diff mbox series

[v5,08/14] x86/mm: Add generic guest initialization hook

Message ID 20231030063652.68675-9-nikunj@amd.com
State New
Headers
Series Add Secure TSC support for SNP guests |

Commit Message

Nikunj A. Dadhania Oct. 30, 2023, 6:36 a.m. UTC 
  Add generic enc_init guest hook for performing any type of
initialization that is vendor specific.

Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
---
 arch/x86/include/asm/x86_init.h | 2 ++
 arch/x86/kernel/x86_init.c      | 2 ++
 arch/x86/mm/mem_encrypt.c       | 3 +++
 3 files changed, 7 insertions(+)

Comments

Dave Hansen Oct. 30, 2023, 5:23 p.m. UTC | #1 
On 10/29/23 23:36, Nikunj A Dadhania wrote:
> diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
> index a37ebd3b4773..a07985a96ca5 100644
> --- a/arch/x86/kernel/x86_init.c
> +++ b/arch/x86/kernel/x86_init.c
> @@ -136,6 +136,7 @@ static bool enc_status_change_finish_noop(unsigned long vaddr, int npages, bool
>  static bool enc_tlb_flush_required_noop(bool enc) { return false; }
>  static bool enc_cache_flush_required_noop(void) { return false; }
>  static bool is_private_mmio_noop(u64 addr) {return false; }
> +static void enc_init_noop(void) { }
>  
>  struct x86_platform_ops x86_platform __ro_after_init = {
>  	.calibrate_cpu			= native_calibrate_cpu_early,
> @@ -158,6 +159,7 @@ struct x86_platform_ops x86_platform __ro_after_init = {
>  		.enc_status_change_finish  = enc_status_change_finish_noop,
>  		.enc_tlb_flush_required	   = enc_tlb_flush_required_noop,
>  		.enc_cache_flush_required  = enc_cache_flush_required_noop,
> +		.enc_init		   = enc_init_noop,
>  	},
>  };
>  
> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
> index 9f27e14e185f..01abecc9a774 100644
> --- a/arch/x86/mm/mem_encrypt.c
> +++ b/arch/x86/mm/mem_encrypt.c
> @@ -84,5 +84,8 @@ void __init mem_encrypt_init(void)
>  	/* Call into SWIOTLB to update the SWIOTLB DMA buffers */
>  	swiotlb_update_mem_attributes();
>  
> +	if (x86_platform.guest.enc_init)
> +		x86_platform.guest.enc_init();
> +
>  	print_mem_encrypt_feature_info();
>  }

How does '.enc_init' ever get set to NULL?  Isn't the point of having
and using a 'noop' function so that you don't have to do NULL checks?
Tom Lendacky Oct. 30, 2023, 7:19 p.m. UTC | #2 
On 10/30/23 01:36, Nikunj A Dadhania wrote:
> Add generic enc_init guest hook for performing any type of
> initialization that is vendor specific.

I think this commit message should be expanded on a bit... like when it is 
intended to be called, etc.

Thanks,
Tom

> 
> Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
> ---
>   arch/x86/include/asm/x86_init.h | 2 ++
>   arch/x86/kernel/x86_init.c      | 2 ++
>   arch/x86/mm/mem_encrypt.c       | 3 +++
>   3 files changed, 7 insertions(+)
> 
> diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
> index 5240d88db52a..6a08dcd1f3c4 100644
> --- a/arch/x86/include/asm/x86_init.h
> +++ b/arch/x86/include/asm/x86_init.h
> @@ -148,12 +148,14 @@ struct x86_init_acpi {
>    * @enc_status_change_finish	Notify HV after the encryption status of a range is changed
>    * @enc_tlb_flush_required	Returns true if a TLB flush is needed before changing page encryption status
>    * @enc_cache_flush_required	Returns true if a cache flush is needed before changing page encryption status
> + * @enc_init			Prepare and initialize encryption features
>    */
>   struct x86_guest {
>   	bool (*enc_status_change_prepare)(unsigned long vaddr, int npages, bool enc);
>   	bool (*enc_status_change_finish)(unsigned long vaddr, int npages, bool enc);
>   	bool (*enc_tlb_flush_required)(bool enc);
>   	bool (*enc_cache_flush_required)(void);
> +	void (*enc_init)(void);
>   };
>   
>   /**
> diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
> index a37ebd3b4773..a07985a96ca5 100644
> --- a/arch/x86/kernel/x86_init.c
> +++ b/arch/x86/kernel/x86_init.c
> @@ -136,6 +136,7 @@ static bool enc_status_change_finish_noop(unsigned long vaddr, int npages, bool
>   static bool enc_tlb_flush_required_noop(bool enc) { return false; }
>   static bool enc_cache_flush_required_noop(void) { return false; }
>   static bool is_private_mmio_noop(u64 addr) {return false; }
> +static void enc_init_noop(void) { }
>   
>   struct x86_platform_ops x86_platform __ro_after_init = {
>   	.calibrate_cpu			= native_calibrate_cpu_early,
> @@ -158,6 +159,7 @@ struct x86_platform_ops x86_platform __ro_after_init = {
>   		.enc_status_change_finish  = enc_status_change_finish_noop,
>   		.enc_tlb_flush_required	   = enc_tlb_flush_required_noop,
>   		.enc_cache_flush_required  = enc_cache_flush_required_noop,
> +		.enc_init		   = enc_init_noop,
>   	},
>   };
>   
> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
> index 9f27e14e185f..01abecc9a774 100644
> --- a/arch/x86/mm/mem_encrypt.c
> +++ b/arch/x86/mm/mem_encrypt.c
> @@ -84,5 +84,8 @@ void __init mem_encrypt_init(void)
>   	/* Call into SWIOTLB to update the SWIOTLB DMA buffers */
>   	swiotlb_update_mem_attributes();
>   
> +	if (x86_platform.guest.enc_init)
> +		x86_platform.guest.enc_init();
> +
>   	print_mem_encrypt_feature_info();
>   }
Nikunj A. Dadhania Nov. 2, 2023, 4:30 a.m. UTC | #3 
On 10/30/2023 10:53 PM, Dave Hansen wrote:
> On 10/29/23 23:36, Nikunj A Dadhania wrote:
>> diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
>> index a37ebd3b4773..a07985a96ca5 100644
>> --- a/arch/x86/kernel/x86_init.c
>> +++ b/arch/x86/kernel/x86_init.c
>> @@ -136,6 +136,7 @@ static bool enc_status_change_finish_noop(unsigned long vaddr, int npages, bool
>>  static bool enc_tlb_flush_required_noop(bool enc) { return false; }
>>  static bool enc_cache_flush_required_noop(void) { return false; }
>>  static bool is_private_mmio_noop(u64 addr) {return false; }
>> +static void enc_init_noop(void) { }
>>  
>>  struct x86_platform_ops x86_platform __ro_after_init = {
>>  	.calibrate_cpu			= native_calibrate_cpu_early,
>> @@ -158,6 +159,7 @@ struct x86_platform_ops x86_platform __ro_after_init = {
>>  		.enc_status_change_finish  = enc_status_change_finish_noop,
>>  		.enc_tlb_flush_required	   = enc_tlb_flush_required_noop,
>>  		.enc_cache_flush_required  = enc_cache_flush_required_noop,
>> +		.enc_init		   = enc_init_noop,
>>  	},
>>  };
>>  
>> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
>> index 9f27e14e185f..01abecc9a774 100644
>> --- a/arch/x86/mm/mem_encrypt.c
>> +++ b/arch/x86/mm/mem_encrypt.c
>> @@ -84,5 +84,8 @@ void __init mem_encrypt_init(void)
>>  	/* Call into SWIOTLB to update the SWIOTLB DMA buffers */
>>  	swiotlb_update_mem_attributes();
>>  
>> +	if (x86_platform.guest.enc_init)
>> +		x86_platform.guest.enc_init();
>> +
>>  	print_mem_encrypt_feature_info();
>>  }
> 
> How does '.enc_init' ever get set to NULL?  Isn't the point of having
> and using a 'noop' function so that you don't have to do NULL checks?

True, I will remove the check.

Regards
Nikunj
Nikunj A. Dadhania Nov. 2, 2023, 5:08 a.m. UTC | #4 
On 10/31/2023 12:49 AM, Tom Lendacky wrote:
> On 10/30/23 01:36, Nikunj A Dadhania wrote:
>> Add generic enc_init guest hook for performing any type of
>> initialization that is vendor specific.
> 
> I think this commit message should be expanded on a bit... like when it is intended to be called, etc.

Sure

Regards
Nikunj
diff mbox series

Patch

diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index 5240d88db52a..6a08dcd1f3c4 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -148,12 +148,14 @@  struct x86_init_acpi {
  * @enc_status_change_finish	Notify HV after the encryption status of a range is changed
  * @enc_tlb_flush_required	Returns true if a TLB flush is needed before changing page encryption status
  * @enc_cache_flush_required	Returns true if a cache flush is needed before changing page encryption status
+ * @enc_init			Prepare and initialize encryption features
  */
 struct x86_guest {
 	bool (*enc_status_change_prepare)(unsigned long vaddr, int npages, bool enc);
 	bool (*enc_status_change_finish)(unsigned long vaddr, int npages, bool enc);
 	bool (*enc_tlb_flush_required)(bool enc);
 	bool (*enc_cache_flush_required)(void);
+	void (*enc_init)(void);
 };
 
 /**
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index a37ebd3b4773..a07985a96ca5 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -136,6 +136,7 @@  static bool enc_status_change_finish_noop(unsigned long vaddr, int npages, bool
 static bool enc_tlb_flush_required_noop(bool enc) { return false; }
 static bool enc_cache_flush_required_noop(void) { return false; }
 static bool is_private_mmio_noop(u64 addr) {return false; }
+static void enc_init_noop(void) { }
 
 struct x86_platform_ops x86_platform __ro_after_init = {
 	.calibrate_cpu			= native_calibrate_cpu_early,
@@ -158,6 +159,7 @@  struct x86_platform_ops x86_platform __ro_after_init = {
 		.enc_status_change_finish  = enc_status_change_finish_noop,
 		.enc_tlb_flush_required	   = enc_tlb_flush_required_noop,
 		.enc_cache_flush_required  = enc_cache_flush_required_noop,
+		.enc_init		   = enc_init_noop,
 	},
 };
 
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index 9f27e14e185f..01abecc9a774 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -84,5 +84,8 @@  void __init mem_encrypt_init(void)
 	/* Call into SWIOTLB to update the SWIOTLB DMA buffers */
 	swiotlb_update_mem_attributes();
 
+	if (x86_platform.guest.enc_init)
+		x86_platform.guest.enc_init();
+
 	print_mem_encrypt_feature_info();
 }