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authorZhang Yanfei <zhangyanfei@cn.fujitsu.com>2012-12-06 23:43:34 +0800
committerGleb Natapov <gleb@redhat.com>2012-12-06 18:26:57 +0200
commit8f536b7697a0d40ef6b5fd04cf2c04953d5ca06f (patch)
treec163bd13b3cc17b7b16ceb3be2d7c96d32400d75 /arch/x86
parentf23d1f4a116038c68df224deae6718fde87d8f0d (diff)
downloadop-kernel-dev-8f536b7697a0d40ef6b5fd04cf2c04953d5ca06f.zip
op-kernel-dev-8f536b7697a0d40ef6b5fd04cf2c04953d5ca06f.tar.gz
KVM: VMX: provide the vmclear function and a bitmap to support VMCLEAR in kdump
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 <zhangyanfei@cn.fujitsu.com> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/vmx.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 94833e2..1a30fd5 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -42,6 +42,7 @@
#include <asm/i387.h>
#include <asm/xcr.h>
#include <asm/perf_event.h>
+#include <asm/kexec.h>
#include "trace.h"
@@ -987,6 +988,46 @@ 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;
@@ -996,6 +1037,7 @@ 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);
/*
@@ -1007,6 +1049,7 @@ static void __loaded_vmcs_clear(void *arg)
smp_wmb();
loaded_vmcs_init(loaded_vmcs);
+ crash_enable_local_vmclear(cpu);
}
static void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs)
@@ -1530,6 +1573,7 @@ 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);
/*
* Read loaded_vmcs->cpu should be before fetching
@@ -1540,6 +1584,7 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int 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();
/*
@@ -2353,6 +2398,18 @@ 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;
@@ -7383,6 +7440,11 @@ 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);
@@ -7420,6 +7482,11 @@ 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();
}
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