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Wed, 2 Dec 2020 14:44:21 +0000 (UTC) Received: from [10.36.112.89] (ovpn-112-89.ams2.redhat.com [10.36.112.89]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AF98760636; Wed, 2 Dec 2020 14:44:15 +0000 (UTC) Subject: Re: [RFC v2 1/1] vfio/platform: add support for msi To: Vikas Gupta , alex.williamson@redhat.com, cohuck@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: vikram.prakash@broadcom.com, srinath.mannam@broadcom.com, ashwin.kamath@broadcom.com, zachary.schroff@broadcom.com, manish.kurup@broadcom.com References: <20201112175852.21572-1-vikas.gupta@broadcom.com> <20201124161646.41191-1-vikas.gupta@broadcom.com> <20201124161646.41191-2-vikas.gupta@broadcom.com> From: Auger Eric Message-ID: <73830e85-035f-88ac-7aec-a818e83c2d5a@redhat.com> Date: Wed, 2 Dec 2020 15:44:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20201124161646.41191-2-vikas.gupta@broadcom.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hi Vikas, On 11/24/20 5:16 PM, Vikas Gupta wrote: > MSI support for platform devices. > > Signed-off-by: Vikas Gupta > --- > drivers/vfio/platform/vfio_platform_common.c | 99 ++++++- > drivers/vfio/platform/vfio_platform_irq.c | 260 +++++++++++++++++- > drivers/vfio/platform/vfio_platform_private.h | 16 ++ > include/uapi/linux/vfio.h | 43 +++ > 4 files changed, 401 insertions(+), 17 deletions(-) > > diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c > index c0771a9567fb..b0bfc0f4ee1f 100644 > --- a/drivers/vfio/platform/vfio_platform_common.c > +++ b/drivers/vfio/platform/vfio_platform_common.c > @@ -16,6 +16,7 @@ > #include > #include > #include > +#include > > #include "vfio_platform_private.h" > > @@ -344,9 +345,16 @@ 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; > + unsigned long capsz; > + int ext_irq_index = vdev->num_irqs - vdev->num_ext_irqs; > > 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; > > @@ -356,9 +364,89 @@ static long vfio_platform_ioctl(void *device_data, > if (info.index >= vdev->num_irqs) > return -EINVAL; > > + if (info.argsz >= capsz) > + minsz = capsz; > + > + if (info.index == ext_irq_index) { nit: n case we add new ext indices afterwards, I would check info.index - ext_irq_index against an VFIO_EXT_IRQ_MSI define. > + struct vfio_irq_info_cap_type cap_type = { > + .header.id = VFIO_IRQ_INFO_CAP_TYPE, > + .header.version = 1 }; > + int i; > + int ret; > + int num_msgs; > + size_t msi_info_size; > + struct vfio_platform_irq *irq; nit: I think generally the opposite order (length) is chosen. This also would better match the existing style in this file > + > + info.index = array_index_nospec(info.index, > + vdev->num_irqs); > + > + irq = &vdev->irqs[info.index]; > + > + info.flags = irq->flags; I think this can be removed given [*] > + 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; do would want to return the cap even if !num_ctx? > + > + 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; > + 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; > + } > + } > + > info.flags = vdev->irqs[info.index].flags; [*] > info.count = vdev->irqs[info.index].count; > > + 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; > > @@ -366,6 +454,7 @@ 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); > @@ -373,8 +462,14 @@ 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; > > diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c > index c5b09ec0a3c9..4066223e5b2e 100644 > --- a/drivers/vfio/platform/vfio_platform_irq.c > +++ b/drivers/vfio/platform/vfio_platform_irq.c > @@ -8,10 +8,12 @@ > > #include > #include > +#include > #include > #include > #include > #include > +#include > > #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; > + struct device *dev = vdev->device; > > while (vdev->get_irq(vdev, cnt) >= 0) > cnt++; > > - vdev->irqs = kcalloc(cnt, sizeof(struct vfio_platform_irq), GFP_KERNEL); > + num_irqs = cnt; > + > + if (dev->msi_domain) > + 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 its an ext irq it is > + */ > + if (dev->msi_domain) { > + vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD; > + vdev->irqs[i].count = NR_IRQS; why NR_IRQS? > + 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..7bbb05988705 100644 > --- a/drivers/vfio/platform/vfio_platform_private.h > +++ b/drivers/vfio/platform/vfio_platform_private.h > @@ -9,6 +9,7 @@ > > #include > #include > +#include > > #define VFIO_PLATFORM_OFFSET_SHIFT 40 > #define VFIO_PLATFORM_OFFSET_MASK (((u64)(1) << VFIO_PLATFORM_OFFSET_SHIFT) - 1) > @@ -19,9 +20,18 @@ > #define VFIO_PLATFORM_INDEX_TO_OFFSET(index) \ > ((u64)(index) << VFIO_PLATFORM_OFFSET_SHIFT) > > +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 +39,11 @@ 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 { > @@ -46,6 +61,7 @@ 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; > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > index 2f313a238a8f..598d1c944283 100644 > --- a/include/uapi/linux/vfio.h > +++ b/include/uapi/linux/vfio.h > @@ -697,11 +697,54 @@ 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; I think you should align a __u32 reserved field to have a 64b alignment > + struct vfio_irq_msi_msg msgs[]; Please can you clarify why this cap is needed versus your prior approach. > +}; > + > /** > * VFIO_DEVICE_SET_IRQS - _IOW(VFIO_TYPE, VFIO_BASE + 10, struct vfio_irq_set) > * > Thanks Eric