[PATCH V7] acpi/prmt: find block with specific type

KobaK posted 1 patch 1 month, 2 weeks ago
There is a newer version of this series
drivers/acpi/prmt.c | 27 ++++++++++++++++++++++-----
1 file changed, 22 insertions(+), 5 deletions(-)
[PATCH V7] acpi/prmt: find block with specific type
Posted by KobaK 1 month, 2 weeks ago
From: kobak <kobak@nvidia.com>

PRMT needs to find the correct type of block to
translate the PA-VA mapping for EFI runtime services.

The issue arises because the PRMT is finding a block of
type EFI_CONVENTIONAL_MEMORY, which is not appropriate for
runtime services as described in Section 2.2.2 (Runtime
Services) of the UEFI Specification [1]. Since the PRM handler is
a type of runtime service, this causes an exception
when the PRM handler is called.

    [Firmware Bug]: Unable to handle paging request in EFI runtime service
    WARNING: CPU: 22 PID: 4330 at drivers/firmware/efi/runtime-wrappers.c:341
        __efi_queue_work+0x11c/0x170
    Call trace:

Find a block with specific type to fix this.
PRMT find a block with EFI_MEMORY_RUNTIME for PRM handler and PRM context.
If no suitable block is found, a warning message will be prompted
but the procedure continues to manage the next PRM handler.
However, if the PRM handler is actually called without proper allocation,
it would result in a failure during error handling.

By using the correct memory types for runtime services,
ensure that the PRM handler and the context are
properly mapped in the virtual address space during runtime,
preventing the paging request error.

The issue is really that only memory that has been remapped for
runtime by the firmware can be used by the PRM handler, and so the
region needs to have the EFI_MEMORY_RUNTIME attribute.

[1] https://uefi.org/sites/default/files/resources/UEFI_Spec_2_10_Aug29.pdf
Fixes: cefc7ca46235 ("ACPI: PRM: implement OperationRegion handler for the PlatformRtMechanism subtype")
Signed-off-by: Koba Ko <kobak@nvidia.com>
Reviewed-by: Matthew R. Ochs <mochs@nvidia.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
---
V2:
1. format the changelog and add more about error handling.
2. replace goto
V3: Warn if parts of handler are missed during va-pa translating.
V4: Fix the 0day
V5: Fix typo and pr_warn warning
V6: use EFI_MOMOERY_RUNTIME to find block and split goto refactor as a single
patch
V7:
1. refine the codes and commit description as per comments
2. drop goto refacotr
---

 drivers/acpi/prmt.c | 27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c
index 1cfaa5957ac4..51f5ae3d4350 100644
--- a/drivers/acpi/prmt.c
+++ b/drivers/acpi/prmt.c
@@ -72,17 +72,21 @@ struct prm_module_info {
 	struct prm_handler_info handlers[] __counted_by(handler_count);
 };
 
-static u64 efi_pa_va_lookup(u64 pa)
+static u64 efi_pa_va_lookup(efi_guid_t *guid, u64 pa)
 {
 	efi_memory_desc_t *md;
 	u64 pa_offset = pa & ~PAGE_MASK;
 	u64 page = pa & PAGE_MASK;
 
 	for_each_efi_memory_desc(md) {
-		if (md->phys_addr < pa && pa < md->phys_addr + PAGE_SIZE * md->num_pages)
+		if ((md->attribute & EFI_MEMORY_RUNTIME) &&
+		    (md->phys_addr < pa && pa < md->phys_addr + PAGE_SIZE * md->num_pages)) {
 			return pa_offset + md->virt_addr + page - md->phys_addr;
+		}
 	}
 
+	pr_warn("Failed to find VA for GUID: %pUL, PA: %p", guid, pa);
+
 	return 0;
 }
 
@@ -148,9 +152,15 @@ acpi_parse_prmt(union acpi_subtable_headers *header, const unsigned long end)
 		th = &tm->handlers[cur_handler];
 
 		guid_copy(&th->guid, (guid_t *)handler_info->handler_guid);
-		th->handler_addr = (void *)efi_pa_va_lookup(handler_info->handler_address);
-		th->static_data_buffer_addr = efi_pa_va_lookup(handler_info->static_data_buffer_address);
-		th->acpi_param_buffer_addr = efi_pa_va_lookup(handler_info->acpi_param_buffer_address);
+		th->handler_addr =
+			(void *)efi_pa_va_lookup(&th->guid, handler_info->handler_address);
+
+		th->static_data_buffer_addr =
+			efi_pa_va_lookup(&th->guid, handler_info->static_data_buffer_address);
+
+		th->acpi_param_buffer_addr =
+			efi_pa_va_lookup(&th->guid, handler_info->acpi_param_buffer_address);
+
 	} while (++cur_handler < tm->handler_count && (handler_info = get_next_handler(handler_info)));
 
 	return 0;
@@ -277,6 +287,13 @@ static acpi_status acpi_platformrt_space_handler(u32 function,
 		if (!handler || !module)
 			goto invalid_guid;
 
+		if (!handler->handler_addr ||
+		    !handler->static_data_buffer_addr ||
+		    !handler->acpi_param_buffer_addr) {
+			buffer->prm_status = PRM_HANDLER_ERROR;
+			return AE_OK;
+		}
+
 		ACPI_COPY_NAMESEG(context.signature, "PRMC");
 		context.revision = 0x0;
 		context.reserved = 0x0;
-- 
2.43.0
Re: [PATCH V7] acpi/prmt: find block with specific type
Posted by kernel test robot 1 month, 2 weeks ago
Hi KobaK,

kernel test robot noticed the following build warnings:

[auto build test WARNING on rafael-pm/linux-next]
[also build test WARNING on rafael-pm/bleeding-edge linus/master v6.12-rc2 next-20241011]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/KobaK/acpi-prmt-find-block-with-specific-type/20241009-144658
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
patch link:    https://lore.kernel.org/r/20241009064517.2678456-1-kobak%40nvidia.com
patch subject: [PATCH V7] acpi/prmt: find block with specific type
config: x86_64-rhel-8.3 (https://download.01.org/0day-ci/archive/20241013/202410130153.COiJzh3R-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241013/202410130153.COiJzh3R-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410130153.COiJzh3R-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from include/linux/kernel.h:31,
                    from drivers/acpi/prmt.c:17:
   drivers/acpi/prmt.c: In function 'efi_pa_va_lookup':
>> include/linux/kern_levels.h:5:25: warning: format '%p' expects argument of type 'void *', but argument 3 has type 'u64' {aka 'long long unsigned int'} [-Wformat=]
       5 | #define KERN_SOH        "\001"          /* ASCII Start Of Header */
         |                         ^~~~~~
   include/linux/printk.h:462:25: note: in definition of macro 'printk_index_wrap'
     462 |                 _p_func(_fmt, ##__VA_ARGS__);                           \
         |                         ^~~~
   include/linux/printk.h:543:9: note: in expansion of macro 'printk'
     543 |         printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
         |         ^~~~~~
   include/linux/kern_levels.h:12:25: note: in expansion of macro 'KERN_SOH'
      12 | #define KERN_WARNING    KERN_SOH "4"    /* warning conditions */
         |                         ^~~~~~~~
   include/linux/printk.h:543:16: note: in expansion of macro 'KERN_WARNING'
     543 |         printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
         |                ^~~~~~~~~~~~
   drivers/acpi/prmt.c:88:9: note: in expansion of macro 'pr_warn'
      88 |         pr_warn("Failed to find VA for GUID: %pUL, PA: %p", guid, pa);
         |         ^~~~~~~


vim +5 include/linux/kern_levels.h

314ba3520e513a Joe Perches 2012-07-30  4  
04d2c8c83d0e3a Joe Perches 2012-07-30 @5  #define KERN_SOH	"\001"		/* ASCII Start Of Header */
04d2c8c83d0e3a Joe Perches 2012-07-30  6  #define KERN_SOH_ASCII	'\001'
04d2c8c83d0e3a Joe Perches 2012-07-30  7  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH V7] acpi/prmt: find block with specific type
Posted by kernel test robot 1 month, 2 weeks ago
Hi KobaK,

kernel test robot noticed the following build warnings:

[auto build test WARNING on rafael-pm/linux-next]
[also build test WARNING on rafael-pm/bleeding-edge linus/master v6.12-rc2 next-20241011]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/KobaK/acpi-prmt-find-block-with-specific-type/20241009-144658
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
patch link:    https://lore.kernel.org/r/20241009064517.2678456-1-kobak%40nvidia.com
patch subject: [PATCH V7] acpi/prmt: find block with specific type
config: x86_64-kexec (https://download.01.org/0day-ci/archive/20241013/202410130117.PZ2JPuxo-lkp@intel.com/config)
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241013/202410130117.PZ2JPuxo-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410130117.PZ2JPuxo-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/acpi/prmt.c:88:60: warning: format specifies type 'void *' but the argument has type 'u64' (aka 'unsigned long long') [-Wformat]
      88 |         pr_warn("Failed to find VA for GUID: %pUL, PA: %p", guid, pa);
         |                                                        ~~         ^~
         |                                                        %llu
   include/linux/printk.h:543:37: note: expanded from macro 'pr_warn'
     543 |         printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
         |                                    ~~~     ^~~~~~~~~~~
   include/linux/printk.h:490:60: note: expanded from macro 'printk'
     490 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__)
         |                                                     ~~~    ^~~~~~~~~~~
   include/linux/printk.h:462:19: note: expanded from macro 'printk_index_wrap'
     462 |                 _p_func(_fmt, ##__VA_ARGS__);                           \
         |                         ~~~~    ^~~~~~~~~~~
>> drivers/acpi/prmt.c:156:29: warning: passing 1-byte aligned argument to 4-byte aligned parameter 1 of 'efi_pa_va_lookup' may result in an unaligned pointer access [-Walign-mismatch]
     156 |                         (void *)efi_pa_va_lookup(&th->guid, handler_info->handler_address);
         |                                                  ^
   drivers/acpi/prmt.c:159:21: warning: passing 1-byte aligned argument to 4-byte aligned parameter 1 of 'efi_pa_va_lookup' may result in an unaligned pointer access [-Walign-mismatch]
     159 |                         efi_pa_va_lookup(&th->guid, handler_info->static_data_buffer_address);
         |                                          ^
   drivers/acpi/prmt.c:162:21: warning: passing 1-byte aligned argument to 4-byte aligned parameter 1 of 'efi_pa_va_lookup' may result in an unaligned pointer access [-Walign-mismatch]
     162 |                         efi_pa_va_lookup(&th->guid, handler_info->acpi_param_buffer_address);
         |                                          ^
   4 warnings generated.


vim +88 drivers/acpi/prmt.c

    74	
    75	static u64 efi_pa_va_lookup(efi_guid_t *guid, u64 pa)
    76	{
    77		efi_memory_desc_t *md;
    78		u64 pa_offset = pa & ~PAGE_MASK;
    79		u64 page = pa & PAGE_MASK;
    80	
    81		for_each_efi_memory_desc(md) {
    82			if ((md->attribute & EFI_MEMORY_RUNTIME) &&
    83			    (md->phys_addr < pa && pa < md->phys_addr + PAGE_SIZE * md->num_pages)) {
    84				return pa_offset + md->virt_addr + page - md->phys_addr;
    85			}
    86		}
    87	
  > 88		pr_warn("Failed to find VA for GUID: %pUL, PA: %p", guid, pa);
    89	
    90		return 0;
    91	}
    92	
    93	#define get_first_handler(a) ((struct acpi_prmt_handler_info *) ((char *) (a) + a->handler_info_offset))
    94	#define get_next_handler(a) ((struct acpi_prmt_handler_info *) (sizeof(struct acpi_prmt_handler_info) + (char *) a))
    95	
    96	static int __init
    97	acpi_parse_prmt(union acpi_subtable_headers *header, const unsigned long end)
    98	{
    99		struct acpi_prmt_module_info *module_info;
   100		struct acpi_prmt_handler_info *handler_info;
   101		struct prm_handler_info *th;
   102		struct prm_module_info *tm;
   103		u64 *mmio_count;
   104		u64 cur_handler = 0;
   105		u32 module_info_size = 0;
   106		u64 mmio_range_size = 0;
   107		void *temp_mmio;
   108	
   109		module_info = (struct acpi_prmt_module_info *) header;
   110		module_info_size = struct_size(tm, handlers, module_info->handler_info_count);
   111		tm = kmalloc(module_info_size, GFP_KERNEL);
   112		if (!tm)
   113			goto parse_prmt_out1;
   114	
   115		guid_copy(&tm->guid, (guid_t *) module_info->module_guid);
   116		tm->major_rev = module_info->major_rev;
   117		tm->minor_rev = module_info->minor_rev;
   118		tm->handler_count = module_info->handler_info_count;
   119		tm->updatable = true;
   120	
   121		if (module_info->mmio_list_pointer) {
   122			/*
   123			 * Each module is associated with a list of addr
   124			 * ranges that it can use during the service
   125			 */
   126			mmio_count = (u64 *) memremap(module_info->mmio_list_pointer, 8, MEMREMAP_WB);
   127			if (!mmio_count)
   128				goto parse_prmt_out2;
   129	
   130			mmio_range_size = struct_size(tm->mmio_info, addr_ranges, *mmio_count);
   131			tm->mmio_info = kmalloc(mmio_range_size, GFP_KERNEL);
   132			if (!tm->mmio_info)
   133				goto parse_prmt_out3;
   134	
   135			temp_mmio = memremap(module_info->mmio_list_pointer, mmio_range_size, MEMREMAP_WB);
   136			if (!temp_mmio)
   137				goto parse_prmt_out4;
   138			memmove(tm->mmio_info, temp_mmio, mmio_range_size);
   139		} else {
   140			tm->mmio_info = kmalloc(sizeof(*tm->mmio_info), GFP_KERNEL);
   141			if (!tm->mmio_info)
   142				goto parse_prmt_out2;
   143	
   144			tm->mmio_info->mmio_count = 0;
   145		}
   146	
   147		INIT_LIST_HEAD(&tm->module_list);
   148		list_add(&tm->module_list, &prm_module_list);
   149	
   150		handler_info = get_first_handler(module_info);
   151		do {
   152			th = &tm->handlers[cur_handler];
   153	
   154			guid_copy(&th->guid, (guid_t *)handler_info->handler_guid);
   155			th->handler_addr =
 > 156				(void *)efi_pa_va_lookup(&th->guid, handler_info->handler_address);
   157	
   158			th->static_data_buffer_addr =
   159				efi_pa_va_lookup(&th->guid, handler_info->static_data_buffer_address);
   160	
   161			th->acpi_param_buffer_addr =
   162				efi_pa_va_lookup(&th->guid, handler_info->acpi_param_buffer_address);
   163	
   164		} while (++cur_handler < tm->handler_count && (handler_info = get_next_handler(handler_info)));
   165	
   166		return 0;
   167	
   168	parse_prmt_out4:
   169		kfree(tm->mmio_info);
   170	parse_prmt_out3:
   171		memunmap(mmio_count);
   172	parse_prmt_out2:
   173		kfree(tm);
   174	parse_prmt_out1:
   175		return -ENOMEM;
   176	}
   177	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH V7] acpi/prmt: find block with specific type
Posted by Ard Biesheuvel 1 month, 2 weeks ago
On Wed, 9 Oct 2024 at 08:45, KobaK <kobak@nvidia.com> wrote:
>
> From: kobak <kobak@nvidia.com>
>
> PRMT needs to find the correct type of block to
> translate the PA-VA mapping for EFI runtime services.
>
> The issue arises because the PRMT is finding a block of
> type EFI_CONVENTIONAL_MEMORY, which is not appropriate for
> runtime services as described in Section 2.2.2 (Runtime
> Services) of the UEFI Specification [1]. Since the PRM handler is
> a type of runtime service, this causes an exception
> when the PRM handler is called.
>
>     [Firmware Bug]: Unable to handle paging request in EFI runtime service
>     WARNING: CPU: 22 PID: 4330 at drivers/firmware/efi/runtime-wrappers.c:341
>         __efi_queue_work+0x11c/0x170
>     Call trace:
>
> Find a block with specific type to fix this.
> PRMT find a block with EFI_MEMORY_RUNTIME for PRM handler and PRM context.
> If no suitable block is found, a warning message will be prompted
> but the procedure continues to manage the next PRM handler.
> However, if the PRM handler is actually called without proper allocation,
> it would result in a failure during error handling.
>
> By using the correct memory types for runtime services,
> ensure that the PRM handler and the context are
> properly mapped in the virtual address space during runtime,
> preventing the paging request error.
>
> The issue is really that only memory that has been remapped for
> runtime by the firmware can be used by the PRM handler, and so the
> region needs to have the EFI_MEMORY_RUNTIME attribute.
>
> [1] https://uefi.org/sites/default/files/resources/UEFI_Spec_2_10_Aug29.pdf
> Fixes: cefc7ca46235 ("ACPI: PRM: implement OperationRegion handler for the PlatformRtMechanism subtype")
> Signed-off-by: Koba Ko <kobak@nvidia.com>
> Reviewed-by: Matthew R. Ochs <mochs@nvidia.com>
> Reviewed-by: Zhang Rui <rui.zhang@intel.com>

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>

This needs a cc:stable too

> ---
> V2:
> 1. format the changelog and add more about error handling.
> 2. replace goto
> V3: Warn if parts of handler are missed during va-pa translating.
> V4: Fix the 0day
> V5: Fix typo and pr_warn warning
> V6: use EFI_MOMOERY_RUNTIME to find block and split goto refactor as a single
> patch
> V7:
> 1. refine the codes and commit description as per comments
> 2. drop goto refacotr
> ---
>
>  drivers/acpi/prmt.c | 27 ++++++++++++++++++++++-----
>  1 file changed, 22 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c
> index 1cfaa5957ac4..51f5ae3d4350 100644
> --- a/drivers/acpi/prmt.c
> +++ b/drivers/acpi/prmt.c
> @@ -72,17 +72,21 @@ struct prm_module_info {
>         struct prm_handler_info handlers[] __counted_by(handler_count);
>  };
>
> -static u64 efi_pa_va_lookup(u64 pa)
> +static u64 efi_pa_va_lookup(efi_guid_t *guid, u64 pa)
>  {
>         efi_memory_desc_t *md;
>         u64 pa_offset = pa & ~PAGE_MASK;
>         u64 page = pa & PAGE_MASK;
>
>         for_each_efi_memory_desc(md) {
> -               if (md->phys_addr < pa && pa < md->phys_addr + PAGE_SIZE * md->num_pages)
> +               if ((md->attribute & EFI_MEMORY_RUNTIME) &&
> +                   (md->phys_addr < pa && pa < md->phys_addr + PAGE_SIZE * md->num_pages)) {
>                         return pa_offset + md->virt_addr + page - md->phys_addr;
> +               }
>         }
>
> +       pr_warn("Failed to find VA for GUID: %pUL, PA: %p", guid, pa);
> +
>         return 0;
>  }
>
> @@ -148,9 +152,15 @@ acpi_parse_prmt(union acpi_subtable_headers *header, const unsigned long end)
>                 th = &tm->handlers[cur_handler];
>
>                 guid_copy(&th->guid, (guid_t *)handler_info->handler_guid);
> -               th->handler_addr = (void *)efi_pa_va_lookup(handler_info->handler_address);
> -               th->static_data_buffer_addr = efi_pa_va_lookup(handler_info->static_data_buffer_address);
> -               th->acpi_param_buffer_addr = efi_pa_va_lookup(handler_info->acpi_param_buffer_address);
> +               th->handler_addr =
> +                       (void *)efi_pa_va_lookup(&th->guid, handler_info->handler_address);
> +
> +               th->static_data_buffer_addr =
> +                       efi_pa_va_lookup(&th->guid, handler_info->static_data_buffer_address);
> +
> +               th->acpi_param_buffer_addr =
> +                       efi_pa_va_lookup(&th->guid, handler_info->acpi_param_buffer_address);
> +
>         } while (++cur_handler < tm->handler_count && (handler_info = get_next_handler(handler_info)));
>
>         return 0;
> @@ -277,6 +287,13 @@ static acpi_status acpi_platformrt_space_handler(u32 function,
>                 if (!handler || !module)
>                         goto invalid_guid;
>
> +               if (!handler->handler_addr ||
> +                   !handler->static_data_buffer_addr ||
> +                   !handler->acpi_param_buffer_addr) {
> +                       buffer->prm_status = PRM_HANDLER_ERROR;
> +                       return AE_OK;
> +               }
> +
>                 ACPI_COPY_NAMESEG(context.signature, "PRMC");
>                 context.revision = 0x0;
>                 context.reserved = 0x0;
> --
> 2.43.0
>
Re: [PATCH V7] acpi/prmt: find block with specific type
Posted by Koba Ko 1 month, 2 weeks ago
On 10/9/24 14:50, Ard Biesheuvel wrote:
> External email: Use caution opening links or attachments
>
>
> On Wed, 9 Oct 2024 at 08:45, KobaK <kobak@nvidia.com> wrote:
>> From: kobak <kobak@nvidia.com>
>>
>> PRMT needs to find the correct type of block to
>> translate the PA-VA mapping for EFI runtime services.
>>
>> The issue arises because the PRMT is finding a block of
>> type EFI_CONVENTIONAL_MEMORY, which is not appropriate for
>> runtime services as described in Section 2.2.2 (Runtime
>> Services) of the UEFI Specification [1]. Since the PRM handler is
>> a type of runtime service, this causes an exception
>> when the PRM handler is called.
>>
>>      [Firmware Bug]: Unable to handle paging request in EFI runtime service
>>      WARNING: CPU: 22 PID: 4330 at drivers/firmware/efi/runtime-wrappers.c:341
>>          __efi_queue_work+0x11c/0x170
>>      Call trace:
>>
>> Find a block with specific type to fix this.
>> PRMT find a block with EFI_MEMORY_RUNTIME for PRM handler and PRM context.
>> If no suitable block is found, a warning message will be prompted
>> but the procedure continues to manage the next PRM handler.
>> However, if the PRM handler is actually called without proper allocation,
>> it would result in a failure during error handling.
>>
>> By using the correct memory types for runtime services,
>> ensure that the PRM handler and the context are
>> properly mapped in the virtual address space during runtime,
>> preventing the paging request error.
>>
>> The issue is really that only memory that has been remapped for
>> runtime by the firmware can be used by the PRM handler, and so the
>> region needs to have the EFI_MEMORY_RUNTIME attribute.
>>
>> [1] https://uefi.org/sites/default/files/resources/UEFI_Spec_2_10_Aug29.pdf
>> Fixes: cefc7ca46235 ("ACPI: PRM: implement OperationRegion handler for the PlatformRtMechanism subtype")
>> Signed-off-by: Koba Ko <kobak@nvidia.com>
>> Reviewed-by: Matthew R. Ochs <mochs@nvidia.com>
>> Reviewed-by: Zhang Rui <rui.zhang@intel.com>
> Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
>
> This needs a cc:stable too
Hi Ard, Rui
Thanks for reviewed.
>
>> ---
>> V2:
>> 1. format the changelog and add more about error handling.
>> 2. replace goto
>> V3: Warn if parts of handler are missed during va-pa translating.
>> V4: Fix the 0day
>> V5: Fix typo and pr_warn warning
>> V6: use EFI_MOMOERY_RUNTIME to find block and split goto refactor as a single
>> patch
>> V7:
>> 1. refine the codes and commit description as per comments
>> 2. drop goto refacotr
>> ---
>>
>>   drivers/acpi/prmt.c | 27 ++++++++++++++++++++++-----
>>   1 file changed, 22 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c
>> index 1cfaa5957ac4..51f5ae3d4350 100644
>> --- a/drivers/acpi/prmt.c
>> +++ b/drivers/acpi/prmt.c
>> @@ -72,17 +72,21 @@ struct prm_module_info {
>>          struct prm_handler_info handlers[] __counted_by(handler_count);
>>   };
>>
>> -static u64 efi_pa_va_lookup(u64 pa)
>> +static u64 efi_pa_va_lookup(efi_guid_t *guid, u64 pa)
>>   {
>>          efi_memory_desc_t *md;
>>          u64 pa_offset = pa & ~PAGE_MASK;
>>          u64 page = pa & PAGE_MASK;
>>
>>          for_each_efi_memory_desc(md) {
>> -               if (md->phys_addr < pa && pa < md->phys_addr + PAGE_SIZE * md->num_pages)
>> +               if ((md->attribute & EFI_MEMORY_RUNTIME) &&
>> +                   (md->phys_addr < pa && pa < md->phys_addr + PAGE_SIZE * md->num_pages)) {
>>                          return pa_offset + md->virt_addr + page - md->phys_addr;
>> +               }
>>          }
>>
>> +       pr_warn("Failed to find VA for GUID: %pUL, PA: %p", guid, pa);
>> +
>>          return 0;
>>   }
>>
>> @@ -148,9 +152,15 @@ acpi_parse_prmt(union acpi_subtable_headers *header, const unsigned long end)
>>                  th = &tm->handlers[cur_handler];
>>
>>                  guid_copy(&th->guid, (guid_t *)handler_info->handler_guid);
>> -               th->handler_addr = (void *)efi_pa_va_lookup(handler_info->handler_address);
>> -               th->static_data_buffer_addr = efi_pa_va_lookup(handler_info->static_data_buffer_address);
>> -               th->acpi_param_buffer_addr = efi_pa_va_lookup(handler_info->acpi_param_buffer_address);
>> +               th->handler_addr =
>> +                       (void *)efi_pa_va_lookup(&th->guid, handler_info->handler_address);
>> +
>> +               th->static_data_buffer_addr =
>> +                       efi_pa_va_lookup(&th->guid, handler_info->static_data_buffer_address);
>> +
>> +               th->acpi_param_buffer_addr =
>> +                       efi_pa_va_lookup(&th->guid, handler_info->acpi_param_buffer_address);
>> +
>>          } while (++cur_handler < tm->handler_count && (handler_info = get_next_handler(handler_info)));
>>
>>          return 0;
>> @@ -277,6 +287,13 @@ static acpi_status acpi_platformrt_space_handler(u32 function,
>>                  if (!handler || !module)
>>                          goto invalid_guid;
>>
>> +               if (!handler->handler_addr ||
>> +                   !handler->static_data_buffer_addr ||
>> +                   !handler->acpi_param_buffer_addr) {
>> +                       buffer->prm_status = PRM_HANDLER_ERROR;
>> +                       return AE_OK;
>> +               }
>> +
>>                  ACPI_COPY_NAMESEG(context.signature, "PRMC");
>>                  context.revision = 0x0;
>>                  context.reserved = 0x0;
>> --
>> 2.43.0
>>