This patch is to provide a way for platforms to register hv tlb remote flush callback and this helps to optimize operation of tlb flush among vcpus for nested virtualization case.
Signed-off-by: Lan Tianyu <[email protected]> --- Change since v2: Rename kvm_arch_hv_flush_remote_tlb with kvm_arch_flush_remote_tlb Rename kvm_x86_ops->hv_tlb_remote_flush with kvm_x86_ops->tlb_remote_flush Fix issue that ignore updating tlbs_dirty during calling kvm_arch_flush_remote_tlbs() Change since v1: Add kvm_arch_hv_flush_remote_tlb() to avoid compilation issue for non-x86 platform. --- arch/x86/include/asm/kvm_host.h | 11 +++++++++++ include/linux/kvm_host.h | 7 +++++++ virt/kvm/kvm_main.c | 3 ++- 3 files changed, 20 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index c13cd28d9d1b..76e806bc4ef8 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -973,6 +973,7 @@ struct kvm_x86_ops { void (*set_rflags)(struct kvm_vcpu *vcpu, unsigned long rflags); void (*tlb_flush)(struct kvm_vcpu *vcpu, bool invalidate_gpa); + int (*tlb_remote_flush)(struct kvm *kvm); void (*run)(struct kvm_vcpu *vcpu); int (*handle_exit)(struct kvm_vcpu *vcpu); @@ -1117,6 +1118,16 @@ static inline void kvm_arch_free_vm(struct kvm *kvm) return kvm_x86_ops->vm_free(kvm); } +#define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLB +static inline int kvm_arch_flush_remote_tlb(struct kvm *kvm) +{ + if (kvm_x86_ops->tlb_remote_flush && + !kvm_x86_ops->tlb_remote_flush(kvm)) + return 0; + else + return -EFAULT; +} + int kvm_mmu_module_init(void); void kvm_mmu_module_exit(void); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 4ee7bc548a83..0781d94200df 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -827,6 +827,13 @@ static inline void kvm_arch_free_vm(struct kvm *kvm) } #endif +#ifndef __KVM_HAVE_ARCH_FLUSH_REMOTE_TLB +static inline int kvm_arch_flush_remote_tlb(struct kvm *kvm) +{ + return -EFAULT; +} +#endif + #ifdef __KVM_HAVE_ARCH_NONCOHERENT_DMA void kvm_arch_register_noncoherent_dma(struct kvm *kvm); void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 8b47507faab5..1a13cdb2822b 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -273,7 +273,8 @@ void kvm_flush_remote_tlbs(struct kvm *kvm) * kvm_make_all_cpus_request() reads vcpu->mode. We reuse that * barrier here. */ - if (kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH)) + if (!kvm_arch_flush_remote_tlb(kvm) + || kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH)) ++kvm->stat.remote_tlb_flush; cmpxchg(&kvm->tlbs_dirty, dirty_count, 0); } -- 2.14.3
