Re: [PATCH v24 08/10] ACPI: Record Generic Error Status Block(GESB) table

[Igor Mammedov <imammedo@redhat.com>]

On Mon, 17 Feb 2020 21:12:46 +0800
Dongjiu Geng <gengdongjiu@huawei.com> wrote:

> kvm_arch_on_sigbus_vcpu() error injection uses source_id as
> index in etc/hardware_errors to find out Error Status Data
> Block entry corresponding to error source. So supported source_id
> values should be assigned here and not be changed afterwards to
> make sure that guest will write error into expected Error Status
> Data Block.
> 
> Before QEMU writes a new error to ACPI table, it will check whether
> previous error has been acknowledged. If not acknowledged, the new
> errors will be ignored and not be recorded. For the errors section
> type, QEMU simulate it to memory section error.
> 
> Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
> Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
> ---
>  hw/acpi/ghes.c         | 218 +++++++++++++++++++++++++++++++++++++++++++++++++
>  include/hw/acpi/ghes.h |   1 +
>  2 files changed, 219 insertions(+)
> 
> diff --git a/hw/acpi/ghes.c b/hw/acpi/ghes.c
> index cea2bff..41ddad9 100644
> --- a/hw/acpi/ghes.c
> +++ b/hw/acpi/ghes.c
> @@ -26,6 +26,7 @@
>  #include "qemu/error-report.h"
>  #include "hw/acpi/generic_event_device.h"
>  #include "hw/nvram/fw_cfg.h"
> +#include "qemu/uuid.h"
>  
>  #define ACPI_GHES_ERRORS_FW_CFG_FILE        "etc/hardware_errors"
>  #define ACPI_GHES_DATA_ADDR_FW_CFG_FILE     "etc/hardware_errors_addr"
> @@ -43,6 +44,36 @@
>  #define GAS_ADDR_OFFSET 4
>  
>  /*
> + * The total size of Generic Error Data Entry
> + * ACPI 6.1/6.2: 18.3.2.7.1 Generic Error Data,
> + * Table 18-343 Generic Error Data Entry
> + */
> +#define ACPI_GHES_DATA_LENGTH               72
> +
> +/* The memory section CPER size, UEFI 2.6: N.2.5 Memory Error Section */
> +#define ACPI_GHES_MEM_CPER_LENGTH           80
> +
> +/* Masks for block_status flags */
> +#define ACPI_GEBS_UNCORRECTABLE         1
> +
> +/*
> + * Total size for Generic Error Status Block except Generic Error Data Entries
> + * ACPI 6.2: 18.3.2.7.1 Generic Error Data,
> + * Table 18-380 Generic Error Status Block
> + */
> +#define ACPI_GHES_GESB_SIZE                 20
> +
> +/*
> + * Values for error_severity field
> + */
> +enum AcpiGenericErrorSeverity {
> +    ACPI_CPER_SEV_RECOVERABLE = 0,
> +    ACPI_CPER_SEV_FATAL = 1,
> +    ACPI_CPER_SEV_CORRECTED = 2,
> +    ACPI_CPER_SEV_NONE = 3,
> +};
> +
> +/*
>   * Hardware Error Notification
>   * ACPI 4.0: 17.3.2.7 Hardware Error Notification
>   * Composes dummy Hardware Error Notification descriptor of specified type
> @@ -73,6 +104,135 @@ static void build_ghes_hw_error_notification(GArray *table, const uint8_t type)
>  }
>  
>  /*
> + * Generic Error Data Entry
> + * ACPI 6.1: 18.3.2.7.1 Generic Error Data
> + */
> +static void acpi_ghes_generic_error_data(GArray *table,
> +                const uint8_t *section_type, uint32_t error_severity,
> +                uint8_t validation_bits, uint8_t flags,
> +                uint32_t error_data_length, QemuUUID fru_id,
> +                uint64_t time_stamp)
> +{
> +    /* Section Type */
> +    g_array_append_vals(table, section_type, 16);
> +
> +    /* Error Severity */
> +    build_append_int_noprefix(table, error_severity, 4);
> +    /* Revision */
> +    build_append_int_noprefix(table, 0x300, 2);
> +    /* Validation Bits */
> +    build_append_int_noprefix(table, validation_bits, 1);
> +    /* Flags */
> +    build_append_int_noprefix(table, flags, 1);
> +    /* Error Data Length */
> +    build_append_int_noprefix(table, error_data_length, 4);
> +
> +    /* FRU Id */
> +    g_array_append_vals(table, fru_id.data, ARRAY_SIZE(fru_id.data));
> +
> +    /* FRU Text */
> +    build_append_int_noprefix(table, 0, 20);

       that ends up calling:

           for (i = 0; i < size; ++i) { 
              uint64_t = uint64_t >> 8
           }

       with size > 8 it's probably undefined behavior

it's safer to use here
      
      g_array_append_vals(table, zerro_array, sizeof(zerro_array))

> +    /* Timestamp */
> +    build_append_int_noprefix(table, time_stamp, 8);
> +}
> +
> +/*
> + * Generic Error Status Block
> + * ACPI 6.1: 18.3.2.7.1 Generic Error Data
> + */
> +static void acpi_ghes_generic_error_status(GArray *table, uint32_t block_status,
> +                uint32_t raw_data_offset, uint32_t raw_data_length,
> +                uint32_t data_length, uint32_t error_severity)
> +{
> +    /* Block Status */
> +    build_append_int_noprefix(table, block_status, 4);
> +    /* Raw Data Offset */
> +    build_append_int_noprefix(table, raw_data_offset, 4);
> +    /* Raw Data Length */
> +    build_append_int_noprefix(table, raw_data_length, 4);
> +    /* Data Length */
> +    build_append_int_noprefix(table, data_length, 4);
> +    /* Error Severity */
> +    build_append_int_noprefix(table, error_severity, 4);
> +}
> +
> +/* UEFI 2.6: N.2.5 Memory Error Section */
> +static void acpi_ghes_build_append_mem_cper(GArray *table,
> +                                            uint64_t error_physical_addr)
> +{
> +    /*
> +     * Memory Error Record
> +     */
> +
> +    /* Validation Bits */
> +    build_append_int_noprefix(table,
> +                              (1ULL << 14) | /* Type Valid */
> +                              (1ULL << 1) /* Physical Address Valid */,
> +                              8);
> +    /* Error Status */
> +    build_append_int_noprefix(table, 0, 8);
> +    /* Physical Address */
> +    build_append_int_noprefix(table, error_physical_addr, 8);
> +    /* Skip all the detailed information normally found in such a record */
> +    build_append_int_noprefix(table, 0, 48);
> +    /* Memory Error Type */
> +    build_append_int_noprefix(table, 0 /* Unknown error */, 1);
> +    /* Skip all the detailed information normally found in such a record */
> +    build_append_int_noprefix(table, 0, 7);
> +}
> +
> +static int acpi_ghes_record_mem_error(uint64_t error_block_address,
> +                                      uint64_t error_physical_addr)
> +{
> +    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;
> +
> +    /*
> +     * Check whether it will run out of the preallocated memory if adding a new
> +     * generic error data entry
> +     */
> +    if ((data_length + ACPI_GHES_GESB_SIZE) > ACPI_GHES_MAX_RAW_DATA_LENGTH) {
> +        error_report("Not enough memory to record new CPER!!!");
> +        g_array_free(block, true);
> +        return -1;
> +    }
> +
> +    /* 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_CPER_SEV_RECOVERABLE, 0, 0,
> +        ACPI_GHES_MEM_CPER_LENGTH, fru_id, 0);
> +
> +    /* 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;
> +}
> +
> +/*
>   * Build table for the hardware error fw_cfg blob.
>   * Initialize "etc/hardware_errors" and "etc/hardware_errors_addr" fw_cfg blobs.
>   * See docs/specs/acpi_hest_ghes.rst for blobs format.
> @@ -230,3 +390,61 @@ void acpi_ghes_add_fw_cfg(AcpiGhesState *ags, FWCfgState *s,
>      fw_cfg_add_file_callback(s, ACPI_GHES_DATA_ADDR_FW_CFG_FILE, NULL, NULL,
>          NULL, &(ags->ghes_addr_le), sizeof(ags->ghes_addr_le), false);
>  }
> +
> +int acpi_ghes_record_errors(uint8_t source_id, uint64_t physical_address)
> +{
> +    uint64_t error_block_addr, read_ack_register_addr, read_ack_register = 0;
> +    uint64_t start_addr;
> +    bool ret = -1;
> +    AcpiGedState *acpi_ged_state;
> +    AcpiGhesState *ags;
> +
> +    assert(source_id < ACPI_HEST_SRC_ID_RESERVED);
> +
> +    acpi_ged_state = ACPI_GED(object_resolve_path_type("", TYPE_ACPI_GED,
> +                                                       NULL));

> +    if (acpi_ged_state) {
> +        ags = &acpi_ged_state->ghes_state;
> +    } else {
> +        error_report("ACPI GED device not found");
> +        return -1;
> +    }

This function is not reachable unless RAS is enabled and therefore GED device
already present. So I'd replace this block with just

         g_assert(acpi_ged_state)
         ags = &acpi_ged_state->ghes_state;

> +
> +    start_addr = le64_to_cpu(ags->ghes_addr_le);
> +
> +    if (physical_address) {
> +
> +        if (source_id < ACPI_HEST_SRC_ID_RESERVED) {
> +            start_addr += source_id * sizeof(uint64_t);
> +        }
> +
> +        cpu_physical_memory_read(start_addr, &error_block_addr,
> +                                 sizeof(error_block_addr));

error_block_addr value is in guest byte order at this point
and then ...

> +
> +        read_ack_register_addr = start_addr +
> +            ACPI_GHES_ERROR_SOURCE_COUNT * sizeof(uint64_t);
> +
> +        cpu_physical_memory_read(read_ack_register_addr,
> +                                 &read_ack_register, sizeof(read_ack_register));
> +
> +        /* zero means OSPM does not acknowledge the error */
> +        if (!read_ack_register) {
> +                error_report("OSPM does not acknowledge previous error,"
> +                    " so can not record CPER for current error anymore");
> +        } else if (error_block_addr) {
> +                read_ack_register = cpu_to_le64(0);
> +                /*
> +                 * Clear the Read Ack Register, OSPM will write it to 1 when
> +                 * it acknowledges this error.
> +                 */
> +                cpu_physical_memory_write(read_ack_register_addr,
> +                    &read_ack_register, sizeof(uint64_t));
> +
> +                ret = acpi_ghes_record_mem_error(error_block_addr,

it's passed to  cpu_physical_memory_write(error_block_address, ...
which uses host byte order.
It looks like le64_to_cpu() was lost somewhere in between.


> +                                                 physical_address);
> +        } else
> +                error_report("can not find Generic Error Status Block");
> +    }
> +
> +    return ret;
> +}
> diff --git a/include/hw/acpi/ghes.h b/include/hw/acpi/ghes.h
> index a3420fc..4ad025e 100644
> --- a/include/hw/acpi/ghes.h
> +++ b/include/hw/acpi/ghes.h
> @@ -70,4 +70,5 @@ void build_ghes_error_table(GArray *hardware_errors, BIOSLinker *linker);
>  void acpi_build_hest(GArray *table_data, BIOSLinker *linker);
>  void acpi_ghes_add_fw_cfg(AcpiGhesState *vms, FWCfgState *s,
>                            GArray *hardware_errors);
> +int acpi_ghes_record_errors(uint8_t notify, uint64_t error_physical_addr);
>  #endif