@@ -142,3 +142,80 @@ region is equal to the memory protection granule advertised by
| | | +---------------------------------------------+
| | | | ``INVALID_PARAMETER (-3)`` |
+---------------------+----------+----+---------------------------------------------+
+
+``ARM_SMCCC_VENDOR_HYP_KVM_MIGRN_TARGET_NUM_FUNC_ID``
+------------------------------------------------------
+
+Query total number of migration target CPUs the Guest VM will be running during its
+lifetime and version information applicable to the data format used for
+``ARM_SMCCC_VENDOR_HYP_KVM_MIGRN_TARGET_CPUS_FUNC_ID``. The maximum number of targets
+supported is 64. Also the version number supported currently is 1.0. This hypercall
+must be handled by the userspace VMM.
+
++---------------------+-------------------------------------------------------------+
+| Presence: | Optional; KVM/ARM64 Guests only |
++---------------------+-------------------------------------------------------------+
+| Calling convention: | HVC64 |
++---------------------+----------+--------------------------------------------------+
+| Function ID: | (uint32) | 0xC600007D |
++---------------------+----------+--------------------------------------------------+
+| Arguments: | None |
++---------------------+----------+----+---------------------------------------------+
+| Return Values: | (int64) | R0 | ``NOT_SUPPORTED (-1)`` on error, else |
+| | | | [0-31] total migration targets |
+| | | | [32-63] version number |
++---------------------+----------+----+---------------------------------------------+
+| | (uint64) | R1 | Reserved / Must be zero |
+| +----------+----+---------------------------------------------+
+| | (uint64) | R2 | Reserved / Must be zero |
++---------------------+----------+----+---------------------------------------------+
+| | (uint64) | R3 | Reserved / Must be zero |
++---------------------+----------+----+---------------------------------------------+
+
+
+``ARM_SMCCC_VENDOR_HYP_KVM_MIGRN_TARGET_CPUS_FUNC_ID``
+-------------------------------------------------------
+
+Request migration target CPU information for the Guest VM. The information must be
+provided as per the format described by the version info in
+``ARM_SMCCC_VENDOR_HYP_KVM_MIGRN_TARGET_NUM_FUNC_ID``. At present, we only support
+the below format which corresponds to version 1.0. This hypercall will always be
+preceded by ``ARM_SMCCC_VENDOR_HYP_KVM_MIGRN_TARGET_NUM_FUNC_ID`` and may be
+invoked multiple times to retrieve the total number of target CPUs information
+advertised. This hypercall must be handled by the userspace VMM.
+
+A typical userspace usage scenario will be like below:
+
+1. Receives ``ARM_SMCCC_VENDOR_HYP_KVM_MIGRN_TARGET_NUM_FUNC_ID``
+
+ * Returns total number of migration targets and version number
+ * Reset current target index to zero
+2. Receives ``ARM_SMCCC_VENDOR_HYP_KVM_MIGRN_TARGET_CPUS_FUNC_ID``
+
+ * Returns MIDR/REVIDR info in return register fields. Can return up to 4
+ * Update current target index based on returned target info
+ * If there are remaining register fields, return zero to indicate the end
+ * Repeat step 2 until current target index == total number of migration targets
+
++---------------------+-------------------------------------------------------------+
+| Presence: | Optional; KVM/ARM64 Guests only |
++---------------------+-------------------------------------------------------------+
+| Calling convention: | HVC64 |
++---------------------+----------+--------------------------------------------------+
+| Function ID: | (uint32) | 0xC600007E |
++---------------------+----------+----+---------------------------------------------+
+| Arguments: | None |
++---------------------+----------+----+---------------------------------------------+
+| Return Values: | (int64) | R0 | ``NOT_SUPPORTED (-1)`` on error, else |
+| | | | [0-31] MIDR, [31-63] REVIDR, else |
+| | | | [0-63] Zero to mark end. |
++---------------------+----------+----+---------------------------------------------+
+| | (uint64) | R1 | [0-31] MIDR, [32-63] REVIDR, else |
+| | | | [0-63] Zero to mark end. |
++---------------------+----------+----+---------------------------------------------+
+| | (uint64) | R2 | [0-31] MIDR, [32-63] REVIDR, else |
+| | | | [0-63] Zero to mark end. |
++---------------------+----------+----+---------------------------------------------+
+| | (uint64) | R3 | [0-31] MIDR, [32-63] REVIDR, else |
+| | | | [0-63] Zero to mark end. |
++---------------------+----------+----+---------------------------------------------+
@@ -179,6 +179,8 @@
#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_MIGRN_TARGET_NUM 125
+#define ARM_SMCCC_KVM_FUNC_MIGRN_TARGET_CPUS 126
#define ARM_SMCCC_KVM_FUNC_FEATURES_2 127
#define ARM_SMCCC_KVM_NUM_FUNCS 128
@@ -225,6 +227,17 @@
ARM_SMCCC_OWNER_VENDOR_HYP, \
ARM_SMCCC_KVM_FUNC_MMIO_GUARD)
+#define ARM_SMCCC_VENDOR_HYP_KVM_MIGRN_TARGET_NUM_FUNC_ID \
+ ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
+ ARM_SMCCC_SMC_64, \
+ ARM_SMCCC_OWNER_VENDOR_HYP, \
+ ARM_SMCCC_KVM_FUNC_MIGRN_TARGET_NUM)
+
+#define ARM_SMCCC_VENDOR_HYP_KVM_MIGRN_TARGET_CPUS_FUNC_ID \
+ ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
+ ARM_SMCCC_SMC_64, \
+ ARM_SMCCC_OWNER_VENDOR_HYP, \
+ ARM_SMCCC_KVM_FUNC_MIGRN_TARGET_CPUS)
/* ptp_kvm counter type ID */
#define KVM_PTP_VIRT_COUNTER 0
#define KVM_PTP_PHYS_COUNTER 1
If the VM requires migration to multiple targets, these hypercalls will provide a way to inform the Guest kernel about those targets. These hypercalls must be handled by userspace VMM to provide the required details. In subsequent patches Guest kernel will use these hypercalls to retrieve the target CPU information. Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> --- Documentation/virt/kvm/arm/hypercalls.rst | 77 +++++++++++++++++++++++ include/linux/arm-smccc.h | 13 ++++ 2 files changed, 90 insertions(+)