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[v5 17/19] KVM: Update Posted-Interrupts Descriptor when vCPU is preempted

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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 <feng.wu@intel.com>
---
 arch/x86/kvm/vmx.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 35ef4c6..dd6f3d5 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -45,6 +45,7 @@
 #include <asm/debugreg.h>
 #include <asm/kexec.h>
 #include <asm/apic.h>
+#include <asm/irq_remapping.h>
 
 #include "trace.h"
 
@@ -2000,10 +2001,43 @@ 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;
 	}
+
+	if (irq_remapping_cap(IRQ_POSTING_CAP)) {
+		struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu);
+		struct pi_desc old, new;
+		unsigned int dest;
+
+		do {
+			old.control = new.control = pi_desc->control;
+			if (vcpu->cpu != cpu) {
+				dest = cpu_physical_id(cpu);
+
+				if (x2apic_enabled())
+					new.ndst = dest;
+				else
+					new.ndst = (dest << 8) & 0xFF00;
+			}
+
+			/* Allow posting non-urgent interrupts */
+			new.sn = 0;
+
+			/* set 'NV' to 'notification vector' */
+			new.nv = POSTED_INTR_VECTOR;
+		} while (cmpxchg(&pi_desc->control, old.control,
+				new.control) != old.control);
+	}
 }
 
 static void vmx_vcpu_put(struct kvm_vcpu *vcpu)
 {
+	if (irq_remapping_cap(IRQ_POSTING_CAP)) {
+		struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu);
+
+		/* Set SN when the vCPU is preempted */
+		if (vcpu->preempted)
+			pi_set_sn(pi_desc);
+	}
+
 	__vmx_load_host_state(to_vmx(vcpu));
 	if (!vmm_exclusive) {
 		__loaded_vmcs_clear(to_vmx(vcpu)->loaded_vmcs);
-- 
2.1.0

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Thread

[v5 00/19] Add VT-d Posted-Interrupts support Feng Wu <feng.wu@intel.com> - 2015-07-13 12:00 +0200
  [v5 07/19] KVM: make kvm_set_msi_irq() public Feng Wu <feng.wu@intel.com> - 2015-07-13 12:00 +0200
  [v5 11/19] KVM: create kvm_irqfd.h Feng Wu <feng.wu@intel.com> - 2015-07-13 12:00 +0200
  [v5 06/19] KVM: Make struct kvm_irq_routing_table accessible Feng Wu <feng.wu@intel.com> - 2015-07-13 12:00 +0200
  [v5 17/19] KVM: Update Posted-Interrupts Descriptor when vCPU is preempted Feng Wu <feng.wu@intel.com> - 2015-07-13 12:00 +0200
  [v5 01/19] KVM: Extend struct pi_desc for VT-d Posted-Interrupts Feng Wu <feng.wu@intel.com> - 2015-07-13 12:00 +0200
  [v5 10/19] KVM, x86: Select IRQ_BYPASS_MANAGER for KVM_INTEL Feng Wu <feng.wu@intel.com> - 2015-07-13 12:10 +0200
  [v5 14/19] KVM: x86: Add arch specific routines for irqbypass manager Feng Wu <feng.wu@intel.com> - 2015-07-13 12:10 +0200
  [v5 16/19] KVM: Add an arch specific hooks in 'struct kvm_kernel_irqfd' Feng Wu <feng.wu@intel.com> - 2015-07-13 12:10 +0200
  [v5 18/19] KVM: Update Posted-Interrupts Descriptor when vCPU is blocked Feng Wu <feng.wu@intel.com> - 2015-07-13 12:10 +0200
  [v5 02/19] KVM: Add some helper functions for Posted-Interrupts Feng Wu <feng.wu@intel.com> - 2015-07-13 12:10 +0200
  [v5 13/19] KVM: x86: Update IRTE for posted-interrupts Feng Wu <feng.wu@intel.com> - 2015-07-13 12:10 +0200
  [v5 15/19] KVM: eventfd: add irq bypass consumer management Feng Wu <feng.wu@intel.com> - 2015-07-13 12:10 +0200
  [v5 12/19] KVM: eventfd: add irq bypass information in irqfd Feng Wu <feng.wu@intel.com> - 2015-07-13 12:10 +0200
  [v5 05/19] KVM: Add interfaces to control PI outside vmx Feng Wu <feng.wu@intel.com> - 2015-07-13 12:10 +0200
  [v5 09/19] vfio: Register/unregister irq_bypass_producer Feng Wu <feng.wu@intel.com> - 2015-07-13 12:10 +0200
    Re: [v5 09/19] vfio: Register/unregister irq_bypass_producer Eric Auger <eric.auger@linaro.org> - 2015-07-13 15:00 +0200
  [v5 03/19] KVM: Define a new interface kvm_intr_is_single_vcpu() Feng Wu <feng.wu@intel.com> - 2015-07-13 12:10 +0200
  [v5 08/19] vfio: Select IRQ_BYPASS_MANAGER for vfio PCI devices Feng Wu <feng.wu@intel.com> - 2015-07-13 12:10 +0200

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