From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D2D9C433EF for ; Tue, 15 Feb 2022 02:17:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233505AbiBOCRO (ORCPT ); Mon, 14 Feb 2022 21:17:14 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:46280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233253AbiBOCRN (ORCPT ); Mon, 14 Feb 2022 21:17:13 -0500 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 01C50658D for ; Mon, 14 Feb 2022 18:17:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1644891423; x=1676427423; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=wkMn/fcWue9Z2kEZkWdolZUMiLcF+WcTi0gwUd3J8vw=; b=huWIAbbzzIgQ9Xng3wxkDf1ihDCxfcKo2fPbrSjgHV5+Q7HfWwNyGEDQ RzLza4I7gM2j0VER1IaoMuUbbINXsIbvIGkBN6inQw3WiZaRHkLCegS2Y PXSs2PjO/mR2u73p4XZ/u2RmuP3AuAiXZY5ZFPos1GFy6U/Jo5MFtjwwT QLMdtPv6IxSn++TP3S7z533QpUW5G4xIn1VU9l1Nk8inblEBEVrn9pYMQ gMI9rxmqjyEwTZP3ds4svFWV2+42LTjjDoSo/nncgS4tgSZYVyHwqHqHD TZ212o8STIogRFwm10fGEGlqlgeKvq8497lrS/dnQzItmHvEHzNVOZeb9 w==; X-IronPort-AV: E=McAfee;i="6200,9189,10258"; a="313505277" X-IronPort-AV: E=Sophos;i="5.88,369,1635231600"; d="scan'208";a="313505277" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Feb 2022 18:17:03 -0800 X-IronPort-AV: E=Sophos;i="5.88,369,1635231600"; d="scan'208";a="528563832" Received: from lingshan-mobl.ccr.corp.intel.com (HELO [10.255.28.149]) ([10.255.28.149]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Feb 2022 18:17:01 -0800 Message-ID: Date: Tue, 15 Feb 2022 10:16:59 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Firefox/91.0 Thunderbird/91.5.1 Subject: Re: [PATCH V4 4/4] vDPA/ifcvf: implement shared IRQ feature Content-Language: en-US To: "Michael S. Tsirkin" , Jason Wang Cc: netdev@vger.kernel.org, virtualization@lists.linux-foundation.org References: <20220203072735.189716-1-lingshan.zhu@intel.com> <20220203072735.189716-5-lingshan.zhu@intel.com> <20220214091842-mutt-send-email-mst@kernel.org> From: "Zhu, Lingshan" In-Reply-To: <20220214091842-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2/14/2022 10:25 PM, Michael S. Tsirkin wrote: > On Mon, Feb 14, 2022 at 03:19:25PM +0800, Jason Wang wrote: >> 在 2022/2/3 下午3:27, Zhu Lingshan 写道: >>> On some platforms/devices, there may not be enough MSI vector >>> slots allocated for virtqueues and config changes. In such a case, >>> the interrupt sources(virtqueues, config changes) must share >>> an IRQ/vector, to avoid initialization failures, keep >>> the device functional. >>> >>> This commit handles three cases: >>> (1) number of the allocated vectors == the number of virtqueues + 1 >>> (config changes), every virtqueue and the config interrupt has >>> a separated vector/IRQ, the best and the most likely case. >>> (2) number of the allocated vectors is less than the best case, but >>> greater than 1. In this case, all virtqueues share a vector/IRQ, >>> the config interrupt has a separated vector/IRQ >>> (3) only one vector is allocated, in this case, the virtqueues and >>> the config interrupt share a vector/IRQ. The worst and most >>> unlikely case. >>> >>> Otherwise, it needs to fail. >>> >>> This commit introduces some helper functions: >>> ifcvf_set_vq_vector() and ifcvf_set_config_vector() sets virtqueue >>> vector and config vector in the device config space, so that >>> the device can send interrupt DMA. >>> >>> This commit adds some fields in struct ifcvf_hw and re-placed >>> the existed fields to be aligned with the cacheline. >>> >>> Signed-off-by: Zhu Lingshan >>> --- >>> drivers/vdpa/ifcvf/ifcvf_base.c | 47 ++++-- >>> drivers/vdpa/ifcvf/ifcvf_base.h | 23 ++- >>> drivers/vdpa/ifcvf/ifcvf_main.c | 243 +++++++++++++++++++++++++++----- >>> 3 files changed, 256 insertions(+), 57 deletions(-) >>> >>> diff --git a/drivers/vdpa/ifcvf/ifcvf_base.c b/drivers/vdpa/ifcvf/ifcvf_base.c >>> index 397692ae671c..18dcb63ab1e3 100644 >>> --- a/drivers/vdpa/ifcvf/ifcvf_base.c >>> +++ b/drivers/vdpa/ifcvf/ifcvf_base.c >>> @@ -15,6 +15,36 @@ struct ifcvf_adapter *vf_to_adapter(struct ifcvf_hw *hw) >>> return container_of(hw, struct ifcvf_adapter, vf); >>> } >>> +int ifcvf_set_vq_vector(struct ifcvf_hw *hw, u16 qid, int vector) >>> +{ >>> + struct virtio_pci_common_cfg __iomem *cfg = hw->common_cfg; >>> + struct ifcvf_adapter *ifcvf = vf_to_adapter(hw); >>> + >>> + ifc_iowrite16(qid, &cfg->queue_select); >>> + ifc_iowrite16(vector, &cfg->queue_msix_vector); >>> + if (ifc_ioread16(&cfg->queue_msix_vector) == VIRTIO_MSI_NO_VECTOR) { >>> + IFCVF_ERR(ifcvf->pdev, "No msix vector for queue %u\n", qid); >>> + return -EINVAL; >>> + } >> >> Let's leave this check for the caller, E.g can caller try to assign >> NO_VECTOR during uni-nit? > > Hmm I'm not sure I agree. Caller will have to write queue select > again, and that's an extra IO, which is a waste. > And having function checking itself just seems better contained. > >>> + >>> + return 0; >>> +} >>> + >>> +int ifcvf_set_config_vector(struct ifcvf_hw *hw, int vector) >>> +{ >>> + struct virtio_pci_common_cfg __iomem *cfg = hw->common_cfg; >>> + struct ifcvf_adapter *ifcvf = vf_to_adapter(hw); >>> + >>> + cfg = hw->common_cfg; >>> + ifc_iowrite16(vector, &cfg->msix_config); >>> + if (ifc_ioread16(&cfg->msix_config) == VIRTIO_MSI_NO_VECTOR) { >>> + IFCVF_ERR(ifcvf->pdev, "No msix vector for device config\n"); >>> + return -EINVAL; >>> + } >> >> Similar question as above. >> >> >>> + >>> + return 0; >>> +} >>> + >>> static void __iomem *get_cap_addr(struct ifcvf_hw *hw, >>> struct virtio_pci_cap *cap) >>> { >>> @@ -140,6 +170,8 @@ int ifcvf_init_hw(struct ifcvf_hw *hw, struct pci_dev *pdev) >>> hw->common_cfg, hw->notify_base, hw->isr, >>> hw->dev_cfg, hw->notify_off_multiplier); >>> + hw->vqs_shared_irq = -EINVAL; >>> + >>> return 0; >>> } >>> @@ -321,12 +353,6 @@ static int ifcvf_hw_enable(struct ifcvf_hw *hw) >>> ifcvf = vf_to_adapter(hw); >>> cfg = hw->common_cfg; >>> - ifc_iowrite16(IFCVF_MSI_CONFIG_OFF, &cfg->msix_config); >>> - >>> - if (ifc_ioread16(&cfg->msix_config) == VIRTIO_MSI_NO_VECTOR) { >>> - IFCVF_ERR(ifcvf->pdev, "No msix vector for device config\n"); >>> - return -EINVAL; >>> - } >>> for (i = 0; i < hw->nr_vring; i++) { >>> if (!hw->vring[i].ready) >>> @@ -340,15 +366,6 @@ static int ifcvf_hw_enable(struct ifcvf_hw *hw) >>> ifc_iowrite64_twopart(hw->vring[i].used, &cfg->queue_used_lo, >>> &cfg->queue_used_hi); >>> ifc_iowrite16(hw->vring[i].size, &cfg->queue_size); >>> - ifc_iowrite16(i + IFCVF_MSI_QUEUE_OFF, &cfg->queue_msix_vector); >>> - >>> - if (ifc_ioread16(&cfg->queue_msix_vector) == >>> - VIRTIO_MSI_NO_VECTOR) { >>> - IFCVF_ERR(ifcvf->pdev, >>> - "No msix vector for queue %u\n", i); >>> - return -EINVAL; >>> - } >>> - >>> ifcvf_set_vq_state(hw, i, hw->vring[i].last_avail_idx); >>> ifc_iowrite16(1, &cfg->queue_enable); >>> } >>> diff --git a/drivers/vdpa/ifcvf/ifcvf_base.h b/drivers/vdpa/ifcvf/ifcvf_base.h >>> index 949b4fb9d554..9cfe088c82e9 100644 >>> --- a/drivers/vdpa/ifcvf/ifcvf_base.h >>> +++ b/drivers/vdpa/ifcvf/ifcvf_base.h >>> @@ -27,8 +27,6 @@ >>> #define IFCVF_QUEUE_ALIGNMENT PAGE_SIZE >>> #define IFCVF_QUEUE_MAX 32768 >>> -#define IFCVF_MSI_CONFIG_OFF 0 >>> -#define IFCVF_MSI_QUEUE_OFF 1 >>> #define IFCVF_PCI_MAX_RESOURCE 6 >>> #define IFCVF_LM_CFG_SIZE 0x40 >>> @@ -42,6 +40,13 @@ >>> #define ifcvf_private_to_vf(adapter) \ >>> (&((struct ifcvf_adapter *)adapter)->vf) >>> +/* all vqs and config interrupt has its own vector */ >>> +#define MSIX_VECTOR_PER_VQ_AND_CONFIG 1 >>> +/* all vqs share a vector, and config interrupt has a separate vector */ >>> +#define MSIX_VECTOR_SHARED_VQ_AND_CONFIG 2 >>> +/* all vqs and config interrupt share a vector */ >>> +#define MSIX_VECTOR_DEV_SHARED 3 >> >> I think there's no much value to differ 2 from 3 consider config interrupt >> should be rare. > > Yes but if we do not have a dedicated vector then we need an > extra device IO (in fact, a read) on each interrupt. > >>> + >>> static inline u8 ifc_ioread8(u8 __iomem *addr) >>> { >>> return ioread8(addr); >>> @@ -97,25 +102,27 @@ struct ifcvf_hw { >>> u8 __iomem *isr; >>> /* Live migration */ >>> u8 __iomem *lm_cfg; >>> - u16 nr_vring; >> >> Any reason for moving nv_vring, config_size, and other stuffs? >> >> >>> /* Notification bar number */ >>> u8 notify_bar; >>> + u8 msix_vector_status; >>> + /* virtio-net or virtio-blk device config size */ >>> + u32 config_size; >>> /* Notificaiton bar address */ >>> void __iomem *notify_base; >>> phys_addr_t notify_base_pa; >>> u32 notify_off_multiplier; >>> + u32 dev_type; >>> u64 req_features; >>> u64 hw_features; >>> - u32 dev_type; >>> struct virtio_pci_common_cfg __iomem *common_cfg; >>> void __iomem *dev_cfg; >>> struct vring_info vring[IFCVF_MAX_QUEUES]; >>> void __iomem * const *base; >>> char config_msix_name[256]; >>> struct vdpa_callback config_cb; >>> - unsigned int config_irq; >>> - /* virtio-net or virtio-blk device config size */ >>> - u32 config_size; >>> + int config_irq; >>> + int vqs_shared_irq; >>> + u16 nr_vring; >>> }; >>> struct ifcvf_adapter { >>> @@ -160,4 +167,6 @@ int ifcvf_set_vq_state(struct ifcvf_hw *hw, u16 qid, u16 num); >>> struct ifcvf_adapter *vf_to_adapter(struct ifcvf_hw *hw); >>> int ifcvf_probed_virtio_net(struct ifcvf_hw *hw); >>> u32 ifcvf_get_config_size(struct ifcvf_hw *hw); >>> +int ifcvf_set_vq_vector(struct ifcvf_hw *hw, u16 qid, int vector); >>> +int ifcvf_set_config_vector(struct ifcvf_hw *hw, int vector); >>> #endif /* _IFCVF_H_ */ >>> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c >>> index 44c89ab0b6da..ca414399f040 100644 >>> --- a/drivers/vdpa/ifcvf/ifcvf_main.c >>> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c >>> @@ -17,6 +17,7 @@ >>> #define DRIVER_AUTHOR "Intel Corporation" >>> #define IFCVF_DRIVER_NAME "ifcvf" >>> +/* handles config interrupt */ >> >> This seems unrelated to the shared IRQ logic and it looks useless since it's >> easily to deduce it from the function name below. >> >> >>> static irqreturn_t ifcvf_config_changed(int irq, void *arg) >>> { >>> struct ifcvf_hw *vf = arg; >>> @@ -27,6 +28,7 @@ static irqreturn_t ifcvf_config_changed(int irq, void *arg) >>> return IRQ_HANDLED; >>> } >>> +/* handles vqs interrupt */ >> >> So did this. >> >> >>> static irqreturn_t ifcvf_intr_handler(int irq, void *arg) >>> { >>> struct vring_info *vring = arg; >>> @@ -37,24 +39,78 @@ static irqreturn_t ifcvf_intr_handler(int irq, void *arg) >>> return IRQ_HANDLED; >>> } >>> +/* handls vqs shared interrupt */ >>> +static irqreturn_t ifcvf_vq_shared_intr_handler(int irq, void *arg) >>> +{ >>> + struct ifcvf_hw *vf = arg; >>> + struct vring_info *vring; >>> + int i; >>> + >>> + for (i = 0; i < vf->nr_vring; i++) { >>> + vring = &vf->vring[i]; >>> + if (vring->cb.callback) >>> + vf->vring->cb.callback(vring->cb.private); >>> + } >>> + >>> + return IRQ_HANDLED; >>> +} >>> + >>> +/* handles a shared interrupt for vqs and config */ >>> +static irqreturn_t ifcvf_dev_shared_intr_handler(int irq, void *arg) > shared is not a good name given IRQ_SHARED is not set. > maybe "common"? "reused"? Sure, I can do better naming Thanks > >>> +{ >>> + struct ifcvf_hw *vf = arg; >>> + u8 isr; >>> + >>> + isr = ifc_ioread8(vf->isr); >> >> We need to exactly what vp_interrupt do here. Checking against vf->isr first >> and return IRQ_NONE if it is not set. > no, vf->isr is not set for VQ interrupts. If need to actually poke > at the VQ to know. > >> Always return IRQ_HANDLED will break the device who shares an irq with >> IFCVF. > > It's a MSI, not INT#. So interrupt is not shared as such - it's only > sharing vector between config and vq. > > >>> + if (isr & VIRTIO_PCI_ISR_CONFIG) >>> + ifcvf_config_changed(irq, arg); >>> + >>> + return ifcvf_vq_shared_intr_handler(irq, arg); >>> +} >>> + >>> static void ifcvf_free_irq_vectors(void *data) >>> { >>> pci_free_irq_vectors(data); >>> } >>> -static void ifcvf_free_irq(struct ifcvf_adapter *adapter, int queues) >>> +static void ifcvf_free_vq_irq(struct ifcvf_adapter *adapter, int queues) >>> { >>> struct pci_dev *pdev = adapter->pdev; >>> struct ifcvf_hw *vf = &adapter->vf; >>> int i; >>> + if (vf->msix_vector_status == MSIX_VECTOR_PER_VQ_AND_CONFIG) { >>> + for (i = 0; i < queues; i++) { >>> + devm_free_irq(&pdev->dev, vf->vring[i].irq, &vf->vring[i]); >>> + vf->vring[i].irq = -EINVAL; >>> + } >>> + } else { >>> + devm_free_irq(&pdev->dev, vf->vqs_shared_irq, vf); >>> + vf->vqs_shared_irq = -EINVAL; >>> + } >>> +} >>> - for (i = 0; i < queues; i++) { >>> - devm_free_irq(&pdev->dev, vf->vring[i].irq, &vf->vring[i]); >>> - vf->vring[i].irq = -EINVAL; >>> +static void ifcvf_free_config_irq(struct ifcvf_adapter *adapter) >>> +{ >>> + struct pci_dev *pdev = adapter->pdev; >>> + struct ifcvf_hw *vf = &adapter->vf; >>> + >>> + /* If the irq is shared by all vqs and the config interrupt, >>> + * it is already freed in ifcvf_free_vq_irq, so here only >>> + * need to free config irq when msix_vector_status != MSIX_VECTOR_DEV_SHARED >>> + */ >>> + if (vf->msix_vector_status != MSIX_VECTOR_DEV_SHARED) { >>> + devm_free_irq(&pdev->dev, vf->config_irq, vf); >>> + vf->config_irq = -EINVAL; >>> } >>> +} >>> + >>> +static void ifcvf_free_irq(struct ifcvf_adapter *adapter, int queues) >>> +{ >>> + struct pci_dev *pdev = adapter->pdev; >>> - devm_free_irq(&pdev->dev, vf->config_irq, vf); >>> + ifcvf_free_vq_irq(adapter, queues); >>> + ifcvf_free_config_irq(adapter); >>> ifcvf_free_irq_vectors(pdev); >>> } >>> @@ -86,58 +142,172 @@ static int ifcvf_alloc_vectors(struct ifcvf_adapter *adapter) >>> return ret; >>> } >>> -static int ifcvf_request_irq(struct ifcvf_adapter *adapter) >>> +static int ifcvf_request_per_vq_irq(struct ifcvf_adapter *adapter) >>> { >>> struct pci_dev *pdev = adapter->pdev; >>> struct ifcvf_hw *vf = &adapter->vf; >>> - int vector, nvectors, i, ret, irq; >>> - u16 max_intr; >>> + int i, vector, ret, irq; >>> - nvectors = ifcvf_alloc_vectors(adapter); >>> - if (!(nvectors > 0)) >>> - return nvectors; >>> + for (i = 0; i < vf->nr_vring; i++) { >>> + snprintf(vf->vring[i].msix_name, 256, "ifcvf[%s]-%d\n", pci_name(pdev), i); >>> + vector = i; >>> + irq = pci_irq_vector(pdev, vector); >>> + ret = devm_request_irq(&pdev->dev, irq, >>> + ifcvf_intr_handler, 0, >>> + vf->vring[i].msix_name, >>> + &vf->vring[i]); >>> + if (ret) { >>> + IFCVF_ERR(pdev, "Failed to request irq for vq %d\n", i); >>> + ifcvf_free_vq_irq(adapter, i); >>> + } else { >>> + vf->vring[i].irq = irq; >>> + ifcvf_set_vq_vector(vf, i, vector); >>> + } >>> + } >>> - max_intr = vf->nr_vring + 1; >>> + vf->vqs_shared_irq = -EINVAL; >>> + >>> + return 0; >>> +} >>> + >>> +static int ifcvf_request_shared_vq_irq(struct ifcvf_adapter *adapter) >>> +{ >>> + struct pci_dev *pdev = adapter->pdev; >>> + struct ifcvf_hw *vf = &adapter->vf; >>> + int i, vector, ret, irq; >>> + >>> + vector = 0; >>> + /* reuse msix_name[256] space of vring0 to store shared vqs interrupt name */ >> >> I think we can remove this comment since the code is straightforward. >> >> >>> + snprintf(vf->vring[0].msix_name, 256, "ifcvf[%s]-vqs-shared-irq\n", pci_name(pdev)); >>> + irq = pci_irq_vector(pdev, vector); >>> + ret = devm_request_irq(&pdev->dev, irq, >>> + ifcvf_vq_shared_intr_handler, 0, >>> + vf->vring[0].msix_name, vf); >>> + if (ret) { >>> + IFCVF_ERR(pdev, "Failed to request shared irq for vf\n"); >>> + >>> + return ret; >>> + } >>> + >>> + vf->vqs_shared_irq = irq; >>> + for (i = 0; i < vf->nr_vring; i++) { >>> + vf->vring[i].irq = -EINVAL; >>> + ifcvf_set_vq_vector(vf, i, vector); >>> + } >>> + >>> + return 0; >>> + >>> +} >>> + >>> +static int ifcvf_request_dev_shared_irq(struct ifcvf_adapter *adapter) >>> +{ >>> + struct pci_dev *pdev = adapter->pdev; >>> + struct ifcvf_hw *vf = &adapter->vf; >>> + int i, vector, ret, irq; >>> + >>> + vector = 0; >>> + /* reuse msix_name[256] space of vring0 to store shared device interrupt name */ >>> + snprintf(vf->vring[0].msix_name, 256, "ifcvf[%s]-dev-shared-irq\n", pci_name(pdev)); >>> + irq = pci_irq_vector(pdev, vector); >>> + ret = devm_request_irq(&pdev->dev, irq, >>> + ifcvf_dev_shared_intr_handler, 0, >>> + vf->vring[0].msix_name, vf); >>> + if (ret) { >>> + IFCVF_ERR(pdev, "Failed to request shared irq for vf\n"); >>> - ret = pci_alloc_irq_vectors(pdev, max_intr, >>> - max_intr, PCI_IRQ_MSIX); >>> - if (ret < 0) { >>> - IFCVF_ERR(pdev, "Failed to alloc IRQ vectors\n"); >>> return ret; >>> } >>> + vf->vqs_shared_irq = irq; >>> + for (i = 0; i < vf->nr_vring; i++) { >>> + vf->vring[i].irq = -EINVAL; >>> + ifcvf_set_vq_vector(vf, i, vector); >>> + } >>> + >>> + vf->config_irq = irq; >>> + ifcvf_set_config_vector(vf, vector); >>> + >>> + return 0; >>> + >>> +} >>> + >>> +static int ifcvf_request_vq_irq(struct ifcvf_adapter *adapter) >>> +{ >>> + struct ifcvf_hw *vf = &adapter->vf; >>> + int ret; >>> + >>> + if (vf->msix_vector_status == MSIX_VECTOR_PER_VQ_AND_CONFIG) >>> + ret = ifcvf_request_per_vq_irq(adapter); >>> + else >>> + ret = ifcvf_request_shared_vq_irq(adapter); >>> + >>> + return ret; >>> +} >>> + >>> +static int ifcvf_request_config_irq(struct ifcvf_adapter *adapter) >>> +{ >>> + struct pci_dev *pdev = adapter->pdev; >>> + struct ifcvf_hw *vf = &adapter->vf; >>> + int config_vector, ret; >>> + >>> + if (vf->msix_vector_status == MSIX_VECTOR_DEV_SHARED) >>> + return 0; >>> + >>> + if (vf->msix_vector_status == MSIX_VECTOR_PER_VQ_AND_CONFIG) >>> + /* vector 0 ~ vf->nr_vring for vqs, num vf->nr_vring vector for config interrupt */ >>> + config_vector = vf->nr_vring; >>> + >>> + if (vf->msix_vector_status == MSIX_VECTOR_SHARED_VQ_AND_CONFIG) >>> + /* vector 0 for vqs and 1 for config interrupt */ >>> + config_vector = 1; >>> + >>> snprintf(vf->config_msix_name, 256, "ifcvf[%s]-config\n", >>> pci_name(pdev)); >>> - vector = 0; >>> - vf->config_irq = pci_irq_vector(pdev, vector); >>> + vf->config_irq = pci_irq_vector(pdev, config_vector); >>> ret = devm_request_irq(&pdev->dev, vf->config_irq, >>> ifcvf_config_changed, 0, >>> vf->config_msix_name, vf); >>> if (ret) { >>> IFCVF_ERR(pdev, "Failed to request config irq\n"); >>> + ifcvf_free_vq_irq(adapter, vf->nr_vring); >>> return ret; >>> } >>> - for (i = 0; i < vf->nr_vring; i++) { >>> - snprintf(vf->vring[i].msix_name, 256, "ifcvf[%s]-%d\n", >>> - pci_name(pdev), i); >>> - vector = i + IFCVF_MSI_QUEUE_OFF; >>> - irq = pci_irq_vector(pdev, vector); >>> - ret = devm_request_irq(&pdev->dev, irq, >>> - ifcvf_intr_handler, 0, >>> - vf->vring[i].msix_name, >>> - &vf->vring[i]); >>> - if (ret) { >>> - IFCVF_ERR(pdev, >>> - "Failed to request irq for vq %d\n", i); >>> - ifcvf_free_irq(adapter, i); >>> + ifcvf_set_config_vector(vf, config_vector); >>> - return ret; >>> - } >>> + return 0; >>> +} >>> + >>> +static int ifcvf_request_irq(struct ifcvf_adapter *adapter) >>> +{ >> >> As replied above, I think having two modes should be sufficient and the code >> could be greatly simplified. >> >> Thanks >> > Well it is claimed there are platforms where we are short > on vectors. 3 versus 2 seems a 50% saving. You disagree? > >>> + struct ifcvf_hw *vf = &adapter->vf; >>> + int nvectors, ret, max_intr; >>> - vf->vring[i].irq = irq; >>> + nvectors = ifcvf_alloc_vectors(adapter); >>> + if (!(nvectors > 0)) >>> + return nvectors; >>> + >>> + vf->msix_vector_status = MSIX_VECTOR_PER_VQ_AND_CONFIG; >>> + max_intr = vf->nr_vring + 1; >>> + if (nvectors < max_intr) >>> + vf->msix_vector_status = MSIX_VECTOR_SHARED_VQ_AND_CONFIG; >>> + >>> + if (nvectors == 1) { >>> + vf->msix_vector_status = MSIX_VECTOR_DEV_SHARED; >>> + ret = ifcvf_request_dev_shared_irq(adapter); >>> + >>> + return ret; >>> } >>> + ret = ifcvf_request_vq_irq(adapter); >>> + if (ret) >>> + return ret; >>> + >>> + ret = ifcvf_request_config_irq(adapter); >>> + >>> + if (ret) >>> + return ret; >>> + >>> return 0; >>> } >>> @@ -441,7 +611,10 @@ static int ifcvf_vdpa_get_vq_irq(struct vdpa_device *vdpa_dev, >>> { >>> struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev); >>> - return vf->vring[qid].irq; >>> + if (vf->vqs_shared_irq < 0) >>> + return vf->vring[qid].irq; >>> + else >>> + return -EINVAL; >>> } >>> static struct vdpa_notification_area ifcvf_get_vq_notification(struct vdpa_device *vdpa_dev,