear_enabled(cpu))
+ vmclear_local_loaded_vmcss();
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block crash_vmclear_notifier = {
+ .notifier_call = crash_vmclear_local_loaded_vmcss,
+};
+#endif
/* Just like cpu_vmxoff(), but with the __kvm_handle_fault_on_reboot()
* tricks.
@@ -2348,6 +2415,14 @@ static void hardware_disable(void *garbage)
{
if (vmm_exclusive) {
vmclear_local_loaded_vmcss();
+#ifdef CONFIG_KEXEC
+ /*
+ * vmclear operation in kdump should be disabled here
+ * because the cpu is going to exit VMX operation
+ * and the loaded_vmcss_on_cpu list may not be empty!
+ */
+ crash_disable_local_vmclear(raw_smp_processor_id());
+#endif
kvm_cpu_vmxoff();
}
write_cr4(read_cr4() & ~X86_CR4_VMXE);
@@ -7230,6 +7305,11 @@ static int __init vmx_init(void)
if (r)
goto out3;
+#ifdef CONFIG_KEXEC
+ atomic_notifier_chain_register(&crash_notifier_list,
+ &crash_vmclear_notifier);
+#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);
@@ -7265,6 +7345,11 @@ 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
+ atomic_notifier_chain_unregister(&crash_notifier_list,
+ &crash_vmclear_notifier);
+#endif
+
kvm_exit();
}
--
1.7.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v5 1/2] x86/kexec: VMCLEAR vmcss on all cpus if necessary
2012-11-21 2:23 ` [PATCH v5 1/2] x86/kexec: VMCLEAR vmcss on all cpus " Zhang Yanfei
@ 2012-11-21 10:33 ` Gleb Natapov
[not found] ` <50AD78E3.7080901@cn.fujitsu.com>
0 siblings, 1 reply; 6+ messages in thread
From: Gleb Natapov @ 2012-11-21 10:33 UTC (permalink / raw)
To: Zhang Yanfei; +Cc: x86, kexec, Marcelo Tosatti, linux-kernel, kvm
On Wed, Nov 21, 2012 at 10:23:12AM +0800, Zhang Yanfei wrote:
> This patch adds an atomic notifier list named crash_notifier_list.
> When loading kvm-intel module, a notifier will be registered in
> the list to enable vmcss loaded on all cpus to be VMCLEAR'd if
> needed.
>
> Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
> ---
> arch/x86/include/asm/kexec.h | 2 ++
> arch/x86/kernel/crash.c | 25 +++++++++++++++++++++++++
> 2 files changed, 27 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
> index 317ff17..5e22b00 100644
> --- a/arch/x86/include/asm/kexec.h
> +++ b/arch/x86/include/asm/kexec.h
> @@ -163,6 +163,8 @@ struct kimage_arch {
> };
> #endif
>
> +extern struct atomic_notifier_head crash_notifier_list;
> +
> #endif /* __ASSEMBLY__ */
>
> #endif /* _ASM_X86_KEXEC_H */
> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> index 13ad899..0f3d5b4 100644
> --- a/arch/x86/kernel/crash.c
> +++ b/arch/x86/kernel/crash.c
> @@ -16,6 +16,8 @@
> #include <linux/delay.h>
> #include <linux/elf.h>
> #include <linux/elfcore.h>
> +#include <linux/module.h>
> +#include <linux/notifier.h>
>
> #include <asm/processor.h>
> #include <asm/hardirq.h>
> @@ -30,6 +32,19 @@
>
> int in_crash_kexec;
>
> +/*
> + * The list is used to VMCLEAR vmcss loaded on all
> + * cpus. And when loading kvm_intel module, the
> + * vmclear function will be registered in the list.
> + */
> +ATOMIC_NOTIFIER_HEAD(crash_notifier_list);
> +EXPORT_SYMBOL_GPL(crash_notifier_list);
> +
> +static inline void cpu_emergency_vmclear_loaded_vmcss(void)
> +{
> + atomic_notifier_call_chain(&crash_notifier_list, 0, NULL);
> +}
> +
The notifier list is not VMX specific. It may be used for other
purposes, so please use better name or just open code it.
ACKs from kexec side are needed.
> #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
>
> static void kdump_nmi_callback(int cpu, struct pt_regs *regs)
> @@ -46,6 +61,11 @@ static void kdump_nmi_callback(int cpu, struct pt_regs *regs)
> #endif
> crash_save_cpu(regs, cpu);
>
> + /*
> + * VMCLEAR vmcss loaded on all cpus if needed.
> + */
> + cpu_emergency_vmclear_loaded_vmcss();
> +
> /* Disable VMX or SVM if needed.
> *
> * We need to disable virtualization on all CPUs.
> @@ -88,6 +108,11 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
>
> kdump_nmi_shootdown_cpus();
>
> + /*
> + * VMCLEAR vmcss loaded on this cpu if needed.
> + */
> + cpu_emergency_vmclear_loaded_vmcss();
> +
> /* Booting kdump kernel with VMX or SVM enabled won't work,
> * because (among other limitations) we can't disable paging
> * with the virt flags.
> --
> 1.7.1
>
> --
> 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/
--
Gleb.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v5 2/2] KVM-INTEL: add a notifier and a bitmap to support VMCLEAR in kdump
2012-11-21 2:26 ` [PATCH v5 2/2] KVM-INTEL: add a notifier and a bitmap to support VMCLEAR in kdump Zhang Yanfei
@ 2012-11-21 10:36 ` Gleb Natapov
0 siblings, 0 replies; 6+ messages in thread
From: Gleb Natapov @ 2012-11-21 10:36 UTC (permalink / raw)
To: Zhang Yanfei; +Cc: x86, kexec, Marcelo Tosatti, linux-kernel, kvm
On Wed, Nov 21, 2012 at 10:26:35AM +0800, Zhang Yanfei wrote:
> The notifier will be registered in crash_notifier_list 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 <zhangyanfei@cn.fujitsu.com>
> ---
> arch/x86/kvm/vmx.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 85 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 4ff0ab9..3bbdd75 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -41,6 +41,7 @@
> #include <asm/i387.h>
> #include <asm/xcr.h>
> #include <asm/perf_event.h>
> +#include <asm/kexec.h>
>
> #include "trace.h"
>
> @@ -963,6 +964,30 @@ 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);
> +}
> +#endif
> +
> static void __loaded_vmcs_clear(void *arg)
> {
> struct loaded_vmcs *loaded_vmcs = arg;
> @@ -972,8 +997,14 @@ 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;
> +#ifdef CONFIG_KEXEC
> + crash_disable_local_vmclear(cpu);
> +#endif
No need for this #ifdef's. Provide empty function if CONFIG_KEXEC is not
defined.
> list_del(&loaded_vmcs->loaded_vmcss_on_cpu_link);
> loaded_vmcs_init(loaded_vmcs);
> +#ifdef CONFIG_KEXEC
> + crash_enable_local_vmclear(cpu);
> +#endif
> }
>
> static void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs)
> @@ -1491,8 +1522,14 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
>
> kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
> local_irq_disable();
> +#ifdef CONFIG_KEXEC
> + crash_disable_local_vmclear(cpu);
> +#endif
> list_add(&vmx->loaded_vmcs->loaded_vmcss_on_cpu_link,
> &per_cpu(loaded_vmcss_on_cpu, cpu));
> +#ifdef CONFIG_KEXEC
> + crash_enable_local_vmclear(cpu);
> +#endif
> local_irq_enable();
>
> /*
> @@ -2302,6 +2339,20 @@ static int hardware_enable(void *garbage)
> return -EBUSY;
>
> INIT_LIST_HEAD(&per_cpu(loaded_vmcss_on_cpu, cpu));
> +
> +#ifdef CONFIG_KEXEC
> + /*
> + * 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);
> +#endif
> +
> rdmsrl(MSR_IA32_FEATURE_CONTROL, old);
>
> test_bits = FEATURE_CONTROL_LOCKED;
> @@ -2335,6 +2386,22 @@ static void vmclear_local_loaded_vmcss(void)
> __loaded_vmcs_clear(v);
> }
>
> +#ifdef CONFIG_KEXEC
> +static int crash_vmclear_local_loaded_vmcss(struct notifier_block *this,
> + unsigned long val, void *ptr)
> +{
> + int cpu = raw_smp_processor_id();
> +
> + if (crash_local_vmclear_enabled(cpu))
> + vmclear_local_loaded_vmcss();
> +
> + return NOTIFY_DONE;
> +}
> +
> +static struct notifier_block crash_vmclear_notifier = {
> + .notifier_call = crash_vmclear_local_loaded_vmcss,
> +};
> +#endif
Move the function under #ifdef CONFIG_KEXEC above.
>
> /* Just like cpu_vmxoff(), but with the __kvm_handle_fault_on_reboot()
> * tricks.
> @@ -2348,6 +2415,14 @@ static void hardware_disable(void *garbage)
> {
> if (vmm_exclusive) {
> vmclear_local_loaded_vmcss();
> +#ifdef CONFIG_KEXEC
> + /*
> + * vmclear operation in kdump should be disabled here
> + * because the cpu is going to exit VMX operation
> + * and the loaded_vmcss_on_cpu list may not be empty!
> + */
> + crash_disable_local_vmclear(raw_smp_processor_id());
> +#endif
> kvm_cpu_vmxoff();
> }
> write_cr4(read_cr4() & ~X86_CR4_VMXE);
> @@ -7230,6 +7305,11 @@ static int __init vmx_init(void)
> if (r)
> goto out3;
>
> +#ifdef CONFIG_KEXEC
> + atomic_notifier_chain_register(&crash_notifier_list,
> + &crash_vmclear_notifier);
> +#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);
> @@ -7265,6 +7345,11 @@ 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
> + atomic_notifier_chain_unregister(&crash_notifier_list,
> + &crash_vmclear_notifier);
> +#endif
> +
> kvm_exit();
> }
>
> --
> 1.7.1
--
Gleb.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v5 1/2] x86/kexec: VMCLEAR vmcss on all cpus if necessary
[not found] ` <50AD78E3.7080901@cn.fujitsu.com>
@ 2012-11-22 6:34 ` Gleb Natapov
0 siblings, 0 replies; 6+ messages in thread
From: Gleb Natapov @ 2012-11-22 6:34 UTC (permalink / raw)
To: Zhang Yanfei; +Cc: x86, kexec, Marcelo Tosatti, linux-kernel, kvm
On Thu, Nov 22, 2012 at 08:59:15AM +0800, Zhang Yanfei wrote:
> 于 2012年11月21日 18:33, Gleb Natapov 写道:
> > On Wed, Nov 21, 2012 at 10:23:12AM +0800, Zhang Yanfei wrote:
> >> This patch adds an atomic notifier list named crash_notifier_list.
> >> When loading kvm-intel module, a notifier will be registered in
> >> the list to enable vmcss loaded on all cpus to be VMCLEAR'd if
> >> needed.
> >>
> >> Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
> >> ---
> >> arch/x86/include/asm/kexec.h | 2 ++
> >> arch/x86/kernel/crash.c | 25 +++++++++++++++++++++++++
> >> 2 files changed, 27 insertions(+), 0 deletions(-)
> >>
> >> diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
> >> index 317ff17..5e22b00 100644
> >> --- a/arch/x86/include/asm/kexec.h
> >> +++ b/arch/x86/include/asm/kexec.h
> >> @@ -163,6 +163,8 @@ struct kimage_arch {
> >> };
> >> #endif
> >>
> >> +extern struct atomic_notifier_head crash_notifier_list;
> >> +
> >> #endif /* __ASSEMBLY__ */
> >>
> >> #endif /* _ASM_X86_KEXEC_H */
> >> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> >> index 13ad899..0f3d5b4 100644
> >> --- a/arch/x86/kernel/crash.c
> >> +++ b/arch/x86/kernel/crash.c
> >> @@ -16,6 +16,8 @@
> >> #include <linux/delay.h>
> >> #include <linux/elf.h>
> >> #include <linux/elfcore.h>
> >> +#include <linux/module.h>
> >> +#include <linux/notifier.h>
> >>
> >> #include <asm/processor.h>
> >> #include <asm/hardirq.h>
> >> @@ -30,6 +32,19 @@
> >>
> >> int in_crash_kexec;
> >>
> >> +/*
> >> + * The list is used to VMCLEAR vmcss loaded on all
> >> + * cpus. And when loading kvm_intel module, the
> >> + * vmclear function will be registered in the list.
> >> + */
> >> +ATOMIC_NOTIFIER_HEAD(crash_notifier_list);
> >> +EXPORT_SYMBOL_GPL(crash_notifier_list);
> >> +
> >> +static inline void cpu_emergency_vmclear_loaded_vmcss(void)
> >> +{
> >> + atomic_notifier_call_chain(&crash_notifier_list, 0, NULL);
> >> +}
> >> +
> > The notifier list is not VMX specific. It may be used for other
> > purposes, so please use better name or just open code it.
>
> OK, thanks. crash_notifier_list --> vmclear_notifier_list?
It is even worse. You are adding general infrastructure here, not
related to KVM at all. Choose neutral names, drop all comments about
VMCLEAR.
> the new v6 version has been sent, any comments are welcome.
>
> >
> > ACKs from kexec side are needed.
> >
> >> #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
> >>
> >> static void kdump_nmi_callback(int cpu, struct pt_regs *regs)
> >> @@ -46,6 +61,11 @@ static void kdump_nmi_callback(int cpu, struct pt_regs *regs)
> >> #endif
> >> crash_save_cpu(regs, cpu);
> >>
> >> + /*
> >> + * VMCLEAR vmcss loaded on all cpus if needed.
> >> + */
> >> + cpu_emergency_vmclear_loaded_vmcss();
> >> +
> >> /* Disable VMX or SVM if needed.
> >> *
> >> * We need to disable virtualization on all CPUs.
> >> @@ -88,6 +108,11 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
> >>
> >> kdump_nmi_shootdown_cpus();
> >>
> >> + /*
> >> + * VMCLEAR vmcss loaded on this cpu if needed.
> >> + */
> >> + cpu_emergency_vmclear_loaded_vmcss();
> >> +
> >> /* Booting kdump kernel with VMX or SVM enabled won't work,
> >> * because (among other limitations) we can't disable paging
> >> * with the virt flags.
> >> --
> >> 1.7.1
> >>
> >> --
> >> 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/
> >
> > --
> > Gleb.
> >
>
--
Gleb.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-11-22 19:31 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-11-21 2:21 [PATCH v5 0/2] x86: vmclear vmcss on all cpus when doing kdump if necessary Zhang Yanfei
2012-11-21 2:23 ` [PATCH v5 1/2] x86/kexec: VMCLEAR vmcss on all cpus " Zhang Yanfei
2012-11-21 10:33 ` Gleb Natapov
[not found] ` <50AD78E3.7080901@cn.fujitsu.com>
2012-11-22 6:34 ` Gleb Natapov
2012-11-21 2:26 ` [PATCH v5 2/2] KVM-INTEL: add a notifier and a bitmap to support VMCLEAR in kdump Zhang Yanfei
2012-11-21 10:36 ` Gleb Natapov
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