[v2 22/25] KVM: Change NDST field after vCPU scheduling

[Feng Wu <feng.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

This patch changes the NDST filed of Posted-Interrupts
Descriptor after vCPU is scheduled to another physical
CPU.

Signed-off-by: Feng Wu <feng.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 arch/x86/kvm/vmx.c |   25 +++++++++++++++++++++++++
 1 files changed, 25 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index a1966b9..e71bf3b 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1906,6 +1906,31 @@ 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) && (vcpu->cpu != cpu)) {
+		struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu);
+		struct pi_desc old, new;
+		unsigned int dest;
+
+		memset(&old, 0, sizeof(old));
+		memset(&new, 0, sizeof(new));
+
+		pi_set_sn(pi_desc);
+
+		do {
+			old.control = new.control = pi_desc->control;
+
+			dest = cpu_physical_id(cpu);
+
+			if (x2apic_enabled())
+				new.ndst = dest;
+			else
+				new.ndst = (dest << 8) & 0xFF00;
+
+		} while (cmpxchg(&pi_desc->control, old.control,
+				new.control) != old.control);
+		pi_clear_sn(pi_desc);
+	}
 }
 
 static void vmx_vcpu_put(struct kvm_vcpu *vcpu)
-- 
1.7.1