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@xxxxxxxxx>
---
arch/x86/kvm/vmx.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 44 insertions(+)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ee3b735..bf2e6cd 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1916,10 +1916,54 @@ 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;
+
+ memset(&old, 0, sizeof(old));
+ memset(&new, 0, sizeof(new));
+
+ 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;
+ }
+
+ pi_clear_sn(&new);
+
+ /* 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);
+ struct pi_desc old, new;
+
+ memset(&old, 0, sizeof(old));
+ memset(&new, 0, sizeof(new));
+
+ /* Set SN when the vCPU is preempted */
+ if (vcpu->preempted) {
+ do {
+ old.control = new.control = pi_desc->control;
+ pi_set_sn(&new);
+ } while (cmpxchg(&pi_desc->control, old.control,
+ new.control) != old.control);
+ }
+ }
+
__vmx_load_host_state(to_vmx(vcpu));
if (!vmm_exclusive) {
__loaded_vmcs_clear(to_vmx(vcpu)->loaded_vmcs);
--
1.9.1
--
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