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@xxxxxxxxxxxxxx>
> ---
> 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@xxxxxxxxxx>
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