Re: [PATCH V3 16/19] virtio-pci: introduce modern device module

From: Michael S. Tsirkin
Date: Fri Feb 05 2021 - 11:17:06 EST

On Mon, Jan 04, 2021 at 02:55:00PM +0800, Jason Wang wrote:
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>

I don't exactly get why we need to split the modern driver out,
and it can confuse people who are used to be seeing virtio-pci.

The vdpa thing so far looks like a development tool, why do
we care that it depends on a bit of extra code?

> ---
> drivers/virtio/Kconfig | 10 +-
> drivers/virtio/Makefile | 1 +
> drivers/virtio/virtio_pci_common.h | 27 +-
> drivers/virtio/virtio_pci_modern.c | 617 -------------------------
> drivers/virtio/virtio_pci_modern_dev.c | 599 ++++++++++++++++++++++++
> include/linux/virtio_pci_modern.h | 111 +++++
> 6 files changed, 721 insertions(+), 644 deletions(-)
> create mode 100644 drivers/virtio/virtio_pci_modern_dev.c
> create mode 100644 include/linux/virtio_pci_modern.h
>
> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> index 7b41130d3f35..6b9b81f4b8c2 100644
> --- a/drivers/virtio/Kconfig
> +++ b/drivers/virtio/Kconfig
> @@ -12,6 +12,14 @@ config ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
> This option is selected if the architecture may need to enforce
> VIRTIO_F_ACCESS_PLATFORM
>
> +config VIRTIO_PCI_MODERN
> + tristate "Modern Virtio PCI Device"
> + depends on PCI
> + help
> + Modern PCI device implementation. This module implements the
> + basic probe and control for devices which are based on modern
> + PCI device with possible vendor specific extensions.
> +
> menuconfig VIRTIO_MENU
> bool "Virtio drivers"
> default y
> @@ -20,7 +28,7 @@ if VIRTIO_MENU
>
> config VIRTIO_PCI
> tristate "PCI driver for virtio devices"
> - depends on PCI
> + depends on VIRTIO_PCI_MODERN
> select VIRTIO
> help
> This driver provides support for virtio based paravirtual device
> diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
> index 591e6f72aa54..f097578aaa8f 100644
> --- a/drivers/virtio/Makefile
> +++ b/drivers/virtio/Makefile
> @@ -1,5 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o
> +obj-$(CONFIG_VIRTIO_PCI_MODERN) += virtio_pci_modern_dev.o
> obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
> obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o
> virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o
> diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h
> index f35ff5b6b467..beec047a8f8d 100644
> --- a/drivers/virtio/virtio_pci_common.h
> +++ b/drivers/virtio/virtio_pci_common.h
> @@ -25,6 +25,7 @@
> #include <linux/virtio_config.h>
> #include <linux/virtio_ring.h>
> #include <linux/virtio_pci.h>
> +#include <linux/virtio_pci_modern.h>
> #include <linux/highmem.h>
> #include <linux/spinlock.h>
>
> @@ -39,32 +40,6 @@ struct virtio_pci_vq_info {
> unsigned msix_vector;
> };
>
> -struct virtio_pci_modern_device {
> - struct pci_dev *pci_dev;
> -
> - struct virtio_pci_common_cfg __iomem *common;
> - /* Device-specific data (non-legacy mode) */
> - void __iomem *device;
> - /* Base of vq notifications (non-legacy mode). */
> - void __iomem *notify_base;
> - /* Where to read and clear interrupt */
> - u8 __iomem *isr;
> -
> - /* So we can sanity-check accesses. */
> - size_t notify_len;
> - size_t device_len;
> -
> - /* Capability for when we need to map notifications per-vq. */
> - int notify_map_cap;
> -
> - /* Multiply queue_notify_off by this value. (non-legacy mode). */
> - u32 notify_offset_multiplier;
> -
> - int modern_bars;
> -
> - struct virtio_device_id id;
> -};
> -
> /* Our device structure */
> struct virtio_pci_device {
> struct virtio_device vdev;
> diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
> index a5e3a5e40323..fbd4ebc00eb6 100644
> --- a/drivers/virtio/virtio_pci_modern.c
> +++ b/drivers/virtio/virtio_pci_modern.c
> @@ -19,158 +19,6 @@
> #define VIRTIO_RING_NO_LEGACY
> #include "virtio_pci_common.h"
>
> -/*
> - * 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(const u8 __iomem *addr)
> -{
> - return ioread8(addr);
> -}
> -static inline u16 vp_ioread16 (const __le16 __iomem *addr)
> -{
> - return ioread16(addr);
> -}
> -
> -static inline u32 vp_ioread32(const __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);
> -}
> -
> -/*
> - * vp_modern_map_capability - map a part of virtio pci capability
> - * @mdev: the modern virtio-pci device
> - * @off: offset of the capability
> - * @minlen: minimal length of the capability
> - * @align: align requirement
> - * @start: start from the capability
> - * @size: map size
> - * @len: the length that is actually mapped
> - *
> - * Returns the io address of for the part of the capability
> - */
> -void __iomem *vp_modern_map_capability(struct virtio_pci_modern_device *mdev, int off,
> - size_t minlen,
> - u32 align,
> - u32 start, u32 size,
> - size_t *len)
> -{
> - struct pci_dev *dev = mdev->pci_dev;
> - u8 bar;
> - u32 offset, length;
> - void __iomem *p;
> -
> - pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap,
> - bar),
> - &bar);
> - pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset),
> - &offset);
> - pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
> - &length);
> -
> - if (length <= start) {
> - dev_err(&dev->dev,
> - "virtio_pci: bad capability len %u (>%u expected)\n",
> - length, start);
> - return NULL;
> - }
> -
> - if (length - start < minlen) {
> - dev_err(&dev->dev,
> - "virtio_pci: bad capability len %u (>=%zu expected)\n",
> - length, minlen);
> - return NULL;
> - }
> -
> - length -= start;
> -
> - if (start + offset < offset) {
> - dev_err(&dev->dev,
> - "virtio_pci: map wrap-around %u+%u\n",
> - start, offset);
> - return NULL;
> - }
> -
> - offset += start;
> -
> - if (offset & (align - 1)) {
> - dev_err(&dev->dev,
> - "virtio_pci: offset %u not aligned to %u\n",
> - offset, align);
> - return NULL;
> - }
> -
> - if (length > size)
> - length = size;
> -
> - if (len)
> - *len = length;
> -
> - if (minlen + offset < minlen ||
> - minlen + offset > pci_resource_len(dev, bar)) {
> - dev_err(&dev->dev,
> - "virtio_pci: map virtio %zu@%u "
> - "out of range on bar %i length %lu\n",
> - minlen, offset,
> - bar, (unsigned long)pci_resource_len(dev, bar));
> - return NULL;
> - }
> -
> - p = pci_iomap_range(dev, bar, offset, length);
> - if (!p)
> - dev_err(&dev->dev,
> - "virtio_pci: unable to map virtio %u@%u on bar %i\n",
> - length, offset, bar);
> - return p;
> -}
> -
> -/*
> - * vp_modern_get_features - get features from device
> - * @mdev: the modern virtio-pci device
> - *
> - * Returns the features read from the device
> - */
> -static u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev)
> -{
> - struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> -
> - u64 features;
> -
> - vp_iowrite32(0, &cfg->device_feature_select);
> - features = vp_ioread32(&cfg->device_feature);
> - vp_iowrite32(1, &cfg->device_feature_select);
> - features |= ((u64)vp_ioread32(&cfg->device_feature) << 32);
> -
> - return features;
> -}
> -
> -/* virtio config->get_features() implementation */
> static u64 vp_get_features(struct virtio_device *vdev)
> {
> struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> @@ -188,149 +36,6 @@ static void vp_transport_features(struct virtio_device *vdev, u64 features)
> __virtio_set_bit(vdev, VIRTIO_F_SR_IOV);
> }
>
> -/*
> - * vp_modern_set_features - set features to device
> - * @mdev: the modern virtio-pci device
> - * @features: the features set to device
> - */
> -static void vp_modern_set_features(struct virtio_pci_modern_device *mdev,
> - u64 features)
> -{
> - struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> -
> - vp_iowrite32(0, &cfg->guest_feature_select);
> - vp_iowrite32((u32)features, &cfg->guest_feature);
> - vp_iowrite32(1, &cfg->guest_feature_select);
> - vp_iowrite32(features >> 32, &cfg->guest_feature);
> -}
> -
> -/*
> - * vp_modern_queue_vector - set the MSIX vector for a specific virtqueue
> - * @mdev: the modern virtio-pci device
> - * @index: queue index
> - * @vector: the config vector
> - *
> - * Returns the config vector read from the device
> - */
> -static u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev,
> - u16 index, u16 vector)
> -{
> - struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> -
> - vp_iowrite16(index, &cfg->queue_select);
> - vp_iowrite16(vector, &cfg->queue_msix_vector);
> - /* Flush the write out to device */
> - return vp_ioread16(&cfg->queue_msix_vector);
> -}
> -
> -/*
> - * vp_modern_queue_address - set the virtqueue address
> - * @mdev: the modern virtio-pci device
> - * @index: the queue index
> - * @desc_addr: address of the descriptor area
> - * @driver_addr: address of the driver area
> - * @device_addr: address of the device area
> - */
> -static void vp_modern_queue_address(struct virtio_pci_modern_device *mdev,
> - u16 index, u64 desc_addr, u64 driver_addr,
> - u64 device_addr)
> -{
> - struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> -
> - vp_iowrite16(index, &cfg->queue_select);
> -
> - vp_iowrite64_twopart(desc_addr, &cfg->queue_desc_lo,
> - &cfg->queue_desc_hi);
> - vp_iowrite64_twopart(driver_addr, &cfg->queue_avail_lo,
> - &cfg->queue_avail_hi);
> - vp_iowrite64_twopart(device_addr, &cfg->queue_used_lo,
> - &cfg->queue_used_hi);
> -}
> -
> -/*
> - * vp_modern_set_queue_enable - enable a virtqueue
> - * @mdev: the modern virtio-pci device
> - * @index: the queue index
> - * @enable: whether the virtqueue is enable or not
> - */
> -static void vp_modern_set_queue_enable(struct virtio_pci_modern_device *mdev,
> - u16 index, bool enable)
> -{
> - vp_iowrite16(index, &mdev->common->queue_select);
> - vp_iowrite16(enable, &mdev->common->queue_enable);
> -}
> -
> -/*
> - * vp_modern_get_queue_enable - enable a virtqueue
> - * @mdev: the modern virtio-pci device
> - * @index: the queue index
> - *
> - * Returns whether a virtqueue is enabled or not
> - */
> -static bool vp_modern_get_queue_enable(struct virtio_pci_modern_device *mdev,
> - u16 index)
> -{
> - vp_iowrite16(index, &mdev->common->queue_select);
> -
> - return vp_ioread16(&mdev->common->queue_enable);
> -}
> -
> -/*
> - * vp_modern_set_queue_size - set size for a virtqueue
> - * @mdev: the modern virtio-pci device
> - * @index: the queue index
> - * @size: the size of the virtqueue
> - */
> -static void vp_modern_set_queue_size(struct virtio_pci_modern_device *mdev,
> - u16 index, u16 size)
> -{
> - vp_iowrite16(index, &mdev->common->queue_select);
> - vp_iowrite16(size, &mdev->common->queue_size);
> -
> -}
> -
> -/*
> - * vp_modern_get_queue_size - get size for a virtqueue
> - * @mdev: the modern virtio-pci device
> - * @index: the queue index
> - *
> - * Returns the size of the virtqueue
> - */
> -static u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev,
> - u16 index)
> -{
> - vp_iowrite16(index, &mdev->common->queue_select);
> -
> - return vp_ioread16(&mdev->common->queue_size);
> -
> -}
> -
> -/*
> - * vp_modern_get_num_queues - get the number of virtqueues
> - * @mdev: the modern virtio-pci device
> - *
> - * Returns the number of virtqueues
> - */
> -static u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev)
> -{
> - return vp_ioread16(&mdev->common->num_queues);
> -}
> -
> -/*
> - * vp_modern_get_queue_notify_off - get notification offset for a virtqueue
> - * @mdev: the modern virtio-pci device
> - * @index: the queue index
> - *
> - * Returns the notification offset for a virtqueue
> - */
> -static u16 vp_modern_get_queue_notify_off(struct virtio_pci_modern_device *mdev,
> - u16 index)
> -{
> - vp_iowrite16(index, &mdev->common->queue_select);
> -
> - return vp_ioread16(&mdev->common->queue_notify_off);
> -}
> -
> /* virtio config->finalize_features() implementation */
> static int vp_finalize_features(struct virtio_device *vdev)
> {
> @@ -429,19 +134,6 @@ static void vp_set(struct virtio_device *vdev, unsigned offset,
> }
> }
>
> -/*
> - * vp_modern_generation - get the device genreation
> - * @mdev: the modern virtio-pci device
> - *
> - * Returns the genreation read from device
> - */
> -static u32 vp_modern_generation(struct virtio_pci_modern_device *mdev)
> -{
> - struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> -
> - return vp_ioread8(&cfg->config_generation);
> -}
> -
> static u32 vp_generation(struct virtio_device *vdev)
> {
> struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> @@ -449,19 +141,6 @@ static u32 vp_generation(struct virtio_device *vdev)
> return vp_modern_generation(&vp_dev->mdev);
> }
>
> -/*
> - * vp_modern_get_status - get the device status
> - * @mdev: the modern virtio-pci device
> - *
> - * Returns the status read from device
> - */
> -static u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev)
> -{
> - struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> -
> - return vp_ioread8(&cfg->device_status);
> -}
> -
> /* config->{get,set}_status() implementations */
> static u8 vp_get_status(struct virtio_device *vdev)
> {
> @@ -470,19 +149,6 @@ static u8 vp_get_status(struct virtio_device *vdev)
> return vp_modern_get_status(&vp_dev->mdev);
> }
>
> -/*
> - * vp_modern_set_status - set status to device
> - * @mdev: the modern virtio-pci device
> - * @status: the status set to device
> - */
> -static void vp_modern_set_status(struct virtio_pci_modern_device *mdev,
> - u8 status)
> -{
> - struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> -
> - vp_iowrite8(status, &cfg->device_status);
> -}
> -
> static void vp_set_status(struct virtio_device *vdev, u8 status)
> {
> struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> @@ -510,25 +176,6 @@ static void vp_reset(struct virtio_device *vdev)
> vp_synchronize_vectors(vdev);
> }
>
> -/*
> - * vp_modern_config_vector - set the vector for config interrupt
> - * @mdev: the modern virtio-pci device
> - * @vector: the config vector
> - *
> - * Returns the config vector read from the device
> - */
> -static u16 vp_modern_config_vector(struct virtio_pci_modern_device *mdev,
> - u16 vector)
> -{
> - struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> -
> - /* Setup the vector used for configuration events */
> - vp_iowrite16(vector, &cfg->msix_config);
> - /* Verify we had enough resources to assign the vector */
> - /* Will also flush the write out to device */
> - return vp_ioread16(&cfg->msix_config);
> -}
> -
> static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
> {
> return vp_modern_config_vector(&vp_dev->mdev, vector);
> @@ -789,253 +436,6 @@ static const struct virtio_config_ops virtio_pci_config_ops = {
> .get_shm_region = vp_get_shm_region,
> };
>
> -/**
> - * virtio_pci_find_capability - walk capabilities to find device info.
> - * @dev: the pci device
> - * @cfg_type: the VIRTIO_PCI_CAP_* value we seek
> - * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO.
> - * @bars: the bitmask of BARs
> - *
> - * Returns offset of the capability, or 0.
> - */
> -static inline int virtio_pci_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;
> -}
> -
> -/* This is part of the ABI. Don't screw with it. */
> -static inline void check_offsets(void)
> -{
> - /* Note: disk space was harmed in compilation of this function. */
> - BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR !=
> - offsetof(struct virtio_pci_cap, cap_vndr));
> - BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT !=
> - offsetof(struct virtio_pci_cap, cap_next));
> - BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN !=
> - offsetof(struct virtio_pci_cap, cap_len));
> - BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE !=
> - offsetof(struct virtio_pci_cap, cfg_type));
> - BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR !=
> - offsetof(struct virtio_pci_cap, bar));
> - BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET !=
> - offsetof(struct virtio_pci_cap, offset));
> - BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH !=
> - offsetof(struct virtio_pci_cap, length));
> - BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT !=
> - offsetof(struct virtio_pci_notify_cap,
> - notify_off_multiplier));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT !=
> - offsetof(struct virtio_pci_common_cfg,
> - device_feature_select));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF !=
> - offsetof(struct virtio_pci_common_cfg, device_feature));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT !=
> - offsetof(struct virtio_pci_common_cfg,
> - guest_feature_select));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF !=
> - offsetof(struct virtio_pci_common_cfg, guest_feature));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX !=
> - offsetof(struct virtio_pci_common_cfg, msix_config));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ !=
> - offsetof(struct virtio_pci_common_cfg, num_queues));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS !=
> - offsetof(struct virtio_pci_common_cfg, device_status));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION !=
> - offsetof(struct virtio_pci_common_cfg, config_generation));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT !=
> - offsetof(struct virtio_pci_common_cfg, queue_select));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE !=
> - offsetof(struct virtio_pci_common_cfg, queue_size));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX !=
> - offsetof(struct virtio_pci_common_cfg, queue_msix_vector));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE !=
> - offsetof(struct virtio_pci_common_cfg, queue_enable));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF !=
> - offsetof(struct virtio_pci_common_cfg, queue_notify_off));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO !=
> - offsetof(struct virtio_pci_common_cfg, queue_desc_lo));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI !=
> - offsetof(struct virtio_pci_common_cfg, queue_desc_hi));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO !=
> - offsetof(struct virtio_pci_common_cfg, queue_avail_lo));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI !=
> - offsetof(struct virtio_pci_common_cfg, queue_avail_hi));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO !=
> - offsetof(struct virtio_pci_common_cfg, queue_used_lo));
> - BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI !=
> - offsetof(struct virtio_pci_common_cfg, queue_used_hi));
> -}
> -
> -/*
> - * vp_modern_probe: probe the modern virtio pci device, note that the
> - * caller is required to enable PCI device before calling this function.
> - * @mdev: the modern virtio-pci device
> - *
> - * Return 0 on succeed otherwise fail
> - */
> -static int vp_modern_probe(struct virtio_pci_modern_device *mdev)
> -{
> - struct pci_dev *pci_dev = mdev->pci_dev;
> - int err, common, isr, notify, device;
> - u32 notify_length;
> - u32 notify_offset;
> -
> - check_offsets();
> -
> - mdev->pci_dev = pci_dev;
> -
> - /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
> - if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
> - return -ENODEV;
> -
> - if (pci_dev->device < 0x1040) {
> - /* Transitional devices: use the PCI subsystem device id as
> - * virtio device id, same as legacy driver always did.
> - */
> - mdev->id.device = pci_dev->subsystem_device;
> - } else {
> - /* Modern devices: simply use PCI device id, but start from 0x1040. */
> - mdev->id.device = pci_dev->device - 0x1040;
> - }
> - mdev->id.vendor = pci_dev->subsystem_vendor;
> -
> - /* check for a common config: if not, use legacy mode (bar 0). */
> - common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
> - IORESOURCE_IO | IORESOURCE_MEM,
> - &mdev->modern_bars);
> - if (!common) {
> - dev_info(&pci_dev->dev,
> - "virtio_pci: leaving for legacy driver\n");
> - return -ENODEV;
> - }
> -
> - /* If common is there, these should be too... */
> - isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
> - IORESOURCE_IO | IORESOURCE_MEM,
> - &mdev->modern_bars);
> - notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
> - IORESOURCE_IO | IORESOURCE_MEM,
> - &mdev->modern_bars);
> - if (!isr || !notify) {
> - dev_err(&pci_dev->dev,
> - "virtio_pci: missing capabilities %i/%i/%i\n",
> - common, isr, notify);
> - return -EINVAL;
> - }
> -
> - err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64));
> - if (err)
> - err = dma_set_mask_and_coherent(&pci_dev->dev,
> - DMA_BIT_MASK(32));
> - if (err)
> - dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
> -
> - /* Device capability is only mandatory for devices that have
> - * device-specific configuration.
> - */
> - device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
> - IORESOURCE_IO | IORESOURCE_MEM,
> - &mdev->modern_bars);
> -
> - err = pci_request_selected_regions(pci_dev, mdev->modern_bars,
> - "virtio-pci-modern");
> - if (err)
> - return err;
> -
> - err = -EINVAL;
> - mdev->common = vp_modern_map_capability(mdev, common,
> - sizeof(struct virtio_pci_common_cfg), 4,
> - 0, sizeof(struct virtio_pci_common_cfg),
> - NULL);
> - if (!mdev->common)
> - goto err_map_common;
> - mdev->isr = vp_modern_map_capability(mdev, isr, sizeof(u8), 1,
> - 0, 1,
> - NULL);
> - if (!mdev->isr)
> - goto err_map_isr;
> -
> - /* Read notify_off_multiplier from config space. */
> - pci_read_config_dword(pci_dev,
> - notify + offsetof(struct virtio_pci_notify_cap,
> - notify_off_multiplier),
> - &mdev->notify_offset_multiplier);
> - /* Read notify length and offset from config space. */
> - pci_read_config_dword(pci_dev,
> - notify + offsetof(struct virtio_pci_notify_cap,
> - cap.length),
> - &notify_length);
> -
> - pci_read_config_dword(pci_dev,
> - notify + offsetof(struct virtio_pci_notify_cap,
> - cap.offset),
> - &notify_offset);
> -
> - /* We don't know how many VQs we'll map, ahead of the time.
> - * If notify length is small, map it all now.
> - * Otherwise, map each VQ individually later.
> - */
> - if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) {
> - mdev->notify_base = vp_modern_map_capability(mdev, notify,
> - 2, 2,
> - 0, notify_length,
> - &mdev->notify_len);
> - if (!mdev->notify_base)
> - goto err_map_notify;
> - } else {
> - mdev->notify_map_cap = notify;
> - }
> -
> - /* Again, we don't know how much we should map, but PAGE_SIZE
> - * is more than enough for all existing devices.
> - */
> - if (device) {
> - mdev->device = vp_modern_map_capability(mdev, device, 0, 4,
> - 0, PAGE_SIZE,
> - &mdev->device_len);
> - if (!mdev->device)
> - goto err_map_device;
> - }
> -
> - return 0;
> -
> -err_map_device:
> - if (mdev->notify_base)
> - pci_iounmap(pci_dev, mdev->notify_base);
> -err_map_notify:
> - pci_iounmap(pci_dev, mdev->isr);
> -err_map_isr:
> - pci_iounmap(pci_dev, mdev->common);
> -err_map_common:
> - return err;
> -}
> -
> /* the PCI probing function */
> int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev)
> {
> @@ -1063,23 +463,6 @@ int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev)
> return 0;
> }
>
> -/*
> - * vp_modern_probe: remove and cleanup the modern virtio pci device
> - * @mdev: the modern virtio-pci device
> - */
> -static void vp_modern_remove(struct virtio_pci_modern_device *mdev)
> -{
> - struct pci_dev *pci_dev = mdev->pci_dev;
> -
> - if (mdev->device)
> - pci_iounmap(pci_dev, mdev->device);
> - if (mdev->notify_base)
> - pci_iounmap(pci_dev, mdev->notify_base);
> - pci_iounmap(pci_dev, mdev->isr);
> - pci_iounmap(pci_dev, mdev->common);
> - pci_release_selected_regions(pci_dev, mdev->modern_bars);
> -}
> -
> void virtio_pci_modern_remove(struct virtio_pci_device *vp_dev)
> {
> struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
> diff --git a/drivers/virtio/virtio_pci_modern_dev.c b/drivers/virtio/virtio_pci_modern_dev.c
> new file mode 100644
> index 000000000000..cbd667496bb1
> --- /dev/null
> +++ b/drivers/virtio/virtio_pci_modern_dev.c
> @@ -0,0 +1,599 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include <linux/virtio_pci_modern.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +
> +/*
> + * vp_modern_map_capability - map a part of virtio pci capability
> + * @mdev: the modern virtio-pci device
> + * @off: offset of the capability
> + * @minlen: minimal length of the capability
> + * @align: align requirement
> + * @start: start from the capability
> + * @size: map size
> + * @len: the length that is actually mapped
> + *
> + * Returns the io address of for the part of the capability
> + */
> +void __iomem *vp_modern_map_capability(struct virtio_pci_modern_device *mdev, int off,
> + size_t minlen,
> + u32 align,
> + u32 start, u32 size,
> + size_t *len)
> +{
> + struct pci_dev *dev = mdev->pci_dev;
> + u8 bar;
> + u32 offset, length;
> + void __iomem *p;
> +
> + pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap,
> + bar),
> + &bar);
> + pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset),
> + &offset);
> + pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
> + &length);
> +
> + if (length <= start) {
> + dev_err(&dev->dev,
> + "virtio_pci: bad capability len %u (>%u expected)\n",
> + length, start);
> + return NULL;
> + }
> +
> + if (length - start < minlen) {
> + dev_err(&dev->dev,
> + "virtio_pci: bad capability len %u (>=%zu expected)\n",
> + length, minlen);
> + return NULL;
> + }
> +
> + length -= start;
> +
> + if (start + offset < offset) {
> + dev_err(&dev->dev,
> + "virtio_pci: map wrap-around %u+%u\n",
> + start, offset);
> + return NULL;
> + }
> +
> + offset += start;
> +
> + if (offset & (align - 1)) {
> + dev_err(&dev->dev,
> + "virtio_pci: offset %u not aligned to %u\n",
> + offset, align);
> + return NULL;
> + }
> +
> + if (length > size)
> + length = size;
> +
> + if (len)
> + *len = length;
> +
> + if (minlen + offset < minlen ||
> + minlen + offset > pci_resource_len(dev, bar)) {
> + dev_err(&dev->dev,
> + "virtio_pci: map virtio %zu@%u "
> + "out of range on bar %i length %lu\n",
> + minlen, offset,
> + bar, (unsigned long)pci_resource_len(dev, bar));
> + return NULL;
> + }
> +
> + p = pci_iomap_range(dev, bar, offset, length);
> + if (!p)
> + dev_err(&dev->dev,
> + "virtio_pci: unable to map virtio %u@%u on bar %i\n",
> + length, offset, bar);
> + return p;
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_map_capability);
> +
> +/**
> + * virtio_pci_find_capability - walk capabilities to find device info.
> + * @dev: the pci device
> + * @cfg_type: the VIRTIO_PCI_CAP_* value we seek
> + * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO.
> + * @bars: the bitmask of BARs
> + *
> + * Returns offset of the capability, or 0.
> + */
> +static inline int virtio_pci_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;
> +}
> +
> +/* This is part of the ABI. Don't screw with it. */
> +static inline void check_offsets(void)
> +{
> + /* Note: disk space was harmed in compilation of this function. */
> + BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR !=
> + offsetof(struct virtio_pci_cap, cap_vndr));
> + BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT !=
> + offsetof(struct virtio_pci_cap, cap_next));
> + BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN !=
> + offsetof(struct virtio_pci_cap, cap_len));
> + BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE !=
> + offsetof(struct virtio_pci_cap, cfg_type));
> + BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR !=
> + offsetof(struct virtio_pci_cap, bar));
> + BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET !=
> + offsetof(struct virtio_pci_cap, offset));
> + BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH !=
> + offsetof(struct virtio_pci_cap, length));
> + BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT !=
> + offsetof(struct virtio_pci_notify_cap,
> + notify_off_multiplier));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT !=
> + offsetof(struct virtio_pci_common_cfg,
> + device_feature_select));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF !=
> + offsetof(struct virtio_pci_common_cfg, device_feature));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT !=
> + offsetof(struct virtio_pci_common_cfg,
> + guest_feature_select));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF !=
> + offsetof(struct virtio_pci_common_cfg, guest_feature));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX !=
> + offsetof(struct virtio_pci_common_cfg, msix_config));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ !=
> + offsetof(struct virtio_pci_common_cfg, num_queues));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS !=
> + offsetof(struct virtio_pci_common_cfg, device_status));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION !=
> + offsetof(struct virtio_pci_common_cfg, config_generation));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT !=
> + offsetof(struct virtio_pci_common_cfg, queue_select));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE !=
> + offsetof(struct virtio_pci_common_cfg, queue_size));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX !=
> + offsetof(struct virtio_pci_common_cfg, queue_msix_vector));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE !=
> + offsetof(struct virtio_pci_common_cfg, queue_enable));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF !=
> + offsetof(struct virtio_pci_common_cfg, queue_notify_off));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO !=
> + offsetof(struct virtio_pci_common_cfg, queue_desc_lo));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI !=
> + offsetof(struct virtio_pci_common_cfg, queue_desc_hi));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO !=
> + offsetof(struct virtio_pci_common_cfg, queue_avail_lo));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI !=
> + offsetof(struct virtio_pci_common_cfg, queue_avail_hi));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO !=
> + offsetof(struct virtio_pci_common_cfg, queue_used_lo));
> + BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI !=
> + offsetof(struct virtio_pci_common_cfg, queue_used_hi));
> +}
> +
> +/*
> + * vp_modern_probe: probe the modern virtio pci device, note that the
> + * caller is required to enable PCI device before calling this function.
> + * @mdev: the modern virtio-pci device
> + *
> + * Return 0 on succeed otherwise fail
> + */
> +int vp_modern_probe(struct virtio_pci_modern_device *mdev)
> +{
> + struct pci_dev *pci_dev = mdev->pci_dev;
> + int err, common, isr, notify, device;
> + u32 notify_length;
> + u32 notify_offset;
> +
> + check_offsets();
> +
> + mdev->pci_dev = pci_dev;
> +
> + /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
> + if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
> + return -ENODEV;
> +
> + if (pci_dev->device < 0x1040) {
> + /* Transitional devices: use the PCI subsystem device id as
> + * virtio device id, same as legacy driver always did.
> + */
> + mdev->id.device = pci_dev->subsystem_device;
> + } else {
> + /* Modern devices: simply use PCI device id, but start from 0x1040. */
> + mdev->id.device = pci_dev->device - 0x1040;
> + }
> + mdev->id.vendor = pci_dev->subsystem_vendor;
> +
> + /* check for a common config: if not, use legacy mode (bar 0). */
> + common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
> + IORESOURCE_IO | IORESOURCE_MEM,
> + &mdev->modern_bars);
> + if (!common) {
> + dev_info(&pci_dev->dev,
> + "virtio_pci: leaving for legacy driver\n");
> + return -ENODEV;
> + }
> +
> + /* If common is there, these should be too... */
> + isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
> + IORESOURCE_IO | IORESOURCE_MEM,
> + &mdev->modern_bars);
> + notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
> + IORESOURCE_IO | IORESOURCE_MEM,
> + &mdev->modern_bars);
> + if (!isr || !notify) {
> + dev_err(&pci_dev->dev,
> + "virtio_pci: missing capabilities %i/%i/%i\n",
> + common, isr, notify);
> + return -EINVAL;
> + }
> +
> + err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64));
> + if (err)
> + err = dma_set_mask_and_coherent(&pci_dev->dev,
> + DMA_BIT_MASK(32));
> + if (err)
> + dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
> +
> + /* Device capability is only mandatory for devices that have
> + * device-specific configuration.
> + */
> + device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
> + IORESOURCE_IO | IORESOURCE_MEM,
> + &mdev->modern_bars);
> +
> + err = pci_request_selected_regions(pci_dev, mdev->modern_bars,
> + "virtio-pci-modern");
> + if (err)
> + return err;
> +
> + err = -EINVAL;
> + mdev->common = vp_modern_map_capability(mdev, common,
> + sizeof(struct virtio_pci_common_cfg), 4,
> + 0, sizeof(struct virtio_pci_common_cfg),
> + NULL);
> + if (!mdev->common)
> + goto err_map_common;
> + mdev->isr = vp_modern_map_capability(mdev, isr, sizeof(u8), 1,
> + 0, 1,
> + NULL);
> + if (!mdev->isr)
> + goto err_map_isr;
> +
> + /* Read notify_off_multiplier from config space. */
> + pci_read_config_dword(pci_dev,
> + notify + offsetof(struct virtio_pci_notify_cap,
> + notify_off_multiplier),
> + &mdev->notify_offset_multiplier);
> + /* Read notify length and offset from config space. */
> + pci_read_config_dword(pci_dev,
> + notify + offsetof(struct virtio_pci_notify_cap,
> + cap.length),
> + &notify_length);
> +
> + pci_read_config_dword(pci_dev,
> + notify + offsetof(struct virtio_pci_notify_cap,
> + cap.offset),
> + &notify_offset);
> +
> + /* We don't know how many VQs we'll map, ahead of the time.
> + * If notify length is small, map it all now.
> + * Otherwise, map each VQ individually later.
> + */
> + if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) {
> + mdev->notify_base = vp_modern_map_capability(mdev, notify,
> + 2, 2,
> + 0, notify_length,
> + &mdev->notify_len);
> + if (!mdev->notify_base)
> + goto err_map_notify;
> + } else {
> + mdev->notify_map_cap = notify;
> + }
> +
> + /* Again, we don't know how much we should map, but PAGE_SIZE
> + * is more than enough for all existing devices.
> + */
> + if (device) {
> + mdev->device = vp_modern_map_capability(mdev, device, 0, 4,
> + 0, PAGE_SIZE,
> + &mdev->device_len);
> + if (!mdev->device)
> + goto err_map_device;
> + }
> +
> + return 0;
> +
> +err_map_device:
> + if (mdev->notify_base)
> + pci_iounmap(pci_dev, mdev->notify_base);
> +err_map_notify:
> + pci_iounmap(pci_dev, mdev->isr);
> +err_map_isr:
> + pci_iounmap(pci_dev, mdev->common);
> +err_map_common:
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_probe);
> +
> +/*
> + * vp_modern_probe: remove and cleanup the modern virtio pci device
> + * @mdev: the modern virtio-pci device
> + */
> +void vp_modern_remove(struct virtio_pci_modern_device *mdev)
> +{
> + struct pci_dev *pci_dev = mdev->pci_dev;
> +
> + if (mdev->device)
> + pci_iounmap(pci_dev, mdev->device);
> + if (mdev->notify_base)
> + pci_iounmap(pci_dev, mdev->notify_base);
> + pci_iounmap(pci_dev, mdev->isr);
> + pci_iounmap(pci_dev, mdev->common);
> + pci_release_selected_regions(pci_dev, mdev->modern_bars);
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_remove);
> +
> +/*
> + * vp_modern_get_features - get features from device
> + * @mdev: the modern virtio-pci device
> + *
> + * Returns the features read from the device
> + */
> +u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev)
> +{
> + struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> +
> + u64 features;
> +
> + vp_iowrite32(0, &cfg->device_feature_select);
> + features = vp_ioread32(&cfg->device_feature);
> + vp_iowrite32(1, &cfg->device_feature_select);
> + features |= ((u64)vp_ioread32(&cfg->device_feature) << 32);
> +
> + return features;
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_get_features);
> +
> +/*
> + * vp_modern_set_features - set features to device
> + * @mdev: the modern virtio-pci device
> + * @features: the features set to device
> + */
> +void vp_modern_set_features(struct virtio_pci_modern_device *mdev,
> + u64 features)
> +{
> + struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> +
> + vp_iowrite32(0, &cfg->guest_feature_select);
> + vp_iowrite32((u32)features, &cfg->guest_feature);
> + vp_iowrite32(1, &cfg->guest_feature_select);
> + vp_iowrite32(features >> 32, &cfg->guest_feature);
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_set_features);
> +
> +/*
> + * vp_modern_generation - get the device genreation
> + * @mdev: the modern virtio-pci device
> + *
> + * Returns the genreation read from device
> + */
> +u32 vp_modern_generation(struct virtio_pci_modern_device *mdev)
> +{
> + struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> +
> + return vp_ioread8(&cfg->config_generation);
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_generation);
> +
> +/*
> + * vp_modern_get_status - get the device status
> + * @mdev: the modern virtio-pci device
> + *
> + * Returns the status read from device
> + */
> +u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev)
> +{
> + struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> +
> + return vp_ioread8(&cfg->device_status);
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_get_status);
> +
> +/*
> + * vp_modern_set_status - set status to device
> + * @mdev: the modern virtio-pci device
> + * @status: the status set to device
> + */
> +void vp_modern_set_status(struct virtio_pci_modern_device *mdev,
> + u8 status)
> +{
> + struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> +
> + vp_iowrite8(status, &cfg->device_status);
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_set_status);
> +
> +/*
> + * vp_modern_queue_vector - set the MSIX vector for a specific virtqueue
> + * @mdev: the modern virtio-pci device
> + * @index: queue index
> + * @vector: the config vector
> + *
> + * Returns the config vector read from the device
> + */
> +u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev,
> + u16 index, u16 vector)
> +{
> + struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> +
> + vp_iowrite16(index, &cfg->queue_select);
> + vp_iowrite16(vector, &cfg->queue_msix_vector);
> + /* Flush the write out to device */
> + return vp_ioread16(&cfg->queue_msix_vector);
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_queue_vector);
> +
> +/*
> + * vp_modern_config_vector - set the vector for config interrupt
> + * @mdev: the modern virtio-pci device
> + * @vector: the config vector
> + *
> + * Returns the config vector read from the device
> + */
> +u16 vp_modern_config_vector(struct virtio_pci_modern_device *mdev,
> + u16 vector)
> +{
> + struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> +
> + /* Setup the vector used for configuration events */
> + vp_iowrite16(vector, &cfg->msix_config);
> + /* Verify we had enough resources to assign the vector */
> + /* Will also flush the write out to device */
> + return vp_ioread16(&cfg->msix_config);
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_config_vector);
> +
> +/*
> + * vp_modern_queue_address - set the virtqueue address
> + * @mdev: the modern virtio-pci device
> + * @index: the queue index
> + * @desc_addr: address of the descriptor area
> + * @driver_addr: address of the driver area
> + * @device_addr: address of the device area
> + */
> +void vp_modern_queue_address(struct virtio_pci_modern_device *mdev,
> + u16 index, u64 desc_addr, u64 driver_addr,
> + u64 device_addr)
> +{
> + struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
> +
> + vp_iowrite16(index, &cfg->queue_select);
> +
> + vp_iowrite64_twopart(desc_addr, &cfg->queue_desc_lo,
> + &cfg->queue_desc_hi);
> + vp_iowrite64_twopart(driver_addr, &cfg->queue_avail_lo,
> + &cfg->queue_avail_hi);
> + vp_iowrite64_twopart(device_addr, &cfg->queue_used_lo,
> + &cfg->queue_used_hi);
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_queue_address);
> +
> +/*
> + * vp_modern_set_queue_enable - enable a virtqueue
> + * @mdev: the modern virtio-pci device
> + * @index: the queue index
> + * @enable: whether the virtqueue is enable or not
> + */
> +void vp_modern_set_queue_enable(struct virtio_pci_modern_device *mdev,
> + u16 index, bool enable)
> +{
> + vp_iowrite16(index, &mdev->common->queue_select);
> + vp_iowrite16(enable, &mdev->common->queue_enable);
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_set_queue_enable);
> +
> +/*
> + * vp_modern_get_queue_enable - enable a virtqueue
> + * @mdev: the modern virtio-pci device
> + * @index: the queue index
> + *
> + * Returns whether a virtqueue is enabled or not
> + */
> +bool vp_modern_get_queue_enable(struct virtio_pci_modern_device *mdev,
> + u16 index)
> +{
> + vp_iowrite16(index, &mdev->common->queue_select);
> +
> + return vp_ioread16(&mdev->common->queue_enable);
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_get_queue_enable);
> +
> +/*
> + * vp_modern_set_queue_size - set size for a virtqueue
> + * @mdev: the modern virtio-pci device
> + * @index: the queue index
> + * @size: the size of the virtqueue
> + */
> +void vp_modern_set_queue_size(struct virtio_pci_modern_device *mdev,
> + u16 index, u16 size)
> +{
> + vp_iowrite16(index, &mdev->common->queue_select);
> + vp_iowrite16(size, &mdev->common->queue_size);
> +
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_set_queue_size);
> +
> +/*
> + * vp_modern_get_queue_size - get size for a virtqueue
> + * @mdev: the modern virtio-pci device
> + * @index: the queue index
> + *
> + * Returns the size of the virtqueue
> + */
> +u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev,
> + u16 index)
> +{
> + vp_iowrite16(index, &mdev->common->queue_select);
> +
> + return vp_ioread16(&mdev->common->queue_size);
> +
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_get_queue_size);
> +
> +/*
> + * vp_modern_get_num_queues - get the number of virtqueues
> + * @mdev: the modern virtio-pci device
> + *
> + * Returns the number of virtqueues
> + */
> +u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev)
> +{
> + return vp_ioread16(&mdev->common->num_queues);
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_get_num_queues);
> +
> +/*
> + * vp_modern_get_queue_notify_off - get notification offset for a virtqueue
> + * @mdev: the modern virtio-pci device
> + * @index: the queue index
> + *
> + * Returns the notification offset for a virtqueue
> + */
> +u16 vp_modern_get_queue_notify_off(struct virtio_pci_modern_device *mdev,
> + u16 index)
> +{
> + vp_iowrite16(index, &mdev->common->queue_select);
> +
> + return vp_ioread16(&mdev->common->queue_notify_off);
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_get_queue_notify_off);
> +
> +MODULE_VERSION("0.1");
> +MODULE_DESCRIPTION("Modern Virtio PCI Device");
> +MODULE_AUTHOR("Jason Wang <jasowang@xxxxxxxxxx>");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/virtio_pci_modern.h b/include/linux/virtio_pci_modern.h
> new file mode 100644
> index 000000000000..f26acbeec965
> --- /dev/null
> +++ b/include/linux/virtio_pci_modern.h
> @@ -0,0 +1,111 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _LINUX_VIRTIO_PCI_MODERN_H
> +#define _LINUX_VIRTIO_PCI_MODERN_H
> +
> +#include <linux/pci.h>
> +#include <linux/virtio_pci.h>
> +
> +struct virtio_pci_modern_device {
> + struct pci_dev *pci_dev;
> +
> + struct virtio_pci_common_cfg __iomem *common;
> + /* Device-specific data (non-legacy mode) */
> + void __iomem *device;
> + /* Base of vq notifications (non-legacy mode). */
> + void __iomem *notify_base;
> + /* Where to read and clear interrupt */
> + u8 __iomem *isr;
> +
> + /* So we can sanity-check accesses. */
> + size_t notify_len;
> + size_t device_len;
> +
> + /* Capability for when we need to map notifications per-vq. */
> + int notify_map_cap;
> +
> + /* Multiply queue_notify_off by this value. (non-legacy mode). */
> + u32 notify_offset_multiplier;
> +
> + int modern_bars;
> +
> + struct virtio_device_id id;
> +};
> +
> +/*
> + * 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(const u8 __iomem *addr)
> +{
> + return ioread8(addr);
> +}
> +static inline u16 vp_ioread16 (const __le16 __iomem *addr)
> +{
> + return ioread16(addr);
> +}
> +
> +static inline u32 vp_ioread32(const __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 inline void vp_iowrite64_twopart(u64 val,
> + __le32 __iomem *lo,
> + __le32 __iomem *hi)
> +{
> + vp_iowrite32((u32)val, lo);
> + vp_iowrite32(val >> 32, hi);
> +}
> +
> +u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev);
> +void vp_modern_set_features(struct virtio_pci_modern_device *mdev,
> + u64 features);
> +u32 vp_modern_generation(struct virtio_pci_modern_device *mdev);
> +u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev);
> +void vp_modern_set_status(struct virtio_pci_modern_device *mdev,
> + u8 status);
> +u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev,
> + u16 idx, u16 vector);
> +u16 vp_modern_config_vector(struct virtio_pci_modern_device *mdev,
> + u16 vector);
> +void vp_modern_queue_address(struct virtio_pci_modern_device *mdev,
> + u16 index, u64 desc_addr, u64 driver_addr,
> + u64 device_addr);
> +void vp_modern_set_queue_enable(struct virtio_pci_modern_device *mdev,
> + u16 idx, bool enable);
> +bool vp_modern_get_queue_enable(struct virtio_pci_modern_device *mdev,
> + u16 idx);
> +void vp_modern_set_queue_size(struct virtio_pci_modern_device *mdev,
> + u16 idx, u16 size);
> +u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev,
> + u16 idx);
> +u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev);
> +u16 vp_modern_get_queue_notify_off(struct virtio_pci_modern_device *mdev,
> + u16 idx);
> +void __iomem *vp_modern_map_capability(struct virtio_pci_modern_device *mdev, int off,
> + size_t minlen,
> + u32 align,
> + u32 start, u32 size,
> + size_t *len);
> +int vp_modern_probe(struct virtio_pci_modern_device *mdev);
> +void vp_modern_remove(struct virtio_pci_modern_device *mdev);
> +#endif
> --
> 2.25.1