diff mbox series

[v2,4/6] arm64/hyperv: Boot in a Virtual Trust Level

Message ID 20240514224508.212318-5-romank@linux.microsoft.com (mailing list archive)
State New, archived
Headers show
Series arm64/hyperv: Support Virtual Trust Level Boot | expand

Commit Message

Roman Kisel May 14, 2024, 10:43 p.m. UTC 
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        | 19 +++++++++++++++++++
 arch/arm64/hyperv/mshyperv.c      |  6 ++++++
 arch/arm64/include/asm/mshyperv.h |  8 ++++++++
 arch/x86/hyperv/hv_vtl.c          |  2 +-
 5 files changed, 35 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm64/hyperv/hv_vtl.c

Comments

Michael Kelley May 15, 2024, 1:39 p.m. UTC | #1 
From: Roman Kisel <romank@linux.microsoft.com> Sent: Tuesday, May 14, 2024 3:44 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        | 19 +++++++++++++++++++
>  arch/arm64/hyperv/mshyperv.c      |  6 ++++++
>  arch/arm64/include/asm/mshyperv.h |  8 ++++++++
>  arch/x86/hyperv/hv_vtl.c          |  2 +-
>  5 files changed, 35 insertions(+), 1 deletion(-)
>  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..9b44cc49594c
> --- /dev/null
> +++ b/arch/arm64/hyperv/hv_vtl.c
> @@ -0,0 +1,19 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023, 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 %d\n", ms_hyperv.vtl);
> +}
> +
> +int __init hv_vtl_early_init(void)
> +{
> +	return 0;
> +}
> +early_initcall(hv_vtl_early_init);
> diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c
> index 208a3bcb9686..cbde483b167a 100644
> --- a/arch/arm64/hyperv/mshyperv.c
> +++ b/arch/arm64/hyperv/mshyperv.c
> @@ -96,6 +96,12 @@ static int __init hyperv_init(void)
>  		return ret;
>  	}
> 
> +	/* Find the VTL */
> +	ms_hyperv.vtl = get_vtl();
> +	if (ms_hyperv.vtl > 0) /* non default VTL */
> +		hv_vtl_early_init();

Since hv_vtl_early_init() doesn't do anything on arm64, is the above
and the empty implementation of hv_vtl_early_init() really needed?
I thought maybe a subsequent patch in this series would populate
hv_vtl_early_init() to do something, but I didn't see such.  I realize
the functions hv_vtl_init_platform() and hv_vtl_early_init() parallel
equivalent functions on x86, but I'd say drop hv_vtl_early_init() on
arm64 if it isn't needed.

Note too that the naming on the x86 side is arguably a bit messed
up. hv_vtl_init_platform() runs *before* hv_vtl_early_init().  But
typically in the Linux kernel, functions with "early init" in the name
run very early in boot, and that's not the case here.  hv_vtl_init_platform()
is actually the function that runs very early in boot, but its name is
set up to parallel ms_hyperv_init_platform(), which calls it.  On the
x86 side, I'd would argue for renaming hv_vtl_init_platform() to
hv_vtl_early_init(), and then hv_vtl_early_init() becomes hv_vtl_init().
But that's probably a separate patch.  Here on arm64, perhaps all
you need is hv_vtl_init().

Michael

> +
> +	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 a975e1a689dd..4a8ff6be389c 100644
> --- a/arch/arm64/include/asm/mshyperv.h
> +++ b/arch/arm64/include/asm/mshyperv.h
> @@ -49,6 +49,14 @@ 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) {}
> +static inline int __init hv_vtl_early_init(void) { return 0; }
> +#endif
> +
>  #include <asm-generic/mshyperv.h>
> 
>  #endif
> diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c
> index 92bd5a55f093..ae3105375a12 100644
> --- a/arch/x86/hyperv/hv_vtl.c
> +++ b/arch/x86/hyperv/hv_vtl.c
> @@ -19,7 +19,7 @@ static struct real_mode_header hv_vtl_real_mode_header;
> 
>  void __init hv_vtl_init_platform(void)
>  {
> -	pr_info("Linux runs in Hyper-V Virtual Trust Level\n");
> +	pr_info("Linux runs in Hyper-V Virtual Trust Level %d\n", ms_hyperv.vtl);
> 
>  	x86_platform.realmode_reserve = x86_init_noop;
>  	x86_platform.realmode_init = x86_init_noop;
> --
> 2.45.0
>
Roman Kisel May 15, 2024, 6:13 p.m. UTC | #2 
On 5/15/2024 6:39 AM, Michael Kelley wrote:
> From: Roman Kisel <romank@linux.microsoft.com> Sent: Tuesday, May 14, 2024 3:44 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        | 19 +++++++++++++++++++
>>   arch/arm64/hyperv/mshyperv.c      |  6 ++++++
>>   arch/arm64/include/asm/mshyperv.h |  8 ++++++++
>>   arch/x86/hyperv/hv_vtl.c          |  2 +-
>>   5 files changed, 35 insertions(+), 1 deletion(-)
>>   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..9b44cc49594c
>> --- /dev/null
>> +++ b/arch/arm64/hyperv/hv_vtl.c
>> @@ -0,0 +1,19 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (C) 2023, 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 %d\n", ms_hyperv.vtl);
>> +}
>> +
>> +int __init hv_vtl_early_init(void)
>> +{
>> +	return 0;
>> +}
>> +early_initcall(hv_vtl_early_init);
>> diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c
>> index 208a3bcb9686..cbde483b167a 100644
>> --- a/arch/arm64/hyperv/mshyperv.c
>> +++ b/arch/arm64/hyperv/mshyperv.c
>> @@ -96,6 +96,12 @@ static int __init hyperv_init(void)
>>   		return ret;
>>   	}
>>
>> +	/* Find the VTL */
>> +	ms_hyperv.vtl = get_vtl();
>> +	if (ms_hyperv.vtl > 0) /* non default VTL */
>> +		hv_vtl_early_init();
> 
> Since hv_vtl_early_init() doesn't do anything on arm64, is the above
> and the empty implementation of hv_vtl_early_init() really needed?
> I thought maybe a subsequent patch in this series would populate
> hv_vtl_early_init() to do something, but I didn't see such.  I realize
> the functions hv_vtl_init_platform() and hv_vtl_early_init() parallel
> equivalent functions on x86, but I'd say drop hv_vtl_early_init() on
> arm64 if it isn't needed.
> 
> Note too that the naming on the x86 side is arguably a bit messed
> up. hv_vtl_init_platform() runs *before* hv_vtl_early_init().  But
> typically in the Linux kernel, functions with "early init" in the name
> run very early in boot, and that's not the case here.  hv_vtl_init_platform()
> is actually the function that runs very early in boot, but its name is
> set up to parallel ms_hyperv_init_platform(), which calls it.  On the
> x86 side, I'd would argue for renaming hv_vtl_init_platform() to
> hv_vtl_early_init(), and then hv_vtl_early_init() becomes hv_vtl_init().
> But that's probably a separate patch.  Here on arm64, perhaps all
> you need is hv_vtl_init().
> 
I'll clean that up, appreciate the thorough explanation!

> Michael
> 
>> +
>> +	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 a975e1a689dd..4a8ff6be389c 100644
>> --- a/arch/arm64/include/asm/mshyperv.h
>> +++ b/arch/arm64/include/asm/mshyperv.h
>> @@ -49,6 +49,14 @@ 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) {}
>> +static inline int __init hv_vtl_early_init(void) { return 0; }
>> +#endif
>> +
>>   #include <asm-generic/mshyperv.h>
>>
>>   #endif
>> diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c
>> index 92bd5a55f093..ae3105375a12 100644
>> --- a/arch/x86/hyperv/hv_vtl.c
>> +++ b/arch/x86/hyperv/hv_vtl.c
>> @@ -19,7 +19,7 @@ static struct real_mode_header hv_vtl_real_mode_header;
>>
>>   void __init hv_vtl_init_platform(void)
>>   {
>> -	pr_info("Linux runs in Hyper-V Virtual Trust Level\n");
>> +	pr_info("Linux runs in Hyper-V Virtual Trust Level %d\n", ms_hyperv.vtl);
>>
>>   	x86_platform.realmode_reserve = x86_init_noop;
>>   	x86_platform.realmode_init = x86_init_noop;
>> --
>> 2.45.0
>>
diff mbox series

Patch

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..9b44cc49594c
--- /dev/null
+++ b/arch/arm64/hyperv/hv_vtl.c
@@ -0,0 +1,19 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023, 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 %d\n", ms_hyperv.vtl);
+}
+
+int __init hv_vtl_early_init(void)
+{
+	return 0;
+}
+early_initcall(hv_vtl_early_init);
diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c
index 208a3bcb9686..cbde483b167a 100644
--- a/arch/arm64/hyperv/mshyperv.c
+++ b/arch/arm64/hyperv/mshyperv.c
@@ -96,6 +96,12 @@  static int __init hyperv_init(void)
 		return ret;
 	}
 
+	/* Find the VTL */
+	ms_hyperv.vtl = get_vtl();
+	if (ms_hyperv.vtl > 0) /* non default VTL */
+		hv_vtl_early_init();
+
+	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 a975e1a689dd..4a8ff6be389c 100644
--- a/arch/arm64/include/asm/mshyperv.h
+++ b/arch/arm64/include/asm/mshyperv.h
@@ -49,6 +49,14 @@  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) {}
+static inline int __init hv_vtl_early_init(void) { return 0; }
+#endif
+
 #include <asm-generic/mshyperv.h>
 
 #endif
diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c
index 92bd5a55f093..ae3105375a12 100644
--- a/arch/x86/hyperv/hv_vtl.c
+++ b/arch/x86/hyperv/hv_vtl.c
@@ -19,7 +19,7 @@  static struct real_mode_header hv_vtl_real_mode_header;
 
 void __init hv_vtl_init_platform(void)
 {
-	pr_info("Linux runs in Hyper-V Virtual Trust Level\n");
+	pr_info("Linux runs in Hyper-V Virtual Trust Level %d\n", ms_hyperv.vtl);
 
 	x86_platform.realmode_reserve = x86_init_noop;
 	x86_platform.realmode_init = x86_init_noop;