There are two components to establishing an encrypted link, provisioning the stream in Partner Port config-space, and programming the keys into the link layer via IDE_KM (IDE Key Management). This new library, drivers/pci/ide.c, enables the former. IDE_KM, via a TSM low-level driver, is saved for later. With the platform TSM implementations of SEV-TIO and TDX Connect in mind this library abstracts small differences in those implementations. For example, TDX Connect handles Root Port register setup while SEV-TIO expects System Software to update the Root Port registers. This is the rationale for fine-grained 'setup' + 'enable' verbs. The other design detail for TSM-coordinated IDE establishment is that the TSM may manage allocation of Stream IDs, this is why the Stream ID value is passed in to pci_ide_stream_setup(). The flow is: pci_ide_stream_alloc() Allocate a Selective IDE Stream Register Block in each Partner Port (Endpoint + Root Port), and reserve a host bridge / platform stream slot. Gather Partner Port specific stream settings like Requester ID. pci_ide_stream_register() Publish the stream in sysfs after allocating a Stream ID. In the TSM case the TSM allocates the Stream ID for the Partner Port pair. pci_ide_stream_setup() Program the stream settings to a Partner Port. Caller is responsible for optionally calling this for the Root Port as well if the TSM implementation requires it. pci_ide_stream_enable() Try to run the stream after IDE_KM. In support of system administrators auditing where platform, Root Port, and Endpoint IDE stream resources are being spent, the allocated stream is reflected as a symlink from the host bridge to the endpoint with the name: stream%d.%d.%d Where the tuple of integers reflects the allocated platform, Root Port, and Endpoint stream index (Selective IDE Stream Register Block) values. Thanks to Wu Hao for a draft implementation of this infrastructure. Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Cc: Lukas Wunner <lukas@xxxxxxxxx> Cc: Samuel Ortiz <sameo@xxxxxxxxxxxx> Co-developed-by: Alexey Kardashevskiy <aik@xxxxxxx> Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxx> Co-developed-by: Yilun Xu <yilun.xu@xxxxxxxxxxxxxxx> Signed-off-by: Yilun Xu <yilun.xu@xxxxxxxxxxxxxxx> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> --- .../ABI/testing/sysfs-devices-pci-host-bridge | 16 + drivers/pci/ide.c | 422 ++++++++++++++++++ include/linux/pci-ide.h | 70 +++ include/linux/pci.h | 6 + 4 files changed, 514 insertions(+) create mode 100644 include/linux/pci-ide.h diff --git a/Documentation/ABI/testing/sysfs-devices-pci-host-bridge b/Documentation/ABI/testing/sysfs-devices-pci-host-bridge index 8c3a652799f1..c67d7c30efa0 100644 --- a/Documentation/ABI/testing/sysfs-devices-pci-host-bridge +++ b/Documentation/ABI/testing/sysfs-devices-pci-host-bridge @@ -17,3 +17,19 @@ Description: PNP0A08 (/sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00). See /sys/devices/pciDDDD:BB entry for details about the DDDD:BB format. + +What: pciDDDD:BB/streamH.R.E +Contact: linux-pci@xxxxxxxxxxxxxxx +Description: + (RO) When a platform has established a secure connection, PCIe + IDE, between two Partner Ports, this symlink appears. The + primary function is to account the stream slot / resources + consumed in each of the (H)ost bridge, (R)oot Port and + (E)ndpoint that will be freed when invoking the tsm/disconnect + flow. The link points to the endpoint PCI device in the + Selective IDE Stream. "R" and "E" represent the assigned + Selective IDE Stream Register Block in the Root Port and + Endpoint, and "H" represents a platform specific pool of stream + resources shared by the Root Ports in a host bridge. See + /sys/devices/pciDDDD:BB entry for details about the DDDD:BB + format. diff --git a/drivers/pci/ide.c b/drivers/pci/ide.c index e15937cdb2a4..cdc773a8b381 100644 --- a/drivers/pci/ide.c +++ b/drivers/pci/ide.c @@ -5,6 +5,8 @@ #define dev_fmt(fmt) "PCI/IDE: " fmt #include <linux/pci.h> +#include <linux/sysfs.h> +#include <linux/pci-ide.h> #include <linux/bitfield.h> #include "pci.h" @@ -24,6 +26,13 @@ static int __sel_ide_offset(u16 ide_cap, u8 nr_link_ide, u8 stream_index, return offset; } +static int sel_ide_offset(struct pci_dev *pdev, + struct pci_ide_partner *settings) +{ + return __sel_ide_offset(pdev->ide_cap, pdev->nr_link_ide, + settings->stream_index, pdev->nr_ide_mem); +} + void pci_ide_init(struct pci_dev *pdev) { u8 nr_link_ide, nr_ide_mem, nr_streams; @@ -89,5 +98,418 @@ void pci_ide_init(struct pci_dev *pdev) pdev->ide_cap = ide_cap; pdev->nr_link_ide = nr_link_ide; + pdev->nr_sel_ide = nr_streams; pdev->nr_ide_mem = nr_ide_mem; } + +struct stream_index { + unsigned long *map; + u8 max, stream_index; +}; + +static void free_stream_index(struct stream_index *stream) +{ + clear_bit_unlock(stream->stream_index, stream->map); +} + +DEFINE_FREE(free_stream, struct stream_index *, if (_T) free_stream_index(_T)) +static struct stream_index *alloc_stream_index(unsigned long *map, u8 max, + struct stream_index *stream) +{ + if (!max) + return NULL; + + do { + u8 stream_index = find_first_zero_bit(map, max); + + if (stream_index == max) + return NULL; + if (!test_and_set_bit_lock(stream_index, map)) { + *stream = (struct stream_index) { + .map = map, + .max = max, + .stream_index = stream_index, + }; + return stream; + } + /* collided with another stream acquisition */ + } while (1); +} + +/** + * pci_ide_stream_alloc() - Reserve stream indices and probe for settings + * @pdev: IDE capable PCIe Endpoint Physical Function + * + * Retrieve the Requester ID range of @pdev for programming its Root + * Port IDE RID Association registers, and conversely retrieve the + * Requester ID of the Root Port for programming @pdev's IDE RID + * Association registers. + * + * Allocate a Selective IDE Stream Register Block instance per port. + * + * Allocate a platform stream resource from the associated host bridge. + * Retrieve stream association parameters for Requester ID range and + * address range restrictions for the stream. + */ +struct pci_ide *pci_ide_stream_alloc(struct pci_dev *pdev) +{ + /* EP, RP, + HB Stream allocation */ + struct stream_index __stream[PCI_IDE_HB + 1]; + struct pci_host_bridge *hb; + struct pci_dev *rp; + int num_vf, rid_end; + + if (!pci_is_pcie(pdev)) + return NULL; + + if (pci_pcie_type(pdev) != PCI_EXP_TYPE_ENDPOINT) + return NULL; + + if (!pdev->ide_cap) + return NULL; + + /* + * Catch buggy PCI platform initialization (missing + * pci_ide_init_nr_streams()) + */ + hb = pci_find_host_bridge(pdev->bus); + if (WARN_ON_ONCE(!hb->nr_ide_streams)) + return NULL; + + struct pci_ide *ide __free(kfree) = kzalloc(sizeof(*ide), GFP_KERNEL); + if (!ide) + return NULL; + + struct stream_index *hb_stream __free(free_stream) = alloc_stream_index( + hb->ide_stream_map, hb->nr_ide_streams, &__stream[PCI_IDE_HB]); + if (!hb_stream) + return NULL; + + rp = pcie_find_root_port(pdev); + struct stream_index *rp_stream __free(free_stream) = alloc_stream_index( + rp->ide_stream_map, rp->nr_sel_ide, &__stream[PCI_IDE_RP]); + if (!rp_stream) + return NULL; + + struct stream_index *ep_stream __free(free_stream) = alloc_stream_index( + pdev->ide_stream_map, pdev->nr_sel_ide, &__stream[PCI_IDE_EP]); + if (!ep_stream) + return NULL; + + /* for SR-IOV case, cover all VFs */ + num_vf = pci_num_vf(pdev); + if (num_vf) + rid_end = PCI_DEVID(pci_iov_virtfn_bus(pdev, num_vf), + pci_iov_virtfn_devfn(pdev, num_vf)); + else + rid_end = pci_dev_id(pdev); + + *ide = (struct pci_ide) { + .pdev = pdev, + .partner = { + [PCI_IDE_EP] = { + .rid_start = pci_dev_id(rp), + .rid_end = pci_dev_id(rp), + .stream_index = no_free_ptr(ep_stream)->stream_index, + }, + [PCI_IDE_RP] = { + .rid_start = pci_dev_id(pdev), + .rid_end = rid_end, + .stream_index = no_free_ptr(rp_stream)->stream_index, + }, + }, + .host_bridge_stream = no_free_ptr(hb_stream)->stream_index, + .stream_id = -1, + }; + + return_ptr(ide); +} +EXPORT_SYMBOL_GPL(pci_ide_stream_alloc); + +/** + * pci_ide_stream_free() - unwind pci_ide_stream_alloc() + * @ide: idle IDE settings descriptor + * + * Free all of the stream index (register block) allocations acquired by + * pci_ide_stream_alloc(). The stream represented by @ide is assumed to + * be unregistered and not instantiated in any device. + */ +void pci_ide_stream_free(struct pci_ide *ide) +{ + struct pci_dev *pdev = ide->pdev; + struct pci_dev *rp = pcie_find_root_port(pdev); + struct pci_host_bridge *hb = pci_find_host_bridge(pdev->bus); + + clear_bit_unlock(ide->partner[PCI_IDE_EP].stream_index, + pdev->ide_stream_map); + clear_bit_unlock(ide->partner[PCI_IDE_RP].stream_index, + rp->ide_stream_map); + clear_bit_unlock(ide->host_bridge_stream, hb->ide_stream_map); + kfree(ide); +} +EXPORT_SYMBOL_GPL(pci_ide_stream_free); + +/** + * pci_ide_stream_release() - unwind and release an @ide context + * @ide: partially or fully registered IDE settings descriptor + * + * In support of automatic cleanup of IDE setup routines perform IDE + * teardown in expected reverse order of setup and with respect to which + * aspects of IDE setup have successfully completed. + * + * Be careful that setup order mirrors this shutdown order. Otherwise, + * open code releasing the IDE context. + */ +void pci_ide_stream_release(struct pci_ide *ide) +{ + struct pci_dev *pdev = ide->pdev; + struct pci_dev *rp = pcie_find_root_port(pdev); + + if (ide->partner[PCI_IDE_RP].enable) + pci_ide_stream_disable(rp, ide); + + if (ide->partner[PCI_IDE_EP].enable) + pci_ide_stream_disable(pdev, ide); + + if (ide->partner[PCI_IDE_RP].setup) + pci_ide_stream_teardown(rp, ide); + + if (ide->partner[PCI_IDE_EP].setup) + pci_ide_stream_teardown(pdev, ide); + + if (ide->name) + pci_ide_stream_unregister(ide); + + pci_ide_stream_free(ide); +} +EXPORT_SYMBOL_GPL(pci_ide_stream_release); + +/** + * pci_ide_stream_register() - Prepare to activate an IDE Stream + * @ide: IDE settings descriptor + * + * After a Stream ID has been acquired for @ide, record the presence of + * the stream in sysfs. The expectation is that @ide is immutable while + * registered. + */ +int pci_ide_stream_register(struct pci_ide *ide) +{ + struct pci_dev *pdev = ide->pdev; + struct pci_host_bridge *hb = pci_find_host_bridge(pdev->bus); + u8 ep_stream, rp_stream; + int rc; + + if (ide->stream_id < 0 || ide->stream_id > U8_MAX) { + pci_err(pdev, "Setup fail: Invalid Stream ID: %d\n", ide->stream_id); + return -ENXIO; + } + + ep_stream = ide->partner[PCI_IDE_EP].stream_index; + rp_stream = ide->partner[PCI_IDE_RP].stream_index; + const char *name __free(kfree) = kasprintf(GFP_KERNEL, "stream%d.%d.%d", + ide->host_bridge_stream, + rp_stream, ep_stream); + if (!name) + return -ENOMEM; + + rc = sysfs_create_link(&hb->dev.kobj, &pdev->dev.kobj, name); + if (rc) + return rc; + + ide->name = no_free_ptr(name); + + return 0; +} +EXPORT_SYMBOL_GPL(pci_ide_stream_register); + +/** + * pci_ide_stream_unregister() - unwind pci_ide_stream_register() + * @ide: idle IDE settings descriptor + * + * In preparation for freeing @ide, remove sysfs enumeration for the + * stream. + */ +void pci_ide_stream_unregister(struct pci_ide *ide) +{ + struct pci_dev *pdev = ide->pdev; + struct pci_host_bridge *hb = pci_find_host_bridge(pdev->bus); + + sysfs_remove_link(&hb->dev.kobj, ide->name); + kfree(ide->name); + ide->name = NULL; +} +EXPORT_SYMBOL_GPL(pci_ide_stream_unregister); + +int pci_ide_domain(struct pci_dev *pdev) +{ + if (pdev->fm_enabled) + return pci_domain_nr(pdev->bus); + return 0; +} +EXPORT_SYMBOL_GPL(pci_ide_domain); + +struct pci_ide_partner *pci_ide_to_settings(struct pci_dev *pdev, struct pci_ide *ide) +{ + if (!pci_is_pcie(pdev)) { + pci_warn_once(pdev, "not a PCIe device\n"); + return NULL; + } + + switch (pci_pcie_type(pdev)) { + case PCI_EXP_TYPE_ENDPOINT: + if (pdev != ide->pdev) { + pci_warn_once(pdev, "setup expected Endpoint: %s\n", pci_name(ide->pdev)); + return NULL; + } + return &ide->partner[PCI_IDE_EP]; + case PCI_EXP_TYPE_ROOT_PORT: { + struct pci_dev *rp = pcie_find_root_port(ide->pdev); + + if (pdev != rp) { + pci_warn_once(pdev, "setup expected Root Port: %s\n", + pci_name(rp)); + return NULL; + } + return &ide->partner[PCI_IDE_RP]; + } + default: + pci_warn_once(pdev, "invalid device type\n"); + return NULL; + } +} +EXPORT_SYMBOL_GPL(pci_ide_to_settings); + +static void set_ide_sel_ctl(struct pci_dev *pdev, struct pci_ide *ide, int pos, + bool enable) +{ + u32 val = FIELD_PREP(PCI_IDE_SEL_CTL_ID_MASK, ide->stream_id) | + FIELD_PREP(PCI_IDE_SEL_CTL_DEFAULT, 1) | + FIELD_PREP(PCI_IDE_SEL_CTL_CFG_EN, pdev->ide_cfg) | + FIELD_PREP(PCI_IDE_SEL_CTL_TEE_LIMITED, pdev->ide_tee_limit) | + FIELD_PREP(PCI_IDE_SEL_CTL_EN, enable); + + pci_write_config_dword(pdev, pos + PCI_IDE_SEL_CTL, val); +} + +/** + * pci_ide_stream_setup() - program settings to Selective IDE Stream registers + * @pdev: PCIe device object for either a Root Port or Endpoint Partner Port + * @ide: registered IDE settings descriptor + * + * When @pdev is a PCI_EXP_TYPE_ENDPOINT then the PCI_IDE_EP partner + * settings are written to @pdev's Selective IDE Stream register block, + * and when @pdev is a PCI_EXP_TYPE_ROOT_PORT, the PCI_IDE_RP settings + * are selected. + */ +void pci_ide_stream_setup(struct pci_dev *pdev, struct pci_ide *ide) +{ + struct pci_ide_partner *settings = pci_ide_to_settings(pdev, ide); + int pos; + u32 val; + + if (!settings) + return; + + pos = sel_ide_offset(pdev, settings); + + val = FIELD_PREP(PCI_IDE_SEL_RID_1_LIMIT_MASK, settings->rid_end); + pci_write_config_dword(pdev, pos + PCI_IDE_SEL_RID_1, val); + + val = FIELD_PREP(PCI_IDE_SEL_RID_2_VALID, 1) | + FIELD_PREP(PCI_IDE_SEL_RID_2_BASE_MASK, settings->rid_start) | + FIELD_PREP(PCI_IDE_SEL_RID_2_SEG_MASK, pci_ide_domain(pdev)); + + pci_write_config_dword(pdev, pos + PCI_IDE_SEL_RID_2, val); + + /* + * Setup control register early for devices that expect + * stream_id is set during key programming. + */ + set_ide_sel_ctl(pdev, ide, pos, false); + settings->setup = 1; +} +EXPORT_SYMBOL_GPL(pci_ide_stream_setup); + +/** + * pci_ide_stream_teardown() - disable the stream and clear all settings + * @pdev: PCIe device object for either a Root Port or Endpoint Partner Port + * @ide: registered IDE settings descriptor + * + * For stream destruction, zero all registers that may have been written + * by pci_ide_stream_setup(). Consider pci_ide_stream_disable() to leave + * settings in place while temporarily disabling the stream. + */ +void pci_ide_stream_teardown(struct pci_dev *pdev, struct pci_ide *ide) +{ + struct pci_ide_partner *settings = pci_ide_to_settings(pdev, ide); + int pos; + + if (!settings) + return; + + pos = sel_ide_offset(pdev, settings); + + pci_write_config_dword(pdev, pos + PCI_IDE_SEL_CTL, 0); + pci_write_config_dword(pdev, pos + PCI_IDE_SEL_RID_2, 0); + pci_write_config_dword(pdev, pos + PCI_IDE_SEL_RID_1, 0); + settings->setup = 0; +} +EXPORT_SYMBOL_GPL(pci_ide_stream_teardown); + +/** + * pci_ide_stream_enable() - try to enable a Selective IDE Stream + * @pdev: PCIe device object for either a Root Port or Endpoint Partner Port + * @ide: registered and setup IDE settings descriptor + * + * Activate the stream by writing to the Selective IDE Stream Control + * Register, report whether the state successfully transitioned to + * secure mode. Note that the state may go "insecure" at any point after + * this check, but that is handled via asynchronous error reporting. + */ +int pci_ide_stream_enable(struct pci_dev *pdev, struct pci_ide *ide) +{ + struct pci_ide_partner *settings = pci_ide_to_settings(pdev, ide); + int pos; + u32 val; + + if (!settings) + return -ENXIO; + + pos = sel_ide_offset(pdev, settings); + + set_ide_sel_ctl(pdev, ide, pos, true); + + pci_read_config_dword(pdev, pos + PCI_IDE_SEL_STS, &val); + if (FIELD_GET(PCI_IDE_SEL_STS_STATE_MASK, val) != + PCI_IDE_SEL_STS_STATE_SECURE) { + set_ide_sel_ctl(pdev, ide, pos, false); + return -ENXIO; + } + + settings->enable = 1; + return 0; +} +EXPORT_SYMBOL_GPL(pci_ide_stream_enable); + +/** + * pci_ide_stream_disable() - disable a Selective IDE Stream + * @pdev: PCIe device object for either a Root Port or Endpoint Partner Port + * @ide: registered and setup IDE settings descriptor + * + * Clear the Selective IDE Stream Control Register, but leave all other + * registers untouched. + */ +void pci_ide_stream_disable(struct pci_dev *pdev, struct pci_ide *ide) +{ + struct pci_ide_partner *settings = pci_ide_to_settings(pdev, ide); + int pos; + + if (!settings) + return; + + pos = sel_ide_offset(pdev, settings); + + pci_write_config_dword(pdev, pos + PCI_IDE_SEL_CTL, 0); + settings->enable = 0; +} +EXPORT_SYMBOL_GPL(pci_ide_stream_disable); diff --git a/include/linux/pci-ide.h b/include/linux/pci-ide.h new file mode 100644 index 000000000000..89c1ef0de841 --- /dev/null +++ b/include/linux/pci-ide.h @@ -0,0 +1,70 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright(c) 2024 Intel Corporation. All rights reserved. */ + +/* PCIe 6.2 section 6.33 Integrity & Data Encryption (IDE) */ + +#ifndef __PCI_IDE_H__ +#define __PCI_IDE_H__ + +enum pci_ide_partner_select { + PCI_IDE_EP, + PCI_IDE_RP, + PCI_IDE_PARTNER_MAX, + /* + * In addition to the resources in each partner port the + * platform / host-bridge additionally has a Stream ID pool that + * it shares across root ports. Let pci_ide_stream_alloc() use + * the alloc_stream_index() helper as endpoints and root ports. + */ + PCI_IDE_HB = PCI_IDE_PARTNER_MAX, +}; + +/** + * struct pci_ide_partner - Per port pair Selective IDE Stream settings + * @rid_start: Partner Port Requester ID range start + * @rid_start: Partner Port Requester ID range end + * @stream_index: Selective IDE Stream Register Block selection + * @setup: flag to track whether to run pci_ide_stream_teardown for this parnter slot + * @enable: flag whether to run pci_ide_stream_disable for this parnter slot + */ +struct pci_ide_partner { + u16 rid_start; + u16 rid_end; + u8 stream_index; + unsigned int setup:1; + unsigned int enable:1; +}; + +/** + * struct pci_ide - PCIe Selective IDE Stream descriptor + * @pdev: PCIe Endpoint in the pci_ide_partner pair + * @partner: Per-partner settings + * @host_bridge_stream: track platform Stream ID + * @stream_id: unique Stream ID (within Partner Port pairing) + * @name: name of the established Selective IDE Stream in sysfs + * + * Negative @stream_id values indicate "uninitialized" on the + * expectation that with TSM established IDE the TSM owns the stream_id + * allocation. + */ +struct pci_ide { + struct pci_dev *pdev; + struct pci_ide_partner partner[PCI_IDE_PARTNER_MAX]; + u8 host_bridge_stream; + int stream_id; + const char *name; +}; + +int pci_ide_domain(struct pci_dev *pdev); +struct pci_ide_partner *pci_ide_to_settings(struct pci_dev *pdev, struct pci_ide *ide); +struct pci_ide *pci_ide_stream_alloc(struct pci_dev *pdev); +void pci_ide_stream_free(struct pci_ide *ide); +int pci_ide_stream_register(struct pci_ide *ide); +void pci_ide_stream_unregister(struct pci_ide *ide); +void pci_ide_stream_setup(struct pci_dev *pdev, struct pci_ide *ide); +void pci_ide_stream_teardown(struct pci_dev *pdev, struct pci_ide *ide); +int pci_ide_stream_enable(struct pci_dev *pdev, struct pci_ide *ide); +void pci_ide_stream_disable(struct pci_dev *pdev, struct pci_ide *ide); +void pci_ide_stream_release(struct pci_ide *ide); +DEFINE_FREE(pci_ide_stream_release, struct pci_ide *, if (_T) pci_ide_stream_release(_T)) +#endif /* __PCI_IDE_H__ */ diff --git a/include/linux/pci.h b/include/linux/pci.h index a7353df51fea..cc83ae274601 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -538,6 +538,8 @@ struct pci_dev { u16 ide_cap; /* Link Integrity & Data Encryption */ u8 nr_ide_mem; /* Address association resources for streams */ u8 nr_link_ide; /* Link Stream count (Selective Stream offset) */ + u8 nr_sel_ide; /* Selective Stream count (register block allocator) */ + DECLARE_BITMAP(ide_stream_map, CONFIG_PCI_IDE_STREAM_MAX); unsigned int ide_cfg:1; /* Config cycles over IDE */ unsigned int ide_tee_limit:1; /* Disallow T=0 traffic over IDE */ #endif @@ -607,6 +609,10 @@ struct pci_host_bridge { int domain_nr; struct list_head windows; /* resource_entry */ struct list_head dma_ranges; /* dma ranges resource list */ +#ifdef CONFIG_PCI_IDE + u8 nr_ide_streams; /* Track available vs in-use streams */ + DECLARE_BITMAP(ide_stream_map, CONFIG_PCI_IDE_STREAM_MAX); +#endif u8 (*swizzle_irq)(struct pci_dev *, u8 *); /* Platform IRQ swizzler */ int (*map_irq)(const struct pci_dev *, u8, u8); void (*release_fn)(struct pci_host_bridge *); -- 2.50.1