From 71ded61bee2af97a218f9dfa0f4019cc4cd3b029 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 3 Mar 2025 23:14:20 -0800 Subject: [PATCH 01/12] configfs-tsm: Namespace TSM report symbols In preparation for new + common TSM (TEE Security Manager) infrastructure, namespace the TSM report symbols in tsm.h with an _REPORT suffix to differentiate them from other incoming tsm work. Cc: Yilun Xu Cc: Samuel Ortiz Cc: Tom Lendacky Cc: Sami Mujawar Cc: Steven Price Reviewed-by: Alexey Kardashevskiy Reviewed-by: Suzuki K Poulose Reviewed-by: Kai Huang Reviewed-by: Kuppuswamy Sathyanarayanan Reviewed-by: Steven Price Link: https://patch.msgid.link/174107246021.1288555.7203769833791489618.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams --- .../{configfs-tsm => configfs-tsm-report} | 0 MAINTAINERS | 2 +- .../virt/coco/arm-cca-guest/arm-cca-guest.c | 8 ++--- drivers/virt/coco/sev-guest/sev-guest.c | 12 +++---- drivers/virt/coco/tdx-guest/tdx-guest.c | 8 ++--- drivers/virt/coco/tsm.c | 32 +++++++++---------- include/linux/tsm.h | 22 ++++++------- 7 files changed, 42 insertions(+), 42 deletions(-) rename Documentation/ABI/testing/{configfs-tsm => configfs-tsm-report} (100%) diff --git a/Documentation/ABI/testing/configfs-tsm b/Documentation/ABI/testing/configfs-tsm-report similarity index 100% rename from Documentation/ABI/testing/configfs-tsm rename to Documentation/ABI/testing/configfs-tsm-report diff --git a/MAINTAINERS b/MAINTAINERS index c59316109e3f..debcd79a264d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -24559,7 +24559,7 @@ TRUSTED SECURITY MODULE (TSM) ATTESTATION REPORTS M: Dan Williams L: linux-coco@lists.linux.dev S: Maintained -F: Documentation/ABI/testing/configfs-tsm +F: Documentation/ABI/testing/configfs-tsm-report F: drivers/virt/coco/tsm.c F: include/linux/tsm.h diff --git a/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c b/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c index 87f162736b2e..0c9ea24a200c 100644 --- a/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c +++ b/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c @@ -96,7 +96,7 @@ static int arm_cca_report_new(struct tsm_report *report, void *data) struct arm_cca_token_info info; void *buf; u8 *token __free(kvfree) = NULL; - struct tsm_desc *desc = &report->desc; + struct tsm_report_desc *desc = &report->desc; if (desc->inblob_len < 32 || desc->inblob_len > 64) return -EINVAL; @@ -181,7 +181,7 @@ static int arm_cca_report_new(struct tsm_report *report, void *data) return ret; } -static const struct tsm_ops arm_cca_tsm_ops = { +static const struct tsm_report_ops arm_cca_tsm_ops = { .name = KBUILD_MODNAME, .report_new = arm_cca_report_new, }; @@ -202,7 +202,7 @@ static int __init arm_cca_guest_init(void) if (!is_realm_world()) return -ENODEV; - ret = tsm_register(&arm_cca_tsm_ops, NULL); + ret = tsm_report_register(&arm_cca_tsm_ops, NULL); if (ret < 0) pr_err("Error %d registering with TSM\n", ret); @@ -216,7 +216,7 @@ module_init(arm_cca_guest_init); */ static void __exit arm_cca_guest_exit(void) { - tsm_unregister(&arm_cca_tsm_ops); + tsm_report_unregister(&arm_cca_tsm_ops); } module_exit(arm_cca_guest_exit); diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c index cf3fb61f4d5b..7a4e2188f109 100644 --- a/drivers/virt/coco/sev-guest/sev-guest.c +++ b/drivers/virt/coco/sev-guest/sev-guest.c @@ -346,7 +346,7 @@ struct snp_msg_cert_entry { static int sev_svsm_report_new(struct tsm_report *report, void *data) { unsigned int rep_len, man_len, certs_len; - struct tsm_desc *desc = &report->desc; + struct tsm_report_desc *desc = &report->desc; struct svsm_attest_call ac = {}; unsigned int retry_count; void *rep, *man, *certs; @@ -481,7 +481,7 @@ static int sev_svsm_report_new(struct tsm_report *report, void *data) static int sev_report_new(struct tsm_report *report, void *data) { struct snp_msg_cert_entry *cert_table; - struct tsm_desc *desc = &report->desc; + struct tsm_report_desc *desc = &report->desc; struct snp_guest_dev *snp_dev = data; struct snp_msg_report_resp_hdr hdr; const u32 report_size = SZ_4K; @@ -610,7 +610,7 @@ static bool sev_report_bin_attr_visible(int n) return false; } -static struct tsm_ops sev_tsm_ops = { +static struct tsm_report_ops sev_tsm_report_ops = { .name = KBUILD_MODNAME, .report_new = sev_report_new, .report_attr_visible = sev_report_attr_visible, @@ -619,7 +619,7 @@ static struct tsm_ops sev_tsm_ops = { static void unregister_sev_tsm(void *data) { - tsm_unregister(&sev_tsm_ops); + tsm_report_unregister(&sev_tsm_report_ops); } static int __init sev_guest_probe(struct platform_device *pdev) @@ -656,9 +656,9 @@ static int __init sev_guest_probe(struct platform_device *pdev) misc->fops = &snp_guest_fops; /* Set the privlevel_floor attribute based on the vmpck_id */ - sev_tsm_ops.privlevel_floor = mdesc->vmpck_id; + sev_tsm_report_ops.privlevel_floor = mdesc->vmpck_id; - ret = tsm_register(&sev_tsm_ops, snp_dev); + ret = tsm_report_register(&sev_tsm_report_ops, snp_dev); if (ret) goto e_msg_init; diff --git a/drivers/virt/coco/tdx-guest/tdx-guest.c b/drivers/virt/coco/tdx-guest/tdx-guest.c index 224e7dde9cde..bd043838ab2e 100644 --- a/drivers/virt/coco/tdx-guest/tdx-guest.c +++ b/drivers/virt/coco/tdx-guest/tdx-guest.c @@ -161,7 +161,7 @@ static int tdx_report_new(struct tsm_report *report, void *data) { u8 *buf, *reportdata = NULL, *tdreport = NULL; struct tdx_quote_buf *quote_buf = quote_data; - struct tsm_desc *desc = &report->desc; + struct tsm_report_desc *desc = &report->desc; int ret; u64 err; @@ -297,7 +297,7 @@ static const struct x86_cpu_id tdx_guest_ids[] = { }; MODULE_DEVICE_TABLE(x86cpu, tdx_guest_ids); -static const struct tsm_ops tdx_tsm_ops = { +static const struct tsm_report_ops tdx_tsm_ops = { .name = KBUILD_MODNAME, .report_new = tdx_report_new, .report_attr_visible = tdx_report_attr_visible, @@ -322,7 +322,7 @@ static int __init tdx_guest_init(void) goto free_misc; } - ret = tsm_register(&tdx_tsm_ops, NULL); + ret = tsm_report_register(&tdx_tsm_ops, NULL); if (ret) goto free_quote; @@ -339,7 +339,7 @@ module_init(tdx_guest_init); static void __exit tdx_guest_exit(void) { - tsm_unregister(&tdx_tsm_ops); + tsm_report_unregister(&tdx_tsm_ops); free_quote_buf(quote_data); misc_deregister(&tdx_misc_dev); } diff --git a/drivers/virt/coco/tsm.c b/drivers/virt/coco/tsm.c index 9432d4e303f1..bcb515b50c68 100644 --- a/drivers/virt/coco/tsm.c +++ b/drivers/virt/coco/tsm.c @@ -13,7 +13,7 @@ #include static struct tsm_provider { - const struct tsm_ops *ops; + const struct tsm_report_ops *ops; void *data; } provider; static DECLARE_RWSEM(tsm_rwsem); @@ -98,7 +98,7 @@ static ssize_t tsm_report_privlevel_store(struct config_item *cfg, * SEV-SNP GHCB) and a minimum of a TSM selected floor value no less * than 0. */ - if (provider.ops->privlevel_floor > val || val > TSM_PRIVLEVEL_MAX) + if (provider.ops->privlevel_floor > val || val > TSM_REPORT_PRIVLEVEL_MAX) return -EINVAL; guard(rwsem_write)(&tsm_rwsem); @@ -202,7 +202,7 @@ static ssize_t tsm_report_inblob_write(struct config_item *cfg, memcpy(report->desc.inblob, buf, count); return count; } -CONFIGFS_BIN_ATTR_WO(tsm_report_, inblob, NULL, TSM_INBLOB_MAX); +CONFIGFS_BIN_ATTR_WO(tsm_report_, inblob, NULL, TSM_REPORT_INBLOB_MAX); static ssize_t tsm_report_generation_show(struct config_item *cfg, char *buf) { @@ -272,7 +272,7 @@ static ssize_t tsm_report_read(struct tsm_report *report, void *buf, size_t count, enum tsm_data_select select) { struct tsm_report_state *state = to_state(report); - const struct tsm_ops *ops; + const struct tsm_report_ops *ops; ssize_t rc; /* try to read from the existing report if present and valid... */ @@ -314,7 +314,7 @@ static ssize_t tsm_report_outblob_read(struct config_item *cfg, void *buf, return tsm_report_read(report, buf, count, TSM_REPORT); } -CONFIGFS_BIN_ATTR_RO(tsm_report_, outblob, NULL, TSM_OUTBLOB_MAX); +CONFIGFS_BIN_ATTR_RO(tsm_report_, outblob, NULL, TSM_REPORT_OUTBLOB_MAX); static ssize_t tsm_report_auxblob_read(struct config_item *cfg, void *buf, size_t count) @@ -323,7 +323,7 @@ static ssize_t tsm_report_auxblob_read(struct config_item *cfg, void *buf, return tsm_report_read(report, buf, count, TSM_CERTS); } -CONFIGFS_BIN_ATTR_RO(tsm_report_, auxblob, NULL, TSM_OUTBLOB_MAX); +CONFIGFS_BIN_ATTR_RO(tsm_report_, auxblob, NULL, TSM_REPORT_OUTBLOB_MAX); static ssize_t tsm_report_manifestblob_read(struct config_item *cfg, void *buf, size_t count) @@ -332,7 +332,7 @@ static ssize_t tsm_report_manifestblob_read(struct config_item *cfg, void *buf, return tsm_report_read(report, buf, count, TSM_MANIFEST); } -CONFIGFS_BIN_ATTR_RO(tsm_report_, manifestblob, NULL, TSM_OUTBLOB_MAX); +CONFIGFS_BIN_ATTR_RO(tsm_report_, manifestblob, NULL, TSM_REPORT_OUTBLOB_MAX); static struct configfs_attribute *tsm_report_attrs[] = { [TSM_REPORT_GENERATION] = &tsm_report_attr_generation, @@ -448,9 +448,9 @@ static struct configfs_subsystem tsm_configfs = { .su_mutex = __MUTEX_INITIALIZER(tsm_configfs.su_mutex), }; -int tsm_register(const struct tsm_ops *ops, void *priv) +int tsm_report_register(const struct tsm_report_ops *ops, void *priv) { - const struct tsm_ops *conflict; + const struct tsm_report_ops *conflict; guard(rwsem_write)(&tsm_rwsem); conflict = provider.ops; @@ -463,9 +463,9 @@ int tsm_register(const struct tsm_ops *ops, void *priv) provider.data = priv; return 0; } -EXPORT_SYMBOL_GPL(tsm_register); +EXPORT_SYMBOL_GPL(tsm_report_register); -int tsm_unregister(const struct tsm_ops *ops) +int tsm_report_unregister(const struct tsm_report_ops *ops) { guard(rwsem_write)(&tsm_rwsem); if (ops != provider.ops) @@ -474,11 +474,11 @@ int tsm_unregister(const struct tsm_ops *ops) provider.data = NULL; return 0; } -EXPORT_SYMBOL_GPL(tsm_unregister); +EXPORT_SYMBOL_GPL(tsm_report_unregister); static struct config_group *tsm_report_group; -static int __init tsm_init(void) +static int __init tsm_report_init(void) { struct config_group *root = &tsm_configfs.su_group; struct config_group *tsm; @@ -499,14 +499,14 @@ static int __init tsm_init(void) return 0; } -module_init(tsm_init); +module_init(tsm_report_init); -static void __exit tsm_exit(void) +static void __exit tsm_report_exit(void) { configfs_unregister_default_group(tsm_report_group); configfs_unregister_subsystem(&tsm_configfs); } -module_exit(tsm_exit); +module_exit(tsm_report_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Provide Trusted Security Module attestation reports via configfs"); diff --git a/include/linux/tsm.h b/include/linux/tsm.h index 11b0c525be30..431054810dca 100644 --- a/include/linux/tsm.h +++ b/include/linux/tsm.h @@ -6,17 +6,17 @@ #include #include -#define TSM_INBLOB_MAX 64 -#define TSM_OUTBLOB_MAX SZ_32K +#define TSM_REPORT_INBLOB_MAX 64 +#define TSM_REPORT_OUTBLOB_MAX SZ_32K /* * Privilege level is a nested permission concept to allow confidential * guests to partition address space, 4-levels are supported. */ -#define TSM_PRIVLEVEL_MAX 3 +#define TSM_REPORT_PRIVLEVEL_MAX 3 /** - * struct tsm_desc - option descriptor for generating tsm report blobs + * struct tsm_report_desc - option descriptor for generating tsm report blobs * @privlevel: optional privilege level to associate with @outblob * @inblob_len: sizeof @inblob * @inblob: arbitrary input data @@ -24,10 +24,10 @@ * @service_guid: optional service-provider service guid to attest * @service_manifest_version: optional service-provider service manifest version requested */ -struct tsm_desc { +struct tsm_report_desc { unsigned int privlevel; size_t inblob_len; - u8 inblob[TSM_INBLOB_MAX]; + u8 inblob[TSM_REPORT_INBLOB_MAX]; char *service_provider; guid_t service_guid; unsigned int service_manifest_version; @@ -44,7 +44,7 @@ struct tsm_desc { * @manifestblob: (optional) manifest data associated with the report */ struct tsm_report { - struct tsm_desc desc; + struct tsm_report_desc desc; size_t outblob_len; u8 *outblob; size_t auxblob_len; @@ -88,7 +88,7 @@ enum tsm_bin_attr_index { }; /** - * struct tsm_ops - attributes and operations for tsm instances + * struct tsm_report_ops - attributes and operations for tsm_report instances * @name: tsm id reflected in /sys/kernel/config/tsm/report/$report/provider * @privlevel_floor: convey base privlevel for nested scenarios * @report_new: Populate @report with the report blob and auxblob @@ -99,7 +99,7 @@ enum tsm_bin_attr_index { * Implementation specific ops, only one is expected to be registered at * a time i.e. only one of "sev-guest", "tdx-guest", etc. */ -struct tsm_ops { +struct tsm_report_ops { const char *name; unsigned int privlevel_floor; int (*report_new)(struct tsm_report *report, void *data); @@ -107,6 +107,6 @@ struct tsm_ops { bool (*report_bin_attr_visible)(int n); }; -int tsm_register(const struct tsm_ops *ops, void *priv); -int tsm_unregister(const struct tsm_ops *ops); +int tsm_report_register(const struct tsm_report_ops *ops, void *priv); +int tsm_report_unregister(const struct tsm_report_ops *ops); #endif /* __TSM_H */ From 7515f45c165269b72ee739e6fc26cc2ef928fc1b Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 3 Mar 2025 23:14:26 -0800 Subject: [PATCH 02/12] coco/guest: Move shared guest CC infrastructure to drivers/virt/coco/guest/ In preparation for creating a new drivers/virt/coco/host/ directory to house shared host driver infrastructure for confidential computing, move configfs-tsm to a guest/ sub-directory. The tsm.ko module is renamed to tsm_reports.ko. The old tsm.ko module was only ever demand loaded by kernel internal dependencies, so it should not affect existing userspace module install scripts. The new drivers/virt/coco/guest/ is also a preparatory landing spot for new / optional TSM Report mechanics like a TCB stability enumeration / watchdog mechanism. To be added later. Cc: Wu Hao Cc: Yilun Xu Cc: Samuel Ortiz Cc: Tom Lendacky Reviewed-by: Alexey Kardashevskiy Reviewed-by: Kuppuswamy Sathyanarayanan Link: https://patch.msgid.link/174107246641.1288555.208426916259466774.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams --- MAINTAINERS | 2 +- drivers/virt/coco/Kconfig | 6 ++---- drivers/virt/coco/Makefile | 2 +- drivers/virt/coco/guest/Kconfig | 7 +++++++ drivers/virt/coco/guest/Makefile | 3 +++ drivers/virt/coco/{tsm.c => guest/report.c} | 0 6 files changed, 14 insertions(+), 6 deletions(-) create mode 100644 drivers/virt/coco/guest/Kconfig create mode 100644 drivers/virt/coco/guest/Makefile rename drivers/virt/coco/{tsm.c => guest/report.c} (100%) diff --git a/MAINTAINERS b/MAINTAINERS index debcd79a264d..0a1ca9233ccf 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -24560,7 +24560,7 @@ M: Dan Williams L: linux-coco@lists.linux.dev S: Maintained F: Documentation/ABI/testing/configfs-tsm-report -F: drivers/virt/coco/tsm.c +F: drivers/virt/coco/guest/ F: include/linux/tsm.h TRUSTED SERVICES TEE DRIVER diff --git a/drivers/virt/coco/Kconfig b/drivers/virt/coco/Kconfig index ff869d883d95..819a97e8ba99 100644 --- a/drivers/virt/coco/Kconfig +++ b/drivers/virt/coco/Kconfig @@ -3,10 +3,6 @@ # Confidential computing related collateral # -config TSM_REPORTS - select CONFIGFS_FS - tristate - source "drivers/virt/coco/efi_secret/Kconfig" source "drivers/virt/coco/pkvm-guest/Kconfig" @@ -16,3 +12,5 @@ source "drivers/virt/coco/sev-guest/Kconfig" source "drivers/virt/coco/tdx-guest/Kconfig" source "drivers/virt/coco/arm-cca-guest/Kconfig" + +source "drivers/virt/coco/guest/Kconfig" diff --git a/drivers/virt/coco/Makefile b/drivers/virt/coco/Makefile index c3d07cfc087e..885c9ef4e9fc 100644 --- a/drivers/virt/coco/Makefile +++ b/drivers/virt/coco/Makefile @@ -2,9 +2,9 @@ # # Confidential computing related collateral # -obj-$(CONFIG_TSM_REPORTS) += tsm.o obj-$(CONFIG_EFI_SECRET) += efi_secret/ obj-$(CONFIG_ARM_PKVM_GUEST) += pkvm-guest/ obj-$(CONFIG_SEV_GUEST) += sev-guest/ obj-$(CONFIG_INTEL_TDX_GUEST) += tdx-guest/ obj-$(CONFIG_ARM_CCA_GUEST) += arm-cca-guest/ +obj-$(CONFIG_TSM_REPORTS) += guest/ diff --git a/drivers/virt/coco/guest/Kconfig b/drivers/virt/coco/guest/Kconfig new file mode 100644 index 000000000000..ed9bafbdd854 --- /dev/null +++ b/drivers/virt/coco/guest/Kconfig @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Confidential computing shared guest collateral +# +config TSM_REPORTS + select CONFIGFS_FS + tristate diff --git a/drivers/virt/coco/guest/Makefile b/drivers/virt/coco/guest/Makefile new file mode 100644 index 000000000000..b3b217af77cf --- /dev/null +++ b/drivers/virt/coco/guest/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_TSM_REPORTS) += tsm_report.o +tsm_report-y := report.o diff --git a/drivers/virt/coco/tsm.c b/drivers/virt/coco/guest/report.c similarity index 100% rename from drivers/virt/coco/tsm.c rename to drivers/virt/coco/guest/report.c From fba4ceaa242d2bdf4c04b77bda41d32d02d3925d Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 30 Apr 2025 13:33:31 -0700 Subject: [PATCH 03/12] configfs-tsm-report: Fix NULL dereference of tsm_ops Unlike sysfs, the lifetime of configfs objects is controlled by userspace. There is no mechanism for the kernel to find and delete all created config-items. Instead, the configfs-tsm-report mechanism has an expectation that tsm_unregister() can happen at any time and cause established config-item access to start failing. That expectation is not fully satisfied. While tsm_report_read(), tsm_report_{is,is_bin}_visible(), and tsm_report_make_item() safely fail if tsm_ops have been unregistered, tsm_report_privlevel_store() tsm_report_provider_show() fail to check for ops registration. Add the missing checks for tsm_ops having been removed. Now, in supporting the ability for tsm_unregister() to always succeed, it leaves the problem of what to do with lingering config-items. The expectation is that the admin that arranges for the ->remove() (unbind) of the ${tsm_arch}-guest driver is also responsible for deletion of all open config-items. Until that deletion happens, ->probe() (reload / bind) of the ${tsm_arch}-guest driver fails. This allows for emergency shutdown / revocation of attestation interfaces, and requires coordinated restart. Fixes: 70e6f7e2b985 ("configfs-tsm: Introduce a shared ABI for attestation reports") Cc: stable@vger.kernel.org Cc: Suzuki K Poulose Cc: Steven Price Cc: Sami Mujawar Cc: Borislav Petkov (AMD) Cc: Tom Lendacky Reviewed-by: Kuppuswamy Sathyanarayanan Reported-by: Cedric Xing Reviewed-by: Kai Huang Link: https://patch.msgid.link/20250430203331.1177062-1-dan.j.williams@intel.com Signed-off-by: Dan Williams --- drivers/virt/coco/tsm.c | 31 +++++++++++++++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-) diff --git a/drivers/virt/coco/tsm.c b/drivers/virt/coco/tsm.c index 9432d4e303f1..8a638bc34d4a 100644 --- a/drivers/virt/coco/tsm.c +++ b/drivers/virt/coco/tsm.c @@ -15,6 +15,7 @@ static struct tsm_provider { const struct tsm_ops *ops; void *data; + atomic_t count; } provider; static DECLARE_RWSEM(tsm_rwsem); @@ -92,6 +93,10 @@ static ssize_t tsm_report_privlevel_store(struct config_item *cfg, if (rc) return rc; + guard(rwsem_write)(&tsm_rwsem); + if (!provider.ops) + return -ENXIO; + /* * The valid privilege levels that a TSM might accept, if it accepts a * privilege level setting at all, are a max of TSM_PRIVLEVEL_MAX (see @@ -101,7 +106,6 @@ static ssize_t tsm_report_privlevel_store(struct config_item *cfg, if (provider.ops->privlevel_floor > val || val > TSM_PRIVLEVEL_MAX) return -EINVAL; - guard(rwsem_write)(&tsm_rwsem); rc = try_advance_write_generation(report); if (rc) return rc; @@ -115,6 +119,10 @@ static ssize_t tsm_report_privlevel_floor_show(struct config_item *cfg, char *buf) { guard(rwsem_read)(&tsm_rwsem); + + if (!provider.ops) + return -ENXIO; + return sysfs_emit(buf, "%u\n", provider.ops->privlevel_floor); } CONFIGFS_ATTR_RO(tsm_report_, privlevel_floor); @@ -217,6 +225,9 @@ CONFIGFS_ATTR_RO(tsm_report_, generation); static ssize_t tsm_report_provider_show(struct config_item *cfg, char *buf) { guard(rwsem_read)(&tsm_rwsem); + if (!provider.ops) + return -ENXIO; + return sysfs_emit(buf, "%s\n", provider.ops->name); } CONFIGFS_ATTR_RO(tsm_report_, provider); @@ -284,7 +295,7 @@ static ssize_t tsm_report_read(struct tsm_report *report, void *buf, guard(rwsem_write)(&tsm_rwsem); ops = provider.ops; if (!ops) - return -ENOTTY; + return -ENXIO; if (!report->desc.inblob_len) return -EINVAL; @@ -421,12 +432,20 @@ static struct config_item *tsm_report_make_item(struct config_group *group, if (!state) return ERR_PTR(-ENOMEM); + atomic_inc(&provider.count); config_item_init_type_name(&state->cfg, name, &tsm_report_type); return &state->cfg; } +static void tsm_report_drop_item(struct config_group *group, struct config_item *item) +{ + config_item_put(item); + atomic_dec(&provider.count); +} + static struct configfs_group_operations tsm_report_group_ops = { .make_item = tsm_report_make_item, + .drop_item = tsm_report_drop_item, }; static const struct config_item_type tsm_reports_type = { @@ -459,6 +478,11 @@ int tsm_register(const struct tsm_ops *ops, void *priv) return -EBUSY; } + if (atomic_read(&provider.count)) { + pr_err("configfs/tsm/report not empty\n"); + return -EBUSY; + } + provider.ops = ops; provider.data = priv; return 0; @@ -470,6 +494,9 @@ int tsm_unregister(const struct tsm_ops *ops) guard(rwsem_write)(&tsm_rwsem); if (ops != provider.ops) return -EBUSY; + if (atomic_read(&provider.count)) + pr_warn("\"%s\" unregistered with items present in configfs/tsm/report\n", + provider.ops->name); provider.ops = NULL; provider.data = NULL; return 0; From b9e22b35d4598aefed642928ed2856a9900e5b37 Mon Sep 17 00:00:00 2001 From: Cedric Xing Date: Thu, 8 May 2025 19:07:39 -0700 Subject: [PATCH 04/12] tsm-mr: Add TVM Measurement Register support Introduce new TSM Measurement helper library (tsm-mr) for TVM guest drivers to expose MRs (Measurement Registers) as sysfs attributes, with Crypto Agility support. Add the following new APIs (see include/linux/tsm-mr.h for details): - tsm_mr_create_attribute_group(): Take on input a `struct tsm_measurements` instance, which includes one `struct tsm_measurement_register` per MR with properties like `TSM_MR_F_READABLE` and `TSM_MR_F_WRITABLE`, to determine the supported operations and create the sysfs attributes accordingly. On success, return a `struct attribute_group` instance that will typically be included by the guest driver into `miscdevice.groups` before calling misc_register(). - tsm_mr_free_attribute_group(): Free the memory allocated to the attrubute group returned by tsm_mr_create_attribute_group(). tsm_mr_create_attribute_group() creates one attribute for each MR, with names following this pattern: MRNAME[:HASH] - MRNAME - Placeholder for the MR name, as specified by `tsm_measurement_register.mr_name`. - :HASH - Optional suffix indicating the hash algorithm associated with this MR, as specified by `tsm_measurement_register.mr_hash`. Support Crypto Agility by allowing multiple definitions of the same MR (i.e., with the same `mr_name`) with distinct HASH algorithms. NOTE: Crypto Agility, introduced in TPM 2.0, allows new hash algorithms to be introduced without breaking compatibility with applications using older algorithms. CC architectures may face the same challenge in the future, needing new hashes for security while retaining compatibility with older hashes, hence the need for Crypto Agility. Signed-off-by: Cedric Xing Reviewed-by: Dan Williams Acked-by: Dionna Amalie Glaze [djbw: fixup bin_attr const conflict] Link: https://patch.msgid.link/20250509020739.882913-1-dan.j.williams@intel.com Signed-off-by: Dan Williams --- Documentation/driver-api/coco/index.rst | 12 + .../driver-api/coco/measurement-registers.rst | 12 + Documentation/driver-api/index.rst | 1 + MAINTAINERS | 5 +- drivers/virt/coco/Kconfig | 5 + drivers/virt/coco/Makefile | 1 + drivers/virt/coco/tsm-mr.c | 251 ++++++++++++++++++ include/linux/tsm-mr.h | 89 +++++++ include/trace/events/tsm_mr.h | 80 ++++++ 9 files changed, 454 insertions(+), 2 deletions(-) create mode 100644 Documentation/driver-api/coco/index.rst create mode 100644 Documentation/driver-api/coco/measurement-registers.rst create mode 100644 drivers/virt/coco/tsm-mr.c create mode 100644 include/linux/tsm-mr.h create mode 100644 include/trace/events/tsm_mr.h diff --git a/Documentation/driver-api/coco/index.rst b/Documentation/driver-api/coco/index.rst new file mode 100644 index 000000000000..af9f08ca0cfd --- /dev/null +++ b/Documentation/driver-api/coco/index.rst @@ -0,0 +1,12 @@ +.. SPDX-License-Identifier: GPL-2.0 + +====================== +Confidential Computing +====================== + +.. toctree:: + :maxdepth: 1 + + measurement-registers + +.. only:: subproject and html diff --git a/Documentation/driver-api/coco/measurement-registers.rst b/Documentation/driver-api/coco/measurement-registers.rst new file mode 100644 index 000000000000..cef85945a9a7 --- /dev/null +++ b/Documentation/driver-api/coco/measurement-registers.rst @@ -0,0 +1,12 @@ +.. SPDX-License-Identifier: GPL-2.0 +.. include:: + +===================== +Measurement Registers +===================== + +.. kernel-doc:: include/linux/tsm-mr.h + :internal: + +.. kernel-doc:: drivers/virt/coco/tsm-mr.c + :export: diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst index 16e2c4ec3c01..3e2a270bd828 100644 --- a/Documentation/driver-api/index.rst +++ b/Documentation/driver-api/index.rst @@ -81,6 +81,7 @@ Subsystem-specific APIs acpi/index backlight/lp855x-driver.rst clk + coco/index console crypto/index dmaengine/index diff --git a/MAINTAINERS b/MAINTAINERS index 69511c3b2b76..5d36823d26b2 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -24648,8 +24648,9 @@ M: Dan Williams L: linux-coco@lists.linux.dev S: Maintained F: Documentation/ABI/testing/configfs-tsm -F: drivers/virt/coco/tsm.c -F: include/linux/tsm.h +F: Documentation/driver-api/coco/ +F: drivers/virt/coco/tsm*.c +F: include/linux/tsm*.h TRUSTED SERVICES TEE DRIVER M: Balint Dobszay diff --git a/drivers/virt/coco/Kconfig b/drivers/virt/coco/Kconfig index ff869d883d95..737106d5dcbc 100644 --- a/drivers/virt/coco/Kconfig +++ b/drivers/virt/coco/Kconfig @@ -7,6 +7,11 @@ config TSM_REPORTS select CONFIGFS_FS tristate +config TSM_MEASUREMENTS + select CRYPTO_HASH_INFO + select CRYPTO + bool + source "drivers/virt/coco/efi_secret/Kconfig" source "drivers/virt/coco/pkvm-guest/Kconfig" diff --git a/drivers/virt/coco/Makefile b/drivers/virt/coco/Makefile index c3d07cfc087e..eb6ec5c1d2e1 100644 --- a/drivers/virt/coco/Makefile +++ b/drivers/virt/coco/Makefile @@ -3,6 +3,7 @@ # Confidential computing related collateral # obj-$(CONFIG_TSM_REPORTS) += tsm.o +obj-$(CONFIG_TSM_MEASUREMENTS) += tsm-mr.o obj-$(CONFIG_EFI_SECRET) += efi_secret/ obj-$(CONFIG_ARM_PKVM_GUEST) += pkvm-guest/ obj-$(CONFIG_SEV_GUEST) += sev-guest/ diff --git a/drivers/virt/coco/tsm-mr.c b/drivers/virt/coco/tsm-mr.c new file mode 100644 index 000000000000..1f0c43a516fb --- /dev/null +++ b/drivers/virt/coco/tsm-mr.c @@ -0,0 +1,251 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2024-2025 Intel Corporation. All rights reserved. */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include + +#define CREATE_TRACE_POINTS +#include + +/* + * struct tm_context - contains everything necessary to implement sysfs + * attributes for MRs. + * @rwsem: protects the MR cache from concurrent access. + * @agrp: contains all MR attributes created by tsm_mr_create_attribute_group(). + * @tm: input to tsm_mr_create_attribute_group() containing MR definitions/ops. + * @in_sync: %true if MR cache is up-to-date. + * @mrs: array of &struct bin_attribute, one for each MR. + * + * This internal structure contains everything needed to implement + * tm_digest_read() and tm_digest_write(). + * + * Given tm->refresh() is potentially expensive, tm_digest_read() caches MR + * values and calls tm->refresh() only when necessary. Only live MRs (i.e., with + * %TSM_MR_F_LIVE set) can trigger tm->refresh(), while others are assumed to + * retain their values from the last tm->write(). @in_sync tracks if there have + * been tm->write() calls since the last tm->refresh(). That is, tm->refresh() + * will be called only when a live MR is being read and the cache is stale + * (@in_sync is %false). + * + * tm_digest_write() sets @in_sync to %false and calls tm->write(), whose + * semantics is arch and MR specific. Most (if not all) writable MRs support the + * extension semantics (i.e., tm->write() extends the input buffer into the MR). + */ +struct tm_context { + struct rw_semaphore rwsem; + struct attribute_group agrp; + const struct tsm_measurements *tm; + bool in_sync; + struct bin_attribute mrs[]; +}; + +static ssize_t tm_digest_read(struct file *filp, struct kobject *kobj, + const struct bin_attribute *attr, char *buffer, + loff_t off, size_t count) +{ + struct tm_context *ctx; + const struct tsm_measurement_register *mr; + int rc; + + ctx = attr->private; + rc = down_read_interruptible(&ctx->rwsem); + if (rc) + return rc; + + mr = &ctx->tm->mrs[attr - ctx->mrs]; + + /* + * @ctx->in_sync indicates if the MR cache is stale. It is a global + * instead of a per-MR flag for simplicity, as most (if not all) archs + * allow reading all MRs in oneshot. + * + * ctx->refresh() is necessary only for LIVE MRs, while others retain + * their values from their respective last ctx->write(). + */ + if ((mr->mr_flags & TSM_MR_F_LIVE) && !ctx->in_sync) { + up_read(&ctx->rwsem); + + rc = down_write_killable(&ctx->rwsem); + if (rc) + return rc; + + if (!ctx->in_sync) { + rc = ctx->tm->refresh(ctx->tm); + ctx->in_sync = !rc; + trace_tsm_mr_refresh(mr, rc); + } + + downgrade_write(&ctx->rwsem); + } + + memcpy(buffer, mr->mr_value + off, count); + trace_tsm_mr_read(mr); + + up_read(&ctx->rwsem); + return rc ?: count; +} + +static ssize_t tm_digest_write(struct file *filp, struct kobject *kobj, + const struct bin_attribute *attr, char *buffer, + loff_t off, size_t count) +{ + struct tm_context *ctx; + const struct tsm_measurement_register *mr; + ssize_t rc; + + /* partial writes are not supported */ + if (off != 0 || count != attr->size) + return -EINVAL; + + ctx = attr->private; + mr = &ctx->tm->mrs[attr - ctx->mrs]; + + rc = down_write_killable(&ctx->rwsem); + if (rc) + return rc; + + rc = ctx->tm->write(ctx->tm, mr, buffer); + + /* mark MR cache stale */ + if (!rc) { + ctx->in_sync = false; + trace_tsm_mr_write(mr, buffer); + } + + up_write(&ctx->rwsem); + return rc ?: count; +} + +/** + * tsm_mr_create_attribute_group() - creates an attribute group for measurement + * registers (MRs) + * @tm: pointer to &struct tsm_measurements containing the MR definitions. + * + * This function creates attributes corresponding to the MR definitions + * provided by @tm->mrs. + * + * The created attributes will reference @tm and its members. The caller must + * not free @tm until after tsm_mr_free_attribute_group() is called. + * + * Context: Process context. May sleep due to memory allocation. + * + * Return: + * * On success, the pointer to a an attribute group is returned; otherwise + * * %-EINVAL - Invalid MR definitions. + * * %-ENOMEM - Out of memory. + */ +const struct attribute_group * +tsm_mr_create_attribute_group(const struct tsm_measurements *tm) +{ + size_t nlen; + + if (!tm || !tm->mrs) + return ERR_PTR(-EINVAL); + + /* aggregated length of all MR names */ + nlen = 0; + for (size_t i = 0; i < tm->nr_mrs; ++i) { + if ((tm->mrs[i].mr_flags & TSM_MR_F_LIVE) && !tm->refresh) + return ERR_PTR(-EINVAL); + + if ((tm->mrs[i].mr_flags & TSM_MR_F_WRITABLE) && !tm->write) + return ERR_PTR(-EINVAL); + + if (!tm->mrs[i].mr_name) + return ERR_PTR(-EINVAL); + + if (tm->mrs[i].mr_flags & TSM_MR_F_NOHASH) + continue; + + if (tm->mrs[i].mr_hash >= HASH_ALGO__LAST) + return ERR_PTR(-EINVAL); + + /* MR sysfs attribute names have the form of MRNAME:HASH */ + nlen += strlen(tm->mrs[i].mr_name) + 1 + + strlen(hash_algo_name[tm->mrs[i].mr_hash]) + 1; + } + + /* + * @attrs and the MR name strings are combined into a single allocation + * so that we don't have to free MR names one-by-one in + * tsm_mr_free_attribute_group() + */ + const struct bin_attribute * const *attrs __free(kfree) = + kzalloc(sizeof(*attrs) * (tm->nr_mrs + 1) + nlen, GFP_KERNEL); + struct tm_context *ctx __free(kfree) = + kzalloc(struct_size(ctx, mrs, tm->nr_mrs), GFP_KERNEL); + char *name, *end; + + if (!ctx || !attrs) + return ERR_PTR(-ENOMEM); + + /* @attrs is followed immediately by MR name strings */ + name = (char *)&attrs[tm->nr_mrs + 1]; + end = name + nlen; + + for (size_t i = 0; i < tm->nr_mrs; ++i) { + /* break const for init */ + struct bin_attribute **bas = (struct bin_attribute **)attrs; + + bas[i] = &ctx->mrs[i]; + sysfs_bin_attr_init(bas[i]); + + if (tm->mrs[i].mr_flags & TSM_MR_F_NOHASH) + bas[i]->attr.name = tm->mrs[i].mr_name; + else if (name < end) { + bas[i]->attr.name = name; + name += snprintf(name, end - name, "%s:%s", + tm->mrs[i].mr_name, + hash_algo_name[tm->mrs[i].mr_hash]); + ++name; + } else + return ERR_PTR(-EINVAL); + + /* check for duplicated MR definitions */ + for (size_t j = 0; j < i; ++j) + if (!strcmp(bas[i]->attr.name, bas[j]->attr.name)) + return ERR_PTR(-EINVAL); + + if (tm->mrs[i].mr_flags & TSM_MR_F_READABLE) { + bas[i]->attr.mode |= 0444; + bas[i]->read_new = tm_digest_read; + } + + if (tm->mrs[i].mr_flags & TSM_MR_F_WRITABLE) { + bas[i]->attr.mode |= 0200; + bas[i]->write_new = tm_digest_write; + } + + bas[i]->size = tm->mrs[i].mr_size; + bas[i]->private = ctx; + } + + if (name != end) + return ERR_PTR(-EINVAL); + + init_rwsem(&ctx->rwsem); + ctx->agrp.name = "measurements"; + ctx->agrp.bin_attrs_new = no_free_ptr(attrs); + ctx->tm = tm; + return &no_free_ptr(ctx)->agrp; +} +EXPORT_SYMBOL_GPL(tsm_mr_create_attribute_group); + +/** + * tsm_mr_free_attribute_group() - frees the attribute group returned by + * tsm_mr_create_attribute_group() + * @attr_grp: attribute group returned by tsm_mr_create_attribute_group() + * + * Context: Process context. + */ +void tsm_mr_free_attribute_group(const struct attribute_group *attr_grp) +{ + if (!IS_ERR_OR_NULL(attr_grp)) { + kfree(attr_grp->bin_attrs); + kfree(container_of(attr_grp, struct tm_context, agrp)); + } +} +EXPORT_SYMBOL_GPL(tsm_mr_free_attribute_group); diff --git a/include/linux/tsm-mr.h b/include/linux/tsm-mr.h new file mode 100644 index 000000000000..50a521f4ac97 --- /dev/null +++ b/include/linux/tsm-mr.h @@ -0,0 +1,89 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __TSM_MR_H +#define __TSM_MR_H + +#include + +/** + * struct tsm_measurement_register - describes an architectural measurement + * register (MR) + * @mr_name: name of the MR + * @mr_value: buffer containing the current value of the MR + * @mr_size: size of the MR - typically the digest size of @mr_hash + * @mr_flags: bitwise OR of one or more flags, detailed below + * @mr_hash: optional hash identifier defined in include/uapi/linux/hash_info.h. + * + * A CC guest driver encloses an array of this structure in struct + * tsm_measurements to detail the measurement facility supported by the + * underlying CC hardware. + * + * @mr_name and @mr_value must stay valid until this structure is no longer in + * use. + * + * @mr_flags is the bitwise-OR of zero or more of the flags below. + * + * * %TSM_MR_F_READABLE - the sysfs attribute corresponding to this MR is readable. + * * %TSM_MR_F_WRITABLE - the sysfs attribute corresponding to this MR is writable. + * The semantics is typically to extend the MR but could vary depending on the + * architecture and the MR. + * * %TSM_MR_F_LIVE - this MR's value may differ from the last value written, so + * must be read back from the underlying CC hardware/firmware. + * * %TSM_MR_F_RTMR - bitwise-OR of %TSM_MR_F_LIVE and %TSM_MR_F_WRITABLE. + * * %TSM_MR_F_NOHASH - this MR does NOT have an associated hash algorithm. + * @mr_hash will be ignored when this flag is set. + */ +struct tsm_measurement_register { + const char *mr_name; + void *mr_value; + u32 mr_size; + u32 mr_flags; + enum hash_algo mr_hash; +}; + +#define TSM_MR_F_NOHASH 1 +#define TSM_MR_F_WRITABLE 2 +#define TSM_MR_F_READABLE 4 +#define TSM_MR_F_LIVE 8 +#define TSM_MR_F_RTMR (TSM_MR_F_LIVE | TSM_MR_F_WRITABLE) + +#define TSM_MR_(mr, hash) \ + .mr_name = #mr, .mr_size = hash##_DIGEST_SIZE, \ + .mr_hash = HASH_ALGO_##hash, .mr_flags = TSM_MR_F_READABLE + +/** + * struct tsm_measurements - defines the CC architecture specific measurement + * facility and methods for updating measurement registers (MRs) + * @mrs: Array of MR definitions. + * @nr_mrs: Number of elements in @mrs. + * @refresh: Callback function to load/sync all MRs from TVM hardware/firmware + * into the kernel cache. + * @write: Callback function to write to the MR specified by the parameter @mr. + * Typically, writing to an MR extends the input buffer to that MR. + * + * The @refresh callback is invoked when an MR with %TSM_MR_F_LIVE set is being + * read and the cache is stale. It must reload all MRs with %TSM_MR_F_LIVE set. + * The function parameter @tm is a pointer pointing back to this structure. + * + * The @write callback is invoked whenever an MR is being written. It takes two + * additional parameters besides @tm: + * + * * @mr - points to the MR (an element of @tm->mrs) being written. + * * @data - contains the bytes to write and whose size is @mr->mr_size. + * + * Both @refresh and @write should return 0 on success and an appropriate error + * code on failure. + */ +struct tsm_measurements { + const struct tsm_measurement_register *mrs; + size_t nr_mrs; + int (*refresh)(const struct tsm_measurements *tm); + int (*write)(const struct tsm_measurements *tm, + const struct tsm_measurement_register *mr, const u8 *data); +}; + +const struct attribute_group * +tsm_mr_create_attribute_group(const struct tsm_measurements *tm); +void tsm_mr_free_attribute_group(const struct attribute_group *attr_grp); + +#endif diff --git a/include/trace/events/tsm_mr.h b/include/trace/events/tsm_mr.h new file mode 100644 index 000000000000..f40de4ad3e2d --- /dev/null +++ b/include/trace/events/tsm_mr.h @@ -0,0 +1,80 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM tsm_mr + +#if !defined(_TRACE_TSM_MR_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_TSM_MR_H + +#include +#include + +TRACE_EVENT(tsm_mr_read, + + TP_PROTO(const struct tsm_measurement_register *mr), + + TP_ARGS(mr), + + TP_STRUCT__entry( + __string(mr, mr->mr_name) + __string(hash, mr->mr_flags & TSM_MR_F_NOHASH ? + "data" : hash_algo_name[mr->mr_hash]) + __dynamic_array(u8, d, mr->mr_size) + ), + + TP_fast_assign( + __assign_str(mr); + __assign_str(hash); + memcpy(__get_dynamic_array(d), mr->mr_value, __get_dynamic_array_len(d)); + ), + + TP_printk("[%s] %s:%s", __get_str(mr), __get_str(hash), + __print_hex_str(__get_dynamic_array(d), __get_dynamic_array_len(d))) +); + +TRACE_EVENT(tsm_mr_refresh, + + TP_PROTO(const struct tsm_measurement_register *mr, int rc), + + TP_ARGS(mr, rc), + + TP_STRUCT__entry( + __string(mr, mr->mr_name) + __field(int, rc) + ), + + TP_fast_assign( + __assign_str(mr); + __entry->rc = rc; + ), + + TP_printk("[%s] %s:%d", __get_str(mr), + __entry->rc ? "failed" : "succeeded", __entry->rc) +); + +TRACE_EVENT(tsm_mr_write, + + TP_PROTO(const struct tsm_measurement_register *mr, const u8 *data), + + TP_ARGS(mr, data), + + TP_STRUCT__entry( + __string(mr, mr->mr_name) + __string(hash, mr->mr_flags & TSM_MR_F_NOHASH ? + "data" : hash_algo_name[mr->mr_hash]) + __dynamic_array(u8, d, mr->mr_size) + ), + + TP_fast_assign( + __assign_str(mr); + __assign_str(hash); + memcpy(__get_dynamic_array(d), data, __get_dynamic_array_len(d)); + ), + + TP_printk("[%s] %s:%s", __get_str(mr), __get_str(hash), + __print_hex_str(__get_dynamic_array(d), __get_dynamic_array_len(d))) +); + +#endif + +/* This part must be outside protection */ +#include From f6953f1f9ec4ad68651d7c677f0c065cb4c1edf7 Mon Sep 17 00:00:00 2001 From: Cedric Xing Date: Tue, 6 May 2025 17:57:08 -0500 Subject: [PATCH 05/12] tsm-mr: Add tsm-mr sample code MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This sample kernel module demonstrates how to make MRs accessible to user mode through the tsm-mr library. Once loaded, this module registers a `miscdevice` that host a set of emulated measurement registers as shown in the directory tree below. /sys/class/misc/tsm_mr_sample └── measurements ├── config_mr ├── report_digest:sha512 ├── rtmr0:sha256 ├── rtmr1:sha384 ├── rtmr_crypto_agile:sha256 ├── rtmr_crypto_agile:sha384 └── static_mr:sha384 Among the MRs in this example: - `config_mr` demonstrates a hashless MR, like MRCONFIGID in Intel TDX or HOSTDATA in AMD SEV. - `static_mr` demonstrates a static MR. The suffix `:sha384` indicates its value is a sha384 digest. - `rtmr0` is an RTMR with `TSM_MR_F_WRITABLE` **cleared**, preventing direct extensions; as a result, the attribute `rtmr0:sha256` is read-only. - `rtmr1` is an RTMR with `TSM_MR_F_WRITABLE` **set**, permitting direct extensions; thus, the attribute `rtmr1:sha384` is writable. - `rtmr_crypto_agile` demonstrates a "single" MR that supports multiple hash algorithms. Each supported algorithm has a corresponding digest, usually referred to as a "bank" in TCG terminology. In this specific sample, the 2 banks are aliased to `rtmr0` and `rtmr1`, respectively. - `report_digest` contains the digest of the internal report structure living in this sample module's memory. It is to demonstrate the use of the `TSM_MR_F_LIVE` flag. Its value changes each time an RTMR is extended. Signed-off-by: Cedric Xing Reviewed-by: Dan Williams Acked-by: Dionna Amalie Glaze Link: https://patch.msgid.link/20250506-tdx-rtmr-v6-2-ac6ff5e9d58a@intel.com Signed-off-by: Dan Williams --- MAINTAINERS | 1 + samples/Kconfig | 11 +++ samples/Makefile | 1 + samples/tsm-mr/Makefile | 2 + samples/tsm-mr/tsm_mr_sample.c | 131 +++++++++++++++++++++++++++++++++ 5 files changed, 146 insertions(+) create mode 100644 samples/tsm-mr/Makefile create mode 100644 samples/tsm-mr/tsm_mr_sample.c diff --git a/MAINTAINERS b/MAINTAINERS index 5d36823d26b2..8bf8a818bce5 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -24651,6 +24651,7 @@ F: Documentation/ABI/testing/configfs-tsm F: Documentation/driver-api/coco/ F: drivers/virt/coco/tsm*.c F: include/linux/tsm*.h +F: samples/tsm/ TRUSTED SERVICES TEE DRIVER M: Balint Dobszay diff --git a/samples/Kconfig b/samples/Kconfig index 09011be2391a..6ade17cb16b4 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -184,6 +184,17 @@ config SAMPLE_TIMER bool "Timer sample" depends on CC_CAN_LINK && HEADERS_INSTALL +config SAMPLE_TSM_MR + tristate "TSM measurement sample" + select TSM_MEASUREMENTS + select VIRT_DRIVERS + help + Build a sample module that emulates MRs (Measurement Registers) and + exposes them to user mode applications through the TSM sysfs + interface (/sys/class/misc/tsm_mr_sample/emulated_mr/). + + The module name will be tsm-mr-sample when built as a module. + config SAMPLE_UHID bool "UHID sample" depends on CC_CAN_LINK && HEADERS_INSTALL diff --git a/samples/Makefile b/samples/Makefile index bf6e6fca5410..c95bac31851c 100644 --- a/samples/Makefile +++ b/samples/Makefile @@ -43,3 +43,4 @@ obj-$(CONFIG_SAMPLES_RUST) += rust/ obj-$(CONFIG_SAMPLE_DAMON_WSSE) += damon/ obj-$(CONFIG_SAMPLE_DAMON_PRCL) += damon/ obj-$(CONFIG_SAMPLE_HUNG_TASK) += hung_task/ +obj-$(CONFIG_SAMPLE_TSM_MR) += tsm-mr/ diff --git a/samples/tsm-mr/Makefile b/samples/tsm-mr/Makefile new file mode 100644 index 000000000000..587c3947b3a7 --- /dev/null +++ b/samples/tsm-mr/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_SAMPLE_TSM_MR) += tsm_mr_sample.o diff --git a/samples/tsm-mr/tsm_mr_sample.c b/samples/tsm-mr/tsm_mr_sample.c new file mode 100644 index 000000000000..f3e16301de40 --- /dev/null +++ b/samples/tsm-mr/tsm_mr_sample.c @@ -0,0 +1,131 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2024-2005 Intel Corporation. All rights reserved. */ + +#define pr_fmt(x) KBUILD_MODNAME ": " x + +#include +#include +#include +#include + +struct { + u8 static_mr[SHA384_DIGEST_SIZE]; + u8 config_mr[SHA512_DIGEST_SIZE]; + u8 rtmr0[SHA256_DIGEST_SIZE]; + u8 rtmr1[SHA384_DIGEST_SIZE]; + u8 report_digest[SHA512_DIGEST_SIZE]; +} sample_report = { + .static_mr = "static_mr", + .config_mr = "config_mr", + .rtmr0 = "rtmr0", + .rtmr1 = "rtmr1", +}; + +static int sample_report_refresh(const struct tsm_measurements *tm) +{ + struct crypto_shash *tfm; + int rc; + + tfm = crypto_alloc_shash(hash_algo_name[HASH_ALGO_SHA512], 0, 0); + if (IS_ERR(tfm)) { + pr_err("crypto_alloc_shash failed: %ld\n", PTR_ERR(tfm)); + return PTR_ERR(tfm); + } + + rc = crypto_shash_tfm_digest(tfm, (u8 *)&sample_report, + offsetof(typeof(sample_report), + report_digest), + sample_report.report_digest); + crypto_free_shash(tfm); + if (rc) + pr_err("crypto_shash_tfm_digest failed: %d\n", rc); + return rc; +} + +static int sample_report_extend_mr(const struct tsm_measurements *tm, + const struct tsm_measurement_register *mr, + const u8 *data) +{ + SHASH_DESC_ON_STACK(desc, 0); + int rc; + + desc->tfm = crypto_alloc_shash(hash_algo_name[mr->mr_hash], 0, 0); + if (IS_ERR(desc->tfm)) { + pr_err("crypto_alloc_shash failed: %ld\n", PTR_ERR(desc->tfm)); + return PTR_ERR(desc->tfm); + } + + rc = crypto_shash_init(desc); + if (!rc) + rc = crypto_shash_update(desc, mr->mr_value, mr->mr_size); + if (!rc) + rc = crypto_shash_finup(desc, data, mr->mr_size, mr->mr_value); + crypto_free_shash(desc->tfm); + if (rc) + pr_err("SHA calculation failed: %d\n", rc); + return rc; +} + +#define MR_(mr, hash) .mr_value = &sample_report.mr, TSM_MR_(mr, hash) +static const struct tsm_measurement_register sample_mrs[] = { + /* static MR, read-only */ + { MR_(static_mr, SHA384) }, + /* config MR, read-only */ + { MR_(config_mr, SHA512) | TSM_MR_F_NOHASH }, + /* RTMR, direct extension prohibited */ + { MR_(rtmr0, SHA256) | TSM_MR_F_LIVE }, + /* RTMR, direct extension allowed */ + { MR_(rtmr1, SHA384) | TSM_MR_F_RTMR }, + /* RTMR, crypto agile, alaised to rtmr0 and rtmr1, respectively */ + { .mr_value = &sample_report.rtmr0, + TSM_MR_(rtmr_crypto_agile, SHA256) | TSM_MR_F_RTMR }, + { .mr_value = &sample_report.rtmr1, + TSM_MR_(rtmr_crypto_agile, SHA384) | TSM_MR_F_RTMR }, + /* sha512 digest of the whole structure */ + { MR_(report_digest, SHA512) | TSM_MR_F_LIVE }, +}; +#undef MR_ + +static struct tsm_measurements sample_tm = { + .mrs = sample_mrs, + .nr_mrs = ARRAY_SIZE(sample_mrs), + .refresh = sample_report_refresh, + .write = sample_report_extend_mr, +}; + +static const struct attribute_group *sample_groups[] = { + NULL, + NULL, +}; + +static struct miscdevice sample_misc_dev = { + .name = KBUILD_MODNAME, + .minor = MISC_DYNAMIC_MINOR, + .groups = sample_groups, +}; + +static int __init tsm_mr_sample_init(void) +{ + int rc; + + sample_groups[0] = tsm_mr_create_attribute_group(&sample_tm); + if (IS_ERR(sample_groups[0])) + return PTR_ERR(sample_groups[0]); + + rc = misc_register(&sample_misc_dev); + if (rc) + tsm_mr_free_attribute_group(sample_groups[0]); + return rc; +} + +static void __exit tsm_mr_sample_exit(void) +{ + misc_deregister(&sample_misc_dev); + tsm_mr_free_attribute_group(sample_groups[0]); +} + +module_init(tsm_mr_sample_init); +module_exit(tsm_mr_sample_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Sample module using tsm-mr to expose emulated MRs"); From 3f88ca9614219cb29548669e18677d2e32099399 Mon Sep 17 00:00:00 2001 From: Cedric Xing Date: Tue, 6 May 2025 17:57:09 -0500 Subject: [PATCH 06/12] x86/tdx: Add tdx_mcall_extend_rtmr() interface The TDX guest exposes one MRTD (Build-time Measurement Register) and four RTMR (Run-time Measurement Register) registers to record the build and boot measurements of a virtual machine (VM). These registers are similar to PCR (Platform Configuration Register) registers in the TPM (Trusted Platform Module) space. This measurement data is used to implement security features like attestation and trusted boot. To facilitate updating the RTMR registers, the TDX module provides support for the `TDG.MR.RTMR.EXTEND` TDCALL which can be used to securely extend the RTMR registers. Add helper function to update RTMR registers. It will be used by the TDX guest driver in enabling RTMR extension support. Co-developed-by: Kuppuswamy Sathyanarayanan Signed-off-by: Kuppuswamy Sathyanarayanan Signed-off-by: Cedric Xing Acked-by: Dionna Amalie Glaze Acked-by: Dave Hansen Link: https://patch.msgid.link/20250506-tdx-rtmr-v6-3-ac6ff5e9d58a@intel.com Signed-off-by: Dan Williams --- arch/x86/coco/tdx/tdx.c | 37 +++++++++++++++++++++++++++++++ arch/x86/include/asm/shared/tdx.h | 1 + arch/x86/include/asm/tdx.h | 2 ++ 3 files changed, 40 insertions(+) diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index edab6d6049be..0b6804d2a5e1 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -36,6 +36,7 @@ /* TDX Module call error codes */ #define TDCALL_RETURN_CODE(a) ((a) >> 32) #define TDCALL_INVALID_OPERAND 0xc0000100 +#define TDCALL_OPERAND_BUSY 0x80000200 #define TDREPORT_SUBTYPE_0 0 @@ -136,6 +137,42 @@ int tdx_mcall_get_report0(u8 *reportdata, u8 *tdreport) } EXPORT_SYMBOL_GPL(tdx_mcall_get_report0); +/** + * tdx_mcall_extend_rtmr() - Wrapper to extend RTMR registers using + * TDG.MR.RTMR.EXTEND TDCALL. + * @index: Index of RTMR register to be extended. + * @data: Address of the input buffer with RTMR register extend data. + * + * Refer to section titled "TDG.MR.RTMR.EXTEND leaf" in the TDX Module v1.0 + * specification for more information on TDG.MR.RTMR.EXTEND TDCALL. + * + * It is used in the TDX guest driver module to allow user to extend the RTMR + * registers. + * + * Return 0 on success, -ENXIO for invalid operands, -EBUSY for busy operation, + * or -EIO on other TDCALL failures. + */ +int tdx_mcall_extend_rtmr(u8 index, u8 *data) +{ + struct tdx_module_args args = { + .rcx = virt_to_phys(data), + .rdx = index, + }; + u64 ret; + + ret = __tdcall(TDG_MR_RTMR_EXTEND, &args); + if (ret) { + if (TDCALL_RETURN_CODE(ret) == TDCALL_INVALID_OPERAND) + return -ENXIO; + if (TDCALL_RETURN_CODE(ret) == TDCALL_OPERAND_BUSY) + return -EBUSY; + return -EIO; + } + + return 0; +} +EXPORT_SYMBOL_GPL(tdx_mcall_extend_rtmr); + /** * tdx_hcall_get_quote() - Wrapper to request TD Quote using GetQuote * hypercall. diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h index a28ff6b14145..738f583f65cb 100644 --- a/arch/x86/include/asm/shared/tdx.h +++ b/arch/x86/include/asm/shared/tdx.h @@ -13,6 +13,7 @@ /* TDX module Call Leaf IDs */ #define TDG_VP_VMCALL 0 #define TDG_VP_INFO 1 +#define TDG_MR_RTMR_EXTEND 2 #define TDG_VP_VEINFO_GET 3 #define TDG_MR_REPORT 4 #define TDG_MEM_PAGE_ACCEPT 6 diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h index 4a1922ec80cf..12d17f3ca301 100644 --- a/arch/x86/include/asm/tdx.h +++ b/arch/x86/include/asm/tdx.h @@ -64,6 +64,8 @@ bool tdx_early_handle_ve(struct pt_regs *regs); int tdx_mcall_get_report0(u8 *reportdata, u8 *tdreport); +int tdx_mcall_extend_rtmr(u8 index, u8 *data); + u64 tdx_hcall_get_quote(u8 *buf, size_t size); void __init tdx_dump_attributes(u64 td_attr); From 2748566da8b03d924fb8ef6f2ce19e8f5d5060c7 Mon Sep 17 00:00:00 2001 From: Cedric Xing Date: Tue, 6 May 2025 17:57:10 -0500 Subject: [PATCH 07/12] x86/tdx: tdx_mcall_get_report0: Return -EBUSY on TDCALL_OPERAND_BUSY error Return `-EBUSY` from tdx_mcall_get_report0() when `TDG.MR.REPORT` returns `TDCALL_OPERAND_BUSY`. This enables the caller to retry obtaining a TDREPORT later if another VCPU is extending an RTMR concurrently. Signed-off-by: Cedric Xing Acked-by: Dionna Amalie Glaze Acked-by: Dave Hansen Link: https://patch.msgid.link/20250506-tdx-rtmr-v6-4-ac6ff5e9d58a@intel.com Signed-off-by: Dan Williams --- arch/x86/coco/tdx/tdx.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index 0b6804d2a5e1..7b2833705d47 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -110,12 +110,13 @@ static inline u64 tdg_vm_wr(u64 field, u64 value, u64 mask) * REPORTDATA to be included into TDREPORT. * @tdreport: Address of the output buffer to store TDREPORT. * - * Refer to section titled "TDG.MR.REPORT leaf" in the TDX Module - * v1.0 specification for more information on TDG.MR.REPORT TDCALL. + * Refer to section titled "TDG.MR.REPORT leaf" in the TDX Module v1.0 + * specification for more information on TDG.MR.REPORT TDCALL. + * * It is used in the TDX guest driver module to get the TDREPORT0. * - * Return 0 on success, -EINVAL for invalid operands, or -EIO on - * other TDCALL failures. + * Return 0 on success, -ENXIO for invalid operands, -EBUSY for busy operation, + * or -EIO on other TDCALL failures. */ int tdx_mcall_get_report0(u8 *reportdata, u8 *tdreport) { @@ -129,7 +130,9 @@ int tdx_mcall_get_report0(u8 *reportdata, u8 *tdreport) ret = __tdcall(TDG_MR_REPORT, &args); if (ret) { if (TDCALL_RETURN_CODE(ret) == TDCALL_INVALID_OPERAND) - return -EINVAL; + return -ENXIO; + else if (TDCALL_RETURN_CODE(ret) == TDCALL_OPERAND_BUSY) + return -EBUSY; return -EIO; } From 4d2a7bfad5b79b3a362fc7cfed8d7ddbd263a838 Mon Sep 17 00:00:00 2001 From: Cedric Xing Date: Wed, 7 May 2025 18:06:06 -0700 Subject: [PATCH 08/12] virt: tdx-guest: Expose TDX MRs as sysfs attributes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Expose the most commonly used TDX MRs (Measurement Registers) as sysfs attributes. Use the ioctl() interface of /dev/tdx_guest to request a full TDREPORT for access to other TD measurements. Directory structure of TDX MRs inside a TDVM is as follows: /sys/class/misc/tdx_guest └── measurements ├── mrconfigid ├── mrowner ├── mrownerconfig ├── mrtd:sha384 ├── rtmr0:sha384 ├── rtmr1:sha384 ├── rtmr2:sha384 └── rtmr3:sha384 Read the file/attribute to retrieve the current value of an MR. Write to the file/attribute (if writable) to extend the corresponding RTMR. Refer to Documentation/ABI/testing/sysfs-devices-virtual-misc-tdx_guest for more information. Signed-off-by: Cedric Xing Acked-by: Dionna Amalie Glaze [djbw: fixup exit order] Link: https://patch.msgid.link/20250508010606.4129953-1-dan.j.williams@intel.com Signed-off-by: Dan Williams --- .../sysfs-devices-virtual-misc-tdx_guest | 63 ++++++++ MAINTAINERS | 1 + drivers/virt/coco/tdx-guest/Kconfig | 1 + drivers/virt/coco/tdx-guest/tdx-guest.c | 151 +++++++++++++++++- 4 files changed, 214 insertions(+), 2 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-devices-virtual-misc-tdx_guest diff --git a/Documentation/ABI/testing/sysfs-devices-virtual-misc-tdx_guest b/Documentation/ABI/testing/sysfs-devices-virtual-misc-tdx_guest new file mode 100644 index 000000000000..8fca56c8c9df --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-virtual-misc-tdx_guest @@ -0,0 +1,63 @@ +What: /sys/devices/virtual/misc/tdx_guest/measurements/MRNAME[:HASH] +Date: April, 2025 +KernelVersion: v6.16 +Contact: linux-coco@lists.linux.dev +Description: + Value of a TDX measurement register (MR). MRNAME and HASH above + are placeholders. The optional suffix :HASH is used for MRs + that have associated hash algorithms. See below for a complete + list of TDX MRs exposed via sysfs. Refer to Intel TDX Module + ABI Specification for the definition of TDREPORT and the full + list of TDX measurements. + + Intel TDX Module ABI Specification can be found at: + https://www.intel.com/content/www/us/en/developer/tools/trust-domain-extensions/documentation.html#architecture + + See also: + https://docs.kernel.org/driver-api/coco/measurement-registers.html + +What: /sys/devices/virtual/misc/tdx_guest/measurements/mrconfigid +Date: April, 2025 +KernelVersion: v6.16 +Contact: linux-coco@lists.linux.dev +Description: + (RO) MRCONFIGID - 48-byte immutable storage typically used for + software-defined ID for non-owner-defined configuration of the + guest TD – e.g., run-time or OS configuration. + +What: /sys/devices/virtual/misc/tdx_guest/measurements/mrowner +Date: April, 2025 +KernelVersion: v6.16 +Contact: linux-coco@lists.linux.dev +Description: + (RO) MROWNER - 48-byte immutable storage typically used for + software-defined ID for the guest TD’s owner. + +What: /sys/devices/virtual/misc/tdx_guest/measurements/mrownerconfig +Date: April, 2025 +KernelVersion: v6.16 +Contact: linux-coco@lists.linux.dev +Description: + (RO) MROWNERCONFIG - 48-byte immutable storage typically used + for software-defined ID for owner-defined configuration of the + guest TD – e.g., specific to the workload rather than the + run-time or OS. + +What: /sys/devices/virtual/misc/tdx_guest/measurements/mrtd:sha384 +Date: April, 2025 +KernelVersion: v6.16 +Contact: linux-coco@lists.linux.dev +Description: + (RO) MRTD - Measurement of the initial contents of the TD. + +What: /sys/devices/virtual/misc/tdx_guest/measurements/rtmr[0123]:sha384 +Date: April, 2025 +KernelVersion: v6.16 +Contact: linux-coco@lists.linux.dev +Description: + (RW) RTMR[0123] - 4 Run-Time extendable Measurement Registers. + Read from any of these returns the current value of the + corresponding RTMR. Write extends the written buffer to the + RTMR. All writes must start at offset 0 and be 48 bytes in + size. Partial writes will result in EINVAL returned by the + write() syscall. diff --git a/MAINTAINERS b/MAINTAINERS index 8bf8a818bce5..912e16ace0b4 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -26321,6 +26321,7 @@ L: x86@kernel.org L: linux-coco@lists.linux.dev S: Supported T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/tdx +F: Documentation/ABI/testing/sysfs-devices-virtual-misc-tdx_guest F: arch/x86/boot/compressed/tdx* F: arch/x86/coco/tdx/ F: arch/x86/include/asm/shared/tdx.h diff --git a/drivers/virt/coco/tdx-guest/Kconfig b/drivers/virt/coco/tdx-guest/Kconfig index 22dd59e19431..dbbdc14383b1 100644 --- a/drivers/virt/coco/tdx-guest/Kconfig +++ b/drivers/virt/coco/tdx-guest/Kconfig @@ -2,6 +2,7 @@ config TDX_GUEST_DRIVER tristate "TDX Guest driver" depends on INTEL_TDX_GUEST select TSM_REPORTS + select TSM_MEASUREMENTS help The driver provides userspace interface to communicate with the TDX module to request the TDX guest details like attestation diff --git a/drivers/virt/coco/tdx-guest/tdx-guest.c b/drivers/virt/coco/tdx-guest/tdx-guest.c index 224e7dde9cde..15810fb02d98 100644 --- a/drivers/virt/coco/tdx-guest/tdx-guest.c +++ b/drivers/virt/coco/tdx-guest/tdx-guest.c @@ -5,6 +5,8 @@ * Copyright (C) 2022 Intel Corporation */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include #include #include @@ -15,14 +17,146 @@ #include #include #include +#include #include -#include +#include #include #include #include +/* TDREPORT buffer */ +static u8 *tdx_report_buf; + +/* Lock to serialize TDG.MR.REPORT and TDG.MR.RTMR.EXTEND TDCALLs */ +static DEFINE_MUTEX(mr_lock); + +/* TDREPORT fields */ +enum { + TDREPORT_reportdata = 128, + TDREPORT_tee_tcb_info = 256, + TDREPORT_tdinfo = TDREPORT_tee_tcb_info + 256, + TDREPORT_attributes = TDREPORT_tdinfo, + TDREPORT_xfam = TDREPORT_attributes + sizeof(u64), + TDREPORT_mrtd = TDREPORT_xfam + sizeof(u64), + TDREPORT_mrconfigid = TDREPORT_mrtd + SHA384_DIGEST_SIZE, + TDREPORT_mrowner = TDREPORT_mrconfigid + SHA384_DIGEST_SIZE, + TDREPORT_mrownerconfig = TDREPORT_mrowner + SHA384_DIGEST_SIZE, + TDREPORT_rtmr0 = TDREPORT_mrownerconfig + SHA384_DIGEST_SIZE, + TDREPORT_rtmr1 = TDREPORT_rtmr0 + SHA384_DIGEST_SIZE, + TDREPORT_rtmr2 = TDREPORT_rtmr1 + SHA384_DIGEST_SIZE, + TDREPORT_rtmr3 = TDREPORT_rtmr2 + SHA384_DIGEST_SIZE, + TDREPORT_servtd_hash = TDREPORT_rtmr3 + SHA384_DIGEST_SIZE, +}; + +static int tdx_do_report(sockptr_t data, sockptr_t tdreport) +{ + scoped_cond_guard(mutex_intr, return -EINTR, &mr_lock) { + u8 *reportdata = tdx_report_buf + TDREPORT_reportdata; + int ret; + + if (!sockptr_is_null(data) && + copy_from_sockptr(reportdata, data, TDX_REPORTDATA_LEN)) + return -EFAULT; + + ret = tdx_mcall_get_report0(reportdata, tdx_report_buf); + if (WARN_ONCE(ret, "tdx_mcall_get_report0() failed: %d", ret)) + return ret; + + if (!sockptr_is_null(tdreport) && + copy_to_sockptr(tdreport, tdx_report_buf, TDX_REPORT_LEN)) + return -EFAULT; + } + return 0; +} + +static int tdx_do_extend(u8 mr_ind, const u8 *data) +{ + scoped_cond_guard(mutex_intr, return -EINTR, &mr_lock) { + /* + * TDX requires @extend_buf to be 64-byte aligned. + * It's safe to use REPORTDATA buffer for that purpose because + * tdx_mr_report/extend_lock() are mutually exclusive. + */ + u8 *extend_buf = tdx_report_buf + TDREPORT_reportdata; + int ret; + + memcpy(extend_buf, data, SHA384_DIGEST_SIZE); + + ret = tdx_mcall_extend_rtmr(mr_ind, extend_buf); + if (WARN_ONCE(ret, "tdx_mcall_extend_rtmr(%u) failed: %d", mr_ind, ret)) + return ret; + } + return 0; +} + +#define TDX_MR_(r) .mr_value = (void *)TDREPORT_##r, TSM_MR_(r, SHA384) +static struct tsm_measurement_register tdx_mrs[] = { + { TDX_MR_(rtmr0) | TSM_MR_F_RTMR }, + { TDX_MR_(rtmr1) | TSM_MR_F_RTMR }, + { TDX_MR_(rtmr2) | TSM_MR_F_RTMR }, + { TDX_MR_(rtmr3) | TSM_MR_F_RTMR }, + { TDX_MR_(mrtd) }, + { TDX_MR_(mrconfigid) | TSM_MR_F_NOHASH }, + { TDX_MR_(mrowner) | TSM_MR_F_NOHASH }, + { TDX_MR_(mrownerconfig) | TSM_MR_F_NOHASH }, +}; +#undef TDX_MR_ + +static int tdx_mr_refresh(const struct tsm_measurements *tm) +{ + return tdx_do_report(KERNEL_SOCKPTR(NULL), KERNEL_SOCKPTR(NULL)); +} + +static int tdx_mr_extend(const struct tsm_measurements *tm, + const struct tsm_measurement_register *mr, + const u8 *data) +{ + return tdx_do_extend(mr - tm->mrs, data); +} + +static struct tsm_measurements tdx_measurements = { + .mrs = tdx_mrs, + .nr_mrs = ARRAY_SIZE(tdx_mrs), + .refresh = tdx_mr_refresh, + .write = tdx_mr_extend, +}; + +static const struct attribute_group *tdx_mr_init(void) +{ + const struct attribute_group *g; + int rc; + + u8 *buf __free(kfree) = kzalloc(TDX_REPORT_LEN, GFP_KERNEL); + if (!buf) + return ERR_PTR(-ENOMEM); + + tdx_report_buf = buf; + rc = tdx_mr_refresh(&tdx_measurements); + if (rc) + return ERR_PTR(rc); + + /* + * @mr_value was initialized with the offset only, while the base + * address is being added here. + */ + for (size_t i = 0; i < ARRAY_SIZE(tdx_mrs); ++i) + *(long *)&tdx_mrs[i].mr_value += (long)buf; + + g = tsm_mr_create_attribute_group(&tdx_measurements); + if (!IS_ERR(g)) + tdx_report_buf = no_free_ptr(buf); + + return g; +} + +static void tdx_mr_deinit(const struct attribute_group *mr_grp) +{ + tsm_mr_free_attribute_group(mr_grp); + kfree(tdx_report_buf); +} + /* * Intel's SGX QE implementation generally uses Quote size less * than 8K (2K Quote data + ~5K of certificate blob). @@ -285,10 +419,16 @@ static const struct file_operations tdx_guest_fops = { .unlocked_ioctl = tdx_guest_ioctl, }; +static const struct attribute_group *tdx_attr_groups[] = { + NULL, /* measurements */ + NULL +}; + static struct miscdevice tdx_misc_dev = { .name = KBUILD_MODNAME, .minor = MISC_DYNAMIC_MINOR, .fops = &tdx_guest_fops, + .groups = tdx_attr_groups, }; static const struct x86_cpu_id tdx_guest_ids[] = { @@ -311,9 +451,13 @@ static int __init tdx_guest_init(void) if (!x86_match_cpu(tdx_guest_ids)) return -ENODEV; + tdx_attr_groups[0] = tdx_mr_init(); + if (IS_ERR(tdx_attr_groups[0])) + return PTR_ERR(tdx_attr_groups[0]); + ret = misc_register(&tdx_misc_dev); if (ret) - return ret; + goto deinit_mr; quote_data = alloc_quote_buf(); if (!quote_data) { @@ -332,6 +476,8 @@ static int __init tdx_guest_init(void) free_quote_buf(quote_data); free_misc: misc_deregister(&tdx_misc_dev); +deinit_mr: + tdx_mr_deinit(tdx_attr_groups[0]); return ret; } @@ -342,6 +488,7 @@ static void __exit tdx_guest_exit(void) tsm_unregister(&tdx_tsm_ops); free_quote_buf(quote_data); misc_deregister(&tdx_misc_dev); + tdx_mr_deinit(tdx_attr_groups[0]); } module_exit(tdx_guest_exit); From 850972bc61eba68552763c937892abb66a114da1 Mon Sep 17 00:00:00 2001 From: Cedric Xing Date: Tue, 6 May 2025 17:57:12 -0500 Subject: [PATCH 09/12] virt: tdx-guest: Refactor and streamline TDREPORT generation Consolidate instances (code segments) of TDREPORT generation to improve readability and maintainability, by refactoring each instance into invoking a unified subroutine throughout the TDX guest driver. Implement proper locking around TDG.MR.REPORT and TDG.MR.RTMR.EXTEND to avoid race inside the TDX module. Preallocate TDREPORT buffer to reduce overhead in subsequent TDREPORT generation. Signed-off-by: Cedric Xing Acked-by: Dionna Amalie Glaze Link: https://patch.msgid.link/20250506-tdx-rtmr-v6-6-ac6ff5e9d58a@intel.com Signed-off-by: Dan Williams --- drivers/virt/coco/tdx-guest/tdx-guest.c | 63 +++---------------------- 1 file changed, 7 insertions(+), 56 deletions(-) diff --git a/drivers/virt/coco/tdx-guest/tdx-guest.c b/drivers/virt/coco/tdx-guest/tdx-guest.c index 15810fb02d98..34125c501833 100644 --- a/drivers/virt/coco/tdx-guest/tdx-guest.c +++ b/drivers/virt/coco/tdx-guest/tdx-guest.c @@ -202,37 +202,8 @@ static u32 getquote_timeout = 30; static long tdx_get_report0(struct tdx_report_req __user *req) { - u8 *reportdata, *tdreport; - long ret; - - reportdata = kmalloc(TDX_REPORTDATA_LEN, GFP_KERNEL); - if (!reportdata) - return -ENOMEM; - - tdreport = kzalloc(TDX_REPORT_LEN, GFP_KERNEL); - if (!tdreport) { - ret = -ENOMEM; - goto out; - } - - if (copy_from_user(reportdata, req->reportdata, TDX_REPORTDATA_LEN)) { - ret = -EFAULT; - goto out; - } - - /* Generate TDREPORT0 using "TDG.MR.REPORT" TDCALL */ - ret = tdx_mcall_get_report0(reportdata, tdreport); - if (ret) - goto out; - - if (copy_to_user(req->tdreport, tdreport, TDX_REPORT_LEN)) - ret = -EFAULT; - -out: - kfree(reportdata); - kfree(tdreport); - - return ret; + return tdx_do_report(USER_SOCKPTR(req->reportdata), + USER_SOCKPTR(req->tdreport)); } static void free_quote_buf(void *buf) @@ -293,7 +264,7 @@ static int wait_for_quote_completion(struct tdx_quote_buf *quote_buf, u32 timeou static int tdx_report_new(struct tsm_report *report, void *data) { - u8 *buf, *reportdata = NULL, *tdreport = NULL; + u8 *buf; struct tdx_quote_buf *quote_buf = quote_data; struct tsm_desc *desc = &report->desc; int ret; @@ -318,34 +289,16 @@ static int tdx_report_new(struct tsm_report *report, void *data) goto done; } - reportdata = kmalloc(TDX_REPORTDATA_LEN, GFP_KERNEL); - if (!reportdata) { - ret = -ENOMEM; - goto done; - } - - tdreport = kzalloc(TDX_REPORT_LEN, GFP_KERNEL); - if (!tdreport) { - ret = -ENOMEM; - goto done; - } - - memcpy(reportdata, desc->inblob, desc->inblob_len); - - /* Generate TDREPORT0 using "TDG.MR.REPORT" TDCALL */ - ret = tdx_mcall_get_report0(reportdata, tdreport); - if (ret) { - pr_err("GetReport call failed\n"); - goto done; - } - memset(quote_data, 0, GET_QUOTE_BUF_SIZE); /* Update Quote buffer header */ quote_buf->version = GET_QUOTE_CMD_VER; quote_buf->in_len = TDX_REPORT_LEN; - memcpy(quote_buf->data, tdreport, TDX_REPORT_LEN); + ret = tdx_do_report(KERNEL_SOCKPTR(desc->inblob), + KERNEL_SOCKPTR(quote_buf->data)); + if (ret) + goto done; err = tdx_hcall_get_quote(quote_data, GET_QUOTE_BUF_SIZE); if (err) { @@ -375,8 +328,6 @@ static int tdx_report_new(struct tsm_report *report, void *data) */ done: mutex_unlock("e_lock); - kfree(reportdata); - kfree(tdreport); return ret; } From 7c3f259dfe03f5dcd898126602818a8fbe94d3c5 Mon Sep 17 00:00:00 2001 From: Cedric Xing Date: Tue, 6 May 2025 17:57:13 -0500 Subject: [PATCH 10/12] virt: tdx-guest: Transition to scoped_cond_guard for mutex operations Replace mutex_lock_interruptible()/mutex_unlock() with scoped_cond_guard to enhance code readability and maintainability. Signed-off-by: Cedric Xing Acked-by: Dionna Amalie Glaze Link: https://patch.msgid.link/20250506-tdx-rtmr-v6-7-ac6ff5e9d58a@intel.com Signed-off-by: Dan Williams --- drivers/virt/coco/tdx-guest/tdx-guest.c | 39 ++++++++++--------------- 1 file changed, 16 insertions(+), 23 deletions(-) diff --git a/drivers/virt/coco/tdx-guest/tdx-guest.c b/drivers/virt/coco/tdx-guest/tdx-guest.c index 34125c501833..60466c439a4b 100644 --- a/drivers/virt/coco/tdx-guest/tdx-guest.c +++ b/drivers/virt/coco/tdx-guest/tdx-guest.c @@ -262,7 +262,7 @@ static int wait_for_quote_completion(struct tdx_quote_buf *quote_buf, u32 timeou return (i == timeout) ? -ETIMEDOUT : 0; } -static int tdx_report_new(struct tsm_report *report, void *data) +static int tdx_report_new_locked(struct tsm_report *report, void *data) { u8 *buf; struct tdx_quote_buf *quote_buf = quote_data; @@ -270,24 +270,16 @@ static int tdx_report_new(struct tsm_report *report, void *data) int ret; u64 err; - /* TODO: switch to guard(mutex_intr) */ - if (mutex_lock_interruptible("e_lock)) - return -EINTR; - /* * If the previous request is timedout or interrupted, and the * Quote buf status is still in GET_QUOTE_IN_FLIGHT (owned by * VMM), don't permit any new request. */ - if (quote_buf->status == GET_QUOTE_IN_FLIGHT) { - ret = -EBUSY; - goto done; - } + if (quote_buf->status == GET_QUOTE_IN_FLIGHT) + return -EBUSY; - if (desc->inblob_len != TDX_REPORTDATA_LEN) { - ret = -EINVAL; - goto done; - } + if (desc->inblob_len != TDX_REPORTDATA_LEN) + return -EINVAL; memset(quote_data, 0, GET_QUOTE_BUF_SIZE); @@ -298,26 +290,23 @@ static int tdx_report_new(struct tsm_report *report, void *data) ret = tdx_do_report(KERNEL_SOCKPTR(desc->inblob), KERNEL_SOCKPTR(quote_buf->data)); if (ret) - goto done; + return ret; err = tdx_hcall_get_quote(quote_data, GET_QUOTE_BUF_SIZE); if (err) { pr_err("GetQuote hypercall failed, status:%llx\n", err); - ret = -EIO; - goto done; + return -EIO; } ret = wait_for_quote_completion(quote_buf, getquote_timeout); if (ret) { pr_err("GetQuote request timedout\n"); - goto done; + return ret; } buf = kvmemdup(quote_buf->data, quote_buf->out_len, GFP_KERNEL); - if (!buf) { - ret = -ENOMEM; - goto done; - } + if (!buf) + return -ENOMEM; report->outblob = buf; report->outblob_len = quote_buf->out_len; @@ -326,12 +315,16 @@ static int tdx_report_new(struct tsm_report *report, void *data) * TODO: parse the PEM-formatted cert chain out of the quote buffer when * provided */ -done: - mutex_unlock("e_lock); return ret; } +static int tdx_report_new(struct tsm_report *report, void *data) +{ + scoped_cond_guard(mutex_intr, return -EINTR, "e_lock) + return tdx_report_new_locked(report, data); +} + static bool tdx_report_attr_visible(int n) { switch (n) { From 1f450730ff39807360e96105adbec1c818905a70 Mon Sep 17 00:00:00 2001 From: Cedric Xing Date: Thu, 8 May 2025 22:03:50 -0500 Subject: [PATCH 11/12] sample/tsm-mr: Fix missing static for sample_report 0day robot reports 'sample_report' can be static, fix it up. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202505090938.avfIhLsl-lkp@intel.com/ Signed-off-by: Cedric Xing Link: https://patch.msgid.link/20250509030350.22363-1-cedric.xing@intel.com Signed-off-by: Dan Williams --- samples/tsm-mr/tsm_mr_sample.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/samples/tsm-mr/tsm_mr_sample.c b/samples/tsm-mr/tsm_mr_sample.c index f3e16301de40..a2c652148639 100644 --- a/samples/tsm-mr/tsm_mr_sample.c +++ b/samples/tsm-mr/tsm_mr_sample.c @@ -8,7 +8,7 @@ #include #include -struct { +static struct { u8 static_mr[SHA384_DIGEST_SIZE]; u8 config_mr[SHA512_DIGEST_SIZE]; u8 rtmr0[SHA256_DIGEST_SIZE]; From b0ca403a9e381140cf626ca94519fb468370fc3e Mon Sep 17 00:00:00 2001 From: Cedric Xing Date: Tue, 13 May 2025 11:41:54 -0500 Subject: [PATCH 12/12] tsm-mr: Fix init breakage after bin_attrs constification by scoping non-const pointers to init phase Commit 9bec944506fa ("sysfs: constify attribute_group::bin_attrs") enforced the ro-after-init principle by making elements of bin_attrs_new pointing to const. To align with this change, introduce a temporary variable `bap` within the initialization loop. This improves code clarity by explicitly marking the initialization scope and eliminates the need for type casts when assigning to bin_attrs_new. Signed-off-by: Cedric Xing Link: https://patch.msgid.link/20250513164154.10109-1-cedric.xing@intel.com Signed-off-by: Dan Williams --- drivers/virt/coco/tsm-mr.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/drivers/virt/coco/tsm-mr.c b/drivers/virt/coco/tsm-mr.c index 1f0c43a516fb..feb30af90a20 100644 --- a/drivers/virt/coco/tsm-mr.c +++ b/drivers/virt/coco/tsm-mr.c @@ -173,7 +173,7 @@ tsm_mr_create_attribute_group(const struct tsm_measurements *tm) * so that we don't have to free MR names one-by-one in * tsm_mr_free_attribute_group() */ - const struct bin_attribute * const *attrs __free(kfree) = + const struct bin_attribute **attrs __free(kfree) = kzalloc(sizeof(*attrs) * (tm->nr_mrs + 1) + nlen, GFP_KERNEL); struct tm_context *ctx __free(kfree) = kzalloc(struct_size(ctx, mrs, tm->nr_mrs), GFP_KERNEL); @@ -187,16 +187,14 @@ tsm_mr_create_attribute_group(const struct tsm_measurements *tm) end = name + nlen; for (size_t i = 0; i < tm->nr_mrs; ++i) { - /* break const for init */ - struct bin_attribute **bas = (struct bin_attribute **)attrs; + struct bin_attribute *bap = &ctx->mrs[i]; - bas[i] = &ctx->mrs[i]; - sysfs_bin_attr_init(bas[i]); + sysfs_bin_attr_init(bap); if (tm->mrs[i].mr_flags & TSM_MR_F_NOHASH) - bas[i]->attr.name = tm->mrs[i].mr_name; + bap->attr.name = tm->mrs[i].mr_name; else if (name < end) { - bas[i]->attr.name = name; + bap->attr.name = name; name += snprintf(name, end - name, "%s:%s", tm->mrs[i].mr_name, hash_algo_name[tm->mrs[i].mr_hash]); @@ -206,21 +204,23 @@ tsm_mr_create_attribute_group(const struct tsm_measurements *tm) /* check for duplicated MR definitions */ for (size_t j = 0; j < i; ++j) - if (!strcmp(bas[i]->attr.name, bas[j]->attr.name)) + if (!strcmp(bap->attr.name, attrs[j]->attr.name)) return ERR_PTR(-EINVAL); if (tm->mrs[i].mr_flags & TSM_MR_F_READABLE) { - bas[i]->attr.mode |= 0444; - bas[i]->read_new = tm_digest_read; + bap->attr.mode |= 0444; + bap->read_new = tm_digest_read; } if (tm->mrs[i].mr_flags & TSM_MR_F_WRITABLE) { - bas[i]->attr.mode |= 0200; - bas[i]->write_new = tm_digest_write; + bap->attr.mode |= 0200; + bap->write_new = tm_digest_write; } - bas[i]->size = tm->mrs[i].mr_size; - bas[i]->private = ctx; + bap->size = tm->mrs[i].mr_size; + bap->private = ctx; + + attrs[i] = bap; } if (name != end) @@ -244,7 +244,7 @@ EXPORT_SYMBOL_GPL(tsm_mr_create_attribute_group); void tsm_mr_free_attribute_group(const struct attribute_group *attr_grp) { if (!IS_ERR_OR_NULL(attr_grp)) { - kfree(attr_grp->bin_attrs); + kfree(attr_grp->bin_attrs_new); kfree(container_of(attr_grp, struct tm_context, agrp)); } }