diff options
| author | Roman Kisel <romank@linux.microsoft.com> | 2025-04-28 14:07:32 -0700 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2025-05-23 16:30:55 +0000 |
| commit | 13423063c7cb7d1c34104a78cae85eb0281bae90 (patch) | |
| tree | 7bff72ae9d6a10634987069fd33da4ffbb7de675 /drivers/firmware | |
| parent | a9c0b33ef2306327dd2db02c6274107065ff9307 (diff) | |
arm64: kvm, smccc: Introduce and use API for getting hypervisor UUID
The KVM/arm64 uses SMCCC to detect hypervisor presence. That code is
private, and it follows the SMCCC specification. Other existing and
emerging hypervisor guest implementations can and should use that
standard approach as well.
Factor out a common infrastructure that the guests can use, update KVM
to employ the new API. The central notion of the SMCCC method is the
UUID of the hypervisor, and the new API follows that.
No functional changes. Validated with a KVM/arm64 guest.
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20250428210742.435282-2-romank@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250428210742.435282-2-romank@linux.microsoft.com>
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/smccc/kvm_guest.c | 10 | ||||
| -rw-r--r-- | drivers/firmware/smccc/smccc.c | 17 |
2 files changed, 19 insertions, 8 deletions
diff --git a/drivers/firmware/smccc/kvm_guest.c b/drivers/firmware/smccc/kvm_guest.c index a123c05cbc9e..49e1de83d2e8 100644 --- a/drivers/firmware/smccc/kvm_guest.c +++ b/drivers/firmware/smccc/kvm_guest.c @@ -17,17 +17,11 @@ static DECLARE_BITMAP(__kvm_arm_hyp_services, ARM_SMCCC_KVM_NUM_FUNCS) __ro_afte void __init kvm_init_hyp_services(void) { + uuid_t kvm_uuid = ARM_SMCCC_VENDOR_HYP_UID_KVM; struct arm_smccc_res res; u32 val[4]; - if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_HVC) - return; - - arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res); - if (res.a0 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0 || - res.a1 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1 || - res.a2 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2 || - res.a3 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3) + if (!arm_smccc_hypervisor_has_uuid(&kvm_uuid)) return; memset(&res, 0, sizeof(res)); diff --git a/drivers/firmware/smccc/smccc.c b/drivers/firmware/smccc/smccc.c index a74600d9f2d7..cd65b434dc6e 100644 --- a/drivers/firmware/smccc/smccc.c +++ b/drivers/firmware/smccc/smccc.c @@ -67,6 +67,23 @@ s32 arm_smccc_get_soc_id_revision(void) } EXPORT_SYMBOL_GPL(arm_smccc_get_soc_id_revision); +bool arm_smccc_hypervisor_has_uuid(const uuid_t *hyp_uuid) +{ + struct arm_smccc_res res = {}; + uuid_t uuid; + + if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_HVC) + return false; + + arm_smccc_1_1_hvc(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res); + if (res.a0 == SMCCC_RET_NOT_SUPPORTED) + return false; + + uuid = smccc_res_to_uuid(res.a0, res.a1, res.a2, res.a3); + return uuid_equal(&uuid, hyp_uuid); +} +EXPORT_SYMBOL_GPL(arm_smccc_hypervisor_has_uuid); + static int __init smccc_devices_init(void) { struct platform_device *pdev; |