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| author | Jeremy Linton <jeremy.linton@arm.com> | 2024-12-20 21:12:36 +0300 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2025-01-08 16:58:49 +0300 |
| commit | a1edec22457e6fabc5450a6eea7fdc0e1b6dab31 (patch) | |
| tree | 282f2490664f0fe82bc9c8c88d5b181f6a80bcc5 | |
| parent | fac04efc5c793dccbd07e2d59af9f90b7fc0dca4 (diff) | |
| download | linux-a1edec22457e6fabc5450a6eea7fdc0e1b6dab31.tar.xz | |
arm64: rsi: Add automatic arm-cca-guest module loading
The TSM module provides guest identification and attestation when a
guest runs in CCA realm mode. By creating a dummy platform device,
let's ensure the module is automatically loaded. The udev daemon loads
the TSM module after it receives a device addition event. Once that
happens, it can be used earlier in the boot process to decrypt the
rootfs.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20241220181236.172060-2-jeremy.linton@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | arch/arm64/include/asm/rsi.h | 2 | ||||
| -rw-r--r-- | arch/arm64/kernel/rsi.c | 15 | ||||
| -rw-r--r-- | drivers/virt/coco/arm-cca-guest/arm-cca-guest.c | 8 |
3 files changed, 25 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/rsi.h b/arch/arm64/include/asm/rsi.h index 188cbb9b23f5..b42aeac05340 100644 --- a/arch/arm64/include/asm/rsi.h +++ b/arch/arm64/include/asm/rsi.h @@ -10,6 +10,8 @@ #include <linux/jump_label.h> #include <asm/rsi_cmds.h> +#define RSI_PDEV_NAME "arm-cca-dev" + DECLARE_STATIC_KEY_FALSE(rsi_present); void __init arm64_rsi_init(void); diff --git a/arch/arm64/kernel/rsi.c b/arch/arm64/kernel/rsi.c index 3031f25c32ef..ce4778141ec7 100644 --- a/arch/arm64/kernel/rsi.c +++ b/arch/arm64/kernel/rsi.c @@ -8,6 +8,7 @@ #include <linux/psci.h> #include <linux/swiotlb.h> #include <linux/cc_platform.h> +#include <linux/platform_device.h> #include <asm/io.h> #include <asm/mem_encrypt.h> @@ -140,3 +141,17 @@ void __init arm64_rsi_init(void) static_branch_enable(&rsi_present); } +static struct platform_device rsi_dev = { + .name = RSI_PDEV_NAME, + .id = PLATFORM_DEVID_NONE +}; + +static int __init arm64_create_dummy_rsi_dev(void) +{ + if (is_realm_world() && + platform_device_register(&rsi_dev)) + pr_err("failed to register rsi platform device\n"); + return 0; +} + +arch_initcall(arm64_create_dummy_rsi_dev) 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 488153879ec9..87f162736b2e 100644 --- a/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c +++ b/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c @@ -6,6 +6,7 @@ #include <linux/arm-smccc.h> #include <linux/cc_platform.h> #include <linux/kernel.h> +#include <linux/mod_devicetable.h> #include <linux/module.h> #include <linux/smp.h> #include <linux/tsm.h> @@ -219,6 +220,13 @@ static void __exit arm_cca_guest_exit(void) } module_exit(arm_cca_guest_exit); +/* modalias, so userspace can autoload this module when RSI is available */ +static const struct platform_device_id arm_cca_match[] __maybe_unused = { + { RSI_PDEV_NAME, 0}, + { } +}; + +MODULE_DEVICE_TABLE(platform, arm_cca_match); MODULE_AUTHOR("Sami Mujawar <sami.mujawar@arm.com>"); MODULE_DESCRIPTION("Arm CCA Guest TSM Driver"); MODULE_LICENSE("GPL"); |