On 2016/5/20 16:22, Wu, Feng wrote:
-----Original Message-----
From: Yang Zhang [mailto:yang.zhang.wz@xxxxxxxxx]
Sent: Friday, May 20, 2016 3:51 PM
To: Paolo Bonzini <pbonzini@xxxxxxxxxx>; rkrcmar@xxxxxxxxxx; Wu, Feng
<feng.wu@xxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Subject: [PATCH] KVM: VMX: check apicv is active before using VT-d posted
interrupt
VT-d posted interrupt is relying on the CPU side's posted interrupt.
Need to check whether VCPU's APICv is active before enabing VT-d posted
interrupt.
Yes, the extra check is good. Just curious, Do you see some hardware with
VT-d PI but no CPU side PI. I remember I was told this cannot happen in
real world.
Hardware is ok. The problem is user can turn off the APICv manually
which cause the device fails to work inside guest.
Thanks,
feng
Signed-off-by: Yang Zhang <yang.zhang.wz@xxxxxxxxx>
Signed-off-by: Shengge Ding <shengge.dsg@xxxxxxxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 7ebf27b..8ba87f3 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2072,7 +2072,8 @@ static void vmx_vcpu_pi_load(struct kvm_vcpu
*vcpu, int cpu)
unsigned int dest;
if (!kvm_arch_has_assigned_device(vcpu->kvm) ||
- !irq_remapping_cap(IRQ_POSTING_CAP))
+ !irq_remapping_cap(IRQ_POSTING_CAP) ||
+ !kvm_vcpu_apicv_active(vcpu))
return;
do {
@@ -2180,7 +2181,8 @@ static void vmx_vcpu_pi_put(struct kvm_vcpu *vcpu)
struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu);
if (!kvm_arch_has_assigned_device(vcpu->kvm) ||
- !irq_remapping_cap(IRQ_POSTING_CAP))
+ !irq_remapping_cap(IRQ_POSTING_CAP) ||
+ !kvm_vcpu_apicv_active(vcpu))
return;
/* Set SN when the vCPU is preempted */
@@ -10698,7 +10700,8 @@ static int vmx_pre_block(struct kvm_vcpu *vcpu)
struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu);
if (!kvm_arch_has_assigned_device(vcpu->kvm) ||
- !irq_remapping_cap(IRQ_POSTING_CAP))
+ !irq_remapping_cap(IRQ_POSTING_CAP) ||
+ !kvm_vcpu_apicv_active(vcpu))
return 0;
vcpu->pre_pcpu = vcpu->cpu;
@@ -10764,7 +10767,8 @@ static void vmx_post_block(struct kvm_vcpu *vcpu)
unsigned long flags;
if (!kvm_arch_has_assigned_device(vcpu->kvm) ||
- !irq_remapping_cap(IRQ_POSTING_CAP))
+ !irq_remapping_cap(IRQ_POSTING_CAP) ||
+ !kvm_vcpu_apicv_active(vcpu))
return;
do {
@@ -10817,7 +10821,8 @@ static int vmx_update_pi_irte(struct kvm *kvm,
unsigned int host_irq,
int idx, ret = -EINVAL;
if (!kvm_arch_has_assigned_device(kvm) ||
- !irq_remapping_cap(IRQ_POSTING_CAP))
+ !irq_remapping_cap(IRQ_POSTING_CAP) ||
+ !kvm_vcpu_apicv_active(kvm->vcpus[0]))
return 0;
idx = srcu_read_lock(&kvm->irq_srcu);
--
1.8.2.1
--
best regards
yang
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