From ff31d2e28549c84d53252b3c36b6f0ba18b78697 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Tue, 13 Jan 2015 11:23:32 +0200 Subject: virtio_pci: move probe/remove code to common Most of initialization is device-independent. Let's move it to common. Signed-off-by: Michael S. Tsirkin Signed-off-by: Rusty Russell --- drivers/virtio/virtio_pci_common.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'drivers/virtio/virtio_pci_common.h') diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h index 5a497289b7e9..2b1e70db44a0 100644 --- a/drivers/virtio/virtio_pci_common.h +++ b/drivers/virtio/virtio_pci_common.h @@ -127,8 +127,7 @@ const char *vp_bus_name(struct virtio_device *vdev); */ int vp_set_vq_affinity(struct virtqueue *vq, int cpu); -int virtio_pci_legacy_probe(struct pci_dev *pci_dev, - const struct pci_device_id *id); -void virtio_pci_legacy_remove(struct pci_dev *pci_dev); +int virtio_pci_legacy_probe(struct virtio_pci_device *); +void virtio_pci_legacy_remove(struct virtio_pci_device *); #endif -- cgit v1.2.3 From 1fcf0512c9c870e78e1c9898ecb9458593403466 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 11 Dec 2014 13:59:51 +0200 Subject: virtio_pci: modern driver Lightly tested against qemu. One thing *not* implemented here is separate mappings for descriptor/avail/used rings. That's nice to have, will be done later after we have core support. This also exposes the PCI layout to userspace, and adds macros for PCI layout offsets: QEMU wants it, so why not? Trust, but verify. Signed-off-by: Rusty Russell Signed-off-by: Michael S. Tsirkin --- drivers/virtio/Makefile | 2 +- drivers/virtio/virtio_pci_common.c | 14 +- drivers/virtio/virtio_pci_common.h | 25 +- drivers/virtio/virtio_pci_modern.c | 587 +++++++++++++++++++++++++++++++++++++ include/uapi/linux/virtio_pci.h | 7 +- 5 files changed, 625 insertions(+), 10 deletions(-) create mode 100644 drivers/virtio/virtio_pci_modern.c (limited to 'drivers/virtio/virtio_pci_common.h') diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile index bf5104b56894..bd230d1c0533 100644 --- a/drivers/virtio/Makefile +++ b/drivers/virtio/Makefile @@ -1,5 +1,5 @@ obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o -virtio_pci-y := virtio_pci_legacy.o virtio_pci_common.o +virtio_pci-y := virtio_pci_modern.o virtio_pci_legacy.o virtio_pci_common.o obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c index 457cbe29c8c4..8ae34a34f3af 100644 --- a/drivers/virtio/virtio_pci_common.c +++ b/drivers/virtio/virtio_pci_common.c @@ -505,7 +505,9 @@ static int virtio_pci_probe(struct pci_dev *pci_dev, if (rc) goto err_request_regions; - rc = virtio_pci_legacy_probe(vp_dev); + rc = virtio_pci_modern_probe(vp_dev); + if (rc == -ENODEV) + rc = virtio_pci_legacy_probe(vp_dev); if (rc) goto err_probe; @@ -518,7 +520,10 @@ static int virtio_pci_probe(struct pci_dev *pci_dev, return 0; err_register: - virtio_pci_legacy_remove(vp_dev); + if (vp_dev->ioaddr) + virtio_pci_legacy_remove(vp_dev); + else + virtio_pci_modern_remove(vp_dev); err_probe: pci_release_regions(pci_dev); err_request_regions: @@ -534,7 +539,10 @@ static void virtio_pci_remove(struct pci_dev *pci_dev) unregister_virtio_device(&vp_dev->vdev); - virtio_pci_legacy_remove(pci_dev); + if (vp_dev->ioaddr) + virtio_pci_legacy_remove(vp_dev); + else + virtio_pci_modern_remove(vp_dev); pci_release_regions(pci_dev); pci_disable_device(pci_dev); diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h index 2b1e70db44a0..610c43f19230 100644 --- a/drivers/virtio/virtio_pci_common.h +++ b/drivers/virtio/virtio_pci_common.h @@ -53,12 +53,29 @@ struct virtio_pci_device { struct virtio_device vdev; struct pci_dev *pci_dev; + /* In legacy mode, these two point to within ->legacy. */ + /* Where to read and clear interrupt */ + u8 __iomem *isr; + + /* Modern only fields */ + /* The IO mapping for the PCI config space (non-legacy mode) */ + struct virtio_pci_common_cfg __iomem *common; + /* Device-specific data (non-legacy mode) */ + void __iomem *device; + + /* So we can sanity-check accesses. */ + 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; + + /* Legacy only field */ /* the IO mapping for the PCI config space */ void __iomem *ioaddr; - /* the IO mapping for ISR operation */ - void __iomem *isr; - /* a list of queues so we can dispatch IRQs */ spinlock_t lock; struct list_head virtqueues; @@ -129,5 +146,7 @@ int vp_set_vq_affinity(struct virtqueue *vq, int cpu); int virtio_pci_legacy_probe(struct virtio_pci_device *); void virtio_pci_legacy_remove(struct virtio_pci_device *); +int virtio_pci_modern_probe(struct virtio_pci_device *); +void virtio_pci_modern_remove(struct virtio_pci_device *); #endif diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c new file mode 100644 index 000000000000..a3d81013e0c2 --- /dev/null +++ b/drivers/virtio/virtio_pci_modern.c @@ -0,0 +1,587 @@ +/* + * Virtio PCI driver - modern (virtio 1.0) device support + * + * This module allows virtio devices to be used over a virtual PCI device. + * This can be used with QEMU based VMMs like KVM or Xen. + * + * Copyright IBM Corp. 2007 + * Copyright Red Hat, Inc. 2014 + * + * Authors: + * Anthony Liguori + * Rusty Russell + * Michael S. Tsirkin + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ + +#define VIRTIO_PCI_NO_LEGACY +#include "virtio_pci_common.h" + +static void __iomem *map_capability(struct pci_dev *dev, int off, + size_t minlen, + u32 align, + u32 start, u32 size, + size_t *len) +{ + 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; +} + +static void iowrite64_twopart(u64 val, __le32 __iomem *lo, __le32 __iomem *hi) +{ + iowrite32((u32)val, lo); + iowrite32(val >> 32, hi); +} + +/* virtio config->get_features() implementation */ +static u64 vp_get_features(struct virtio_device *vdev) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + u64 features; + + iowrite32(0, &vp_dev->common->device_feature_select); + features = ioread32(&vp_dev->common->device_feature); + iowrite32(1, &vp_dev->common->device_feature_select); + features |= ((u64)ioread32(&vp_dev->common->device_feature) << 32); + + return features; +} + +/* virtio config->finalize_features() implementation */ +static int vp_finalize_features(struct virtio_device *vdev) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + + /* Give virtio_ring a chance to accept features. */ + vring_transport_features(vdev); + + if (!__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) { + dev_err(&vdev->dev, "virtio: device uses modern interface " + "but does not have VIRTIO_F_VERSION_1\n"); + return -EINVAL; + } + + iowrite32(0, &vp_dev->common->guest_feature_select); + iowrite32((u32)vdev->features, &vp_dev->common->guest_feature); + iowrite32(1, &vp_dev->common->guest_feature_select); + iowrite32(vdev->features >> 32, &vp_dev->common->guest_feature); + + return 0; +} + +/* virtio config->get() implementation */ +static void vp_get(struct virtio_device *vdev, unsigned offset, + void *buf, unsigned len) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + u8 b; + __le16 w; + __le32 l; + + BUG_ON(offset + len > vp_dev->device_len); + + switch (len) { + case 1: + b = ioread8(vp_dev->device + offset); + memcpy(buf, &b, sizeof b); + break; + case 2: + w = cpu_to_le16(ioread16(vp_dev->device + offset)); + memcpy(buf, &w, sizeof w); + break; + case 4: + l = cpu_to_le32(ioread32(vp_dev->device + offset)); + memcpy(buf, &l, sizeof l); + break; + case 8: + l = cpu_to_le32(ioread32(vp_dev->device + offset)); + memcpy(buf, &l, sizeof l); + l = cpu_to_le32(ioread32(vp_dev->device + offset + sizeof l)); + memcpy(buf + sizeof l, &l, sizeof l); + break; + default: + BUG(); + } +} + +/* the config->set() implementation. it's symmetric to the config->get() + * implementation */ +static void vp_set(struct virtio_device *vdev, unsigned offset, + const void *buf, unsigned len) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + u8 b; + __le16 w; + __le32 l; + + BUG_ON(offset + len > vp_dev->device_len); + + switch (len) { + case 1: + memcpy(&b, buf, sizeof b); + iowrite8(b, vp_dev->device + offset); + break; + case 2: + memcpy(&w, buf, sizeof w); + iowrite16(le16_to_cpu(w), vp_dev->device + offset); + break; + case 4: + memcpy(&l, buf, sizeof l); + iowrite32(le32_to_cpu(l), vp_dev->device + offset); + break; + case 8: + memcpy(&l, buf, sizeof l); + iowrite32(le32_to_cpu(l), vp_dev->device + offset); + memcpy(&l, buf + sizeof l, sizeof l); + iowrite32(le32_to_cpu(l), vp_dev->device + offset + sizeof l); + break; + default: + BUG(); + } +} + +static u32 vp_generation(struct virtio_device *vdev) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + return ioread8(&vp_dev->common->config_generation); +} + +/* config->{get,set}_status() implementations */ +static u8 vp_get_status(struct virtio_device *vdev) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + return ioread8(&vp_dev->common->device_status); +} + +static void vp_set_status(struct virtio_device *vdev, u8 status) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + /* We should never be setting status to 0. */ + BUG_ON(status == 0); + iowrite8(status, &vp_dev->common->device_status); +} + +static void vp_reset(struct virtio_device *vdev) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + /* 0 status means a reset. */ + iowrite8(0, &vp_dev->common->device_status); + /* Flush out the status write, and flush in device writes, + * including MSI-X interrupts, if any. */ + ioread8(&vp_dev->common->device_status); + /* Flush pending VQ/configuration callbacks. */ + vp_synchronize_vectors(vdev); +} + +static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector) +{ + /* Setup the vector used for configuration events */ + iowrite16(vector, &vp_dev->common->msix_config); + /* Verify we had enough resources to assign the vector */ + /* Will also flush the write out to device */ + return ioread16(&vp_dev->common->msix_config); +} + +static size_t vring_pci_size(u16 num) +{ + /* We only need a cacheline separation. */ + return PAGE_ALIGN(vring_size(num, SMP_CACHE_BYTES)); +} + +static void *alloc_virtqueue_pages(int *num) +{ + void *pages; + + /* TODO: allocate each queue chunk individually */ + for (; *num && vring_pci_size(*num) > PAGE_SIZE; *num /= 2) { + pages = alloc_pages_exact(vring_pci_size(*num), + GFP_KERNEL|__GFP_ZERO|__GFP_NOWARN); + if (pages) + return pages; + } + + if (!*num) + return NULL; + + /* Try to get a single page. You are my only hope! */ + return alloc_pages_exact(vring_pci_size(*num), GFP_KERNEL|__GFP_ZERO); +} + +static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, + struct virtio_pci_vq_info *info, + unsigned index, + void (*callback)(struct virtqueue *vq), + const char *name, + u16 msix_vec) +{ + struct virtio_pci_common_cfg __iomem *cfg = vp_dev->common; + struct virtqueue *vq; + u16 num, off; + int err; + + if (index >= ioread16(&cfg->num_queues)) + return ERR_PTR(-ENOENT); + + /* Select the queue we're interested in */ + iowrite16(index, &cfg->queue_select); + + /* Check if queue is either not available or already active. */ + num = ioread16(&cfg->queue_size); + if (!num || ioread8(&cfg->queue_enable)) + return ERR_PTR(-ENOENT); + + if (num & (num - 1)) { + dev_warn(&vp_dev->pci_dev->dev, "bad queue size %u", num); + return ERR_PTR(-EINVAL); + } + + /* get offset of notification word for this vq */ + off = ioread16(&cfg->queue_notify_off); + + info->num = num; + info->msix_vector = msix_vec; + + info->queue = alloc_virtqueue_pages(&info->num); + if (info->queue == NULL) + return ERR_PTR(-ENOMEM); + + /* create the vring */ + vq = vring_new_virtqueue(index, info->num, + SMP_CACHE_BYTES, &vp_dev->vdev, + true, info->queue, vp_notify, callback, name); + if (!vq) { + err = -ENOMEM; + goto err_new_queue; + } + + /* activate the queue */ + iowrite16(num, &cfg->queue_size); + iowrite64_twopart(virt_to_phys(info->queue), + &cfg->queue_desc_lo, &cfg->queue_desc_hi); + iowrite64_twopart(virt_to_phys(virtqueue_get_avail(vq)), + &cfg->queue_avail_lo, &cfg->queue_avail_hi); + iowrite64_twopart(virt_to_phys(virtqueue_get_used(vq)), + &cfg->queue_used_lo, &cfg->queue_used_hi); + + vq->priv = (void __force *)map_capability(vp_dev->pci_dev, + vp_dev->notify_map_cap, 2, 2, + off * vp_dev->notify_offset_multiplier, 2, + NULL); + + if (!vq->priv) { + err = -ENOMEM; + goto err_map_notify; + } + + if (msix_vec != VIRTIO_MSI_NO_VECTOR) { + iowrite16(msix_vec, &cfg->queue_msix_vector); + msix_vec = ioread16(&cfg->queue_msix_vector); + if (msix_vec == VIRTIO_MSI_NO_VECTOR) { + err = -EBUSY; + goto err_assign_vector; + } + } + + return vq; + +err_assign_vector: + pci_iounmap(vp_dev->pci_dev, (void __iomem __force *)vq->priv); +err_map_notify: + vring_del_virtqueue(vq); +err_new_queue: + free_pages_exact(info->queue, vring_pci_size(info->num)); + return ERR_PTR(err); +} + +static int vp_modern_find_vqs(struct virtio_device *vdev, unsigned nvqs, + struct virtqueue *vqs[], + vq_callback_t *callbacks[], + const char *names[]) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + struct virtqueue *vq; + int rc = vp_find_vqs(vdev, nvqs, vqs, callbacks, names); + + if (rc) + return rc; + + /* Select and activate all queues. Has to be done last: once we do + * this, there's no way to go back except reset. + */ + list_for_each_entry(vq, &vdev->vqs, list) { + iowrite16(vq->index, &vp_dev->common->queue_select); + iowrite8(1, &vp_dev->common->queue_enable); + } + + return 0; +} + +static void del_vq(struct virtio_pci_vq_info *info) +{ + struct virtqueue *vq = info->vq; + struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev); + + iowrite16(vq->index, &vp_dev->common->queue_select); + + if (vp_dev->msix_enabled) { + iowrite16(VIRTIO_MSI_NO_VECTOR, + &vp_dev->common->queue_msix_vector); + /* Flush the write out to device */ + ioread16(&vp_dev->common->queue_msix_vector); + } + + pci_iounmap(vp_dev->pci_dev, (void __force __iomem *)vq->priv); + + vring_del_virtqueue(vq); + + free_pages_exact(info->queue, vring_pci_size(info->num)); +} + +static const struct virtio_config_ops virtio_pci_config_ops = { + .get = vp_get, + .set = vp_set, + .generation = vp_generation, + .get_status = vp_get_status, + .set_status = vp_set_status, + .reset = vp_reset, + .find_vqs = vp_modern_find_vqs, + .del_vqs = vp_del_vqs, + .get_features = vp_get_features, + .finalize_features = vp_finalize_features, + .bus_name = vp_bus_name, + .set_vq_affinity = vp_set_vq_affinity, +}; + +/** + * 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. + * + * 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 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) + return pos; + } + } + return 0; +} + +static void virtio_pci_release_dev(struct device *_d) +{ + struct virtio_device *vdev = dev_to_virtio(_d); + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + + kfree(vp_dev); +} + +/* TODO: validate the ABI statically. */ +static inline void check_offsets(void) +{ +} + +/* the PCI probing function */ +int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev) +{ + struct pci_dev *pci_dev = vp_dev->pci_dev; + int err, common, isr, notify, device; + u32 notify_length; + + check_offsets(); + + /* 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. + */ + vp_dev->vdev.id.device = pci_dev->subsystem_device; + } else { + /* Modern devices: simply use PCI device id, but start from 0x1040. */ + vp_dev->vdev.id.device = pci_dev->device - 0x1040; + } + vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor; + + if (virtio_device_is_legacy_only(vp_dev->vdev.id)) + return -ENODEV; + + /* 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); + 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); + notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG, + IORESOURCE_IO | IORESOURCE_MEM); + if (!isr || !notify) { + dev_err(&pci_dev->dev, + "virtio_pci: missing capabilities %i/%i/%i\n", + common, isr, notify); + return -EINVAL; + } + + /* 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); + + err = -EINVAL; + vp_dev->common = map_capability(pci_dev, common, + sizeof(struct virtio_pci_common_cfg), 4, + 0, sizeof(struct virtio_pci_common_cfg), + NULL); + if (!vp_dev->common) + goto err_map_common; + vp_dev->isr = map_capability(pci_dev, isr, sizeof(u8), 1, + 0, 1, + NULL); + if (!vp_dev->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), + &vp_dev->notify_offset_multiplier); + /* Read notify length from config space. */ + pci_read_config_dword(pci_dev, + notify + offsetof(struct virtio_pci_notify_cap, + cap.length), + ¬ify_length); + + vp_dev->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) { + vp_dev->device = map_capability(pci_dev, device, 0, 4, + 0, PAGE_SIZE, + &vp_dev->device_len); + if (!vp_dev->device) + goto err_map_device; + } + + vp_dev->vdev.config = &virtio_pci_config_ops; + + vp_dev->config_vector = vp_config_vector; + vp_dev->setup_vq = setup_vq; + vp_dev->del_vq = del_vq; + + return 0; + +err_map_device: + pci_iounmap(pci_dev, vp_dev->isr); +err_map_isr: + pci_iounmap(pci_dev, vp_dev->common); +err_map_common: + return err; +} + +void virtio_pci_modern_remove(struct virtio_pci_device *vp_dev) +{ + struct pci_dev *pci_dev = vp_dev->pci_dev; + + if (vp_dev->device) + pci_iounmap(pci_dev, vp_dev->device); + pci_iounmap(pci_dev, vp_dev->isr); + pci_iounmap(pci_dev, vp_dev->common); +} diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h index 4e054235358f..a2b2e1353e30 100644 --- a/include/uapi/linux/virtio_pci.h +++ b/include/uapi/linux/virtio_pci.h @@ -117,10 +117,11 @@ struct virtio_pci_cap { __u8 cap_vndr; /* Generic PCI field: PCI_CAP_ID_VNDR */ __u8 cap_next; /* Generic PCI field: next ptr. */ __u8 cap_len; /* Generic PCI field: capability length */ - __u8 type_and_bar; /* Upper 3 bits: bar. - * Lower 3 is VIRTIO_PCI_CAP_*_CFG. */ + __u8 cfg_type; /* Identifies the structure. */ + __u8 bar; /* Where to find it. */ + __u8 padding[3]; /* Pad to full dword. */ __le32 offset; /* Offset within bar. */ - __le32 length; /* Length. */ + __le32 length; /* Length of the structure, in bytes. */ }; #define VIRTIO_PCI_CAP_BAR_SHIFT 5 -- cgit v1.2.3 From 3909213cfd9224cb1827d557fb6eb5ebdb8ddcbe Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Wed, 14 Jan 2015 18:50:55 +0200 Subject: virtio_pci_modern: reduce number of mappings We don't know the # of VQs that drivers are going to use so it's hard to predict how much memory we'll need to map. However, the relevant capability does give us an upper limit. If that's below a page, we can reduce the number of required mappings by mapping it all once ahead of the time. Signed-off-by: Michael S. Tsirkin Signed-off-by: Rusty Russell --- drivers/virtio/virtio_pci_common.h | 3 ++ drivers/virtio/virtio_pci_modern.c | 57 ++++++++++++++++++++++++++++++++------ 2 files changed, 52 insertions(+), 8 deletions(-) (limited to 'drivers/virtio/virtio_pci_common.h') diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h index 610c43f19230..d39180512761 100644 --- a/drivers/virtio/virtio_pci_common.h +++ b/drivers/virtio/virtio_pci_common.h @@ -62,8 +62,11 @@ struct virtio_pci_device { 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; /* So we can sanity-check accesses. */ + size_t notify_len; size_t device_len; /* Capability for when we need to map notifications per-vq. */ diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c index b2e707ad81cf..0e54cc88fdf5 100644 --- a/drivers/virtio/virtio_pci_modern.c +++ b/drivers/virtio/virtio_pci_modern.c @@ -330,10 +330,26 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, iowrite64_twopart(virt_to_phys(virtqueue_get_used(vq)), &cfg->queue_used_lo, &cfg->queue_used_hi); - vq->priv = (void __force *)map_capability(vp_dev->pci_dev, - vp_dev->notify_map_cap, 2, 2, - off * vp_dev->notify_offset_multiplier, 2, - NULL); + if (vp_dev->notify_base) { + /* offset should not wrap */ + if ((u64)off * vp_dev->notify_offset_multiplier + 2 + > vp_dev->notify_len) { + dev_warn(&vp_dev->pci_dev->dev, + "bad notification offset %u (x %u) " + "for queue %u > %zd", + off, vp_dev->notify_offset_multiplier, + index, vp_dev->notify_len); + err = -EINVAL; + goto err_map_notify; + } + vq->priv = (void __force *)vp_dev->notify_base + + off * vp_dev->notify_offset_multiplier; + } else { + vq->priv = (void __force *)map_capability(vp_dev->pci_dev, + vp_dev->notify_map_cap, 2, 2, + off * vp_dev->notify_offset_multiplier, 2, + NULL); + } if (!vq->priv) { err = -ENOMEM; @@ -352,7 +368,8 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, return vq; err_assign_vector: - pci_iounmap(vp_dev->pci_dev, (void __iomem __force *)vq->priv); + if (!vp_dev->notify_base) + pci_iounmap(vp_dev->pci_dev, (void __iomem __force *)vq->priv); err_map_notify: vring_del_virtqueue(vq); err_new_queue: @@ -397,7 +414,8 @@ static void del_vq(struct virtio_pci_vq_info *info) ioread16(&vp_dev->common->queue_msix_vector); } - pci_iounmap(vp_dev->pci_dev, (void __force __iomem *)vq->priv); + if (!vp_dev->notify_base) + pci_iounmap(vp_dev->pci_dev, (void __force __iomem *)vq->priv); vring_del_virtqueue(vq); @@ -533,6 +551,7 @@ int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev) struct pci_dev *pci_dev = vp_dev->pci_dev; int err, common, isr, notify, device; u32 notify_length; + u32 notify_offset; check_offsets(); @@ -599,13 +618,30 @@ int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev) notify + offsetof(struct virtio_pci_notify_cap, notify_off_multiplier), &vp_dev->notify_offset_multiplier); - /* Read notify length from config space. */ + /* Read notify length and offset from config space. */ pci_read_config_dword(pci_dev, notify + offsetof(struct virtio_pci_notify_cap, cap.length), ¬ify_length); - vp_dev->notify_map_cap = notify; + pci_read_config_dword(pci_dev, + notify + offsetof(struct virtio_pci_notify_cap, + cap.length), + ¬ify_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) { + vp_dev->notify_base = map_capability(pci_dev, notify, 2, 2, + 0, notify_length, + &vp_dev->notify_len); + if (!vp_dev->notify_base) + goto err_map_notify; + } else { + vp_dev->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. @@ -627,6 +663,9 @@ int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev) return 0; err_map_device: + if (vp_dev->notify_base) + pci_iounmap(pci_dev, vp_dev->notify_base); +err_map_notify: pci_iounmap(pci_dev, vp_dev->isr); err_map_isr: pci_iounmap(pci_dev, vp_dev->common); @@ -640,6 +679,8 @@ void virtio_pci_modern_remove(struct virtio_pci_device *vp_dev) if (vp_dev->device) pci_iounmap(pci_dev, vp_dev->device); + if (vp_dev->notify_base) + pci_iounmap(pci_dev, vp_dev->notify_base); pci_iounmap(pci_dev, vp_dev->isr); pci_iounmap(pci_dev, vp_dev->common); } -- cgit v1.2.3 From 46506da5f365efe7fe3e4c9da73ab679c0382fac Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 15 Jan 2015 16:06:26 +0200 Subject: virtio_pci: add an option to disable legacy driver Useful for testing device virtio 1 compatibility. Based on patch by Rusty - couldn't resist putting that flying car joke in there! Signed-off-by: Michael S. Tsirkin Signed-off-by: Rusty Russell --- drivers/virtio/Kconfig | 19 +++++++++++++++++++ drivers/virtio/Makefile | 3 ++- drivers/virtio/virtio_pci_common.h | 10 ++++++++++ 3 files changed, 31 insertions(+), 1 deletion(-) (limited to 'drivers/virtio/virtio_pci_common.h') diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index 083fb45950f5..b546da5d8ea3 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -19,6 +19,25 @@ config VIRTIO_PCI If unsure, say M. +config VIRTIO_PCI_LEGACY + bool "Support for legacy virtio draft 0.9.X and older devices" + default y + depends on VIRTIO_PCI + ---help--- + Virtio PCI Card 0.9.X Draft (circa 2014) and older device support. + + This option enables building a transitional driver, supporting + both devices conforming to Virtio 1 specification, and legacy devices. + If disabled, you get a slightly smaller, non-transitional driver, + with no legacy compatibility. + + So look out into your driveway. Do you have a flying car? If + so, you can happily disable this option and virtio will not + break. Otherwise, leave it set. Unless you're testing what + life will be like in The Future. + + If unsure, say Y. + config VIRTIO_BALLOON tristate "Virtio balloon driver" depends on VIRTIO diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile index bd230d1c0533..d85565b8ea46 100644 --- a/drivers/virtio/Makefile +++ b/drivers/virtio/Makefile @@ -1,5 +1,6 @@ obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o -virtio_pci-y := virtio_pci_modern.o virtio_pci_legacy.o virtio_pci_common.o +virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o +virtio_pci-$(CONFIG_VIRTIO_PCI_LEGACY) += virtio_pci_legacy.o obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h index d39180512761..28ee4e56badf 100644 --- a/drivers/virtio/virtio_pci_common.h +++ b/drivers/virtio/virtio_pci_common.h @@ -147,8 +147,18 @@ const char *vp_bus_name(struct virtio_device *vdev); */ int vp_set_vq_affinity(struct virtqueue *vq, int cpu); +#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY) int virtio_pci_legacy_probe(struct virtio_pci_device *); void virtio_pci_legacy_remove(struct virtio_pci_device *); +#else +static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev) +{ + return -ENODEV; +} +static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev) +{ +} +#endif int virtio_pci_modern_probe(struct virtio_pci_device *); void virtio_pci_modern_remove(struct virtio_pci_device *); -- cgit v1.2.3