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-rw-r--r--drivers/virtio/virtio_mmio.c31
-rw-r--r--drivers/virtio/virtio_pci_modern.c95
-rw-r--r--include/linux/virtio_config.h17
-rw-r--r--include/uapi/linux/virtio_mmio.h11
-rw-r--r--include/uapi/linux/virtio_pci.h11
5 files changed, 164 insertions, 1 deletions
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 627ac0487494..238383ff1064 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -498,6 +498,36 @@ static const char *vm_bus_name(struct virtio_device *vdev)
return vm_dev->pdev->name;
}
+static bool vm_get_shm_region(struct virtio_device *vdev,
+ struct virtio_shm_region *region, u8 id)
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+ u64 len, addr;
+
+ /* Select the region we're interested in */
+ writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL);
+
+ /* Read the region size */
+ len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW);
+ len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32;
+
+ region->len = len;
+
+ /* Check if region length is -1. If that's the case, the shared memory
+ * region does not exist and there is no need to proceed further.
+ */
+ if (len == ~(u64)0)
+ return false;
+
+ /* Read the region base address */
+ addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW);
+ addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32;
+
+ region->addr = addr;
+
+ return true;
+}
+
static const struct virtio_config_ops virtio_mmio_config_ops = {
.get = vm_get,
.set = vm_set,
@@ -510,6 +540,7 @@ static const struct virtio_config_ops virtio_mmio_config_ops = {
.get_features = vm_get_features,
.finalize_features = vm_finalize_features,
.bus_name = vm_bus_name,
+ .get_shm_region = vm_get_shm_region,
};
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index 3e14e700b231..3d6ae5a5e252 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -444,6 +444,99 @@ static void del_vq(struct virtio_pci_vq_info *info)
vring_del_virtqueue(vq);
}
+static int virtio_pci_find_shm_cap(struct pci_dev *dev, u8 required_id,
+ u8 *bar, u64 *offset, u64 *len)
+{
+ 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, cap_len, id;
+ u32 tmp32;
+ u64 res_offset, res_length;
+
+ pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
+ cfg_type), &type);
+ if (type != VIRTIO_PCI_CAP_SHARED_MEMORY_CFG)
+ continue;
+
+ pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
+ cap_len), &cap_len);
+ if (cap_len != sizeof(struct virtio_pci_cap64)) {
+ dev_err(&dev->dev, "%s: shm cap with bad size offset:"
+ " %d size: %d\n", __func__, pos, cap_len);
+ continue;
+ }
+
+ pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
+ id), &id);
+ if (id != required_id)
+ continue;
+
+ /* Type, and ID match, looks good */
+ pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
+ bar), bar);
+
+ /* Read the lower 32bit of length and offset */
+ pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap,
+ offset), &tmp32);
+ res_offset = tmp32;
+ pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap,
+ length), &tmp32);
+ res_length = tmp32;
+
+ /* and now the top half */
+ pci_read_config_dword(dev,
+ pos + offsetof(struct virtio_pci_cap64,
+ offset_hi), &tmp32);
+ res_offset |= ((u64)tmp32) << 32;
+ pci_read_config_dword(dev,
+ pos + offsetof(struct virtio_pci_cap64,
+ length_hi), &tmp32);
+ res_length |= ((u64)tmp32) << 32;
+
+ *offset = res_offset;
+ *len = res_length;
+
+ return pos;
+ }
+ return 0;
+}
+
+static bool vp_get_shm_region(struct virtio_device *vdev,
+ struct virtio_shm_region *region, u8 id)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ struct pci_dev *pci_dev = vp_dev->pci_dev;
+ u8 bar;
+ u64 offset, len;
+ phys_addr_t phys_addr;
+ size_t bar_len;
+
+ if (!virtio_pci_find_shm_cap(pci_dev, id, &bar, &offset, &len))
+ return false;
+
+ phys_addr = pci_resource_start(pci_dev, bar);
+ bar_len = pci_resource_len(pci_dev, bar);
+
+ if ((offset + len) < offset) {
+ dev_err(&pci_dev->dev, "%s: cap offset+len overflow detected\n",
+ __func__);
+ return false;
+ }
+
+ if (offset + len > bar_len) {
+ dev_err(&pci_dev->dev, "%s: bar shorter than cap offset+len\n",
+ __func__);
+ return false;
+ }
+
+ region->len = len;
+ region->addr = (u64) phys_addr + offset;
+
+ return true;
+}
+
static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
.get = NULL,
.set = NULL,
@@ -458,6 +551,7 @@ static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
.bus_name = vp_bus_name,
.set_vq_affinity = vp_set_vq_affinity,
.get_vq_affinity = vp_get_vq_affinity,
+ .get_shm_region = vp_get_shm_region,
};
static const struct virtio_config_ops virtio_pci_config_ops = {
@@ -474,6 +568,7 @@ static const struct virtio_config_ops virtio_pci_config_ops = {
.bus_name = vp_bus_name,
.set_vq_affinity = vp_set_vq_affinity,
.get_vq_affinity = vp_get_vq_affinity,
+ .get_shm_region = vp_get_shm_region,
};
/**
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 8fe857e27ef3..4b8e38c5c4d8 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -11,6 +11,11 @@
struct irq_affinity;
+struct virtio_shm_region {
+ u64 addr;
+ u64 len;
+};
+
/**
* virtio_config_ops - operations for configuring a virtio device
* Note: Do not assume that a transport implements all of the operations
@@ -66,6 +71,7 @@ struct irq_affinity;
* the caller can then copy.
* @set_vq_affinity: set the affinity for a virtqueue (optional).
* @get_vq_affinity: get the affinity for a virtqueue (optional).
+ * @get_shm_region: get a shared memory region based on the index.
*/
typedef void vq_callback_t(struct virtqueue *);
struct virtio_config_ops {
@@ -89,6 +95,8 @@ struct virtio_config_ops {
const struct cpumask *cpu_mask);
const struct cpumask *(*get_vq_affinity)(struct virtio_device *vdev,
int index);
+ bool (*get_shm_region)(struct virtio_device *vdev,
+ struct virtio_shm_region *region, u8 id);
};
/* If driver didn't advertise the feature, it will never appear. */
@@ -251,6 +259,15 @@ int virtqueue_set_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask)
return 0;
}
+static inline
+bool virtio_get_shm_region(struct virtio_device *vdev,
+ struct virtio_shm_region *region, u8 id)
+{
+ if (!vdev->config->get_shm_region)
+ return false;
+ return vdev->config->get_shm_region(vdev, region, id);
+}
+
static inline bool virtio_is_little_endian(struct virtio_device *vdev)
{
return virtio_has_feature(vdev, VIRTIO_F_VERSION_1) ||
diff --git a/include/uapi/linux/virtio_mmio.h b/include/uapi/linux/virtio_mmio.h
index c4b09689ab64..0650f91bea6c 100644
--- a/include/uapi/linux/virtio_mmio.h
+++ b/include/uapi/linux/virtio_mmio.h
@@ -122,6 +122,17 @@
#define VIRTIO_MMIO_QUEUE_USED_LOW 0x0a0
#define VIRTIO_MMIO_QUEUE_USED_HIGH 0x0a4
+/* Shared memory region id */
+#define VIRTIO_MMIO_SHM_SEL 0x0ac
+
+/* Shared memory region length, 64 bits in two halves */
+#define VIRTIO_MMIO_SHM_LEN_LOW 0x0b0
+#define VIRTIO_MMIO_SHM_LEN_HIGH 0x0b4
+
+/* Shared memory region base address, 64 bits in two halves */
+#define VIRTIO_MMIO_SHM_BASE_LOW 0x0b8
+#define VIRTIO_MMIO_SHM_BASE_HIGH 0x0bc
+
/* Configuration atomicity value */
#define VIRTIO_MMIO_CONFIG_GENERATION 0x0fc
diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h
index 90007a1abcab..3a86f36d7e3d 100644
--- a/include/uapi/linux/virtio_pci.h
+++ b/include/uapi/linux/virtio_pci.h
@@ -113,6 +113,8 @@
#define VIRTIO_PCI_CAP_DEVICE_CFG 4
/* PCI configuration access */
#define VIRTIO_PCI_CAP_PCI_CFG 5
+/* Additional shared memory capability */
+#define VIRTIO_PCI_CAP_SHARED_MEMORY_CFG 8
/* This is the PCI capability header: */
struct virtio_pci_cap {
@@ -121,11 +123,18 @@ struct virtio_pci_cap {
__u8 cap_len; /* Generic PCI field: capability length */
__u8 cfg_type; /* Identifies the structure. */
__u8 bar; /* Where to find it. */
- __u8 padding[3]; /* Pad to full dword. */
+ __u8 id; /* Multiple capabilities of the same type */
+ __u8 padding[2]; /* Pad to full dword. */
__le32 offset; /* Offset within bar. */
__le32 length; /* Length of the structure, in bytes. */
};
+struct virtio_pci_cap64 {
+ struct virtio_pci_cap cap;
+ __le32 offset_hi; /* Most sig 32 bits of offset */
+ __le32 length_hi; /* Most sig 32 bits of length */
+};
+
struct virtio_pci_notify_cap {
struct virtio_pci_cap cap;
__le32 notify_off_multiplier; /* Multiplier for queue_notify_off. */