Hi,
On 2020/7/2 21:55, Keqian Zhu wrote:
> For that using arm64 DBM to log dirty pages has the side effect
> of long time dirty log sync, we should give userspace opportunity
> to enable or disable this feature, to realize some policy.
>
> This feature is disabled by default.
>
> Signed-off-by: Keqian Zhu <zhukeqian1@xxxxxxxxxx>
> Signed-off-by: Peng Liang <liangpeng10@xxxxxxxxxx>
> ---
> arch/arm64/include/asm/kvm_host.h | 1 +
> arch/arm64/kvm/arm.c | 35 +++++++++++++++++++++++++++++++
> arch/arm64/kvm/mmu.c | 22 +++++++++++++++++++
> arch/arm64/kvm/reset.c | 5 +++++
> include/uapi/linux/kvm.h | 1 +
> tools/include/uapi/linux/kvm.h | 1 +
> 6 files changed, 65 insertions(+)
>
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 86b9c210ba43..69a5317c7049 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -481,6 +481,7 @@ u64 __kvm_call_hyp(void *hypfn, ...);
> void force_vm_exit(const cpumask_t *mask);
> void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot);
> void kvm_mmu_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot);
> +void kvm_mmu_sync_dirty_log_all(struct kvm *kvm);
>
> int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
> int exception_index);
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index fefa5406e037..9e3f765d5467 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -78,6 +78,11 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
> struct kvm_enable_cap *cap)
> {
> int r;
> +#ifdef CONFIG_ARM64_HW_AFDBM
> + int i;
> + struct kvm_vcpu *vcpu;
> + bool enable_hw_dirty_log;
> +#endif
>
> if (cap->flags)
> return -EINVAL;
> @@ -87,6 +92,36 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
> r = 0;
> kvm->arch.return_nisv_io_abort_to_user = true;
> break;
> +#ifdef CONFIG_ARM64_HW_AFDBM
> + case KVM_CAP_ARM_HW_DIRTY_LOG:
> + if (!arm_mmu_hw_dbm_supported() || (cap->args[0] & ~0x1))
> + r = -EINVAL;
Miss "break" here :-( . Code is converted from "return -EINVAL".
> +
> + enable_hw_dirty_log = !!(cap->args[0] & 0x1);
> + if (!!(kvm->arch.vtcr & VTCR_EL2_HD) != enable_hw_dirty_log) {
> + if (enable_hw_dirty_log)
> + kvm->arch.vtcr |= VTCR_EL2_HD;
> + else
> + kvm->arch.vtcr &= ~VTCR_EL2_HD;
> +
> + /*
> + * We should kick vcpus out of guest mode here to
> + * load new vtcr value to vtcr_el2 register when
> + * re-enter guest mode.
> + */
> + kvm_for_each_vcpu(i, vcpu, kvm)
> + kvm_vcpu_kick(vcpu);
> +
> + if (!enable_hw_dirty_log) {
> + mutex_lock(&kvm->slots_lock);
> + kvm_mmu_sync_dirty_log_all(kvm);
> + mutex_unlock(&kvm->slots_lock);
> + }
> + }
> +
> + r = 0;
> + break;
> +#endif
> default:
> r = -EINVAL;
> break;
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index adfa62f1fced..1a48554accb0 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -2590,6 +2590,28 @@ void kvm_mmu_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
> spin_unlock(&kvm->mmu_lock);
> srcu_read_unlock(&kvm->srcu, srcu_idx);
> }
> +
> +/**
> + * kvm_mmu_sync_dirty_log_all() - synchronize dirty log from PTEs for whole VM
> + * @kvm: The KVM pointer
> + *
> + * Called with kvm->slots_lock mutex acquired
> + */
> +void kvm_mmu_sync_dirty_log_all(struct kvm *kvm)
> +{
> + struct kvm_memslots *slots = kvm_memslots(kvm);
> + struct kvm_memory_slot *memslots = slots->memslots;
> + struct kvm_memory_slot *memslot;
> + int slot;
> +
> + if (unlikely(!slots->used_slots))
> + return;
> +
> + for (slot = 0; slot < slots->used_slots; slot++) {
> + memslot = &memslots[slot];
> + kvm_mmu_sync_dirty_log(kvm, memslot);
> + }
> +}
> #endif /* CONFIG_ARM64_HW_AFDBM */
>
> void kvm_arch_commit_memory_region(struct kvm *kvm,
> diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
> index d3b209023727..a3be703dd54b 100644
> --- a/arch/arm64/kvm/reset.c
> +++ b/arch/arm64/kvm/reset.c
> @@ -83,6 +83,11 @@ int kvm_arch_vm_ioctl_check_extension(struct kvm *kvm, long ext)
> r = has_vhe() && system_supports_address_auth() &&
> system_supports_generic_auth();
> break;
> +#ifdef CONFIG_ARM64_HW_AFDBM
> + case KVM_CAP_ARM_HW_DIRTY_LOG:
> + r = arm_mmu_hw_dbm_supported();
> + break;
> +#endif /* CONFIG_ARM64_HW_AFDBM */
> default:
> r = 0;
> }
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index 4fdf30316582..e0b12c43397b 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -1031,6 +1031,7 @@ struct kvm_ppc_resize_hpt {
> #define KVM_CAP_PPC_SECURE_GUEST 181
> #define KVM_CAP_HALT_POLL 182
> #define KVM_CAP_ASYNC_PF_INT 183
> +#define KVM_CAP_ARM_HW_DIRTY_LOG 184
>
> #ifdef KVM_CAP_IRQ_ROUTING
>
> diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h
> index 4fdf30316582..e0b12c43397b 100644
> --- a/tools/include/uapi/linux/kvm.h
> +++ b/tools/include/uapi/linux/kvm.h
> @@ -1031,6 +1031,7 @@ struct kvm_ppc_resize_hpt {
> #define KVM_CAP_PPC_SECURE_GUEST 181
> #define KVM_CAP_HALT_POLL 182
> #define KVM_CAP_ASYNC_PF_INT 183
> +#define KVM_CAP_ARM_HW_DIRTY_LOG 184
>
> #ifdef KVM_CAP_IRQ_ROUTING
>
>
