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SubjectRe: [PATCH V3] vdpa: introduce virtio pci driver
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On 2020/6/10 下午3:08, Michael S. Tsirkin wrote:
> On Wed, Jun 10, 2020 at 02:52:17PM +0800, Jason Wang wrote:
>> This patch introduce a vDPA driver for virtio-pci device. It bridges
>> the virtio-pci control command to the vDPA bus. This will be used for
>> developing new features for both software vDPA framework and hardware
>> vDPA feature.
>>
>> Compared to vdpa_sim, it has several advantages:
>>
>> - it's a real device driver which allow us to play with real hardware
>> features
>> - type independent instead of networking specific
>>
>> Note that since virtio specification does not support get/restore
>> virtqueue state. So we can not use this driver for VM. This can be
>> addressed by extending the virtio specification.
>>
>> Consider the driver is mainly for testing and development for vDPA
>> features, it can only be bound via dynamic ids to make sure it's not
>> conflict with the drivers like virtio-pci or IFCVF.
>>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>> ---
>> Changes from V2:
>> - rebase on vhost.git vhost branch
>> ---
>> drivers/vdpa/Kconfig | 8 +
>> drivers/vdpa/Makefile | 1 +
>> drivers/vdpa/vp_vdpa/Makefile | 2 +
>> drivers/vdpa/vp_vdpa/vp_vdpa.c | 601 +++++++++++++++++++++++++++++++++
>> 4 files changed, 612 insertions(+)
>> create mode 100644 drivers/vdpa/vp_vdpa/Makefile
>> create mode 100644 drivers/vdpa/vp_vdpa/vp_vdpa.c
>>
>> diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig
>> index 3e1ceb8e9f2b..deb85e43a4c2 100644
>> --- a/drivers/vdpa/Kconfig
>> +++ b/drivers/vdpa/Kconfig
>> @@ -28,4 +28,12 @@ config IFCVF
>> To compile this driver as a module, choose M here: the module will
>> be called ifcvf.
>>
>> +config VP_VDPA
>> + tristate "Virtio PCI bridge vDPA driver"
>> + depends on PCI_MSI
>> + help
>> + This kernel module that bridges virtio PCI device to vDPA
>> + bus. It allows us to test and develop vDPA subsystem inside
>> + an VM with the emulated virtio-pci device
>> +
>> endif # VDPA
>> diff --git a/drivers/vdpa/Makefile b/drivers/vdpa/Makefile
>> index 8bbb686ca7a2..37d00f49b3bf 100644
>> --- a/drivers/vdpa/Makefile
>> +++ b/drivers/vdpa/Makefile
>> @@ -2,3 +2,4 @@
>> obj-$(CONFIG_VDPA) += vdpa.o
>> obj-$(CONFIG_VDPA_SIM) += vdpa_sim/
>> obj-$(CONFIG_IFCVF) += ifcvf/
>> +obj-$(CONFIG_VP_VDPA) += vp_vdpa/
>> diff --git a/drivers/vdpa/vp_vdpa/Makefile b/drivers/vdpa/vp_vdpa/Makefile
>> new file mode 100644
>> index 000000000000..231088d3af7d
>> --- /dev/null
>> +++ b/drivers/vdpa/vp_vdpa/Makefile
>> @@ -0,0 +1,2 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +obj-$(CONFIG_VP_VDPA) += vp_vdpa.o
>> diff --git a/drivers/vdpa/vp_vdpa/vp_vdpa.c b/drivers/vdpa/vp_vdpa/vp_vdpa.c
>> new file mode 100644
>> index 000000000000..2070298ab9fc
>> --- /dev/null
>> +++ b/drivers/vdpa/vp_vdpa/vp_vdpa.c
>> @@ -0,0 +1,601 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * vDPA bridge driver for modern virtio-pci device
> And judging by the code, transitional too?
> Or maybe we should drop transitional device support here.


Yes, I will simply drop the transitional device support.


>
>> + *
>> + * Copyright (c) 2020, Red Hat Inc. All rights reserved.
>> + * Author: Jason Wang <jasowang@redhat.com>
>> + *
>> + * Based on virtio_pci_modern.c.
>> + */
>> +
>> +#include <linux/interrupt.h>
>> +#include <linux/module.h>
>> +#include <linux/pci.h>
>> +#include <linux/vdpa.h>
>> +#include <linux/virtio.h>
>> +#include <linux/virtio_config.h>
>> +#include <linux/virtio_ring.h>
>> +#include <linux/virtio_pci.h>
>> +
>> +/* TBD: read from config space */
>> +#define VP_VDPA_MAX_QUEUE 2
> We need to fix that right? Otherwise lots of devices break ...


Yes, will fix.


>
>> +#define VP_VDPA_DRIVER_NAME "vp_vdpa"
> not sure why you need this macro ...


Used only once, so I will remove this.


>
>> +
>> +#define VP_VDPA_FEATURES \
>> + ((1ULL << VIRTIO_F_ANY_LAYOUT) | \
>
> This is presumably for transitional devices only. In fact looking at
> code it seems that only net in legacy mode accepts VIRTIO_F_ANY_LAYOUT.
> Spec violation I guess ... but what should we do? Relax the spec
> or fix drivers?


I don't get how it violates the spec.


>
>
>> + (1ULL << VIRTIO_F_VERSION_1) | \
>> + (1ULL << VIRTIO_F_ORDER_PLATFORM) | \
>> + (1ULL << VIRTIO_F_IOMMU_PLATFORM))
>> +
>> +struct vp_vring {
>> + void __iomem *notify;
>> + char msix_name[256];
>> + resource_size_t notify_pa;
>> + struct vdpa_callback cb;
>> + int irq;
>> +};
>> +
>> +struct vp_vdpa {
>> + struct vdpa_device vdpa;
>> + struct pci_dev *pdev;
>> +
>> + struct virtio_device_id id;
>> +
>> + struct vp_vring vring[VP_VDPA_MAX_QUEUE];
>> +
>> + /* The IO mapping for the PCI config space */
>> + void __iomem * const *base;
>> + struct virtio_pci_common_cfg __iomem *common;
>> + void __iomem *device;
>> + /* Base of vq notifications */
>> + void __iomem *notify;
>> +
>> + /* Multiplier for queue_notify_off. */
>> + u32 notify_off_multiplier;
>> +
>> + int modern_bars;
>> + int vectors;
>> +};
>> +
>> +static struct vp_vdpa *vdpa_to_vp(struct vdpa_device *vdpa)
>> +{
>> + return container_of(vdpa, struct vp_vdpa, vdpa);
>> +}
>> +
>> +/*
>> + * Type-safe wrappers for io accesses.
>> + * Use these to enforce at compile time the following spec requirement:
>> + *
>> + * The driver MUST access each field using the “natural” access
>> + * method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses
>> + * for 16-bit fields and 8-bit accesses for 8-bit fields.
>> + */
>> +static inline u8 vp_ioread8(u8 __iomem *addr)
>> +{
>> + return ioread8(addr);
>> +}
>> +static inline u16 vp_ioread16(__le16 __iomem *addr)
>> +{
>> + return ioread16(addr);
>> +}
>> +
>> +static inline u32 vp_ioread32(__le32 __iomem *addr)
>> +{
>> + return ioread32(addr);
>> +}
>> +
>> +static inline void vp_iowrite8(u8 value, u8 __iomem *addr)
>> +{
>> + iowrite8(value, addr);
>> +}
>> +
>> +static inline void vp_iowrite16(u16 value, __le16 __iomem *addr)
>> +{
>> + iowrite16(value, addr);
>> +}
>> +
>> +static inline void vp_iowrite32(u32 value, __le32 __iomem *addr)
>> +{
>> + iowrite32(value, addr);
>> +}
>> +
>> +static void vp_iowrite64_twopart(u64 val,
>> + __le32 __iomem *lo, __le32 __iomem *hi)
>> +{
>> + vp_iowrite32((u32)val, lo);
>> + vp_iowrite32(val >> 32, hi);
>> +}
>> +
>> +static int find_capability(struct pci_dev *dev, u8 cfg_type,
>> + u32 ioresource_types, int *bars)
>> +{
>> + int pos;
>> +
>> + for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
>> + pos > 0;
>> + pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
>> + u8 type, bar;
>> +
>> + pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
>> + cfg_type),
>> + &type);
>> + pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
>> + bar),
>> + &bar);
>> +
>> + /* Ignore structures with reserved BAR values */
>> + if (bar > 0x5)
>> + continue;
>> +
>> + if (type == cfg_type) {
>> + if (pci_resource_len(dev, bar) &&
>> + pci_resource_flags(dev, bar) & ioresource_types) {
>> + *bars |= (1 << bar);
>> + return pos;
>> + }
>> + }
>> + }
>> + return 0;
>> +}
>> +
>> +static void __iomem *map_capability(struct vp_vdpa *vp_vdpa, int off,
>> + resource_size_t *pa)
>> +{
>> + struct pci_dev *pdev = vp_vdpa->pdev;
>> + u32 offset;
>> + u8 bar;
>> +
>> + pci_read_config_byte(pdev,
>> + off + offsetof(struct virtio_pci_cap, bar),
>> + &bar);
>> + pci_read_config_dword(pdev,
>> + off + offsetof(struct virtio_pci_cap, offset),
>> + &offset);
>> +
>> + if (pa)
>> + *pa = pci_resource_start(pdev, bar) + offset;
>> +
>> + return vp_vdpa->base[bar] + offset;
>> +}
>> +
>> +static u64 vp_vdpa_get_features(struct vdpa_device *vdpa)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> + u64 features;
>> +
>> + vp_iowrite32(0, &vp_vdpa->common->device_feature_select);
>> + features = vp_ioread32(&vp_vdpa->common->device_feature);
>> + vp_iowrite32(1, &vp_vdpa->common->device_feature_select);
>> + features |= ((u64)vp_ioread32(&vp_vdpa->common->device_feature) << 32);
>> + features &= VP_VDPA_FEATURES;
>> +
>> + return features;
>> +}
>> +
>> +static int vp_vdpa_set_features(struct vdpa_device *vdpa, u64 features)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> +
>> + vp_iowrite32(0, &vp_vdpa->common->guest_feature_select);
>> + vp_iowrite32((u32)features, &vp_vdpa->common->guest_feature);
>> + vp_iowrite32(1, &vp_vdpa->common->guest_feature_select);
>> + vp_iowrite32(features >> 32, &vp_vdpa->common->guest_feature);
>> +
>> + return 0;
>> +}
>> +
>> +static u8 vp_vdpa_get_status(struct vdpa_device *vdpa)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> +
>> + return vp_ioread8(&vp_vdpa->common->device_status);
>> +}
>> +
>> +static void vp_vdpa_free_irq(struct vp_vdpa *vp_vdpa)
>> +{
>> + struct pci_dev *pdev = vp_vdpa->pdev;
>> + int i;
>> +
>> + for (i = 0; i < VP_VDPA_MAX_QUEUE; i++) {
>> + if (vp_vdpa->vring[i].irq != -1) {
>> + vp_iowrite16(i, &vp_vdpa->common->queue_select);
>> + vp_iowrite16(VIRTIO_MSI_NO_VECTOR,
>> + &vp_vdpa->common->queue_msix_vector);
>> + devm_free_irq(&pdev->dev, vp_vdpa->vring[i].irq,
>> + &vp_vdpa->vring[i]);
>> + vp_vdpa->vring[i].irq = -1;
>> + }
>> + }
>> +
>> + if (vp_vdpa->vectors) {
>> + pci_free_irq_vectors(pdev);
>> + vp_vdpa->vectors = 0;
>> + }
>> +}
>> +
>> +static irqreturn_t vp_vdpa_intr_handler(int irq, void *arg)
>> +{
>> + struct vp_vring *vring = arg;
>> +
>> + if (vring->cb.callback)
>> + return vring->cb.callback(vring->cb.private);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int vp_vdpa_request_irq(struct vp_vdpa *vp_vdpa)
>> +{
>> + struct pci_dev *pdev = vp_vdpa->pdev;
>> + int i, ret, irq;
>> +
>> + ret = pci_alloc_irq_vectors(pdev, VP_VDPA_MAX_QUEUE,
>> + VP_VDPA_MAX_QUEUE, PCI_IRQ_MSIX);
>> + if (ret != VP_VDPA_MAX_QUEUE) {
>> + dev_err(&pdev->dev, "vp_vdpa: fail to allocate irq vectors\n");
>> + return ret;
>> + }
>> +
>> + vp_vdpa->vectors = VP_VDPA_MAX_QUEUE;
>> +
>> + for (i = 0; i < VP_VDPA_MAX_QUEUE; i++) {
>> + snprintf(vp_vdpa->vring[i].msix_name, 256,
>> + "vp-vdpa[%s]-%d\n", pci_name(pdev), i);
>> + irq = pci_irq_vector(pdev, i);
>> + ret = devm_request_irq(&pdev->dev, irq,
>> + vp_vdpa_intr_handler,
>> + 0, vp_vdpa->vring[i].msix_name,
>> + &vp_vdpa->vring[i]);
>> + if (ret) {
>> + dev_err(&pdev->dev, "vp_vdpa: fail to request irq for vq %d\n",
>> + i);
>> + goto err;
>> + }
>> + vp_iowrite16(i, &vp_vdpa->common->queue_select);
>> + vp_iowrite16(i, &vp_vdpa->common->queue_msix_vector);
>> + vp_vdpa->vring[i].irq = irq;
>> + }
>> +
>> + return 0;
>> +err:
>> + vp_vdpa_free_irq(vp_vdpa);
>> + return ret;
>> +}
>> +
>> +static void vp_vdpa_set_status(struct vdpa_device *vdpa, u8 status)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> + u8 s = vp_vdpa_get_status(vdpa);
>> +
>> + if (status & VIRTIO_CONFIG_S_DRIVER_OK &&
>> + !(s & VIRTIO_CONFIG_S_DRIVER_OK)) {
>> + vp_vdpa_request_irq(vp_vdpa);
>> + }
>> +
>> + vp_iowrite8(status, &vp_vdpa->common->device_status);
>> +
>> + if (!(status & VIRTIO_CONFIG_S_DRIVER_OK) &&
>> + (s & VIRTIO_CONFIG_S_DRIVER_OK))
>> + vp_vdpa_free_irq(vp_vdpa);
>> +}
>> +
>> +static u16 vp_vdpa_get_vq_num_max(struct vdpa_device *vdpa)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> +
>> + return vp_ioread16(&vp_vdpa->common->queue_size);
>> +}
>> +
>> +static u64 vp_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 qid)
>> +{
>> + return 0;
>> +}
>> +
>> +static struct vdpa_notification_area
>> +vp_vdpa_get_vq_notification(struct vdpa_device *vdpa, u16 qid)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> + struct vdpa_notification_area notify;
>> +
>> + notify.addr = vp_vdpa->vring[qid].notify_pa;
>> + notify.size = vp_vdpa->notify_off_multiplier;
>> +
>> + return notify;
>> +}
>> +
>> +static int vp_vdpa_set_vq_state(struct vdpa_device *vdpa, u16 qid,
>> + u64 num)
>> +{
>> + /* Note that this is not supported by virtio specification, so
>> + * we return -ENOTSUPP here. This means we can't support live
>> + * migration, vhost device start/stop.
>> + */
>> +
>> + return -ENOTSUPP;
>> +}
>> +
>> +static void vp_vdpa_set_vq_cb(struct vdpa_device *vdpa, u16 qid,
>> + struct vdpa_callback *cb)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> +
>> + vp_vdpa->vring[qid].cb = *cb;
>> +}
>> +
>> +static void vp_vdpa_set_vq_ready(struct vdpa_device *vdpa,
>> + u16 qid, bool ready)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> +
>> + vp_iowrite16(qid, &vp_vdpa->common->queue_select);
>> + vp_iowrite16(ready, &vp_vdpa->common->queue_enable);
>> +}
>> +
>> +static bool vp_vdpa_get_vq_ready(struct vdpa_device *vdpa, u16 qid)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> +
>> + vp_iowrite16(qid, &vp_vdpa->common->queue_select);
>> +
>> + return vp_ioread16(&vp_vdpa->common->queue_enable);
>> +}
>> +
>> +static void vp_vdpa_set_vq_num(struct vdpa_device *vdpa, u16 qid,
>> + u32 num)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> +
>> + vp_iowrite16(num, &vp_vdpa->common->queue_size);
>> +}
>> +
>> +static int vp_vdpa_set_vq_address(struct vdpa_device *vdpa, u16 qid,
>> + u64 desc_area, u64 driver_area,
>> + u64 device_area)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> + struct virtio_pci_common_cfg __iomem *cfg = vp_vdpa->common;
>> +
>> + vp_iowrite16(qid, &cfg->queue_select);
>> + vp_iowrite64_twopart(desc_area,
>> + &cfg->queue_desc_lo, &cfg->queue_desc_hi);
>> + vp_iowrite64_twopart(driver_area,
>> + &cfg->queue_avail_lo, &cfg->queue_avail_hi);
>> + vp_iowrite64_twopart(device_area,
>> + &cfg->queue_used_lo, &cfg->queue_used_hi);
>> +
>> + return 0;
>> +}
>> +
>> +static void vp_vdpa_kick_vq(struct vdpa_device *vdpa, u16 qid)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> +
>> + vp_iowrite16(qid, vp_vdpa->vring[qid].notify);
>> +}
>> +
>> +static u32 vp_vdpa_get_generation(struct vdpa_device *vdpa)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> +
>> + return vp_ioread8(&vp_vdpa->common->config_generation);
>> +}
>> +
>> +static u32 vp_vdpa_get_device_id(struct vdpa_device *vdpa)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> +
>> + return vp_vdpa->id.device;
>> +}
>> +
>> +static u32 vp_vdpa_get_vendor_id(struct vdpa_device *vdpa)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> +
>> + return vp_vdpa->id.vendor;
>> +}
>> +
>> +static u32 vp_vdpa_get_vq_align(struct vdpa_device *vdpa)
>> +{
>> + return PAGE_SIZE;
>> +}
>> +
>> +static void vp_vdpa_get_config(struct vdpa_device *vdpa,
>> + unsigned int offset,
>> + void *buf, unsigned int len)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> + u8 old, new;
>> + u8 *p;
>> + int i;
>> +
>> + do {
>> + old = vp_ioread8(&vp_vdpa->common->config_generation);
>> + p = buf;
>> + for (i = 0; i < len; i++)
>> + *p++ = vp_ioread8(vp_vdpa->device + offset + i);
>> +
>> + new = vp_ioread8(&vp_vdpa->common->config_generation);
>> + } while (old != new);
>> +}
>> +
>> +static void vp_vdpa_set_config(struct vdpa_device *vdpa,
>> + unsigned int offset, const void *buf,
>> + unsigned int len)
>> +{
>> + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
>> + const u8 *p = buf;
>> + int i;
>> +
>> + for (i = 0; i < len; i++)
>> + vp_iowrite8(*p++, vp_vdpa->device + offset + i);
>> +}
>> +
>> +static void vp_vdpa_set_config_cb(struct vdpa_device *vdpa,
>> + struct vdpa_callback *cb)
>> +{
>> + /* We don't support config interrupt */
> Breaks things like balloon or migration notifications with virtio net, doesn't it?


Right, will fix.


>
>> +}
>> +
>> +static const struct vdpa_config_ops vp_vdpa_ops = {
>> + .get_features = vp_vdpa_get_features,
>> + .set_features = vp_vdpa_set_features,
>> + .get_status = vp_vdpa_get_status,
>> + .set_status = vp_vdpa_set_status,
>> + .get_vq_num_max = vp_vdpa_get_vq_num_max,
>> + .get_vq_state = vp_vdpa_get_vq_state,
>> + .get_vq_notification = vp_vdpa_get_vq_notification,
>> + .set_vq_state = vp_vdpa_set_vq_state,
>> + .set_vq_cb = vp_vdpa_set_vq_cb,
>> + .set_vq_ready = vp_vdpa_set_vq_ready,
>> + .get_vq_ready = vp_vdpa_get_vq_ready,
>> + .set_vq_num = vp_vdpa_set_vq_num,
>> + .set_vq_address = vp_vdpa_set_vq_address,
>> + .kick_vq = vp_vdpa_kick_vq,
>> + .get_generation = vp_vdpa_get_generation,
>> + .get_device_id = vp_vdpa_get_device_id,
>> + .get_vendor_id = vp_vdpa_get_vendor_id,
>> + .get_vq_align = vp_vdpa_get_vq_align,
>> + .get_config = vp_vdpa_get_config,
>> + .set_config = vp_vdpa_set_config,
>> + .set_config_cb = vp_vdpa_set_config_cb,
>> +};
>> +
>> +static int vp_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>> +{
>> + struct device *dev = &pdev->dev;
>> + struct vp_vdpa *vp_vdpa;
>> + int common, notify, device, ret, i;
>> + struct virtio_device_id virtio_id;
>> + resource_size_t notify_pa;
>> + u16 notify_off;
>> +
>> + /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
>> + if (pdev->device < 0x1000 || pdev->device > 0x107f)
>> + return -ENODEV;
>> +
>> + if (pdev->device < 0x1040) {
>> + /* Transitional devices: use the PCI subsystem device id as
>> + * virtio device id, same as legacy driver always did.
>> + */
>> + virtio_id.device = pdev->subsystem_device;
>> + } else {
>> + /* Modern devices: simply use PCI device id,
>> + * but start from 0x1040.
>> + */
>> + virtio_id.device = pdev->device - 0x1040;
>> + }
>> + virtio_id.vendor = pdev->subsystem_vendor;
>> +
>> + ret = pcim_enable_device(pdev);
>> + if (ret) {
>> + dev_err(dev, "vp_vdpa: Fail to enable PCI device\n");
>> + return ret;
>> + }
>> +
>> + vp_vdpa = vdpa_alloc_device(struct vp_vdpa, vdpa,
>> + dev, &vp_vdpa_ops);
>> + if (vp_vdpa == NULL) {
>> + dev_err(dev, "vp_vdpa: Failed to allocate vDPA structure\n");
>> + return -ENOMEM;
>> + }
>> +
>> + pci_set_master(pdev);
>> + pci_set_drvdata(pdev, vp_vdpa);
>> +
>> + vp_vdpa->pdev = pdev;
>> + vp_vdpa->vdpa.dma_dev = &pdev->dev;
>> +
>> + common = find_capability(pdev, VIRTIO_PCI_CAP_COMMON_CFG,
>> + IORESOURCE_IO | IORESOURCE_MEM,
>> + &vp_vdpa->modern_bars);
>> + if (!common) {
>> + dev_err(&pdev->dev,
>> + "vp_vdpa: legacy device is not supported\n");
>> + ret = -ENODEV;
>> + goto err;
>> + }
>> +
>> + notify = find_capability(pdev, VIRTIO_PCI_CAP_NOTIFY_CFG,
>> + IORESOURCE_IO | IORESOURCE_MEM,
>> + &vp_vdpa->modern_bars);
>> + if (!notify) {
>> + dev_err(&pdev->dev,
>> + "vp_vdpa: missing notification capabilities\n");
>> + ret = -EINVAL;
>> + goto err;
>> + }
>> +
>> + device = find_capability(pdev, VIRTIO_PCI_CAP_DEVICE_CFG,
>> + IORESOURCE_IO | IORESOURCE_MEM,
>> + &vp_vdpa->modern_bars);
>> + if (!device) {
>> + dev_err(&pdev->dev,
>> + "vp_vdpa: missing device capabilities\n");
>> + ret = -EINVAL;
>> + goto err;
>> + }
>> +
>> + ret = pcim_iomap_regions(pdev, vp_vdpa->modern_bars,
>> + VP_VDPA_DRIVER_NAME);
>> + if (ret)
>> + goto err;
>> +
>> + vp_vdpa->base = pcim_iomap_table(pdev);
>> +
>> + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
>> + if (ret)
>> + ret = dma_set_mask_and_coherent(&pdev->dev,
>> + DMA_BIT_MASK(32));
>> + if (ret)
>> + dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
>> +
>> + vp_vdpa->device = map_capability(vp_vdpa, device, NULL);
>> + vp_vdpa->notify = map_capability(vp_vdpa, notify, &notify_pa);
>> + vp_vdpa->common = map_capability(vp_vdpa, common, NULL);
>> + vp_vdpa->id = virtio_id;
>> +
>> + ret = vdpa_register_device(&vp_vdpa->vdpa);
>> + if (ret) {
>> + dev_err(&pdev->dev, "Failed to register to vdpa bus\n");
>> + goto err;
>> + }
>> +
>> + pci_read_config_dword(pdev, notify + sizeof(struct virtio_pci_cap),
>> + &vp_vdpa->notify_off_multiplier);
>> +
>> + for (i = 0; i < VP_VDPA_MAX_QUEUE; i++) {
>> + vp_iowrite16(i, &vp_vdpa->common->queue_select);
>> + notify_off = vp_ioread16(&vp_vdpa->common->queue_notify_off);
>> + vp_vdpa->vring[i].irq = -1;
>> + vp_vdpa->vring[i].notify = vp_vdpa->notify +
>> + notify_off * vp_vdpa->notify_off_multiplier;
>> + vp_vdpa->vring[i].notify_pa = notify_pa +
>> + notify_off * vp_vdpa->notify_off_multiplier;
>> + }
>> +
>> + return 0;
>> +
>> +err:
>> + put_device(&vp_vdpa->vdpa.dev);
>> + return ret;
>> +}
>> +
>> +static void vp_vdpa_remove(struct pci_dev *pdev)
>> +{
>> + struct vp_vdpa *vp_vdpa = pci_get_drvdata(pdev);
>> +
>> + vdpa_unregister_device(&vp_vdpa->vdpa);
>> +}
>> +
>> +static struct pci_driver vp_vdpa_driver = {
>> + .name = "vp-vdpa",
>> + .id_table = NULL, /* only dynamic ids */
>> + .probe = vp_vdpa_probe,
>> + .remove = vp_vdpa_remove,
>> +};
>> +
>> +module_pci_driver(vp_vdpa_driver);
>> +
>> +MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>");
>> +MODULE_DESCRIPTION("vp-vdpa");
>> +MODULE_LICENSE("GPL");
>> +MODULE_VERSION("1");
>
> Isn't there something we can do to reduce the amount of code
> duplication? virtio, ifcvf and now this share a ton of code ...
> Let's make a library?


I do think about this since IFCVF driver is posted.

It depends on what level we want to share. Do we have to have a common
parent structure for modern pci device? If yes, it probably requires
non-trivial refactoring on the existed modern virtio-pci driver. If we
just want to share some helpers, it would be easy.

I think we can do those stuffs on top.

Thanks


>
>> --
>> 2.20.1

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