x86: vmclear vmcss on all cpus when doing kdump if necessary
Subsystems (5)
v5 cover x86: vmclear 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 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(-)
PATCH v5 1/2 x86/kexec: VMCLEAR vmcss on all cpus if necessary
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.
--- arch/x86/include/asm/kexec.h | 2 ++ arch/x86/kernel/crash.c | 25 +++++++++++++++++++++++++ 2 files changed, 27 insertions(+), 0 deletions(-)
arch/x86/include/asm/kexec.h +2 -0
@@ -163,6 +163,8 @@ struct kimage_arch { };#endif +extern struct atomic_notifier_head crash_notifier_list; +#endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_KEXEC_H */
arch/x86/kernel/crash.c +25 -0
@@ -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.
Signature · 1 line
1.7.1
Re: [PATCH v5 1/2] x86/kexec: VMCLEAR vmcss on all cpus if necessary
Quoted 44 lines · Zhang Yanfei
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 <[email protected]>--- arch/x86/include/asm/kexec.h | 2 ++ arch/x86/kernel/crash.c | 25 +++++++++++++++++++++++++ 2 files changed, 27 insertions(+), 0 deletions(-)arch/x86/include/asm/kexec.h +2
-0@@ -163,6 +163,8 @@ struct kimage_arch { };#endif +extern struct atomic_notifier_head crash_notifier_list; +#endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_KEXEC_H */ arch/x86/kernel/crash.c +5
-0@@ -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
arch/x86/kernel/crash.c line 47
Quoted 10 lines
arch/x86/kernel/crash.c +10
-0+* 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.
Quoted 35 lines
arch/x86/kernel/crash.c +10
-0#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. Signature · 7 lines
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Re: [PATCH v5 1/2] x86/kexec: VMCLEAR vmcss on all cpus if necessary
Quoted 42 lines · Gleb Natapov
Quoted 41 lines · Zhang Yanfei
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 <[email protected]>--- arch/x86/include/asm/kexec.h | 2 ++ arch/x86/kernel/crash.c | 25 +++++++++++++++++++++++++ 2 files changed, 27 insertions(+), 0 deletions(-)arch/x86/include/asm/kexec.h +2
-0@@ -163,6 +163,8 @@ struct kimage_arch { };#endif +extern struct atomic_notifier_head crash_notifier_list; +#endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_KEXEC_H */ arch/x86/kernel/crash.c +2
-0@@ -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;
Quoted 15 lines
arch/x86/kernel/crash.c line 47
Quoted 13 lines
arch/x86/kernel/crash.c +13
-0+/* +* 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? the new v6 version has been sent, any comments are welcome.
Quoted 33 lines
ACKs from kexec side are needed.
Quoted 30 lines
arch/x86/kernel/crash.c +10
-0#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. Signature · 1 line
1.7.1
Quoted 9 lines
Quoted 5 lines
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Re: [PATCH v5 1/2] x86/kexec: VMCLEAR vmcss on all cpus if necessary
Quoted 59 lines · Zhang Yanfei
Quoted 42 lines · Gleb Natapov
Quoted 41 lines · Zhang Yanfei
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 <[email protected]>--- arch/x86/include/asm/kexec.h | 2 ++ arch/x86/kernel/crash.c | 25 +++++++++++++++++++++++++ 2 files changed, 27 insertions(+), 0 deletions(-)arch/x86/include/asm/kexec.h +2
-0@@ -163,6 +163,8 @@ struct kimage_arch { };#endif +extern struct atomic_notifier_head crash_notifier_list; +#endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_KEXEC_H */ arch/x86/kernel/crash.c +2
-0@@ -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;Quoted 15 lines
arch/x86/kernel/crash.c line 47
Quoted 13 lines
arch/x86/kernel/crash.c +13
-0+/* +* 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.
Quoted 1 line
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.
Quoted 45 lines
the new v6 version has been sent, any comments are welcome.
Quoted 42 lines
ACKs from kexec side are needed.
Quoted 35 lines
arch/x86/kernel/crash.c +10
-0#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. Signature · 7 lines
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Re: [PATCH v5 1/2] x86/kexec: VMCLEAR vmcss on all cpus if necessary
Quoted 60 lines · Gleb Natapov
Quoted 59 lines · Zhang Yanfei
Quoted 57 lines · Gleb Natapov
Quoted 44 lines · Zhang Yanfei
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 <[email protected]>--- arch/x86/include/asm/kexec.h | 2 ++ arch/x86/kernel/crash.c | 25 +++++++++++++++++++++++++ 2 files changed, 27 insertions(+), 0 deletions(-)arch/x86/include/asm/kexec.h +2
-0@@ -163,6 +163,8 @@ struct kimage_arch { };#endif +extern struct atomic_notifier_head crash_notifier_list; +#endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_KEXEC_H */ arch/x86/kernel/crash.c +5
-0@@ -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 arch/x86/kernel/crash.c line 47
Quoted 10 lines
arch/x86/kernel/crash.c +10
-0+* 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.
Quoted 4 lines
Quoted 1 line
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.
Ah, I think I misunderstood what you mean before.
OK, I know what you mean now: make crash_notifier_list unchanged and remove the comments related to VMX
and open code the atomic_notifier_call_chain function.
Thanks
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PATCH v5 2/2 KVM-INTEL: add a notifier and a bitmap to support VMCLEAR in kdump
In reply to Zhang YanfeiThe 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.
--- arch/x86/kvm/vmx.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 85 insertions(+), 0 deletions(-)
arch/x86/kvm/vmx.c +85 -0
@@ -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 (); }
Signature · 1 line
1.7.1
Re: [PATCH v5 2/2] KVM-INTEL: add a notifier and a bitmap to support VMCLEAR in kdump
Quoted 54 lines · Zhang Yanfei
The notifier will be registered in
crash_notifier_listwhen 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 <[email protected]>--- arch/x86/kvm/vmx.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 85 insertions(+), 0 deletions(-)arch/x86/kvm/vmx.c +25
-0@@ -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;
arch/x86/kvm/vmx.c static void __loaded_vmcs_clear(void *arg) · line 1002
Quoted 6 lines
arch/x86/kvm/vmx.c +3
-0@@ -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.
Quoted 54 lines
arch/x86/kvm/vmx.c +29
-0list_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 (); +
arch/x86/kvm/vmx.c static void vmclear_local_loaded_vmcss(void) · line 2404
Quoted 10 lines
arch/x86/kvm/vmx.c +10
-0+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.
Quoted 44 lines
arch/x86/kvm/vmx.c +18
-0/* 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 (); }Signature · 1 line
1.7.1
--
Gleb.
Re: [PATCH v5 2/2] KVM-INTEL: add a notifier and a bitmap to support VMCLEAR in kdump
Quoted 55 lines · Gleb Natapov
Quoted 54 lines · Zhang Yanfei
The notifier will be registered in
crash_notifier_listwhen 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 <[email protected]>--- arch/x86/kvm/vmx.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 85 insertions(+), 0 deletions(-)arch/x86/kvm/vmx.c +25
-0@@ -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)
Quoted 8 lines
arch/x86/kvm/vmx.c static void __loaded_vmcs_clear(void *arg) · line 1002
Quoted 6 lines
arch/x86/kvm/vmx.c +3
-0return ;/* 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_KEXECis not defined.
OK.
the new v6 version has been sent, any comments are welcome.
Quoted 58 lines
Quoted 58 lines
arch/x86/kvm/vmx.c +32
-0list_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 (); +
Quoted 8 lines
arch/x86/kvm/vmx.c static void vmclear_local_loaded_vmcss(void) · line 2404
Quoted 7 lines
arch/x86/kvm/vmx.c +7
-0+ return NOTIFY_DONE; +} + +static struct notifier_block crash_vmclear_notifier = { + .notifier_call = crash_vmclear_local_loaded_vmcss, +}; +#endif Move the function under #ifdef
CONFIG_KEXECabove.
ok.
Quoted 43 lines
Quoted 43 lines
arch/x86/kvm/vmx.c +18
-0/* 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 (); }
Quoted 11 lines
Quoted 2 lines
Signature · 1 line
1.7.1--
Gleb.
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