On 04/10/2024 16:27, Steven Price wrote:
Query the RMI version number and check if it is a compatible version. A static key is also provided to signal that a supported RMM is available. Functions are provided to query if a VM or VCPU is a realm (or rec) which currently will always return false. Signed-off-by: Steven Price <steven.price@xxxxxxx> ---
diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c new file mode 100644 index 000000000000..418685fbf6ed --- /dev/null +++ b/arch/arm64/kvm/rme.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023 ARM Ltd. + */ + +#include <linux/kvm_host.h> + +#include <asm/rmi_cmds.h> +#include <asm/virt.h> + +static int rmi_check_version(void) +{ + struct arm_smccc_res res; + int version_major, version_minor; + unsigned long host_version = RMI_ABI_VERSION(RMI_ABI_MAJOR_VERSION, + RMI_ABI_MINOR_VERSION); + + arm_smccc_1_1_invoke(SMC_RMI_VERSION, host_version, &res); + + if (res.a0 == SMCCC_RET_NOT_SUPPORTED) + return -ENXIO; + + version_major = RMI_ABI_VERSION_GET_MAJOR(res.a1); + version_minor = RMI_ABI_VERSION_GET_MINOR(res.a1); + + if (res.a0 != RMI_SUCCESS) { + kvm_err("Unsupported RMI ABI (v%d.%d) host supports v%d.%d\n",
minor nit: s/host supports/we want ? (or something similar) "host" could be confusing from a user perspective ? Rest looks good to me Suzuki