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

Vikas Gupta
2021-01-05T05:55:19Z

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On Tue, Dec 22, 2020 at 10:57 PM Auger Eric <eric.auger@redhat.com> wrote:
>
> 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?

Hi Eric,
The earlier module was serving two purposes
a) Max number of MSI(s) supported by the device. Since the module is
back this information can be filled in .count.
b) Writing msi_msg(s) to devices for MSI sources.
We want b) to be handled in the user space so that they need not be
dependent on the kernel. VFIO_IRQ_INFO_CAP_MSI_DESCS is helping user
space to get MSI configuration data and thus they can independently
configure MSI sources. For example, user space can just ask for ‘N’
MSI vectors and related msi_msg for ‘N’ vectors is exported to user
space using this CAP. User space can now use ‘N’ vectors to configure
any ‘N’ MSI sources and these sources might be in any order.
However, this design is different from vfio-pci as MSI configuration
is being handled in kernel only.
Let us know if implementing VFIO_IRQ_INFO_CAP_MSI_DESCS does not fit
with the CAP framework.

Thanks,
Vikas

>
> 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?
Will check on this what
>
> 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)
> > *
> >
>

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