? 2012?11?22? 09:13, Marcelo Tosatti ??:
> On Wed, Nov 21, 2012 at 11:27:19PM +0800, Zhang Yanfei wrote:
>> The notifier will be registered in vmclear_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 at cn.fujitsu.com>
>> ---
>> arch/x86/kvm/vmx.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++-
>> 1 files changed, 76 insertions(+), 1 deletions(-)
>>
>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
>> index 4ff0ab9..eea55b3 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 +964,49 @@ 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 vmclear_local_loaded_vmcss(void);
>> +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,
>> +};
>> +#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;
>> @@ -972,8 +1016,10 @@ 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)
>> @@ -1491,8 +1537,10 @@ 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();
>>
>> /*
>> @@ -2302,6 +2350,18 @@ 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;
>> @@ -2335,7 +2395,6 @@ static void vmclear_local_loaded_vmcss(void)
>> __loaded_vmcs_clear(v);
>> }
>>
>> -
>> /* Just like cpu_vmxoff(), but with the __kvm_handle_fault_on_reboot()
>> * tricks.
>> */
>> @@ -2348,6 +2407,12 @@ static void hardware_disable(void *garbage)
>> {
>> if (vmm_exclusive) {
>> vmclear_local_loaded_vmcss();
>> + /*
>> + * 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());
>> kvm_cpu_vmxoff();
>
> How come its not empty? vmclear_local_loaded_vmcss cleared it, didnt it?
You are right. I forget that vmclear_local_loaded_vmcss will delete the vmcs
when it clears one.
Thanks, I will fix this and resend the patch.
Zhang
