[PATCH 1/2] KVM: not register a IRQ bypass producer if unsupported or disabled
From: Zhenzhong Duan <hidden>
Date: 2020-10-19 09:07:22
Also in:
kvm, lkml
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, virtio host (vhost), x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, "Michael S. Tsirkin", Jason Wang, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
If Post interrupt is disabled due to hardware limit or forcely disabled by "intremap=nopost" parameter, return -EINVAL so that the legacy mode IRQ isn't registered as IRQ bypass producer. With this change, below message is printed: "vfio-pci 0000:db:00.0: irq bypass producer (token 0000000060c8cda5) registration fails: -22" ..which also hints us if a vfio or vdpa device works in PI mode or legacy remapping mode. Add a print to vdpa code just like what vfio_msi_set_vector_signal() does. Signed-off-by: Zhenzhong Duan <redacted> --- arch/x86/kvm/svm/avic.c | 3 +-- arch/x86/kvm/vmx/vmx.c | 5 ++--- drivers/vhost/vdpa.c | 5 +++++ 3 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index ac830cd..316142a 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c@@ -814,7 +814,7 @@ int svm_update_pi_irte(struct kvm *kvm, unsigned int host_irq, if (!kvm_arch_has_assigned_device(kvm) || !irq_remapping_cap(IRQ_POSTING_CAP)) - return 0; + return ret; pr_debug("SVM: %s: host_irq=%#x, guest_irq=%#x, set=%#x\n", __func__, host_irq, guest_irq, set);
@@ -899,7 +899,6 @@ int svm_update_pi_irte(struct kvm *kvm, unsigned int host_irq, } } - ret = 0; out: srcu_read_unlock(&kvm->irq_srcu, idx); return ret;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index f0a9954..1fed6d6 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c@@ -7716,12 +7716,12 @@ static int vmx_update_pi_irte(struct kvm *kvm, unsigned int host_irq, struct kvm_lapic_irq irq; struct kvm_vcpu *vcpu; struct vcpu_data vcpu_info; - int idx, ret = 0; + int idx, ret = -EINVAL; if (!kvm_arch_has_assigned_device(kvm) || !irq_remapping_cap(IRQ_POSTING_CAP) || !kvm_vcpu_apicv_active(kvm->vcpus[0])) - return 0; + return ret; idx = srcu_read_lock(&kvm->irq_srcu); irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
@@ -7787,7 +7787,6 @@ static int vmx_update_pi_irte(struct kvm *kvm, unsigned int host_irq, } } - ret = 0; out: srcu_read_unlock(&kvm->irq_srcu, idx); return ret;
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 62a9bb0..b20060a 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c@@ -107,6 +107,11 @@ static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid) vq->call_ctx.producer.token = vq->call_ctx.ctx; vq->call_ctx.producer.irq = irq; ret = irq_bypass_register_producer(&vq->call_ctx.producer); + if (unlikely(ret)) + dev_info(&vdpa->dev, + "irq bypass producer (token %p) registration fails: %d\n", + vq->call_ctx.producer.token, ret); + spin_unlock(&vq->call_ctx.ctx_lock); }
--
1.8.3.1