diff options
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/pci/controller/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/pci/controller/Makefile | 1 | ||||
| -rw-r--r-- | drivers/pci/controller/pci-hyperv-intf.c | 67 | ||||
| -rw-r--r-- | drivers/pci/controller/pci-hyperv.c | 308 |
5 files changed, 384 insertions, 0 deletions
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index 2ab92409210a..c313de96a357 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -182,6 +182,7 @@ config PCI_LABEL config PCI_HYPERV tristate "Hyper-V PCI Frontend" depends on X86 && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && X86_64 + select PCI_HYPERV_INTERFACE help The PCI device frontend driver allows the kernel to import arbitrary PCI devices from a PCI backend to support PCI driver domains. diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig index fe9f9f13ce11..70e078238899 100644 --- a/drivers/pci/controller/Kconfig +++ b/drivers/pci/controller/Kconfig @@ -281,5 +281,12 @@ config VMD To compile this driver as a module, choose M here: the module will be called vmd. +config PCI_HYPERV_INTERFACE + tristate "Hyper-V PCI Interface" + depends on X86 && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && X86_64 + help + The Hyper-V PCI Interface is a helper driver allows other drivers to + have a common interface with the Hyper-V PCI frontend driver. + source "drivers/pci/controller/dwc/Kconfig" endmenu diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile index d56a507495c5..a2a22c9d91af 100644 --- a/drivers/pci/controller/Makefile +++ b/drivers/pci/controller/Makefile @@ -4,6 +4,7 @@ obj-$(CONFIG_PCIE_CADENCE_HOST) += pcie-cadence-host.o obj-$(CONFIG_PCIE_CADENCE_EP) += pcie-cadence-ep.o obj-$(CONFIG_PCI_FTPCI100) += pci-ftpci100.o obj-$(CONFIG_PCI_HYPERV) += pci-hyperv.o +obj-$(CONFIG_PCI_HYPERV_INTERFACE) += pci-hyperv-intf.o obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o obj-$(CONFIG_PCI_AARDVARK) += pci-aardvark.o obj-$(CONFIG_PCI_TEGRA) += pci-tegra.o diff --git a/drivers/pci/controller/pci-hyperv-intf.c b/drivers/pci/controller/pci-hyperv-intf.c new file mode 100644 index 000000000000..cc96be450360 --- /dev/null +++ b/drivers/pci/controller/pci-hyperv-intf.c @@ -0,0 +1,67 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) Microsoft Corporation. + * + * Author: + * Haiyang Zhang <haiyangz@microsoft.com> + * + * This small module is a helper driver allows other drivers to + * have a common interface with the Hyper-V PCI frontend driver. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/hyperv.h> + +struct hyperv_pci_block_ops hvpci_block_ops; +EXPORT_SYMBOL_GPL(hvpci_block_ops); + +int hyperv_read_cfg_blk(struct pci_dev *dev, void *buf, unsigned int buf_len, + unsigned int block_id, unsigned int *bytes_returned) +{ + if (!hvpci_block_ops.read_block) + return -EOPNOTSUPP; + + return hvpci_block_ops.read_block(dev, buf, buf_len, block_id, + bytes_returned); +} +EXPORT_SYMBOL_GPL(hyperv_read_cfg_blk); + +int hyperv_write_cfg_blk(struct pci_dev *dev, void *buf, unsigned int len, + unsigned int block_id) +{ + if (!hvpci_block_ops.write_block) + return -EOPNOTSUPP; + + return hvpci_block_ops.write_block(dev, buf, len, block_id); +} +EXPORT_SYMBOL_GPL(hyperv_write_cfg_blk); + +int hyperv_reg_block_invalidate(struct pci_dev *dev, void *context, + void (*block_invalidate)(void *context, + u64 block_mask)) +{ + if (!hvpci_block_ops.reg_blk_invalidate) + return -EOPNOTSUPP; + + return hvpci_block_ops.reg_blk_invalidate(dev, context, + block_invalidate); +} +EXPORT_SYMBOL_GPL(hyperv_reg_block_invalidate); + +static void __exit exit_hv_pci_intf(void) +{ +} + +static int __init init_hv_pci_intf(void) +{ + return 0; +} + +module_init(init_hv_pci_intf); +module_exit(exit_hv_pci_intf); + +MODULE_DESCRIPTION("Hyper-V PCI Interface"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c index 97056f3dd317..0ca73c851e0f 100644 --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -365,6 +365,39 @@ struct pci_delete_interrupt { 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; @@ -499,6 +532,9 @@ struct hv_pci_dev { 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. @@ -817,6 +853,253 @@ static struct pci_ops hv_pcifront_ops = { .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; +} + +/** + * 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; +} + +/** + * 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; + +} + /* Interrupt management hooks */ static void hv_int_desc_free(struct hv_pci_dev *hpdev, struct tran_int_desc *int_desc) @@ -1968,6 +2251,7 @@ static void hv_pci_onchannelcallback(void *context) 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; @@ -2045,6 +2329,21 @@ static void hv_pci_onchannelcallback(void *context) } 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", @@ -2751,10 +3050,19 @@ static struct hv_driver hv_pci_drv = { static void __exit exit_hv_pci_drv(void) { vmbus_driver_unregister(&hv_pci_drv); + + hvpci_block_ops.read_block = NULL; + hvpci_block_ops.write_block = NULL; + hvpci_block_ops.reg_blk_invalidate = NULL; } static int __init init_hv_pci_drv(void) { + /* Initialize PCI block r/w interface */ + hvpci_block_ops.read_block = hv_read_config_block; + hvpci_block_ops.write_block = hv_write_config_block; + hvpci_block_ops.reg_blk_invalidate = hv_register_block_invalidate; + return vmbus_driver_register(&hv_pci_drv); } |