From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753222AbbIPJEc (ORCPT ); Wed, 16 Sep 2015 05:04:32 -0400 Received: from mga14.intel.com ([192.55.52.115]:38797 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752007AbbIPJE1 (ORCPT ); Wed, 16 Sep 2015 05:04:27 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,538,1437462000"; d="scan'208";a="790482372" From: Feng Wu To: pbonzini@redhat.com, alex.williamson@redhat.com, joro@8bytes.org, mtosatti@redhat.com Cc: eric.auger@linaro.org, kvm@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Feng Wu Subject: [PATCH v8 10/13] KVM: Update Posted-Interrupts Descriptor when vCPU is preempted Date: Wed, 16 Sep 2015 16:50:06 +0800 Message-Id: <1442393409-2623-11-git-send-email-feng.wu@intel.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1442393409-2623-1-git-send-email-feng.wu@intel.com> References: <1442393409-2623-1-git-send-email-feng.wu@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch updates the Posted-Interrupts Descriptor when vCPU is preempted. sched out: - Set 'SN' to suppress furture non-urgent interrupts posted for the vCPU. sched in: - Clear 'SN' - Change NDST if vCPU is scheduled to a different CPU - Set 'NV' to POSTED_INTR_VECTOR Signed-off-by: Feng Wu --- v8: - Add two wrapper fucntion vmx_vcpu_pi_load() and vmx_vcpu_pi_put(). - Only handle VT-d PI related logic when the VM has assigned devices. arch/x86/kvm/vmx.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 5a25651..5ceb280 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1943,6 +1943,52 @@ static void vmx_load_host_state(struct vcpu_vmx *vmx) preempt_enable(); } +static void vmx_vcpu_pi_load(struct kvm_vcpu *vcpu, int cpu) +{ + struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu); + struct pi_desc old, new; + unsigned int dest; + + if (!irq_remapping_cap(IRQ_POSTING_CAP) || + (!kvm_arch_has_assigned_device(vcpu->kvm))) + return; + + do { + old.control = new.control = pi_desc->control; + + /* + * If 'nv' field is POSTED_INTR_WAKEUP_VECTOR, there + * are two possible cases: + * 1. After running 'pi_pre_block', context switch + * happened. For this case, 'sn' was set in + * vmx_vcpu_put(), so we need to clear it here. + * 2. After running 'pi_pre_block', we were blocked, + * and woken up by some other guy. For this case, + * we don't need to do anything, 'pi_post_block' + * will do everything for us. However, we cannot + * check whether it is case #1 or case #2 here + * (maybe, not needed), so we also clear sn here, + * I think it is not a big deal. + */ + if (pi_desc->nv != POSTED_INTR_WAKEUP_VECTOR) { + if (vcpu->cpu != cpu) { + dest = cpu_physical_id(cpu); + + if (x2apic_enabled()) + new.ndst = dest; + else + new.ndst = (dest << 8) & 0xFF00; + } + + /* set 'NV' to 'notification vector' */ + new.nv = POSTED_INTR_VECTOR; + } + + /* Allow posting non-urgent interrupts */ + new.sn = 0; + } while (cmpxchg(&pi_desc->control, old.control, + new.control) != old.control); +} /* * Switches to specified vcpu, until a matching vcpu_put(), but assumes * vcpu mutex is already taken. @@ -1993,10 +2039,27 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu) vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */ vmx->loaded_vmcs->cpu = cpu; } + + vmx_vcpu_pi_load(vcpu, cpu); +} + +static void vmx_vcpu_pi_put(struct kvm_vcpu *vcpu) +{ + struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu); + + if (!irq_remapping_cap(IRQ_POSTING_CAP) || + (!kvm_arch_has_assigned_device(vcpu->kvm))) + return; + + /* Set SN when the vCPU is preempted */ + if (vcpu->preempted) + pi_set_sn(pi_desc); } static void vmx_vcpu_put(struct kvm_vcpu *vcpu) { + vmx_vcpu_pi_put(vcpu); + __vmx_load_host_state(to_vmx(vcpu)); if (!vmm_exclusive) { __loaded_vmcs_clear(to_vmx(vcpu)->loaded_vmcs); -- 2.1.0