@@ -142,3 +142,33 @@ region is equal to the memory protection granule advertised by
| | | +---------------------------------------------+
| | | | ``INVALID_PARAMETER (-3)`` |
+---------------------+----------+----+---------------------------------------------+
+
+``ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_CPUS_FUNC_ID``
+-------------------------------------------------------
+
+Request the target CPU implementation information for the Guest VM. This hypercall
+must be handled by the userspace VMM. The Guest kernel will use this information to
+enable the associated errata. A maximum of 64 implementations is supported.
+
++---------------------+-------------------------------------------------------------+
+| Presence: | Optional; KVM/ARM64 Guests only |
++---------------------+-------------------------------------------------------------+
+| Calling convention: | HVC64 |
++---------------------+----------+--------------------------------------------------+
+| Function ID: | (uint32) | 0xC600007E |
++---------------------+----------+----+---------------------------------------------+
+| Arguments: | (uint64) | R1 | selected implementation index |
+| +----------+----+---------------------------------------------+
+| | (uint64) | R2 | Reserved / Must be zero |
+| +----------+----+---------------------------------------------+
+| | (uint64) | R3 | Reserved / Must be zero |
++---------------------+----------+----+---------------------------------------------+
+| Return Values: | (int64) | R0 | -1 on error else the maximum required CPU |
+| | | | implementation index. |
+| +----------+----+---------------------------------------------+
+| | (uint64) | R1 | MIDR_EL1 of the selected implementation |
+| +----------+----+---------------------------------------------+
+| | (uint64) | R2 | REVIDR_EL1 of the selected implementation |
+| +----------+----+---------------------------------------------+
+| | (uint64) | R3 | Reserved / Must be zero |
++---------------------+----------+----+---------------------------------------------+
@@ -179,6 +179,7 @@
#define ARM_SMCCC_KVM_FUNC_PKVM_RESV_62 62
#define ARM_SMCCC_KVM_FUNC_PKVM_RESV_63 63
/* End of pKVM hypercall range */
+#define ARM_SMCCC_KVM_FUNC_DISCOVER_IMPL_CPUS 126
#define ARM_SMCCC_KVM_FUNC_FEATURES_2 127
#define ARM_SMCCC_KVM_NUM_FUNCS 128
@@ -225,6 +226,12 @@
ARM_SMCCC_OWNER_VENDOR_HYP, \
ARM_SMCCC_KVM_FUNC_MMIO_GUARD)
+#define ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_CPUS_FUNC_ID \
+ ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
+ ARM_SMCCC_SMC_64, \
+ ARM_SMCCC_OWNER_VENDOR_HYP, \
+ ARM_SMCCC_KVM_FUNC_DISCOVER_IMPL_CPUS)
+
/* ptp_kvm counter type ID */
#define KVM_PTP_VIRT_COUNTER 0
#define KVM_PTP_PHYS_COUNTER 1
If the Guest requires migration to multiple targets, this hypercall will provide a way to retrieve the target CPU implementations from the user space VMM. Subsequent patch will use this to enable the associated errata. Suggested-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> --- Documentation/virt/kvm/arm/hypercalls.rst | 30 +++++++++++++++++++++++ include/linux/arm-smccc.h | 7 ++++++ 2 files changed, 37 insertions(+)