Re: [PATCH v2 0/2] x86: clear vmcss on all cpus when doing kdump if necessary
Would anyone help review the patch, and give some comments, please ? Avi? 于 2012年10月19日 13:41, Zhang Yanfei 写道: > 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 v1 to v2: > 1. remove the sysctl and clear VMCSs unconditionally. > > zhangyanfei (2): > x86/kexec: VMCLEAR vmcss on all cpus if necessary > KVM: make crash_clear_loaded_vmcss valid when loading kvm_intel > module > > arch/x86/include/asm/kexec.h |2 ++ > arch/x86/kernel/crash.c | 27 +++ > arch/x86/kvm/vmx.c |9 + > 3 files changed, 38 insertions(+), 0 deletions(-) > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3 2/2] KVM: make crash_clear_loaded_vmcss valid when loading kvm_intel module
于 2012年10月31日 17:01, Hatayama, Daisuke 写道: > > >> -Original Message- >> From: kexec-boun...@lists.infradead.org >> [mailto:kexec-boun...@lists.infradead.org] On Behalf Of zhangyanfei >> Sent: Wednesday, October 31, 2012 12:34 PM >> To: x...@kernel.org; ke...@lists.infradead.org; Avi Kivity; Marcelo >> Tosatti >> Cc: linux-kernel@vger.kernel.org; k...@vger.kernel.org >> Subject: [PATCH v3 2/2] KVM: make crash_clear_loaded_vmcss valid when >> loading kvm_intel module >> >> Signed-off-by: Zhang Yanfei > > [...] > >> @@ -7230,6 +7231,10 @@ static int __init vmx_init(void) >> if (r) >> goto out3; >> >> +#ifdef CONFIG_KEXEC >> +crash_clear_loaded_vmcss = vmclear_local_loaded_vmcss; >> +#endif >> + > > Assignment here cannot cover the case where NMI is initiated after VMX is on > in kvm_init and before vmclear_local_loaded_vmcss is assigned, though rare > but can happen. > By saying "VMX is on in kvm init", you mean kvm_init enables the VMX feature in the logical processor? No, only there is a vcpu to be created, kvm will enable the VMX feature. I think there is no difference with this assignment before or after kvm_init because the vmcs linked list must be empty before vmx_init is finished. Thanks Zhang Yanfei > What does happen if calling vmclear_local_loaded_vmcss before kvm_init? I > think it no problem since the list is initially empty. > >> 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 +7270,10 @@ 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 >> +crash_clear_loaded_vmcss = NULL; >> +#endif >> + >> kvm_exit(); >> } > > Also, this is converse to the above. > > Thanks. > HATAYAMA, Daisuke > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 1/2] x86/kexec: VMCLEAR vmcss on all cpus if necessary
于 2012年10月31日 08:18, Marcelo Tosatti 写道:
> On Fri, Oct 19, 2012 at 01:44:31PM +0800, Zhang Yanfei wrote:
>> This patch 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.
>>
>> Signed-off-by: zhangyanfei
>> ---
>> arch/x86/include/asm/kexec.h |2 ++
>> arch/x86/kernel/crash.c | 27 +++
>> 2 files changed, 29 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
>> index 317ff17..fc05440 100644
>> --- a/arch/x86/include/asm/kexec.h
>> +++ b/arch/x86/include/asm/kexec.h
>> @@ -163,6 +163,8 @@ struct kimage_arch {
>> };
>> #endif
>>
>> +extern void (*crash_clear_loaded_vmcss)(void);
>> +
>> #endif /* __ASSEMBLY__ */
>>
>> #endif /* _ASM_X86_KEXEC_H */
>> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
>> index 13ad899..7289976 100644
>> --- a/arch/x86/kernel/crash.c
>> +++ b/arch/x86/kernel/crash.c
>> @@ -16,6 +16,7 @@
>> #include
>> #include
>> #include
>> +#include
>>
>> #include
>> #include
>> @@ -30,6 +31,22 @@
>>
>> int in_crash_kexec;
>>
>> +/*
>> + * This is used to VMCLEAR vmcss loaded on all
>> + * cpus. And when loading kvm_intel module, the
>> + * function pointer will be made valid.
>> + */
>> +void (*crash_clear_loaded_vmcss)(void) = NULL;
>> +EXPORT_SYMBOL_GPL(crash_clear_loaded_vmcss);
>> +
>> +static void cpu_emergency_clear_loaded_vmcss(void)
>> +{
>> +if (crash_clear_loaded_vmcss &&
>> +cpu_has_vmx() && cpu_vmx_enabled()) {
>> +crash_clear_loaded_vmcss();
>> +}
>> +}
>> +
>
> Are all this checks necessary?
>
> if (crash_clear_loaded_vmcss)
> crash_clear_loaded_vmcss();
>
> Should be enough ? (callback only set if kvm-vmx module loaded).
Hmm, it is enough. Thanks.
>
>> #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
>>
>> static void kdump_nmi_callback(int cpu, struct pt_regs *regs)
>> @@ -46,6 +63,11 @@ 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_clear_loaded_vmcss();
>> +
>> /* Disable VMX or SVM if needed.
>> *
>> * We need to disable virtualization on all CPUs.
>> @@ -88,6 +110,11 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
>>
>> kdump_nmi_shootdown_cpus();
>>
>> +/*
>> + * VMCLEAR vmcss loaded on this cpu if needed.
>> + */
>> +cpu_emergency_clear_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
>>
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[PATCH v3 0/2] x86: clear vmcss on all cpus when doing kdump if necessary
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 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: make crash_clear_loaded_vmcss valid when loading kvm_intel module arch/x86/include/asm/kexec.h |2 ++ arch/x86/kernel/crash.c | 25 + arch/x86/kvm/vmx.c |9 + 3 files changed, 36 insertions(+), 0 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH v3 1/2] x86/kexec: VMCLEAR vmcss on all cpus if necessary
This patch 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.
Signed-off-by: Zhang Yanfei
---
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..fc05440 100644
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -163,6 +163,8 @@ struct kimage_arch {
};
#endif
+extern void (*crash_clear_loaded_vmcss)(void);
+
#endif /* __ASSEMBLY__ */
#endif /* _ASM_X86_KEXEC_H */
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 13ad899..9ed65c1 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -16,6 +16,7 @@
#include
#include
#include
+#include
#include
#include
@@ -30,6 +31,20 @@
int in_crash_kexec;
+/*
+ * This is used to VMCLEAR vmcss loaded on all
+ * cpus. And when loading kvm_intel module, the
+ * function pointer will be made valid.
+ */
+void (*crash_clear_loaded_vmcss)(void) = NULL;
+EXPORT_SYMBOL_GPL(crash_clear_loaded_vmcss);
+
+static void cpu_emergency_clear_loaded_vmcss(void)
+{
+ if (crash_clear_loaded_vmcss)
+ crash_clear_loaded_vmcss();
+}
+
#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_clear_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_clear_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
--
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH v3 2/2] KVM: make crash_clear_loaded_vmcss valid when loading kvm_intel module
Signed-off-by: Zhang Yanfei --- arch/x86/kvm/vmx.c |9 + 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 4ff0ab9..f6a16b2 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -41,6 +41,7 @@ #include #include #include +#include #include "trace.h" @@ -7230,6 +7231,10 @@ static int __init vmx_init(void) if (r) goto out3; +#ifdef CONFIG_KEXEC + crash_clear_loaded_vmcss = 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); @@ -7265,6 +7270,10 @@ 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 + crash_clear_loaded_vmcss = NULL; +#endif + kvm_exit(); } -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3 0/2] x86: clear vmcss on all cpus when doing kdump if necessary
Hello Marcelo, Do you have any comments about this version? Thanks Zhang 于 2012年10月31日 11:30, zhangyanfei 写道: > 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 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: make crash_clear_loaded_vmcss valid when loading kvm_intel > module > > arch/x86/include/asm/kexec.h |2 ++ > arch/x86/kernel/crash.c | 25 + > arch/x86/kvm/vmx.c |9 + > 3 files changed, 36 insertions(+), 0 deletions(-) > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3 2/2] KVM: make crash_clear_loaded_vmcss valid when loading kvm_intel module
于 2012年11月14日 05:22, Marcelo Tosatti 写道: > On Thu, Nov 01, 2012 at 01:55:04PM +0800, zhangyanfei wrote: >> 于 2012年10月31日 17:01, Hatayama, Daisuke 写道: >>> >>> >>>> -Original Message- >>>> From: kexec-boun...@lists.infradead.org >>>> [mailto:kexec-boun...@lists.infradead.org] On Behalf Of zhangyanfei >>>> Sent: Wednesday, October 31, 2012 12:34 PM >>>> To: x...@kernel.org; ke...@lists.infradead.org; Avi Kivity; Marcelo >>>> Tosatti >>>> Cc: linux-kernel@vger.kernel.org; k...@vger.kernel.org >>>> Subject: [PATCH v3 2/2] KVM: make crash_clear_loaded_vmcss valid when >>>> loading kvm_intel module >>>> >>>> Signed-off-by: Zhang Yanfei >>> >>> [...] >>> >>>> @@ -7230,6 +7231,10 @@ static int __init vmx_init(void) >>>>if (r) >>>>goto out3; >>>> >>>> +#ifdef CONFIG_KEXEC >>>> + crash_clear_loaded_vmcss = vmclear_local_loaded_vmcss; >>>> +#endif >>>> + >>> >>> Assignment here cannot cover the case where NMI is initiated after VMX is >>> on in kvm_init and before vmclear_local_loaded_vmcss is assigned, though >>> rare but can happen. >>> >> >> By saying "VMX is on in kvm init", you mean kvm_init enables the VMX feature >> in the logical processor? >> No, only there is a vcpu to be created, kvm will enable the VMX feature. >> >> I think there is no difference with this assignment before or after kvm_init >> because the vmcs linked >> list must be empty before vmx_init is finished. > > The list is not initialized before hardware_enable(), though. Should > move the assignment after that. > > Also, it is possible that the loaded_vmcss_on_cpu list is being modified > _while_ crash executes say via NMI, correct? If that is the case, better > flag that the list is under manipulation so the vmclear can be skipped. > Thanks for your comments. In the new patchset, I didn't move the crash_clear_loaded_vmcss assignment. I added a new percpu variable vmclear_skipped to indicate everything: 1. Before the loaded_vmcss_on_cpu list is initialized, vmclear_skipped is 1 and this means if the machine crashes and doing kdump, crash_clear_loaded_vmcss still will not be called. 2. If the loaded_vmcss_on_cpu list is under manipulation, vmclear_skipped is set to 1 and after the manipulation is finished, the variable is set to 0. 3. After all loaded vmcss are vmcleared, vmclear_skipped is set to 1. So we needn't repeat to vmclear loaded vmcss in kdump path. Please refer to the new version of the patchset I sent. If you have any suggestions, that'll be helpful. Thanks Zhang -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH v4 0/2] x86: clear vmcss on all cpus when doing kdump if necessary
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 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: set/unset crash_clear_loaded_vmcss and vmclear_skipped in kvm_intel module arch/x86/include/asm/kexec.h |3 +++ arch/x86/kernel/crash.c | 32 arch/x86/kvm/vmx.c | 32 3 files changed, 67 insertions(+), 0 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH v4 1/2] x86/kexec: VMCLEAR vmcss on all cpus if necessary
crash_clear_loaded_vmcss is added to VMCLEAR vmcss loaded on all
cpus. And when loading kvm_intel module, the function pointer will be
made valid.
The percpu variable vmclear_skipped is added to flag the case that
if loaded_vmcss_on_cpu list is being modified while the machine crashes
and doing kdump, the vmclear here can be skipped.
Signed-off-by: Zhang Yanfei
---
arch/x86/include/asm/kexec.h |3 +++
arch/x86/kernel/crash.c | 32
2 files changed, 35 insertions(+), 0 deletions(-)
diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
index 317ff17..d892211 100644
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -163,6 +163,9 @@ struct kimage_arch {
};
#endif
+extern void (*crash_clear_loaded_vmcss)(void);
+DECLARE_PER_CPU(int, vmclear_skipped);
+
#endif /* __ASSEMBLY__ */
#endif /* _ASM_X86_KEXEC_H */
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 13ad899..b9f264e 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -16,6 +16,7 @@
#include
#include
#include
+#include
#include
#include
@@ -30,6 +31,27 @@
int in_crash_kexec;
+/*
+ * This is used to VMCLEAR vmcss loaded on all
+ * cpus. And when loading kvm_intel module, the
+ * function pointer will be made valid.
+ */
+void (*crash_clear_loaded_vmcss)(void) = NULL;
+EXPORT_SYMBOL_GPL(crash_clear_loaded_vmcss);
+
+DEFINE_PER_CPU(int, vmclear_skipped) = 1;
+EXPORT_SYMBOL_GPL(vmclear_skipped);
+
+static void cpu_emergency_clear_loaded_vmcss(void)
+{
+ int cpu = raw_smp_processor_id();
+ int skipped;
+
+ skipped = per_cpu(vmclear_skipped, cpu);
+ if (!skipped && crash_clear_loaded_vmcss)
+ crash_clear_loaded_vmcss();
+}
+
#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
static void kdump_nmi_callback(int cpu, struct pt_regs *regs)
@@ -46,6 +68,11 @@ 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_clear_loaded_vmcss();
+
/* Disable VMX or SVM if needed.
*
* We need to disable virtualization on all CPUs.
@@ -88,6 +115,11 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
kdump_nmi_shootdown_cpus();
+ /*
+* VMCLEAR vmcss loaded on this cpu if needed.
+*/
+ cpu_emergency_clear_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
--
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[PATCH v4 2/2] KVM: set/unset crash_clear_loaded_vmcss and vmclear_skipped in kvm_intel module
Signed-off-by: Zhang Yanfei
---
arch/x86/kvm/vmx.c | 32
1 files changed, 32 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 4ff0ab9..029ec7b 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -41,6 +41,7 @@
#include
#include
#include
+#include
#include "trace.h"
@@ -963,6 +964,20 @@ static void vmcs_load(struct vmcs *vmcs)
vmcs, phys_addr);
}
+static inline void enable_vmclear_in_kdump(int cpu)
+{
+#ifdef CONFIG_KEXEC
+ per_cpu(vmclear_skipped, cpu) = 0;
+#endif
+}
+
+static inline void disable_vmclear_in_kdump(int cpu)
+{
+#ifdef CONFIG_KEXEC
+ per_cpu(vmclear_skipped, cpu) = 1;
+#endif
+}
+
static void __loaded_vmcs_clear(void *arg)
{
struct loaded_vmcs *loaded_vmcs = arg;
@@ -972,8 +987,10 @@ 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;
+ disable_vmclear_in_kdump(cpu);
list_del(&loaded_vmcs->loaded_vmcss_on_cpu_link);
loaded_vmcs_init(loaded_vmcs);
+ enable_vmclear_in_kdump(cpu);
}
static void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs)
@@ -1491,8 +1508,10 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
local_irq_disable();
+ disable_vmclear_in_kdump(cpu);
list_add(&vmx->loaded_vmcs->loaded_vmcss_on_cpu_link,
&per_cpu(loaded_vmcss_on_cpu, cpu));
+ enable_vmclear_in_kdump(cpu);
local_irq_enable();
/*
@@ -2302,6 +2321,9 @@ static int hardware_enable(void *garbage)
return -EBUSY;
INIT_LIST_HEAD(&per_cpu(loaded_vmcss_on_cpu, cpu));
+
+ enable_vmclear_in_kdump(cpu);
+
rdmsrl(MSR_IA32_FEATURE_CONTROL, old);
test_bits = FEATURE_CONTROL_LOCKED;
@@ -2333,6 +2355,8 @@ static void vmclear_local_loaded_vmcss(void)
list_for_each_entry_safe(v, n, &per_cpu(loaded_vmcss_on_cpu, cpu),
loaded_vmcss_on_cpu_link)
__loaded_vmcs_clear(v);
+
+ disable_vmclear_in_kdump(cpu);
}
@@ -7230,6 +7254,10 @@ static int __init vmx_init(void)
if (r)
goto out3;
+#ifdef CONFIG_KEXEC
+ crash_clear_loaded_vmcss = 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);
@@ -7265,6 +7293,10 @@ 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
+ crash_clear_loaded_vmcss = NULL;
+#endif
+
kvm_exit();
}
--
1.7.1
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Re: [PATCH v4 0/2] x86: clear vmcss on all cpus when doing kdump if necessary
Hello Marcelo, Any thoughts? 于 2012年11月14日 17:29, zhangyanfei 写道: > 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 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: set/unset crash_clear_loaded_vmcss and vmclear_skipped in > kvm_intel module > > arch/x86/include/asm/kexec.h |3 +++ > arch/x86/kernel/crash.c | 32 > arch/x86/kvm/vmx.c | 32 > 3 files changed, 67 insertions(+), 0 deletions(-) > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v4 0/2] x86: clear vmcss on all cpus when doing kdump if necessary
于 2012年11月20日 08:32, Marcelo Tosatti 写道: > On Fri, Nov 16, 2012 at 06:12:58PM +0800, zhangyanfei wrote: >> Hello Marcelo, >> >> Any thoughts? > > I thought a function call was OK, but its better to have all code in > vmx.c. Please have an atomic notifier in kexec.c (registered by KVM > module via atomic_notifier_chain_register etc). > > Other than that, which is largely cosmetic, it looks fine. > Sorry for not expressing this earlier. > > Hmm, Thanks. I will resend a new patch set. Thanks Zhang -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
