diff mbox series

[v9,2/9] mm/mmzone: Tag pg_data_t with crypto capabilities

Message ID 20220704135833.1496303-3-martin.fernandez@eclypsium.com
State New
Headers show
Series x86: Show in sysfs if a memory node is able to do encryption | expand

Commit Message

Martin Fernandez July 4, 2022, 1:58 p.m. UTC
Add a new member in the pg_data_t struct to tell whether the node
corresponding to that pg_data_t is able to do hardware memory
encryption.

This will be read from sysfs.

Signed-off-by: Martin Fernandez <martin.fernandez@eclypsium.com>
---
 include/linux/mmzone.h | 3 +++
 mm/page_alloc.c        | 1 +
 2 files changed, 4 insertions(+)

Comments

Kirill A. Shutemov Oct. 7, 2022, 3:53 p.m. UTC | #1
On Mon, Jul 04, 2022 at 10:58:26AM -0300, Martin Fernandez wrote:
> Add a new member in the pg_data_t struct to tell whether the node
> corresponding to that pg_data_t is able to do hardware memory
> encryption.
> 
> This will be read from sysfs.
> 
> Signed-off-by: Martin Fernandez <martin.fernandez@eclypsium.com>
> ---
>  include/linux/mmzone.h | 3 +++
>  mm/page_alloc.c        | 1 +
>  2 files changed, 4 insertions(+)
> 
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index aab70355d64f..6fd4785f1d05 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -883,6 +883,9 @@ typedef struct pglist_data {
>  	struct task_struct *kcompactd;
>  	bool proactive_compact_trigger;
>  #endif
> +
> +	bool crypto_capable;
> +

There's already pgdat->flags. Any reason we cannot encode it there?

>  	/*
>  	 * This is a per-node reserve of pages that are not available
>  	 * to userspace allocations.
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index e008a3df0485..147437329ac7 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -7729,6 +7729,7 @@ static void __init free_area_init_node(int nid)
>  	pgdat->node_id = nid;
>  	pgdat->node_start_pfn = start_pfn;
>  	pgdat->per_cpu_nodestats = NULL;
> +	pgdat->crypto_capable = memblock_node_is_crypto_capable(nid);
>  
>  	if (start_pfn != end_pfn) {
>  		pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
> -- 
> 2.30.2
>
Martin Fernandez Oct. 11, 2022, 1:28 p.m. UTC | #2
On 10/7/22, Kirill A. Shutemov <kirill@shutemov.name> wrote:
> On Mon, Jul 04, 2022 at 10:58:26AM -0300, Martin Fernandez wrote:
>> Add a new member in the pg_data_t struct to tell whether the node
>> corresponding to that pg_data_t is able to do hardware memory
>> encryption.
>>
>> This will be read from sysfs.
>>
>> Signed-off-by: Martin Fernandez <martin.fernandez@eclypsium.com>
>> ---
>>  include/linux/mmzone.h | 3 +++
>>  mm/page_alloc.c        | 1 +
>>  2 files changed, 4 insertions(+)
>>
>> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
>> index aab70355d64f..6fd4785f1d05 100644
>> --- a/include/linux/mmzone.h
>> +++ b/include/linux/mmzone.h
>> @@ -883,6 +883,9 @@ typedef struct pglist_data {
>>  	struct task_struct *kcompactd;
>>  	bool proactive_compact_trigger;
>>  #endif
>> +
>> +	bool crypto_capable;
>> +
>
> There's already pgdat->flags. Any reason we cannot encode it there?

Not really a reason, I'll considerate when I send then next version. I
tried to quickly find for references of what kind of flags does it
have, I didn't find any. Do you suggest it should work?

>>  	/*
>>  	 * This is a per-node reserve of pages that are not available
>>  	 * to userspace allocations.
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index e008a3df0485..147437329ac7 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -7729,6 +7729,7 @@ static void __init free_area_init_node(int nid)
>>  	pgdat->node_id = nid;
>>  	pgdat->node_start_pfn = start_pfn;
>>  	pgdat->per_cpu_nodestats = NULL;
>> +	pgdat->crypto_capable = memblock_node_is_crypto_capable(nid);
>>
>>  	if (start_pfn != end_pfn) {
>>  		pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
>> --
>> 2.30.2
>>
>
> --
>   Kiryl Shutsemau / Kirill A. Shutemov
>
Kirill A. Shutemov Oct. 11, 2022, 3:27 p.m. UTC | #3
On Tue, Oct 11, 2022 at 10:28:44AM -0300, Martin Fernandez wrote:
> On 10/7/22, Kirill A. Shutemov <kirill@shutemov.name> wrote:
> > On Mon, Jul 04, 2022 at 10:58:26AM -0300, Martin Fernandez wrote:
> >> Add a new member in the pg_data_t struct to tell whether the node
> >> corresponding to that pg_data_t is able to do hardware memory
> >> encryption.
> >>
> >> This will be read from sysfs.
> >>
> >> Signed-off-by: Martin Fernandez <martin.fernandez@eclypsium.com>
> >> ---
> >>  include/linux/mmzone.h | 3 +++
> >>  mm/page_alloc.c        | 1 +
> >>  2 files changed, 4 insertions(+)
> >>
> >> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> >> index aab70355d64f..6fd4785f1d05 100644
> >> --- a/include/linux/mmzone.h
> >> +++ b/include/linux/mmzone.h
> >> @@ -883,6 +883,9 @@ typedef struct pglist_data {
> >>  	struct task_struct *kcompactd;
> >>  	bool proactive_compact_trigger;
> >>  #endif
> >> +
> >> +	bool crypto_capable;
> >> +
> >
> > There's already pgdat->flags. Any reason we cannot encode it there?
> 
> Not really a reason, I'll considerate when I send then next version. I
> tried to quickly find for references of what kind of flags does it
> have, I didn't find any. Do you suggest it should work?

Maybe. Or maybe introduce capabilities bitfield and make crypto as one of
them.

We consider to re-use the approach for other cases. Like if the memory in
the node is TDX-compatible (there's more requirements for it than just
encryption).
diff mbox series

Patch

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index aab70355d64f..6fd4785f1d05 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -883,6 +883,9 @@  typedef struct pglist_data {
 	struct task_struct *kcompactd;
 	bool proactive_compact_trigger;
 #endif
+
+	bool crypto_capable;
+
 	/*
 	 * This is a per-node reserve of pages that are not available
 	 * to userspace allocations.
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e008a3df0485..147437329ac7 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7729,6 +7729,7 @@  static void __init free_area_init_node(int nid)
 	pgdat->node_id = nid;
 	pgdat->node_start_pfn = start_pfn;
 	pgdat->per_cpu_nodestats = NULL;
+	pgdat->crypto_capable = memblock_node_is_crypto_capable(nid);
 
 	if (start_pfn != end_pfn) {
 		pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,