Re: [RFC v3 1/2] vfio/platform: add support for msi

Auger Eric
2020-12-22T17:28:53Z

Hi Vikas,

On 12/14/20 6:45 PM, Vikas Gupta wrote:
> MSI support for platform devices.The MSI block
> is added as an extended IRQ which exports caps
> VFIO_IRQ_INFO_CAP_TYPE and VFIO_IRQ_INFO_CAP_MSI_DESCS.
>
> Signed-off-by: Vikas Gupta <vikas.gupta@broadcom.com>
> ---
> drivers/vfio/platform/vfio_platform_common.c | 179 +++++++++++-
> drivers/vfio/platform/vfio_platform_irq.c | 260 +++++++++++++++++-
> drivers/vfio/platform/vfio_platform_private.h | 32 +++
> include/uapi/linux/vfio.h | 44 +++
> 4 files changed, 496 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
> index fb4b385191f2..c936852f35d7 100644
> --- a/drivers/vfio/platform/vfio_platform_common.c
> +++ b/drivers/vfio/platform/vfio_platform_common.c
> @@ -16,6 +16,7 @@
> #include <linux/types.h>
> #include <linux/uaccess.h>
> #include <linux/vfio.h>
> +#include <linux/nospec.h>
>
> #include "vfio_platform_private.h"
>
> @@ -26,6 +27,8 @@
> #define VFIO_PLATFORM_IS_ACPI(vdev) ((vdev)->acpihid != NULL)
>
> static LIST_HEAD(reset_list);
> +/* devices having MSI support */
nit: for devices using MSIs?
> +static LIST_HEAD(msi_list);
> static DEFINE_MUTEX(driver_lock);
>
> static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat,
> @@ -47,6 +50,25 @@ static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat,
> return reset_fn;
> }
>
> +static bool vfio_platform_lookup_msi(struct vfio_platform_device *vdev)
> +{
> + bool has_msi = false;
> + struct vfio_platform_msi_node *iter;
> +
> + mutex_lock(&driver_lock);
> + list_for_each_entry(iter, &msi_list, link) {
> + if (!strcmp(iter->compat, vdev->compat) &&
> + try_module_get(iter->owner)) {
> + vdev->msi_module = iter->owner;
> + vdev->of_get_msi = iter->of_get_msi;
> + has_msi = true;
> + break;
> + }
> + }
> + mutex_unlock(&driver_lock);
> + return has_msi;
> +}
> +
> static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev,
> struct device *dev)
> {
> @@ -126,6 +148,19 @@ static int vfio_platform_get_reset(struct vfio_platform_device *vdev)
> return vdev->of_reset ? 0 : -ENOENT;
> }
>
> +static int vfio_platform_get_msi(struct vfio_platform_device *vdev)
> +{
> + bool has_msi;
> +
> + has_msi = vfio_platform_lookup_msi(vdev);
> + if (!has_msi) {
> + request_module("vfio-msi:%s", vdev->compat);
> + has_msi = vfio_platform_lookup_msi(vdev);
> + }
> +
> + return has_msi ? 0 : -ENOENT;
> +}
> +
> static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
> {
> if (VFIO_PLATFORM_IS_ACPI(vdev))
> @@ -135,6 +170,12 @@ static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
> module_put(vdev->reset_module);
> }
>
> +static void vfio_platform_put_msi(struct vfio_platform_device *vdev)
> +{
> + if (vdev->of_get_msi)
> + module_put(vdev->msi_module);
> +}
> +
> static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
> {
> int cnt = 0, i;
> @@ -343,9 +384,17 @@ static long vfio_platform_ioctl(void *device_data,
>
> } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
> struct vfio_irq_info info;
> + struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
> + struct vfio_irq_info_cap_msi *msi_info = NULL;
> + int ext_irq_index = vdev->num_irqs - vdev->num_ext_irqs;
> + unsigned long capsz;
> + u32 index;
>
> minsz = offsetofend(struct vfio_irq_info, count);
>
> + /* For backward compatibility, cannot require this */
> + capsz = offsetofend(struct vfio_irq_info, cap_offset);
> +
> if (copy_from_user(&info, (void __user *)arg, minsz))
> return -EFAULT;
>
> @@ -355,8 +404,94 @@ static long vfio_platform_ioctl(void *device_data,
> if (info.index >= vdev->num_irqs)
> return -EINVAL;
>
> - info.flags = vdev->irqs[info.index].flags;
> - info.count = vdev->irqs[info.index].count;
> + if (info.argsz >= capsz)
> + minsz = capsz;
> +
> + index = info.index;
> +
> + info.flags = vdev->irqs[index].flags;
> + info.count = vdev->irqs[index].count;
> +
> + if (ext_irq_index - index == VFIO_EXT_IRQ_MSI) {
> + struct vfio_irq_info_cap_type cap_type = {
> + .header.id = VFIO_IRQ_INFO_CAP_TYPE,
> + .header.version = 1 };
> + struct vfio_platform_irq *irq;
> + size_t msi_info_size;
> + int num_msgs;
> + int ret;
> + int i;
> +
> + index = array_index_nospec(index,
> + vdev->num_irqs);
> + irq = &vdev->irqs[index];
> +
> + cap_type.type = irq->type;
> + cap_type.subtype = irq->subtype;
> +
> + ret = vfio_info_add_capability(&caps,
> + &cap_type.header,
> + sizeof(cap_type));
> + if (ret)
> + return ret;
> +
> + num_msgs = irq->num_ctx;
> + if (num_msgs) {
> + msi_info_size = struct_size(msi_info,
> + msgs, num_msgs);
> +
> + msi_info = kzalloc(msi_info_size, GFP_KERNEL);
> + if (!msi_info) {
> + kfree(caps.buf);
> + return -ENOMEM;
> + }
> +
> + msi_info->header.id =
> + VFIO_IRQ_INFO_CAP_MSI_DESCS;
I thought you would remove this cap now the module is back. What is the
motivation to keep it?

Thanks

Eric
> + msi_info->header.version = 1;
> + msi_info->nr_msgs = num_msgs;
> +
> + for (i = 0; i < num_msgs; i++) {
> + struct vfio_irq_ctx *ctx = &irq->ctx[i];
> +
> + msi_info->msgs[i].addr_lo =
> + ctx->msg.address_lo;
> + msi_info->msgs[i].addr_hi =
> + ctx->msg.address_hi;
> + msi_info->msgs[i].data = ctx->msg.data;
> + }
> +
> + ret = vfio_info_add_capability(&caps,
> + &msi_info->header,
> + msi_info_size);
> + if (ret) {
> + kfree(msi_info);
> + kfree(caps.buf);
> + return ret;
> + }
> + }
> + }
> +
> + if (caps.size) {
> + info.flags |= VFIO_IRQ_INFO_FLAG_CAPS;
> + if (info.argsz < sizeof(info) + caps.size) {
> + info.argsz = sizeof(info) + caps.size;
> + info.cap_offset = 0;
> + } else {
> + vfio_info_cap_shift(&caps, sizeof(info));
> + if (copy_to_user((void __user *)arg +
> + sizeof(info), caps.buf,
> + caps.size)) {
> + kfree(msi_info);
> + kfree(caps.buf);
> + return -EFAULT;
> + }
> + info.cap_offset = sizeof(info);
> + }
> +
> + kfree(msi_info);
> + kfree(caps.buf);
> + }
>
> return copy_to_user((void __user *)arg, &info, minsz) ?
> -EFAULT : 0;
> @@ -365,6 +500,7 @@ static long vfio_platform_ioctl(void *device_data,
> struct vfio_irq_set hdr;
> u8 *data = NULL;
> int ret = 0;
> + int max;
> size_t data_size = 0;
>
> minsz = offsetofend(struct vfio_irq_set, count);
> @@ -372,8 +508,14 @@ static long vfio_platform_ioctl(void *device_data,
> if (copy_from_user(&hdr, (void __user *)arg, minsz))
> return -EFAULT;
>
> - ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs,
> - vdev->num_irqs, &data_size);
> + if (hdr.index >= vdev->num_irqs)
> + return -EINVAL;
> +
> + max = vdev->irqs[hdr.index].count;
> +
> + ret = vfio_set_irqs_validate_and_prepare(&hdr, max,
> + vdev->num_irqs,
> + &data_size);
> if (ret)
> return ret;
>
> @@ -678,6 +820,10 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
> return ret;
> }
>
> + ret = vfio_platform_get_msi(vdev);
> + if (ret)
> + dev_info(vdev->device, "msi not supported\n");
I don't think we should output this message. This is printed for
amd-xgbe which does not have msi so this is misleading. I would say
either the vfio_platform_get_msi() can return an actual error or we
return a void?

Thanks

Eric
> +
> group = vfio_iommu_group_get(dev);
> if (!group) {
> dev_err(dev, "No IOMMU group for device %s\n", vdev->name);
> @@ -697,6 +843,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
> put_iommu:
> vfio_iommu_group_put(group, dev);
> put_reset:
> + vfio_platform_put_msi(vdev);
> vfio_platform_put_reset(vdev);
> return ret;
> }
> @@ -744,6 +891,30 @@ void vfio_platform_unregister_reset(const char *compat,
> }
> EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);
>
> +void __vfio_platform_register_msi(struct vfio_platform_msi_node *node)
> +{
> + mutex_lock(&driver_lock);
> + list_add(&node->link, &msi_list);
> + mutex_unlock(&driver_lock);
> +}
> +EXPORT_SYMBOL_GPL(__vfio_platform_register_msi);
> +
> +void vfio_platform_unregister_msi(const char *compat)
> +{
> + struct vfio_platform_msi_node *iter, *temp;
> +
> + mutex_lock(&driver_lock);
> + list_for_each_entry_safe(iter, temp, &msi_list, link) {
> + if (!strcmp(iter->compat, compat)) {
> + list_del(&iter->link);
> + break;
> + }
> + }
> +
> + mutex_unlock(&driver_lock);
> +}
> +EXPORT_SYMBOL_GPL(vfio_platform_unregister_msi);
> +
> MODULE_VERSION(DRIVER_VERSION);
> MODULE_LICENSE("GPL v2");
> MODULE_AUTHOR(DRIVER_AUTHOR);
> diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
> index c5b09ec0a3c9..e0f4696afedd 100644
> --- a/drivers/vfio/platform/vfio_platform_irq.c
> +++ b/drivers/vfio/platform/vfio_platform_irq.c
> @@ -8,10 +8,12 @@
>
> #include <linux/eventfd.h>
> #include <linux/interrupt.h>
> +#include <linux/eventfd.h>
> #include <linux/slab.h>
> #include <linux/types.h>
> #include <linux/vfio.h>
> #include <linux/irq.h>
> +#include <linux/msi.h>
>
> #include "vfio_platform_private.h"
>
> @@ -253,6 +255,195 @@ static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev,
> return 0;
> }
>
> +/* MSI/MSIX */
> +static irqreturn_t vfio_msihandler(int irq, void *arg)
> +{
> + struct eventfd_ctx *trigger = arg;
> +
> + eventfd_signal(trigger, 1);
> + return IRQ_HANDLED;
> +}
> +
> +static void msi_write(struct msi_desc *desc, struct msi_msg *msg)
> +{
> + int i;
> + struct vfio_platform_irq *irq;
> + u16 index = desc->platform.msi_index;
> + struct device *dev = msi_desc_to_dev(desc);
> + struct vfio_device *device = dev_get_drvdata(dev);
> + struct vfio_platform_device *vdev = (struct vfio_platform_device *)
> + vfio_device_data(device);
> +
> + for (i = 0; i < vdev->num_irqs; i++)
> + if (vdev->irqs[i].type == VFIO_IRQ_TYPE_MSI)
> + irq = &vdev->irqs[i];
> +
> + irq->ctx[index].msg.address_lo = msg->address_lo;
> + irq->ctx[index].msg.address_hi = msg->address_hi;
> + irq->ctx[index].msg.data = msg->data;
> +}
> +
> +static int vfio_msi_enable(struct vfio_platform_device *vdev,
> + struct vfio_platform_irq *irq, int nvec)
> +{
> + int ret;
> + int msi_idx = 0;
> + struct msi_desc *desc;
> + struct device *dev = vdev->device;
> +
> + irq->ctx = kcalloc(nvec, sizeof(struct vfio_irq_ctx), GFP_KERNEL);
> + if (!irq->ctx)
> + return -ENOMEM;
> +
> + /* Allocate platform MSIs */
> + ret = platform_msi_domain_alloc_irqs(dev, nvec, msi_write);
> + if (ret < 0) {
> + kfree(irq->ctx);
> + return ret;
> + }
> +
> + for_each_msi_entry(desc, dev) {
> + irq->ctx[msi_idx].hwirq = desc->irq;
> + msi_idx++;
> + }
> +
> + irq->num_ctx = nvec;
> + irq->config_msi = 1;
> +
> + return 0;
> +}
> +
> +static int vfio_msi_set_vector_signal(struct vfio_platform_irq *irq,
> + int vector, int fd)
> +{
> + struct eventfd_ctx *trigger;
> + int irq_num, ret;
> +
> + if (vector < 0 || vector >= irq->num_ctx)
> + return -EINVAL;
> +
> + irq_num = irq->ctx[vector].hwirq;
> +
> + if (irq->ctx[vector].trigger) {
> + free_irq(irq_num, irq->ctx[vector].trigger);
> + kfree(irq->ctx[vector].name);
> + eventfd_ctx_put(irq->ctx[vector].trigger);
> + irq->ctx[vector].trigger = NULL;
> + }
> +
> + if (fd < 0)
> + return 0;
> +
> + irq->ctx[vector].name = kasprintf(GFP_KERNEL,
> + "vfio-msi[%d]", vector);
> + if (!irq->ctx[vector].name)
> + return -ENOMEM;
> +
> + trigger = eventfd_ctx_fdget(fd);
> + if (IS_ERR(trigger)) {
> + kfree(irq->ctx[vector].name);
> + return PTR_ERR(trigger);
> + }
> +
> + ret = request_irq(irq_num, vfio_msihandler, 0,
> + irq->ctx[vector].name, trigger);
> + if (ret) {
> + kfree(irq->ctx[vector].name);
> + eventfd_ctx_put(trigger);
> + return ret;
> + }
> +
> + irq->ctx[vector].trigger = trigger;
> +
> + return 0;
> +}
> +
> +static int vfio_msi_set_block(struct vfio_platform_irq *irq, unsigned int start,
> + unsigned int count, int32_t *fds)
> +{
> + int i, j, ret = 0;
> +
> + if (start >= irq->num_ctx || start + count > irq->num_ctx)
> + return -EINVAL;
> +
> + for (i = 0, j = start; i < count && !ret; i++, j++) {
> + int fd = fds ? fds[i] : -1;
> +
> + ret = vfio_msi_set_vector_signal(irq, j, fd);
> + }
> +
> + if (ret) {
> + for (--j; j >= (int)start; j--)
> + vfio_msi_set_vector_signal(irq, j, -1);
> + }
> +
> + return ret;
> +}
> +
> +static void vfio_msi_disable(struct vfio_platform_device *vdev,
> + struct vfio_platform_irq *irq)
> +{
> + struct device *dev = vdev->device;
> +
> + vfio_msi_set_block(irq, 0, irq->num_ctx, NULL);
> +
> + platform_msi_domain_free_irqs(dev);
> +
> + irq->config_msi = 0;
> + irq->num_ctx = 0;
> +
> + kfree(irq->ctx);
> +}
> +
> +static int vfio_set_msi_trigger(struct vfio_platform_device *vdev,
> + unsigned int index, unsigned int start,
> + unsigned int count, uint32_t flags, void *data)
> +{
> + int i;
> + struct vfio_platform_irq *irq = &vdev->irqs[index];
> +
> + if (start + count > irq->count)
> + return -EINVAL;
> +
> + if (!count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
> + vfio_msi_disable(vdev, irq);
> + return 0;
> + }
> +
> + if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
> + s32 *fds = data;
> + int ret;
> +
> + if (irq->config_msi)
> + return vfio_msi_set_block(irq, start, count,
> + fds);
> + ret = vfio_msi_enable(vdev, irq, start + count);
> + if (ret)
> + return ret;
> +
> + ret = vfio_msi_set_block(irq, start, count, fds);
> + if (ret)
> + vfio_msi_disable(vdev, irq);
> +
> + return ret;
> + }
> +
> + for (i = start; i < start + count; i++) {
> + if (!irq->ctx[i].trigger)
> + continue;
> + if (flags & VFIO_IRQ_SET_DATA_NONE) {
> + eventfd_signal(irq->ctx[i].trigger, 1);
> + } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
> + u8 *bools = data;
> +
> + if (bools[i - start])
> + eventfd_signal(irq->ctx[i].trigger, 1);
> + }
> + }
> +
> + return 0;
> +}
> +
> int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,
> uint32_t flags, unsigned index, unsigned start,
> unsigned count, void *data)
> @@ -261,16 +452,29 @@ int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,
> unsigned start, unsigned count, uint32_t flags,
> void *data) = NULL;
>
> - switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
> - case VFIO_IRQ_SET_ACTION_MASK:
> - func = vfio_platform_set_irq_mask;
> - break;
> - case VFIO_IRQ_SET_ACTION_UNMASK:
> - func = vfio_platform_set_irq_unmask;
> - break;
> - case VFIO_IRQ_SET_ACTION_TRIGGER:
> - func = vfio_platform_set_irq_trigger;
> - break;
> + struct vfio_platform_irq *irq = &vdev->irqs[index];
> +
> + if (irq->type == VFIO_IRQ_TYPE_MSI) {
> + switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
> + case VFIO_IRQ_SET_ACTION_MASK:
> + case VFIO_IRQ_SET_ACTION_UNMASK:
> + break;
> + case VFIO_IRQ_SET_ACTION_TRIGGER:
> + func = vfio_set_msi_trigger;
> + break;
> + }
> + } else {
> + switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
> + case VFIO_IRQ_SET_ACTION_MASK:
> + func = vfio_platform_set_irq_mask;
> + break;
> + case VFIO_IRQ_SET_ACTION_UNMASK:
> + func = vfio_platform_set_irq_unmask;
> + break;
> + case VFIO_IRQ_SET_ACTION_TRIGGER:
> + func = vfio_platform_set_irq_trigger;
> + break;
> + }
> }
>
> if (!func)
> @@ -281,12 +485,21 @@ int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,
>
> int vfio_platform_irq_init(struct vfio_platform_device *vdev)
> {
> - int cnt = 0, i;
> + int i;
> + int cnt = 0;
> + int num_irqs;
> + int msi_cnt = 0;
>
> while (vdev->get_irq(vdev, cnt) >= 0)
> cnt++;
>
> - vdev->irqs = kcalloc(cnt, sizeof(struct vfio_platform_irq), GFP_KERNEL);
> + if (vdev->of_get_msi) {
> + msi_cnt = vdev->of_get_msi(vdev);
> + num_irqs++;
> + }
> +
> + vdev->irqs = kcalloc(num_irqs, sizeof(struct vfio_platform_irq),
> + GFP_KERNEL);
> if (!vdev->irqs)
> return -ENOMEM;
>
> @@ -309,7 +522,19 @@ int vfio_platform_irq_init(struct vfio_platform_device *vdev)
> vdev->irqs[i].masked = false;
> }
>
> - vdev->num_irqs = cnt;
> + /*
> + * MSI block is added at last index and it is an ext irq
> + */
> + if (msi_cnt > 0) {
> + vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD;
> + vdev->irqs[i].count = msi_cnt;
> + vdev->irqs[i].hwirq = 0;
> + vdev->irqs[i].masked = false;
> + vdev->irqs[i].type = VFIO_IRQ_TYPE_MSI;
> + vdev->num_ext_irqs = 1;
> + }
> +
> + vdev->num_irqs = num_irqs;
>
> return 0;
> err:
> @@ -321,8 +546,13 @@ void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev)
> {
> int i;
>
> - for (i = 0; i < vdev->num_irqs; i++)
> - vfio_set_trigger(vdev, i, -1, NULL);
> + for (i = 0; i < vdev->num_irqs; i++) {
> + if (vdev->irqs[i].type == VFIO_IRQ_TYPE_MSI)
> + vfio_set_msi_trigger(vdev, i, 0, 0,
> + VFIO_IRQ_SET_DATA_NONE, NULL);
> + else
> + vfio_set_trigger(vdev, i, -1, NULL);
> + }
>
> vdev->num_irqs = 0;
> kfree(vdev->irqs);
> diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
> index 289089910643..1307feddda21 100644
> --- a/drivers/vfio/platform/vfio_platform_private.h
> +++ b/drivers/vfio/platform/vfio_platform_private.h
> @@ -9,6 +9,7 @@
>
> #include <linux/types.h>
> #include <linux/interrupt.h>
> +#include <linux/msi.h>
>
> #define VFIO_PLATFORM_OFFSET_SHIFT 40
> #define VFIO_PLATFORM_OFFSET_MASK (((u64)(1) << VFIO_PLATFORM_OFFSET_SHIFT) - 1)
> @@ -19,9 +20,21 @@
> #define VFIO_PLATFORM_INDEX_TO_OFFSET(index) \
> ((u64)(index) << VFIO_PLATFORM_OFFSET_SHIFT)
>
> +/* IRQ index for MSI in ext IRQs */
> +#define VFIO_EXT_IRQ_MSI 0
> +
> +struct vfio_irq_ctx {
> + int hwirq;
> + char *name;
> + struct msi_msg msg;
> + struct eventfd_ctx *trigger;
> +};
> +
> struct vfio_platform_irq {
> u32 flags;
> u32 count;
> + int num_ctx;
> + struct vfio_irq_ctx *ctx;
> int hwirq;
> char *name;
> struct eventfd_ctx *trigger;
> @@ -29,6 +42,11 @@ struct vfio_platform_irq {
> spinlock_t lock;
> struct virqfd *unmask;
> struct virqfd *mask;
> +
> + /* for extended irqs */
> + u32 type;
> + u32 subtype;
> + int config_msi;
> };
>
> struct vfio_platform_region {
> @@ -46,12 +64,14 @@ struct vfio_platform_device {
> u32 num_regions;
> struct vfio_platform_irq *irqs;
> u32 num_irqs;
> + int num_ext_irqs;
> int refcnt;
> struct mutex igate;
> struct module *parent_module;
> const char *compat;
> const char *acpihid;
> struct module *reset_module;
> + struct module *msi_module;
> struct device *device;
>
> /*
> @@ -65,11 +85,13 @@ struct vfio_platform_device {
> (*get_resource)(struct vfio_platform_device *vdev, int i);
> int (*get_irq)(struct vfio_platform_device *vdev, int i);
> int (*of_reset)(struct vfio_platform_device *vdev);
> + u32 (*of_get_msi)(struct vfio_platform_device *vdev);
>
> bool reset_required;
> };
>
> typedef int (*vfio_platform_reset_fn_t)(struct vfio_platform_device *vdev);
> +typedef u32 (*vfio_platform_get_msi_fn_t)(struct vfio_platform_device *vdev);
>
> struct vfio_platform_reset_node {
> struct list_head link;
> @@ -78,6 +100,13 @@ struct vfio_platform_reset_node {
> vfio_platform_reset_fn_t of_reset;
> };
>
> +struct vfio_platform_msi_node {
> + struct list_head link;
> + char *compat;
> + struct module *owner;
> + vfio_platform_get_msi_fn_t of_get_msi;
> +};
> +
> extern int vfio_platform_probe_common(struct vfio_platform_device *vdev,
> struct device *dev);
> extern struct vfio_platform_device *vfio_platform_remove_common
> @@ -94,6 +123,9 @@ extern int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,
> extern void __vfio_platform_register_reset(struct vfio_platform_reset_node *n);
> extern void vfio_platform_unregister_reset(const char *compat,
> vfio_platform_reset_fn_t fn);
> +void __vfio_platform_register_msi(struct vfio_platform_msi_node *n);
> +void vfio_platform_unregister_msi(const char *compat);
> +
> #define vfio_platform_register_reset(__compat, __reset) \
> static struct vfio_platform_reset_node __reset ## _node = { \
> .owner = THIS_MODULE, \
> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> index d1812777139f..53a7ff2b524e 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -697,11 +697,55 @@ struct vfio_irq_info {
> #define VFIO_IRQ_INFO_MASKABLE (1 << 1)
> #define VFIO_IRQ_INFO_AUTOMASKED (1 << 2)
> #define VFIO_IRQ_INFO_NORESIZE (1 << 3)
> +#define VFIO_IRQ_INFO_FLAG_CAPS (1 << 4) /* Info supports caps */
> __u32 index; /* IRQ index */
> __u32 count; /* Number of IRQs within this index */
> + __u32 cap_offset; /* Offset within info struct of first cap */
> };
> #define VFIO_DEVICE_GET_IRQ_INFO _IO(VFIO_TYPE, VFIO_BASE + 9)
>
> +/*
> + * The irq type capability allows IRQs unique to a specific device or
> + * class of devices to be exposed.
> + *
> + * The structures below define version 1 of this capability.
> + */
> +#define VFIO_IRQ_INFO_CAP_TYPE 3
> +
> +struct vfio_irq_info_cap_type {
> + struct vfio_info_cap_header header;
> + __u32 type; /* global per bus driver */
> + __u32 subtype; /* type specific */
> +};
> +
> +/*
> + * List of IRQ types, global per bus driver.
> + * If you introduce a new type, please add it here.
> + */
> +
> +/* Non PCI devices having MSI(s) support */
> +#define VFIO_IRQ_TYPE_MSI (1)
> +
> +/*
> + * The msi capability allows the user to use the msi msg to
> + * configure the iova for the msi configuration.
> + * The structures below define version 1 of this capability.
> + */
> +#define VFIO_IRQ_INFO_CAP_MSI_DESCS 4
> +
> +struct vfio_irq_msi_msg {
> + __u32 addr_lo;
> + __u32 addr_hi;
> + __u32 data;
> +};
> +
> +struct vfio_irq_info_cap_msi {
> + struct vfio_info_cap_header header;
> + __u32 nr_msgs;
> + __u32 reserved;
> + struct vfio_irq_msi_msg msgs[];
> +};
> +
> /**
> * VFIO_DEVICE_SET_IRQS - _IOW(VFIO_TYPE, VFIO_BASE + 10, struct vfio_irq_set)
> *
>