struct tran_int_desc int_desc;
} __packed;
+/*
+ * Note: the VM must pass a valid block id, wslot and bytes_requested.
+ */
+struct pci_read_block {
+ struct pci_message message_type;
+ u32 block_id;
+ union win_slot_encoding wslot;
+ u32 bytes_requested;
+} __packed;
+
+struct pci_read_block_response {
+ struct vmpacket_descriptor hdr;
+ u32 status;
+ u8 bytes[HV_CONFIG_BLOCK_SIZE_MAX];
+} __packed;
+
+/*
+ * Note: the VM must pass a valid block id, wslot and byte_count.
+ */
+struct pci_write_block {
+ struct pci_message message_type;
+ u32 block_id;
+ union win_slot_encoding wslot;
+ u32 byte_count;
+ u8 bytes[HV_CONFIG_BLOCK_SIZE_MAX];
+} __packed;
+
+struct pci_dev_inval_block {
+ struct pci_incoming_message incoming;
+ union win_slot_encoding wslot;
+ u64 block_mask;
+} __packed;
+
struct pci_dev_incoming {
struct pci_incoming_message incoming;
union win_slot_encoding wslot;
struct hv_pcibus_device *hbus;
struct work_struct wrk;
+ void (*block_invalidate)(void *context, u64 block_mask);
+ void *invalidate_context;
+
/*
* What would be observed if one wrote 0xFFFFFFFF to a BAR and then
* read it back, for each of the BAR offsets within config space.
.write = hv_pcifront_write_config,
};
+/*
+ * Paravirtual backchannel
+ *
+ * Hyper-V SR-IOV provides a backchannel mechanism in software for
+ * communication between a VF driver and a PF driver. These
+ * "configuration blocks" are similar in concept to PCI configuration space,
+ * but instead of doing reads and writes in 32-bit chunks through a very slow
+ * path, packets of up to 128 bytes can be sent or received asynchronously.
+ *
+ * Nearly every SR-IOV device contains just such a communications channel in
+ * hardware, so using this one in software is usually optional. Using the
+ * software channel, however, allows driver implementers to leverage software
+ * tools that fuzz the communications channel looking for vulnerabilities.
+ *
+ * The usage model for these packets puts the responsibility for reading or
+ * writing on the VF driver. The VF driver sends a read or a write packet,
+ * indicating which "block" is being referred to by number.
+ *
+ * If the PF driver wishes to initiate communication, it can "invalidate" one or
+ * more of the first 64 blocks. This invalidation is delivered via a callback
+ * supplied by the VF driver by this driver.
+ *
+ * No protocol is implied, except that supplied by the PF and VF drivers.
+ */
+
+struct hv_read_config_compl {
+ struct hv_pci_compl comp_pkt;
+ void *buf;
+ unsigned int len;
+ unsigned int bytes_returned;
+};
+
+/**
+ * hv_pci_read_config_compl() - Invoked when a response packet
+ * for a read config block operation arrives.
+ * @context: Identifies the read config operation
+ * @resp: The response packet itself
+ * @resp_packet_size: Size in bytes of the response packet
+ */
+static void hv_pci_read_config_compl(void *context, struct pci_response *resp,
+ int resp_packet_size)
+{
+ struct hv_read_config_compl *comp = context;
+ struct pci_read_block_response *read_resp =
+ (struct pci_read_block_response *)resp;
+ unsigned int data_len, hdr_len;
+
+ hdr_len = offsetof(struct pci_read_block_response, bytes);
+ if (resp_packet_size < hdr_len) {
+ comp->comp_pkt.completion_status = -1;
+ goto out;
+ }
+
+ data_len = resp_packet_size - hdr_len;
+ if (data_len > 0 && read_resp->status == 0) {
+ comp->bytes_returned = min(comp->len, data_len);
+ memcpy(comp->buf, read_resp->bytes, comp->bytes_returned);
+ } else {
+ comp->bytes_returned = 0;
+ }
+
+ comp->comp_pkt.completion_status = read_resp->status;
+out:
+ complete(&comp->comp_pkt.host_event);
+}
+
+/**
+ * hv_read_config_block() - Sends a read config block request to
+ * the back-end driver running in the Hyper-V parent partition.
+ * @pdev: The PCI driver's representation for this device.
+ * @buf: Buffer into which the config block will be copied.
+ * @len: Size in bytes of buf.
+ * @block_id: Identifies the config block which has been requested.
+ * @bytes_returned: Size which came back from the back-end driver.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int hv_read_config_block(struct pci_dev *pdev, void *buf, unsigned int len,
+ unsigned int block_id, unsigned int *bytes_returned)
+{
+ struct hv_pcibus_device *hbus =
+ container_of(pdev->bus->sysdata, struct hv_pcibus_device,
+ sysdata);
+ struct {
+ struct pci_packet pkt;
+ char buf[sizeof(struct pci_read_block)];
+ } pkt;
+ struct hv_read_config_compl comp_pkt;
+ struct pci_read_block *read_blk;
+ int ret;
+
+ if (len == 0 || len > HV_CONFIG_BLOCK_SIZE_MAX)
+ return -EINVAL;
+
+ init_completion(&comp_pkt.comp_pkt.host_event);
+ comp_pkt.buf = buf;
+ comp_pkt.len = len;
+
+ memset(&pkt, 0, sizeof(pkt));
+ pkt.pkt.completion_func = hv_pci_read_config_compl;
+ pkt.pkt.compl_ctxt = &comp_pkt;
+ read_blk = (struct pci_read_block *)&pkt.pkt.message;
+ read_blk->message_type.type = PCI_READ_BLOCK;
+ read_blk->wslot.slot = devfn_to_wslot(pdev->devfn);
+ read_blk->block_id = block_id;
+ read_blk->bytes_requested = len;
+
+ ret = vmbus_sendpacket(hbus->hdev->channel, read_blk,
+ sizeof(*read_blk), (unsigned long)&pkt.pkt,
+ VM_PKT_DATA_INBAND,
+ VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+ if (ret)
+ return ret;
+
+ ret = wait_for_response(hbus->hdev, &comp_pkt.comp_pkt.host_event);
+ if (ret)
+ return ret;
+
+ if (comp_pkt.comp_pkt.completion_status != 0 ||
+ comp_pkt.bytes_returned == 0) {
+ dev_err(&hbus->hdev->device,
+ "Read Config Block failed: 0x%x, bytes_returned=%d\n",
+ comp_pkt.comp_pkt.completion_status,
+ comp_pkt.bytes_returned);
+ return -EIO;
+ }
+
+ *bytes_returned = comp_pkt.bytes_returned;
+ return 0;
+}
+EXPORT_SYMBOL(hv_read_config_block);
+
+/**
+ * hv_pci_write_config_compl() - Invoked when a response packet for a write
+ * config block operation arrives.
+ * @context: Identifies the write config operation
+ * @resp: The response packet itself
+ * @resp_packet_size: Size in bytes of the response packet
+ */
+static void hv_pci_write_config_compl(void *context, struct pci_response *resp,
+ int resp_packet_size)
+{
+ struct hv_pci_compl *comp_pkt = context;
+
+ comp_pkt->completion_status = resp->status;
+ complete(&comp_pkt->host_event);
+}
+
+/**
+ * hv_write_config_block() - Sends a write config block request to the
+ * back-end driver running in the Hyper-V parent partition.
+ * @pdev: The PCI driver's representation for this device.
+ * @buf: Buffer from which the config block will be copied.
+ * @len: Size in bytes of buf.
+ * @block_id: Identifies the config block which is being written.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int hv_write_config_block(struct pci_dev *pdev, void *buf, unsigned int len,
+ unsigned int block_id)
+{
+ struct hv_pcibus_device *hbus =
+ container_of(pdev->bus->sysdata, struct hv_pcibus_device,
+ sysdata);
+ struct {
+ struct pci_packet pkt;
+ char buf[sizeof(struct pci_write_block)];
+ u32 reserved;
+ } pkt;
+ struct hv_pci_compl comp_pkt;
+ struct pci_write_block *write_blk;
+ u32 pkt_size;
+ int ret;
+
+ if (len == 0 || len > HV_CONFIG_BLOCK_SIZE_MAX)
+ return -EINVAL;
+
+ init_completion(&comp_pkt.host_event);
+
+ memset(&pkt, 0, sizeof(pkt));
+ pkt.pkt.completion_func = hv_pci_write_config_compl;
+ pkt.pkt.compl_ctxt = &comp_pkt;
+ write_blk = (struct pci_write_block *)&pkt.pkt.message;
+ write_blk->message_type.type = PCI_WRITE_BLOCK;
+ write_blk->wslot.slot = devfn_to_wslot(pdev->devfn);
+ write_blk->block_id = block_id;
+ write_blk->byte_count = len;
+ memcpy(write_blk->bytes, buf, len);
+ pkt_size = offsetof(struct pci_write_block, bytes) + len;
+ /*
+ * This quirk is required on some hosts shipped around 2018, because
+ * these hosts don't check the pkt_size correctly (new hosts have been
+ * fixed since early 2019). The quirk is also safe on very old hosts
+ * and new hosts, because, on them, what really matters is the length
+ * specified in write_blk->byte_count.
+ */
+ pkt_size += sizeof(pkt.reserved);
+
+ ret = vmbus_sendpacket(hbus->hdev->channel, write_blk, pkt_size,
+ (unsigned long)&pkt.pkt, VM_PKT_DATA_INBAND,
+ VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+ if (ret)
+ return ret;
+
+ ret = wait_for_response(hbus->hdev, &comp_pkt.host_event);
+ if (ret)
+ return ret;
+
+ if (comp_pkt.completion_status != 0) {
+ dev_err(&hbus->hdev->device,
+ "Write Config Block failed: 0x%x\n",
+ comp_pkt.completion_status);
+ return -EIO;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(hv_write_config_block);
+
+/**
+ * hv_register_block_invalidate() - Invoked when a config block invalidation
+ * arrives from the back-end driver.
+ * @pdev: The PCI driver's representation for this device.
+ * @context: Identifies the device.
+ * @block_invalidate: Identifies all of the blocks being invalidated.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int hv_register_block_invalidate(struct pci_dev *pdev, void *context,
+ void (*block_invalidate)(void *context,
+ u64 block_mask))
+{
+ struct hv_pcibus_device *hbus =
+ container_of(pdev->bus->sysdata, struct hv_pcibus_device,
+ sysdata);
+ struct hv_pci_dev *hpdev;
+
+ hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
+ if (!hpdev)
+ return -ENODEV;
+
+ hpdev->block_invalidate = block_invalidate;
+ hpdev->invalidate_context = context;
+
+ put_pcichild(hpdev);
+ return 0;
+
+}
+EXPORT_SYMBOL(hv_register_block_invalidate);
+
/* Interrupt management hooks */
static void hv_int_desc_free(struct hv_pci_dev *hpdev,
struct tran_int_desc *int_desc)
struct pci_response *response;
struct pci_incoming_message *new_message;
struct pci_bus_relations *bus_rel;
+ struct pci_dev_inval_block *inval;
struct pci_dev_incoming *dev_message;
struct hv_pci_dev *hpdev;
}
break;
+ case PCI_INVALIDATE_BLOCK:
+
+ inval = (struct pci_dev_inval_block *)buffer;
+ hpdev = get_pcichild_wslot(hbus,
+ inval->wslot.slot);
+ if (hpdev) {
+ if (hpdev->block_invalidate) {
+ hpdev->block_invalidate(
+ hpdev->invalidate_context,
+ inval->block_mask);
+ }
+ put_pcichild(hpdev);
+ }
+ break;
+
default:
dev_warn(&hbus->hdev->device,
"Unimplemented protocol message %x\n",
projects / openwrt / staging / blogic.git / commitdiff