From: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
To: "x86@kernel.org" <x86@kernel.org>,
Marcelo Tosatti <mtosatti@redhat.com>,
Gleb Natapov <gleb@redhat.com>,
"Eric W. Biederman" <ebiederm@xmission.com>
Cc: "kexec@lists.infradead.org" <kexec@lists.infradead.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: [PATCH v9 2/2] KVM-INTEL: provide the vmclear function and a bitmap to support VMCLEAR in kdump
Date: Tue, 27 Nov 2012 11:26:59 +0800 [thread overview]
Message-ID: <50B43303.7070909@cn.fujitsu.com> (raw)
In-Reply-To: <50B43299.9030409@cn.fujitsu.com>
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>
---
arch/x86/kvm/vmx.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 65 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 4ff0ab9..561d3b6 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 +964,46 @@ 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;
@@ -972,8 +1013,10 @@ 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 +1534,10 @@ 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 +2347,18 @@ 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;
@@ -7230,6 +7287,10 @@ static int __init vmx_init(void)
if (r)
goto out3;
+#ifdef CONFIG_KEXEC
+ 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);
@@ -7265,6 +7326,10 @@ 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_vmclear_loaded_vmcss = NULL;
+#endif
+
kvm_exit();
}
--
1.7.1
prev parent reply other threads:[~2012-11-27 3:28 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-27 3:25 [PATCH v9 0/2] x86: vmclear vmcss on all cpus when doing kdump if necessary Zhang Yanfei
2012-11-27 3:26 ` [PATCH v9 1/2] x86/kexec: VMCLEAR VMCSs loaded on all cpus " Zhang Yanfei
2012-11-27 12:18 ` Gleb Natapov
2012-12-03 13:46 ` Gleb Natapov
2012-12-04 20:14 ` Eric W. Biederman
2012-12-05 7:55 ` Zhang Yanfei
2012-11-27 3:26 ` Zhang Yanfei [this message]
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