| Message ID | 20240726225910.1912537-5-romank@linux.microsoft.com |
|---|---|
| State | New |
| Headers | show |
| Series | arm64: hyperv: Support Virtual Trust Level Boot | expand |
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@linux.microsoft.com> > --- > 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@linux.microsoft.com> > + */ > + > +#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(); It doesn't make sense to me because this function unconditionally prints Linux runs in Hyper-V Virtual Trust Level. Thanks, Wei. > + > 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 > + > #include <asm-generic/mshyperv.h> > > #define ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_0 0x7948734d > -- > 2.34.1 >
From: Roman Kisel <romank@linux.microsoft.com> Sent: Friday, July 26, 2024 3:59 PM > > 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@linux.microsoft.com> > --- > 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@linux.microsoft.com> > + */ > + > +#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); This declaration is spurious since you removed the function. Michael > +#else > +static inline void __init hv_vtl_init_platform(void) {} > +#endif > + > #include <asm-generic/mshyperv.h> > > #define ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_0 0x7948734d > -- > 2.34.1 >
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@linux.microsoft.com> > --- > 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@linux.microsoft.com> > + */ > + > +#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
On 8/2/2024 6:22 PM, Wei Liu wrote: > 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@linux.microsoft.com> >> --- >> 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@linux.microsoft.com> >> + */ >> + >> +#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(); > > It doesn't make sense to me because this function unconditionally prints > Linux runs in Hyper-V Virtual Trust Level. > Thought to structure this as the similar parts of the VTL support are. Will remove, thank you! > Thanks, > Wei. > >> + >> 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 >> + >> #include <asm-generic/mshyperv.h> >> >> #define ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_0 0x7948734d >> -- >> 2.34.1 >>
On 8/4/2024 11:28 PM, Saurabh Singh Sengar wrote: > 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@linux.microsoft.com> >> --- >> 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@linux.microsoft.com> >> + */ >> + >> +#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. > Will do, thanks! > - Saurabh
On 8/4/2024 8:02 PM, Michael Kelley wrote: > From: Roman Kisel <romank@linux.microsoft.com> Sent: Friday, July 26, 2024 3:59 PM >> >> 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@linux.microsoft.com> >> --- >> 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@linux.microsoft.com> >> + */ >> + >> +#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); > > This declaration is spurious since you removed the function. > Will clean this up, thanks! > Michael > >> +#else >> +static inline void __init hv_vtl_init_platform(void) {} >> +#endif >> + >> #include <asm-generic/mshyperv.h> >> >> #define ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_0 0x7948734d >> -- >> 2.34.1 >>
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@linux.microsoft.com> + */ + +#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 + #include <asm-generic/mshyperv.h> #define ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_0 0x7948734d
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@linux.microsoft.com> --- 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