From: Eric Auger <eric.auger@linaro.org>
To: Alex Williamson <alex.williamson@redhat.com>,
Feng Wu <feng.wu@intel.com>
Cc: pbonzini@redhat.com, joro@8bytes.org, mtosatti@redhat.com,
kvm@vger.kernel.org, iommu@lists.linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v9 12/18] vfio: Register/unregister irq_bypass_producer
Date: Thu, 28 Apr 2016 17:35:12 +0200 [thread overview]
Message-ID: <57222DB0.7080205@linaro.org> (raw)
In-Reply-To: <20160426140816.67b8b37c@t450s.home>
Hi Alex,
On 04/26/2016 10:08 PM, Alex Williamson wrote:
> On Fri, 18 Sep 2015 22:29:50 +0800
> Feng Wu <feng.wu@intel.com> wrote:
>
> @@ -360,6 +361,14 @@ static int vfio_msi_set_vector_signal(struct
> vfio_pci_device *vdev,
>> return ret;
>> }
>>
>> + vdev->ctx[vector].producer.token = trigger;
>> + vdev->ctx[vector].producer.irq = irq;
>> + ret = irq_bypass_register_producer(&vdev->ctx[vector].producer);
>> + if (unlikely(ret))
>> + dev_info(&pdev->dev,
>> + "irq bypass producer (token %p) registeration fails: %d\n",
>> + vdev->ctx[vector].producer.token, ret);
>> +
>> vdev->ctx[vector].trigger = trigger;
>>
>> return 0;
>
> Digging back into the IRQ producer/consumer thing, I'm not sure how we
> should be handling a failure here, but it turns out that what we have
> is pretty sub-optimal. Any sort of testing on AMD hits this dev_info
> because kvm_arch_irq_bypass_add_producer() returns -EINVAL without
> kvm_x86_ops->update_pi_irte which is only implemented for vmx. Clearly
> we don't want to spew confusing error messages for a feature that does
> not exist.
>
> The easiest option is to simply make this error silent, but should
> registering a producer/consumer really fail due to a mismatch on the
> other end or should the __connect sequence fail silently, which both
> ends would know about (if they care) due to the add/del handshake
> between them? Perhaps for now we simply need a stable suitable fix to
> silence the dev_info above, but longer term, registration shouldn't
> fail for mismatches like this. Thoughts? Thanks,
Regarding the ARM IRQ forwarding use case, I think it is OK to fail
silently. We would fall back to the irqfd standard mechanism. Anyway
this series still is waiting for ARM new-vgic dependency to be resolved,
as discussed with Christoffer and Marc.
Best Regards
Eric
>
> Alex
>
next prev parent reply other threads:[~2016-04-28 15:36 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-18 14:29 [PATCH v9 00/18] Add VT-d Posted-Interrupts support - including prerequisite series Feng Wu
2015-09-18 14:29 ` [PATCH v9 01/18] virt: IRQ bypass manager Feng Wu
2015-09-18 15:34 ` Wu, Feng
2015-09-18 14:29 ` [PATCH v9 02/18] KVM: x86: select IRQ_BYPASS_MANAGER Feng Wu
2015-09-18 14:29 ` [PATCH v9 03/18] KVM: arm/arm64: " Feng Wu
2015-09-21 19:32 ` Eric Auger
2015-09-18 14:29 ` [PATCH v9 04/18] KVM: create kvm_irqfd.h Feng Wu
2015-09-18 15:35 ` Wu, Feng
2015-09-18 14:29 ` [PATCH v9 05/18] KVM: introduce kvm_arch functions for IRQ bypass Feng Wu
2015-09-18 14:29 ` [PATCH v9 06/18] KVM: eventfd: add irq bypass consumer management Feng Wu
2015-09-18 14:29 ` [PATCH v9 07/18] KVM: Extend struct pi_desc for VT-d Posted-Interrupts Feng Wu
2015-09-18 14:29 ` [PATCH v9 08/18] KVM: Add some helper functions for Posted-Interrupts Feng Wu
2015-09-18 14:29 ` [PATCH v9 09/18] KVM: Define a new interface kvm_intr_is_single_vcpu() Feng Wu
2015-09-18 14:29 ` [PATCH v9 10/18] KVM: Make struct kvm_irq_routing_table accessible Feng Wu
2015-09-18 14:29 ` [PATCH v9 11/18] KVM: make kvm_set_msi_irq() public Feng Wu
2015-09-18 14:29 ` [PATCH v9 12/18] vfio: Register/unregister irq_bypass_producer Feng Wu
2015-09-18 17:19 ` Alex Williamson
2015-09-21 8:56 ` Wu, Feng
2015-09-21 9:32 ` Paolo Bonzini
2015-09-21 11:35 ` Wu, Feng
2015-09-21 12:06 ` Paolo Bonzini
2015-09-21 12:08 ` Wu, Feng
2015-09-21 12:53 ` Wu, Feng
2015-09-21 13:02 ` Paolo Bonzini
2015-09-21 19:46 ` Eric Auger
2016-04-26 20:08 ` Alex Williamson
2016-04-27 1:32 ` Wu, Feng
2016-04-28 16:40 ` Alex Williamson
2016-04-28 15:35 ` Eric Auger [this message]
2015-09-18 14:29 ` [PATCH v9 13/18] KVM: x86: Update IRTE for posted-interrupts Feng Wu
2015-09-18 14:29 ` [PATCH v9 14/18] KVM: Implement IRQ bypass consumer callbacks for x86 Feng Wu
2015-09-18 14:29 ` [PATCH v9 15/18] KVM: Add an arch specific hooks in 'struct kvm_kernel_irqfd' Feng Wu
2015-09-18 14:29 ` [PATCH v9 16/18] KVM: Update Posted-Interrupts Descriptor when vCPU is preempted Feng Wu
2015-09-18 14:29 ` [PATCH v9 17/18] KVM: Update Posted-Interrupts Descriptor when vCPU is blocked Feng Wu
2015-09-18 16:06 ` Paolo Bonzini
2015-09-19 7:11 ` Wu, Feng
2015-09-21 2:16 ` Wu, Feng
2015-09-21 5:32 ` Paolo Bonzini
2015-09-21 5:45 ` Wu, Feng
2015-10-14 23:41 ` David Matlack
2015-10-15 1:33 ` Wu, Feng
2015-10-15 17:39 ` David Matlack
2015-10-15 18:13 ` Paolo Bonzini
2015-10-16 1:45 ` Wu, Feng
2015-09-18 14:29 ` [PATCH v9 18/18] iommu/vt-d: Add a command line parameter for VT-d posted-interrupts Feng Wu
2015-09-21 13:46 ` Joerg Roedel
2015-09-18 14:58 ` [PATCH v9 00/18] Add VT-d Posted-Interrupts support - including prerequisite series Paolo Bonzini
2015-09-18 15:08 ` Wu, Feng
2015-09-18 15:21 ` Paolo Bonzini
2015-09-18 15:38 ` Wu, Feng
2015-09-18 17:57 ` Alex Williamson
2015-09-25 1:49 ` Wu, Feng
2015-09-25 11:14 ` Paolo Bonzini
2015-09-28 10:14 ` Wu, Feng
2015-09-28 10:18 ` Paolo Bonzini
2015-09-28 10:22 ` Wu, Feng
2015-09-22 9:01 [PATCH v9 12/18] vfio: Register/unregister irq_bypass_producer Wu, Feng
2015-09-23 1:35 ` Eric Auger
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