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, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] vDPA/ifcvf: implement doorbell mapping for ifcvf Date: Wed, 28 Apr 2021 17:21:48 +0800 [thread overview] Message-ID: <1984491f-cd5e-d4bc-b328-41e2f2e935fd@redhat.com> (raw) In-Reply-To: <5052fced-cd9a-e453-5cb2-39cdde60a208@intel.com> 在 2021/4/28 下午4:59, Zhu, Lingshan 写道: > > > On 4/28/2021 4:42 PM, Jason Wang wrote: >> >> 在 2021/4/28 下午4:21, 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 | 18 ++++++++++++++++++ >>> 1 file changed, 18 insertions(+) >>> >>> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c >>> b/drivers/vdpa/ifcvf/ifcvf_main.c >>> index e48e6b74fe2e..afcb71bc0f51 100644 >>> --- a/drivers/vdpa/ifcvf/ifcvf_main.c >>> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c >>> @@ -413,6 +413,23 @@ 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_hw *vf = vdpa_to_vf(vdpa_dev); >>> + struct vdpa_notification_area area; >>> + >>> + if (vf->notify_pa % PAGE_SIZE) { >>> + area.addr = 0; >>> + area.size = 0; >> >> >> We don't need this since: >> >> 1) there's a check in the vhost vDPA > I think you mean this code block in vdpa.c > notify = ops->get_vq_notification(vdpa, index); > if (notify.addr & (PAGE_SIZE - 1)) > return -EINVAL; > > This should work, however, I think the parent driver should ensure it > passes a PAGE_SIZE aligned address to userspace, to be robust, to be > reliable. The point is parent is unaware of whether or not there's a userspace. >> 2) device is unaware of the bound driver, non page aligned doorbell >> doesn't necessarily meant it can be used > Yes, non page aligned doorbell can not be used, so there is a check. Typo, what I meant is "it can't be used". That is to say, we should let the vDPA bus driver to decide whether or not it can be used. Thanks > > Thanks > Zhu Lingshan >> >> Let's leave those polices to the driver. >> >> Thanks >> >> >>> + } else { >>> + area.addr = vf->notify_pa; >>> + area.size = PAGE_SIZE; >>> + } >>> + >>> + return area; >>> +} >>> + >>> /* >>> * IFCVF currently does't have on-chip IOMMU, so not >>> * implemented set_map()/dma_map()/dma_unmap() >>> @@ -440,6 +457,7 @@ 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, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: Re: [PATCH 2/2] vDPA/ifcvf: implement doorbell mapping for ifcvf Date: Wed, 28 Apr 2021 17:21:48 +0800 [thread overview] Message-ID: <1984491f-cd5e-d4bc-b328-41e2f2e935fd@redhat.com> (raw) In-Reply-To: <5052fced-cd9a-e453-5cb2-39cdde60a208@intel.com> 在 2021/4/28 下午4:59, Zhu, Lingshan 写道: > > > On 4/28/2021 4:42 PM, Jason Wang wrote: >> >> 在 2021/4/28 下午4:21, 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 | 18 ++++++++++++++++++ >>> 1 file changed, 18 insertions(+) >>> >>> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c >>> b/drivers/vdpa/ifcvf/ifcvf_main.c >>> index e48e6b74fe2e..afcb71bc0f51 100644 >>> --- a/drivers/vdpa/ifcvf/ifcvf_main.c >>> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c >>> @@ -413,6 +413,23 @@ 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_hw *vf = vdpa_to_vf(vdpa_dev); >>> + struct vdpa_notification_area area; >>> + >>> + if (vf->notify_pa % PAGE_SIZE) { >>> + area.addr = 0; >>> + area.size = 0; >> >> >> We don't need this since: >> >> 1) there's a check in the vhost vDPA > I think you mean this code block in vdpa.c > notify = ops->get_vq_notification(vdpa, index); > if (notify.addr & (PAGE_SIZE - 1)) > return -EINVAL; > > This should work, however, I think the parent driver should ensure it > passes a PAGE_SIZE aligned address to userspace, to be robust, to be > reliable. The point is parent is unaware of whether or not there's a userspace. >> 2) device is unaware of the bound driver, non page aligned doorbell >> doesn't necessarily meant it can be used > Yes, non page aligned doorbell can not be used, so there is a check. Typo, what I meant is "it can't be used". That is to say, we should let the vDPA bus driver to decide whether or not it can be used. Thanks > > Thanks > Zhu Lingshan >> >> Let's leave those polices to the driver. >> >> Thanks >> >> >>> + } else { >>> + area.addr = vf->notify_pa; >>> + area.size = PAGE_SIZE; >>> + } >>> + >>> + return area; >>> +} >>> + >>> /* >>> * IFCVF currently does't have on-chip IOMMU, so not >>> * implemented set_map()/dma_map()/dma_unmap() >>> @@ -440,6 +457,7 @@ 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:[~2021-04-28 9:22 UTC|newest] Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-04-28 8:21 [PATCH 0/2] vDPA/ifcvf: implement doorbell mapping feature Zhu Lingshan 2021-04-28 8:21 ` [PATCH 1/2] vDPA/ifcvf: record virtio notify base Zhu Lingshan 2021-04-28 8:39 ` Jason Wang 2021-04-28 8:39 ` Jason Wang 2021-04-28 10:00 ` Zhu, Lingshan 2021-04-28 10:09 ` Jason Wang 2021-04-28 10:09 ` Jason Wang 2021-04-28 10:18 ` Zhu, Lingshan 2021-04-28 11:48 ` kernel test robot 2021-04-28 11:48 ` kernel test robot 2021-04-28 11:48 ` kernel test robot 2021-04-28 8:21 ` [PATCH 2/2] vDPA/ifcvf: implement doorbell mapping for ifcvf Zhu Lingshan 2021-04-28 8:42 ` Jason Wang 2021-04-28 8:42 ` Jason Wang 2021-04-28 8:59 ` Zhu, Lingshan 2021-04-28 9:21 ` Jason Wang [this message] 2021-04-28 9:21 ` Jason Wang 2021-04-28 9:56 ` Zhu, Lingshan 2021-04-28 10:03 ` Jason Wang 2021-04-28 10:03 ` Jason Wang 2021-04-28 10:20 ` Zhu, Lingshan 2021-04-28 13:08 ` Jason Wang 2021-04-28 13:08 ` Jason Wang 2021-04-29 11:26 ` Zhu, Lingshan
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