linux-kernel - Re: [PATCH 09/15] acpi/ghes: make the GHES record generation more generic

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Message-ID: <20240926130056.00001e12@Huawei.com>
Date: Thu, 26 Sep 2024 13:00:56 +0100
From: Jonathan Cameron <Jonathan.Cameron@...wei.com>
To: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
CC: Igor Mammedov <imammedo@...hat.com>, Shiju Jose <shiju.jose@...wei.com>,
	"Michael S. Tsirkin" <mst@...hat.com>, Ani Sinha <anisinha@...hat.com>,
	Dongjiu Geng <gengdongjiu1@...il.com>, <linux-kernel@...r.kernel.org>,
	<qemu-arm@...gnu.org>, <qemu-devel@...gnu.org>
Subject: Re: [PATCH 09/15] acpi/ghes: make the GHES record generation more
 generic

On Wed, 25 Sep 2024 06:04:14 +0200
Mauro Carvalho Chehab <mchehab+huawei@...nel.org> wrote:

> Split the code into separate functions to allow using the
> common CPER filling code by different error sources.
> 
> The generic code was moved to ghes_record_cper_errors(),
> and ghes_gen_err_data_uncorrectable_recoverable() now contains
> only a logic to fill GEGB part of the record.
> 
> The remaining code to generate a memory error now belongs to
> acpi_ghes_record_errors() function.
> 
> A further patch will give it a better name.

That bit is fine, I'm less sure about
ghes_gen_err_data_uncorrectable_recoverable()
Maybe you refactor that later, but I'd suggest doing so in this
patch to make it 
ghes_gen_data() with the uncorrectable and recoverable bits
passed in as parameters.

Jonathan

> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
> ---
>  hw/acpi/ghes.c         | 118 +++++++++++++++++++++++++----------------
>  include/hw/acpi/ghes.h |   3 ++
>  2 files changed, 74 insertions(+), 47 deletions(-)
> 
> diff --git a/hw/acpi/ghes.c b/hw/acpi/ghes.c
> index 340a0263faf8..307b5a41d539 100644
> --- a/hw/acpi/ghes.c
> +++ b/hw/acpi/ghes.c
> @@ -181,51 +181,30 @@ static void acpi_ghes_build_append_mem_cper(GArray *table,
>      build_append_int_noprefix(table, 0, 7);
>  }
>  
> -static int acpi_ghes_record_mem_error(uint64_t error_block_address,
> -                                      uint64_t error_physical_addr)
> +static void
> +ghes_gen_err_data_uncorrectable_recoverable(GArray *block,
> +                                            const uint8_t *section_type,
> +                                            int data_length)
>  {

That's an ugly name .  Suggestion below on instead passing parameters
for the uncorrectable and recoverable parts and amking this
ghes_gen_err_data()

> -    GArray *block;
> -
> -    /* Memory Error Section Type */
> -    const uint8_t uefi_cper_mem_sec[] =
> -          UUID_LE(0xA5BC1114, 0x6F64, 0x4EDE, 0xB8, 0x63, 0x3E, 0x83, \
> -                  0xED, 0x7C, 0x83, 0xB1);
> -
>      /* invalid fru id: ACPI 4.0: 17.3.2.6.1 Generic Error Data,
>       * Table 17-13 Generic Error Data Entry
>       */
>      QemuUUID fru_id = {};
> -    uint32_t data_length;
>  
> -    block = g_array_new(false, true /* clear */, 1);
> -
> -    /* This is the length if adding a new generic error data entry*/
> -    data_length = ACPI_GHES_DATA_LENGTH + ACPI_GHES_MEM_CPER_LENGTH;
>      /*
> -     * It should not run out of the preallocated memory if adding a new generic
> -     * error data entry
> +     * Calculate the size with this block. No need to check for
> +     * too big CPER, as CPER size is checked at ghes_record_cper_errors()
>       */
> -    assert((data_length + ACPI_GHES_GESB_SIZE) <=
> -            ACPI_GHES_MAX_RAW_DATA_LENGTH);
> +    data_length += ACPI_GHES_GESB_SIZE;
>  
>      /* Build the new generic error status block header */
>      acpi_ghes_generic_error_status(block, ACPI_GEBS_UNCORRECTABLE,
>          0, 0, data_length, ACPI_CPER_SEV_RECOVERABLE);
>  
>      /* Build this new generic error data entry header */
> -    acpi_ghes_generic_error_data(block, uefi_cper_mem_sec,
> +    acpi_ghes_generic_error_data(block, section_type,
>          ACPI_CPER_SEV_RECOVERABLE, 0, 0,
>          ACPI_GHES_MEM_CPER_LENGTH, fru_id, 0);
Maybe should just pass in ACPI_CPER_SEV_RECOVERABLE 
and ACPI_GEBS_UNCORRECTABLE in parameters.

Main advantage being that should allow reuse for other combinations
and it gets rid of the nasty function name!

> -
> -    /* Build the memory section CPER for above new generic error data entry */
> -    acpi_ghes_build_append_mem_cper(block, error_physical_addr);
> -
> -    /* Write the generic error data entry into guest memory */
> -    cpu_physical_memory_write(error_block_address, block->data, block->len);
> -
> -    g_array_free(block, true);
> -
> -    return 0;
>  }
>  
>  /*
> @@ -399,14 +378,19 @@ void acpi_ghes_add_fw_cfg(AcpiGhesState *ags, FWCfgState *s,
>      ags->present = true;
>  }
>  
> -int acpi_ghes_record_errors(uint16_t source_id, uint64_t physical_address)
> +void ghes_record_cper_errors(const void *cper, size_t len,
> +                             uint16_t source_id, Error **errp)
>  {

> -    return ret;
> +    read_ack_register = cpu_to_le64(0);
> +    /*
> +        * Clear the Read Ack Register, OSPM will write it to 1 when
> +        * it acknowledges this error.
> +        */

Indent issue.

> +    cpu_physical_memory_write(read_ack_register_addr,
> +        &read_ack_register, sizeof(uint64_t));
> +
> +    /* Write the generic error data entry into guest memory */
> +    cpu_physical_memory_write(error_block_addr, cper, len);
> +
> +    return;
> +}