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

From: Auger Eric
Date: Fri Jan 15 2021 - 04:28:12 EST

Hi Vikas,

On 1/15/21 7:26 AM, Vikas Gupta wrote:
> Hi Eric,
>
> On Tue, Jan 12, 2021 at 2:30 PM Auger Eric <eric.auger@xxxxxxxxxx> wrote:
>>
>> Hi Vikas,
>>
>> On 1/5/21 6:53 AM, Vikas Gupta wrote:
>>> On Tue, Dec 22, 2020 at 10:57 PM Auger Eric <eric.auger@xxxxxxxxxx> 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@xxxxxxxxxxxx>
>>>>> ---
>>>>> 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.
>> understood
>>> 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.
>> I fail to understand the problem with the "dependency on the kernel".
>> What is the functional difference when exposing this to the userspace,
>> please could you highlight the benefits?
> We do not see any functional difference here, the benefit we see is
> that user space can configure MSI sources with msi_msg rather than
> doing it in 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
>> this is induced by vfio_msi_enable(), right?
>>
> Yes
>>
>> 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.
>> I think it is OK reporting them through the cap but I fail to understand
>> the benefits.
>
> I believe, since there is no significant benefit this CAP should be
> avoided. I plan to remove this CAP in the next patch set.

OK thank you for the confirmation.

Thanks

Eric
>
> Thanks,
> Vikas
>>
>> Thanks
>>
>> Eric
>>>
>>> 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)
>>>>> *
>>>>>
>>>>
>>>
>>