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 force a L1->L0 exit or L2->L0 exit when shared apic access page is
> migrated using mmu notifier. Since apic access page is only used on intel x86,
> this is arch specific code.
>
> Signed-off-by: Tang Chen <tangc...@cn.fujitsu.com>
> ---
> arch/x86/kvm/x86.c | 11 +++++++++++
> include/linux/kvm_host.h | 14 +++++++++++++-
> virt/kvm/kvm_main.c | 3 +++
> 3 files changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 2ae2dc7..7dd4179 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -6011,6 +6011,17 @@ void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu
> *vcpu)
> }
> EXPORT_SYMBOL_GPL(kvm_vcpu_reload_apic_access_page);
>
> +void kvm_arch_mmu_notifier_invalidate_page(struct kvm *kvm,
> + unsigned long address)
> +{
> + /*
> + * The physical address of apic access page is stored in VMCS.
> + * Update it when it becomes invalid.
> + */
> + if (address == gfn_to_hva(kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT))
> + kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD);
> +}
> +
> /*
> * Returns 1 to let __vcpu_run() continue the guest execution loop without
> * exiting to the userspace. Otherwise, the value will be returned to the
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 73de13c..b6e4d38 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -917,7 +917,19 @@ static inline int mmu_notifier_retry(struct kvm *kvm,
> unsigned long mmu_seq)
> return 1;
> return 0;
> }
> -#endif
> +
> +#ifdef _ASM_X86_KVM_HOST_H
> +void kvm_arch_mmu_notifier_invalidate_page(struct kvm *kvm,
> + unsigned long address);
> +#else /* _ASM_X86_KVM_HOST_H */
> +inline void kvm_arch_mmu_notifier_invalidate_page(struct kvm *kvm,
> + unsigned long address)
This needs to be static.
However, do not add it here. Instead, touch all
arch/*/include/asm/kvm_host.h files, adding either the prototype or the
inline function.
Apart from this, the patch looks good.
Paolo
> +{
> + return;
> +}
> +#endif /* _ASM_X86_KVM_HOST_H */
> +
> +#endif /* CONFIG_MMU_NOTIFIER & KVM_ARCH_WANT_MMU_NOTIFIER */
>
> #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 0f8b6f6..5427973d 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -295,6 +295,9 @@ static void kvm_mmu_notifier_invalidate_page(struct
> mmu_notifier *mn,
> kvm_flush_remote_tlbs(kvm);
>
> spin_unlock(&kvm->mmu_lock);
> +
> + kvm_arch_mmu_notifier_invalidate_page(kvm, address);
> +
> srcu_read_unlock(&kvm->srcu, idx);
> }
>
>
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