From: Jason Wang <jasowang@redhat.com> To: "Zhu, Lingshan" <lingshan.zhu@intel.com>, mst@redhat.com Cc: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH V2 RESEND 2/2] vDPA/ifcvf: implement doorbell mapping for ifcvf Date: Tue, 1 Jun 2021 11:31:56 +0800 [thread overview] Message-ID: <91c64c0c-7b78-4c41-a6d7-6d9f084c7cc5@redhat.com> (raw) In-Reply-To: <5dbdc6a5-1510-9411-6b85-d947d091089c@intel.com> 在 2021/6/1 上午11:27, Zhu, Lingshan 写道: > > > On 5/31/2021 3:56 PM, Jason Wang wrote: >> >> 在 2021/5/31 下午3:33, Zhu Lingshan 写道: >>> This commit implements doorbell mapping feature for ifcvf. >>> This feature maps the notify page to userspace, to eliminate >>> vmexit when kick a vq. >>> >>> Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com> >>> --- >>> drivers/vdpa/ifcvf/ifcvf_main.c | 17 +++++++++++++++++ >>> 1 file changed, 17 insertions(+) >>> >>> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c >>> b/drivers/vdpa/ifcvf/ifcvf_main.c >>> index ab0ab5cf0f6e..effb0e549135 100644 >>> --- a/drivers/vdpa/ifcvf/ifcvf_main.c >>> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c >>> @@ -413,6 +413,22 @@ static int ifcvf_vdpa_get_vq_irq(struct >>> vdpa_device *vdpa_dev, >>> return vf->vring[qid].irq; >>> } >>> +static struct vdpa_notification_area >>> ifcvf_get_vq_notification(struct vdpa_device *vdpa_dev, >>> + u16 idx) >>> +{ >>> + struct ifcvf_adapter *adapter = vdpa_to_adapter(vdpa_dev); >>> + struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev); >>> + struct pci_dev *pdev = adapter->pdev; >>> + struct vdpa_notification_area area; >>> + >>> + area.addr = vf->vring[idx].notify_pa; >>> + area.size = PAGE_SIZE; >>> + if (area.addr % PAGE_SIZE) >>> + IFCVF_DBG(pdev, "vq %u doorbell address is not PAGE_SIZE >>> aligned\n", idx); >> >> >> Let's leave the decision to upper layer by: (see >> vp_vdpa_get_vq_notification) >> >> area.addr = notify_pa; >> area.size = notify_offset_multiplier; >> >> Thanks > > Hi Jason, > > notify_offset_multiplier can be zero, means vqs share the same > doorbell address, distinguished by qid. > and in vdpa.c: > > if (vma->vm_end - vma->vm_start != notify.size) > return -ENOTSUPP; > > so a zero size would cause this feature failure. > mmap should work on at least a page, so if we really want "area.size = > notify_offset_multiplier;" > I think we should add some code in vdpa.c, like: > > if(!notify.size) > notify.size = PAGE_SIZE; > > sounds good? It's the responsibility of the driver to report a correct one. So I think it's better to tweak it as: area.size = notify_offset_multiplier ?: PAGE_SIZE; Thanks > > Thanks > Zhu Lingshan >> >> >>> + >>> + return area; >>> +} >>> + >>> /* >>> * IFCVF currently does't have on-chip IOMMU, so not >>> * implemented set_map()/dma_map()/dma_unmap() >>> @@ -440,6 +456,7 @@ static const struct vdpa_config_ops ifc_vdpa_ops >>> = { >>> .get_config = ifcvf_vdpa_get_config, >>> .set_config = ifcvf_vdpa_set_config, >>> .set_config_cb = ifcvf_vdpa_set_config_cb, >>> + .get_vq_notification = ifcvf_get_vq_notification, >>> }; >>> static int ifcvf_probe(struct pci_dev *pdev, const struct >>> pci_device_id *id) >> >
WARNING: multiple messages have this Message-ID (diff)
From: Jason Wang <jasowang@redhat.com> To: "Zhu, Lingshan" <lingshan.zhu@intel.com>, mst@redhat.com Cc: netdev@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: Re: [PATCH V2 RESEND 2/2] vDPA/ifcvf: implement doorbell mapping for ifcvf Date: Tue, 1 Jun 2021 11:31:56 +0800 [thread overview] Message-ID: <91c64c0c-7b78-4c41-a6d7-6d9f084c7cc5@redhat.com> (raw) In-Reply-To: <5dbdc6a5-1510-9411-6b85-d947d091089c@intel.com> 在 2021/6/1 上午11:27, Zhu, Lingshan 写道: > > > On 5/31/2021 3:56 PM, Jason Wang wrote: >> >> 在 2021/5/31 下午3:33, Zhu Lingshan 写道: >>> This commit implements doorbell mapping feature for ifcvf. >>> This feature maps the notify page to userspace, to eliminate >>> vmexit when kick a vq. >>> >>> Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com> >>> --- >>> drivers/vdpa/ifcvf/ifcvf_main.c | 17 +++++++++++++++++ >>> 1 file changed, 17 insertions(+) >>> >>> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c >>> b/drivers/vdpa/ifcvf/ifcvf_main.c >>> index ab0ab5cf0f6e..effb0e549135 100644 >>> --- a/drivers/vdpa/ifcvf/ifcvf_main.c >>> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c >>> @@ -413,6 +413,22 @@ static int ifcvf_vdpa_get_vq_irq(struct >>> vdpa_device *vdpa_dev, >>> return vf->vring[qid].irq; >>> } >>> +static struct vdpa_notification_area >>> ifcvf_get_vq_notification(struct vdpa_device *vdpa_dev, >>> + u16 idx) >>> +{ >>> + struct ifcvf_adapter *adapter = vdpa_to_adapter(vdpa_dev); >>> + struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev); >>> + struct pci_dev *pdev = adapter->pdev; >>> + struct vdpa_notification_area area; >>> + >>> + area.addr = vf->vring[idx].notify_pa; >>> + area.size = PAGE_SIZE; >>> + if (area.addr % PAGE_SIZE) >>> + IFCVF_DBG(pdev, "vq %u doorbell address is not PAGE_SIZE >>> aligned\n", idx); >> >> >> Let's leave the decision to upper layer by: (see >> vp_vdpa_get_vq_notification) >> >> area.addr = notify_pa; >> area.size = notify_offset_multiplier; >> >> Thanks > > Hi Jason, > > notify_offset_multiplier can be zero, means vqs share the same > doorbell address, distinguished by qid. > and in vdpa.c: > > if (vma->vm_end - vma->vm_start != notify.size) > return -ENOTSUPP; > > so a zero size would cause this feature failure. > mmap should work on at least a page, so if we really want "area.size = > notify_offset_multiplier;" > I think we should add some code in vdpa.c, like: > > if(!notify.size) > notify.size = PAGE_SIZE; > > sounds good? It's the responsibility of the driver to report a correct one. So I think it's better to tweak it as: area.size = notify_offset_multiplier ?: PAGE_SIZE; Thanks > > Thanks > Zhu Lingshan >> >> >>> + >>> + return area; >>> +} >>> + >>> /* >>> * IFCVF currently does't have on-chip IOMMU, so not >>> * implemented set_map()/dma_map()/dma_unmap() >>> @@ -440,6 +456,7 @@ static const struct vdpa_config_ops ifc_vdpa_ops >>> = { >>> .get_config = ifcvf_vdpa_get_config, >>> .set_config = ifcvf_vdpa_set_config, >>> .set_config_cb = ifcvf_vdpa_set_config_cb, >>> + .get_vq_notification = ifcvf_get_vq_notification, >>> }; >>> static int ifcvf_probe(struct pci_dev *pdev, const struct >>> pci_device_id *id) >> > _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2021-06-01 3:32 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-05-31 7:33 [PATCH V2 RESEND 0/2] vDPA/ifcvf: implement doorbell mapping feature Zhu Lingshan 2021-05-31 7:33 ` [PATCH V2 RESEND 1/2] vDPA/ifcvf: record virtio notify base Zhu Lingshan 2021-05-31 7:33 ` [PATCH V2 RESEND 2/2] vDPA/ifcvf: implement doorbell mapping for ifcvf Zhu Lingshan 2021-05-31 7:56 ` Jason Wang 2021-05-31 7:56 ` Jason Wang 2021-06-01 3:27 ` Zhu, Lingshan 2021-06-01 3:31 ` Jason Wang [this message] 2021-06-01 3:31 ` Jason Wang
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