Re: [PATCH V5] acpi/prmt: find block with specific type

[Koba Ko <kobak@nvidia.com>]

On 10/3/24 02:05, Rafael J. Wysocki wrote:
> External email: Use caution opening links or attachments
>
>
> On Wed, Sep 11, 2024 at 5:55 PM KobaK <kobak@nvidia.com> wrote:
>> 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:
>>        __efi_queue_work+0x11c/0x170
>>        efi_call_acpi_prm_handler+0x68/0xd0
>>        acpi_platformrt_space_handler+0x198/0x258
>>        acpi_ev_address_space_dispatch+0x144/0x388
>>        acpi_ex_access_region+0x9c/0x118
>>        acpi_ex_write_serial_bus+0xc4/0x218
>>        acpi_ex_write_data_to_field+0x168/0x218
>>        acpi_ex_store_object_to_node+0x1a8/0x258
>>        acpi_ex_store+0xec/0x330
>>        acpi_ex_opcode_1A_1T_1R+0x15c/0x618
>>        acpi_ds_exec_end_op+0x274/0x548
>>        acpi_ps_parse_loop+0x10c/0x6b8
>>        acpi_ps_parse_aml+0x140/0x3b0
>>        acpi_ps_execute_method+0x12c/0x2a0
>>        acpi_ns_evaluate+0x210/0x310
>>        acpi_evaluate_object+0x178/0x358
>>        acpi_proc_write+0x1a8/0x8a0 [acpi_call]
>>        proc_reg_write+0xcc/0x150
>>        vfs_write+0xd8/0x380
>>        ksys_write+0x70/0x120
>>        __arm64_sys_write+0x24/0x48
>>        invoke_syscall.constprop.0+0x80/0xf8
>>        do_el0_svc+0x50/0x110
>>        el0_svc+0x48/0x1d0
>>        el0t_64_sync_handler+0x15c/0x178
>>        el0t_64_sync+0x1a8/0x1b0
>>
>> Find a block with specific type to fix this.
>> prmt find a block with EFI_RUNTIME_SERVICES_DATA for prm handler and
>> find a block with EFI_RUNTIME_SERVICES_CODE for prm context.
>> If no suitable block is found, a warning message will be prompted
>> but the procedue continues to manage the next prm handler.
>> However, if the prm handler is actullay 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.
>>
>> [1] https://uefi.org/sites/default/files/resources/UEFI_Spec_2_10_Aug29.pdf
> I need input from EFI people on this, so can you please resend the
> patch with a CC to linux-efi@vger.kernel.org?
Ok, i will CC in next push
>> Fixes: cefc7ca46235 ("ACPI: PRM: implement OperationRegion handler for the PlatformRtMechanism subtype")
>> Signed-off-by: KobaK <kobak@nvidia.com>
>> Reviewed-by: Matthew R. Ochs <mochs@nvidia.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
>> ---
>>   drivers/acpi/prmt.c | 49 +++++++++++++++++++++++++++++++--------------
>>   1 file changed, 34 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c
>> index c78453c74ef5..cd4a7f5491d6 100644
>> --- a/drivers/acpi/prmt.c
>> +++ b/drivers/acpi/prmt.c
>> @@ -72,15 +72,17 @@ 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(u64 pa, u32 type)
>>   {
>>          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->type == type) &&
>> +                       (md->phys_addr < pa && pa < md->phys_addr + PAGE_SIZE * md->num_pages)) {
>>                          return pa_offset + md->virt_addr + page - md->phys_addr;
>> +               }
>>          }
>>
>>          return 0;
>> @@ -148,9 +150,18 @@ 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(handler_info->handler_address, EFI_RUNTIME_SERVICES_CODE);
>> +               th->static_data_buffer_addr =
>> +                       efi_pa_va_lookup(handler_info->static_data_buffer_address, EFI_RUNTIME_SERVICES_DATA);
>> +               th->acpi_param_buffer_addr =
>> +                       efi_pa_va_lookup(handler_info->acpi_param_buffer_address, EFI_RUNTIME_SERVICES_DATA);
>> +
>> +               if (!th->handler_addr || !th->static_data_buffer_addr || !th->acpi_param_buffer_addr)
>> +                       pr_warn(
>> +                               "Idx: %llu, Parts of handler(GUID: %pUL) are missed, handler_addr %p, data_addr %p, param_addr %p",
>> +                               cur_handler, &th->guid, th->handler_addr,
>> +                               (void *)th->static_data_buffer_addr, (void *)th->acpi_param_buffer_addr);
>>          } while (++cur_handler < tm->handler_count && (handler_info = get_next_handler(handler_info)));
>>
>>          return 0;
>> @@ -250,8 +261,16 @@ static acpi_status acpi_platformrt_space_handler(u32 function,
>>
>>                  handler = find_prm_handler(&buffer->handler_guid);
>>                  module = find_prm_module(&buffer->handler_guid);
>> -               if (!handler || !module)
>> -                       goto invalid_guid;
>> +               if (!handler || !module) {
>> +                       buffer->prm_status = PRM_HANDLER_GUID_NOT_FOUND;
>> +                       return AE_OK;
>> +               }
>> +
>> +               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;
>> @@ -274,8 +293,10 @@ static acpi_status acpi_platformrt_space_handler(u32 function,
>>          case PRM_CMD_START_TRANSACTION:
>>
>>                  module = find_prm_module(&buffer->handler_guid);
>> -               if (!module)
>> -                       goto invalid_guid;
>> +               if (!module) {
>> +                       buffer->prm_status = PRM_HANDLER_GUID_NOT_FOUND;
>> +                       return AE_OK;
>> +               }
>>
>>                  if (module->updatable)
>>                          module->updatable = false;
>> @@ -286,8 +307,10 @@ static acpi_status acpi_platformrt_space_handler(u32 function,
>>          case PRM_CMD_END_TRANSACTION:
>>
>>                  module = find_prm_module(&buffer->handler_guid);
>> -               if (!module)
>> -                       goto invalid_guid;
>> +               if (!module) {
>> +                       buffer->prm_status = PRM_HANDLER_GUID_NOT_FOUND;
>> +                       return AE_OK;
>> +               }
>>
>>                  if (module->updatable)
>>                          buffer->prm_status = UPDATE_UNLOCK_WITHOUT_LOCK;
>> @@ -302,10 +325,6 @@ static acpi_status acpi_platformrt_space_handler(u32 function,
>>          }
>>
>>          return AE_OK;
>> -
>> -invalid_guid:
>> -       buffer->prm_status = PRM_HANDLER_GUID_NOT_FOUND;
>> -       return AE_OK;
>>   }
>>
>>   void __init init_prmt(void)
>> --
>> 2.43.0
>>
>>