diff mbox

[v7,7/9] kvm, mem-hotplug: Reload L1's apic access page on migration when L2 is running.

Message ID 1411210071-14727-8-git-send-email-tangchen@cn.fujitsu.com (mailing list archive)
State New, archived
Headers show

Commit Message

tangchen Sept. 20, 2014, 10:47 a.m. UTC
We are handling "L1 and L2 share one apic access page" situation when migrating
apic access page. We should do some handling when migration happens in the
following situations:

   1) when L0 is running: Update L1's vmcs in the next L0->L1 entry and L2's
      vmcs in the next L1->L2 entry.

   2) when L1 is running: Force a L1->L0 exit, update L1's vmcs in the next
      L0->L1 entry and L2's vmcs in the next L1->L2 entry.

   3) when L2 is running: Force a L2->L0 exit, update L2's vmcs in the next
      L0->L2 entry and L1's vmcs in the next L2->L1 exit.

This patch handles 3).

In L0->L2 entry, L2's vmcs will be updated in prepare_vmcs02() called by
nested_vm_run(). So we need to do nothing.

In L2->L1 exit, this patch requests apic access page reload in L2->L1 vmexit.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/vmx.c              | 6 ++++++
 arch/x86/kvm/x86.c              | 3 ++-
 3 files changed, 9 insertions(+), 1 deletion(-)

Comments

Paolo Bonzini Sept. 22, 2014, 9:29 a.m. UTC | #1
Il 20/09/2014 12:47, Tang Chen ha scritto:
> We are handling "L1 and L2 share one apic access page" situation when migrating
> apic access page. We should do some handling when migration happens in the
> following situations:
> 
>    1) when L0 is running: Update L1's vmcs in the next L0->L1 entry and L2's
>       vmcs in the next L1->L2 entry.
> 
>    2) when L1 is running: Force a L1->L0 exit, update L1's vmcs in the next
>       L0->L1 entry and L2's vmcs in the next L1->L2 entry.
> 
>    3) when L2 is running: Force a L2->L0 exit, update L2's vmcs in the next
>       L0->L2 entry and L1's vmcs in the next L2->L1 exit.
> 
> This patch handles 3).
> 
> In L0->L2 entry, L2's vmcs will be updated in prepare_vmcs02() called by
> nested_vm_run(). So we need to do nothing.
> 
> In L2->L1 exit, this patch requests apic access page reload in L2->L1 vmexit.
> 
> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
> ---
>  arch/x86/include/asm/kvm_host.h | 1 +
>  arch/x86/kvm/vmx.c              | 6 ++++++
>  arch/x86/kvm/x86.c              | 3 ++-
>  3 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 56156eb..1a8317e 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1047,6 +1047,7 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
>  int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
>  int kvm_cpu_get_interrupt(struct kvm_vcpu *v);
>  void kvm_vcpu_reset(struct kvm_vcpu *vcpu);
> +void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu);
>  
>  void kvm_define_shared_msr(unsigned index, u32 msr);
>  void kvm_set_shared_msr(unsigned index, u64 val, u64 mask);
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index c8e90ec..baac78a 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -8803,6 +8803,12 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
>  	}
>  
>  	/*
> +	 * We are now running in L2, mmu_notifier will force to reload the
> +	 * page's hpa for L2 vmcs. Need to reload it for L1 before entering L1.
> +	 */
> +	kvm_vcpu_reload_apic_access_page(vcpu);
> +
> +	/*
>  	 * Exiting from L2 to L1, we're now back to L1 which thinks it just
>  	 * finished a VMLAUNCH or VMRESUME instruction, so we need to set the
>  	 * success or failure flag accordingly.
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index fc54fa6..2ae2dc7 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -5989,7 +5989,7 @@ static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
>  	kvm_apic_update_tmr(vcpu, tmr);
>  }
>  
> -static void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
> +void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
>  {
>  	/*
>  	 * Only APIC access page shared by L1 and L2 vm is handled. The APIC
> @@ -6009,6 +6009,7 @@ static void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
>  				page_to_phys(vcpu->kvm->arch.apic_access_page));
>  	}
>  }
> +EXPORT_SYMBOL_GPL(kvm_vcpu_reload_apic_access_page);
>  
>  /*
>   * Returns 1 to let __vcpu_run() continue the guest execution loop without
> 

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
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diff mbox

Patch

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 56156eb..1a8317e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1047,6 +1047,7 @@  int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
 int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
 int kvm_cpu_get_interrupt(struct kvm_vcpu *v);
 void kvm_vcpu_reset(struct kvm_vcpu *vcpu);
+void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu);
 
 void kvm_define_shared_msr(unsigned index, u32 msr);
 void kvm_set_shared_msr(unsigned index, u64 val, u64 mask);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c8e90ec..baac78a 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8803,6 +8803,12 @@  static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
 	}
 
 	/*
+	 * We are now running in L2, mmu_notifier will force to reload the
+	 * page's hpa for L2 vmcs. Need to reload it for L1 before entering L1.
+	 */
+	kvm_vcpu_reload_apic_access_page(vcpu);
+
+	/*
 	 * Exiting from L2 to L1, we're now back to L1 which thinks it just
 	 * finished a VMLAUNCH or VMRESUME instruction, so we need to set the
 	 * success or failure flag accordingly.
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fc54fa6..2ae2dc7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5989,7 +5989,7 @@  static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
 	kvm_apic_update_tmr(vcpu, tmr);
 }
 
-static void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
+void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
 {
 	/*
 	 * Only APIC access page shared by L1 and L2 vm is handled. The APIC
@@ -6009,6 +6009,7 @@  static void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
 				page_to_phys(vcpu->kvm->arch.apic_access_page));
 	}
 }
+EXPORT_SYMBOL_GPL(kvm_vcpu_reload_apic_access_page);
 
 /*
  * Returns 1 to let __vcpu_run() continue the guest execution loop without