Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752202AbaKJGjL (ORCPT ); Mon, 10 Nov 2014 01:39:11 -0500 Received: from mga11.intel.com ([192.55.52.93]:54491 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751877AbaKJGgh (ORCPT ); Mon, 10 Nov 2014 01:36:37 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,351,1413270000"; d="scan'208";a="629364149" From: Feng Wu To: gleb@kernel.org, pbonzini@redhat.com, dwmw2@infradead.org, joro@8bytes.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org Cc: kvm@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Feng Wu Subject: [PATCH 10/13] KVM: Add the handler for Wake-up Vector Date: Mon, 10 Nov 2014 14:26:49 +0800 Message-Id: <1415600812-27773-11-git-send-email-feng.wu@intel.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1415600812-27773-1-git-send-email-feng.wu@intel.com> References: <1415600812-27773-1-git-send-email-feng.wu@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When VCPU is blocked and an external interrupts from assigned devices is delivered to it, VT-d Posted-Interrupts mechanism will deliver a interrrupt to the associated physical CPU with Wake-up Vector. In its handler, we find the destination VCPU and wake up it. Signed-off-by: Feng Wu --- arch/x86/include/asm/kvm_host.h | 2 + arch/x86/kvm/vmx.c | 52 +++++++++++++++++++++++++++++++++++++++ arch/x86/kvm/x86.c | 22 +++++++++++----- include/linux/kvm_host.h | 3 ++ virt/kvm/kvm_main.c | 3 ++ 5 files changed, 75 insertions(+), 7 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 71cfe3e..ca231a3 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -99,6 +99,8 @@ static inline gfn_t gfn_to_index(gfn_t gfn, gfn_t base_gfn, int level) #define ASYNC_PF_PER_VCPU 64 +extern void (*wakeup_handler_callback)(void); + enum kvm_reg { VCPU_REGS_RAX = 0, VCPU_REGS_RCX = 1, diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index fa77714..51d2c8a 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -822,6 +822,13 @@ static DEFINE_PER_CPU(struct vmcs *, current_vmcs); static DEFINE_PER_CPU(struct list_head, loaded_vmcss_on_cpu); static DEFINE_PER_CPU(struct desc_ptr, host_gdt); +/* + * We maintian a per-CPU linked-list of VCPU, so in wakeup_handler() we + * can find which VCPU should be waken up. + */ +static DEFINE_PER_CPU(struct list_head, blocked_vcpu_on_cpu); +static DEFINE_PER_CPU(spinlock_t, blocked_vcpu_on_cpu_lock); + static unsigned long *vmx_io_bitmap_a; static unsigned long *vmx_io_bitmap_b; static unsigned long *vmx_msr_bitmap_legacy; @@ -2813,6 +2820,8 @@ static int hardware_enable(void) return -EBUSY; INIT_LIST_HEAD(&per_cpu(loaded_vmcss_on_cpu, cpu)); + INIT_LIST_HEAD(&per_cpu(blocked_vcpu_on_cpu, cpu)); + spin_lock_init(&per_cpu(blocked_vcpu_on_cpu_lock, cpu)); /* * Now we can enable the vmclear operation in kdump @@ -9183,6 +9192,7 @@ static int vmx_vcpu_pre_block(struct kvm_vcpu *vcpu) struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu); struct pi_desc old; struct pi_desc new; + unsigned long flags; if (!irq_post_enabled) return 0; @@ -9222,9 +9232,22 @@ static int vmx_vcpu_pre_block(struct kvm_vcpu *vcpu) /* set 'NV' to 'wakeup vector' */ new.nv = POSTED_INTR_WAKEUP_VECTOR; + + /* + * We should save physical cpu id here, vcpu->cpu may + * be changed due to preemption, in that case, this + * do-while loop will run again. + */ + vcpu->wakeup_cpu = vcpu->cpu; } while (cmpxchg(&pi_desc->control, old.control, new.control) != old.control); + spin_lock_irqsave(&per_cpu(blocked_vcpu_on_cpu_lock, + vcpu->wakeup_cpu), flags); + list_add_tail(&vcpu->blocked_vcpu_list, + &per_cpu(blocked_vcpu_on_cpu, vcpu->wakeup_cpu)); + spin_unlock_irqrestore(&per_cpu(blocked_vcpu_on_cpu_lock, + vcpu->wakeup_cpu), flags); return 0; } @@ -9234,6 +9257,7 @@ static void vmx_vcpu_post_block(struct kvm_vcpu *vcpu) struct pi_desc old; struct pi_desc new; unsigned int dest = 0; + unsigned long flags; if (!irq_post_enabled) return; @@ -9255,6 +9279,13 @@ static void vmx_vcpu_post_block(struct kvm_vcpu *vcpu) } while (cmpxchg(&pi_desc->control, old.control, new.control) != old.control); + spin_lock_irqsave(&per_cpu(blocked_vcpu_on_cpu_lock, + vcpu->wakeup_cpu), flags); + list_del(&vcpu->blocked_vcpu_list); + spin_unlock_irqrestore(&per_cpu(blocked_vcpu_on_cpu_lock, + vcpu->wakeup_cpu), flags); + vcpu->wakeup_cpu = -1; + pi_clear_sn(pi_desc); } @@ -9372,6 +9403,25 @@ static struct kvm_x86_ops vmx_x86_ops = { .vcpu_post_block = vmx_vcpu_post_block, }; +/* + * Handler for POSTED_INTERRUPT_WAKEUP_VECTOR. + */ +void wakeup_handler(void) +{ + struct kvm_vcpu *vcpu; + int cpu = smp_processor_id(); + + spin_lock(&per_cpu(blocked_vcpu_on_cpu_lock, cpu)); + list_for_each_entry(vcpu, &per_cpu(blocked_vcpu_on_cpu, cpu), + blocked_vcpu_list) { + struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu); + + if (pi_test_on(pi_desc) == 1) + kvm_vcpu_kick(vcpu); + } + spin_unlock(&per_cpu(blocked_vcpu_on_cpu_lock, cpu)); +} + static int __init vmx_init(void) { int r, i, msr; @@ -9486,6 +9536,8 @@ static int __init vmx_init(void) update_ple_window_actual_max(); + wakeup_handler_callback = wakeup_handler; + return 0; out7: diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d0c8bb2..2061b3d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6156,6 +6156,21 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_vcpu_reload_apic_access_page(vcpu); } + /* + * Since posted-interrupts can be set by VT-d HW now, in this + * case, KVM_REQ_EVENT is not set. We move the following + * operations out of the if statement. + */ + if (kvm_lapic_enabled(vcpu)) { + /* + * Update architecture specific hints for APIC + * virtual interrupt delivery. + */ + if (kvm_x86_ops->hwapic_irr_update) + kvm_x86_ops->hwapic_irr_update(vcpu, + kvm_lapic_find_highest_irr(vcpu)); + } + if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) { kvm_apic_accept_events(vcpu); if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) { @@ -6172,13 +6187,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_x86_ops->enable_irq_window(vcpu); if (kvm_lapic_enabled(vcpu)) { - /* - * Update architecture specific hints for APIC - * virtual interrupt delivery. - */ - if (kvm_x86_ops->hwapic_irr_update) - kvm_x86_ops->hwapic_irr_update(vcpu, - kvm_lapic_find_highest_irr(vcpu)); update_cr8_intercept(vcpu); kvm_lapic_sync_to_vapic(vcpu); } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 6bb8287..614b4ba 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -239,6 +239,9 @@ struct kvm_vcpu { unsigned long requests; unsigned long guest_debug; + int wakeup_cpu; + struct list_head blocked_vcpu_list; + struct mutex mutex; struct kvm_run *run; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 1be1a45..fb3e504 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -224,6 +224,9 @@ int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) init_waitqueue_head(&vcpu->wq); kvm_async_pf_vcpu_init(vcpu); + vcpu->wakeup_cpu = -1; + INIT_LIST_HEAD(&vcpu->blocked_vcpu_list); + page = alloc_page(GFP_KERNEL | __GFP_ZERO); if (!page) { r = -ENOMEM; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/