On Fri, Jul 26, 2024 at 03:59:07PM -0700, Roman Kisel wrote:
> To run in the VTL mode, Hyper-V drivers have to know what
> VTL the system boots in, and the arm64/hyperv code does not
> update the variable that stores the value.
>
> Update the variable to enable the Hyper-V drivers to boot
> in the VTL mode and print the VTL the code runs in.
>
> Signed-off-by: Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx>
> ---
> arch/arm64/hyperv/Makefile | 1 +
> arch/arm64/hyperv/hv_vtl.c | 13 +++++++++++++
> arch/arm64/hyperv/mshyperv.c | 4 ++++
> arch/arm64/include/asm/mshyperv.h | 7 +++++++
> 4 files changed, 25 insertions(+)
> create mode 100644 arch/arm64/hyperv/hv_vtl.c
>
> diff --git a/arch/arm64/hyperv/Makefile b/arch/arm64/hyperv/Makefile
> index 87c31c001da9..9701a837a6e1 100644
> --- a/arch/arm64/hyperv/Makefile
> +++ b/arch/arm64/hyperv/Makefile
> @@ -1,2 +1,3 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-y := hv_core.o mshyperv.o
> +obj-$(CONFIG_HYPERV_VTL_MODE) += hv_vtl.o
> diff --git a/arch/arm64/hyperv/hv_vtl.c b/arch/arm64/hyperv/hv_vtl.c
> new file mode 100644
> index 000000000000..38642b7b6be0
> --- /dev/null
> +++ b/arch/arm64/hyperv/hv_vtl.c
> @@ -0,0 +1,13 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2024, Microsoft, Inc.
> + *
> + * Author : Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx>
> + */
> +
> +#include <asm/mshyperv.h>
> +
> +void __init hv_vtl_init_platform(void)
> +{
> + pr_info("Linux runs in Hyper-V Virtual Trust Level\n");
> +}
> diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c
> index 341f98312667..8fd04d6e4800 100644
> --- a/arch/arm64/hyperv/mshyperv.c
> +++ b/arch/arm64/hyperv/mshyperv.c
> @@ -98,6 +98,10 @@ static int __init hyperv_init(void)
> return ret;
> }
>
> + /* Find the VTL */
> + ms_hyperv.vtl = get_vtl();
> + hv_vtl_init_platform();
> +
> ms_hyperv_late_init();
>
> hyperv_initialized = true;
> diff --git a/arch/arm64/include/asm/mshyperv.h b/arch/arm64/include/asm/mshyperv.h
> index a7a3586f7cb1..63d6bb6998fc 100644
> --- a/arch/arm64/include/asm/mshyperv.h
> +++ b/arch/arm64/include/asm/mshyperv.h
> @@ -49,6 +49,13 @@ static inline u64 hv_get_msr(unsigned int reg)
> ARM_SMCCC_OWNER_VENDOR_HYP, \
> HV_SMCCC_FUNC_NUMBER)
>
> +#ifdef CONFIG_HYPERV_VTL_MODE
> +void __init hv_vtl_init_platform(void);
> +int __init hv_vtl_early_init(void);
> +#else
> +static inline void __init hv_vtl_init_platform(void) {}
> +#endif
> +
These functions are defined in x86 header as well. We can move it to generic header.
- Saurabh
