================     ==========================================
                     +-----------+
+--------------+     | address   |         +-> +--------------+
|    HEST      +     | registers |         |   | Error Status |
+ +------------+     | +---------+         |   | Data Block 0 |
| | GHES0      | --> | |address0 | --------+   | +------------+
| | GHES1      | --> | |address1 | ------+     | |  CPER      |
| | GHES2      | --> | |address2 | ----+ |     | |  CPER      |
| |  ....      | --> | | ....... |     | |     | |  CPER      |
| | GHES10     | --> | |address10| -+  | |     | |  CPER      |
+-+------------+     +-+---------+  |  | |     +-+------------+
                                    |  | |
                                    |  | +---> +--------------+
                                    |  |       | Error Status |
                                    |  |       | Data Block 1 |
                                    |  |       | +------------+
                                    |  |       | |  CPER      |
                                    |  |       | |  CPER      |
                                    |  |       +-+------------+
                                    |  |
                                    |  +-----> +--------------+
                                    |          | Error Status |
                                    |          | Data Block 2 |
                                    |          | +------------+
                                    |          | |  CPER      |
                                    |          +-+------------+
                                    |            ...........
                                    +--------> +--------------+
                                               | Error Status |
                                               | Data Block 10|
                                               | +------------+
                                               | |  CPER      |
                                               | |  CPER      |
                                               | |  CPER      |
                                               +-+------------+
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
---
thanks a lot Laszlo's review and comments: 

change since v4:
1. fix email threading in this series is incorrect issue

change since v3:
1. remove the unnecessary include for "hw/acpi/vmgenid.h" in 
   hw/arm/virt-acpi-build.c
2. add conversion between LE and host-endian for the CPER record
3. handle the case that run out of the preallocated memory for the CPER record
4. change to use g_malloc0 instead of g_malloc 
5. change block_reqr_size name to block_rer_size
6. change QEMU coding style, that is, the operator is at the end of the line.
7. drop the ERROR_STATUS_ADDRESS_OFFSET and GAS_ADDRESS_OFFSET macros (from
   the header file as well), and use the offsetof to replace it.
8. remove the init_aml_allocator() / free_aml_allocator(), calculate the
   needed size, and push that many bytes directly to "table_data".
9. take an "OVMF header probe suppressor" into account
10.corrct HEST and CPER value assigment, for example, correct the source_id
   for every error source, this identifier of source_id should be unique among
   all error sources; 
11. create only one WRITE_POINTER command, for the base address of "etc/hardware_errors".
   This should be done outside of the loop.The base addresses of the individual error
   status data blocks should be calculated in ghes_update_guest(), based on the error
   source / notification type
12.correct the commit message lists error sources / notification types 0 through 10 (count=11 in total). 
13.correct the size calculation for GHES_DATA_ADDR_FW_CFG_FILE 
14.range-checked the value of "notify" before using it as an array subscript
---
 hw/acpi/aml-build.c      |   2 +
 hw/acpi/hest_ghes.c      | 219 +++++++++++++++++++++++++++++++++++++++++++++++
 hw/arm/virt-acpi-build.c |   6 ++
 3 files changed, 227 insertions(+)
 create mode 100644 hw/acpi/hest_ghes.c

diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
index c6f2032..802b98d 100644
--- a/hw/acpi/aml-build.c
+++ b/hw/acpi/aml-build.c
@@ -1560,6 +1560,7 @@ void acpi_build_tables_init(AcpiBuildTables *tables)
     tables->table_data = g_array_new(false, true /* clear */, 1);
     tables->tcpalog = g_array_new(false, true /* clear */, 1);
     tables->vmgenid = g_array_new(false, true /* clear */, 1);
+    tables->hardware_errors = g_array_new(false, true /* clear */, 1);
     tables->linker = bios_linker_loader_init();
 }
 
@@ -1570,6 +1571,7 @@ void acpi_build_tables_cleanup(AcpiBuildTables *tables, bool mfre)
     g_array_free(tables->table_data, true);
     g_array_free(tables->tcpalog, mfre);
     g_array_free(tables->vmgenid, mfre);
+    g_array_free(tables->hardware_errors, mfre);
 }
 
 /* Build rsdt table */
diff --git a/hw/acpi/hest_ghes.c b/hw/acpi/hest_ghes.c
new file mode 100644
index 0000000..c9442b6
--- /dev/null
+++ b/hw/acpi/hest_ghes.c
@@ -0,0 +1,219 @@
+/*
+ *  APEI GHES table Generation
+ *
+ *  Copyright (C) 2017 huawei.
+ *
+ *  Author: Dongjiu Geng <gengdongjiu@huawei.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qmp-commands.h"
+#include "hw/acpi/acpi.h"
+#include "hw/acpi/aml-build.h"
+#include "hw/acpi/hest_ghes.h"
+#include "hw/nvram/fw_cfg.h"
+#include "sysemu/sysemu.h"
+
+static int ghes_record_cper(uint64_t error_block_address,
+                                    uint64_t error_physical_addr)
+{
+    AcpiGenericErrorStatus block;
+    AcpiGenericErrorData *gdata;
+    UefiCperSecMemErr *mem_err;
+    uint64_t current_block_length;
+    unsigned char *buffer;
+    QemuUUID section_id_le = UEFI_CPER_SEC_PLATFORM_MEM;
+
+
+    cpu_physical_memory_read(error_block_address, &block,
+                                sizeof(AcpiGenericErrorStatus));
+
+    /* Get the current generic error status block length */
+    current_block_length = sizeof(AcpiGenericErrorStatus) +
+        le32_to_cpu(block.data_length);
+
+    /* If the Generic Error Status Block is NULL, update
+     * the block header
+     */
+    if (!block.block_status) {
+        block.block_status = ACPI_GEBS_UNCORRECTABLE;
+        block.error_severity = ACPI_CPER_SEV_FATAL;
+    }
+
+    block.data_length += cpu_to_le32(sizeof(AcpiGenericErrorData));
+    block.data_length += cpu_to_le32(sizeof(UefiCperSecMemErr));
+
+    /* check whether it runs out of the preallocated memory */
+    if ((le32_to_cpu(block.data_length) + sizeof(AcpiGenericErrorStatus)) >
+       GHES_MAX_RAW_DATA_LENGTH) {
+        return GHES_CPER_FAIL;
+    }
+    /* Write back the Generic Error Status Block to guest memory */
+    cpu_physical_memory_write(error_block_address, &block,
+                        sizeof(AcpiGenericErrorStatus));
+
+    /* Fill in Generic Error Data Entry */
+    buffer = g_malloc0(sizeof(AcpiGenericErrorData) +
+                       sizeof(UefiCperSecMemErr));
+    memset(buffer, 0, sizeof(AcpiGenericErrorData) + sizeof(UefiCperSecMemErr));
+    gdata = (AcpiGenericErrorData *)buffer;
+
+    qemu_uuid_bswap(&section_id_le);
+    memcpy(&(gdata->section_type_le), &section_id_le,
+                sizeof(QemuUUID));
+    gdata->error_data_length = cpu_to_le32(sizeof(UefiCperSecMemErr));
+
+    mem_err = (UefiCperSecMemErr *) (gdata + 1);
+
+    /* In order to simplify simulation, hard code the CPER section to memory
+     * section.
+     */
+
+    /* Hard code to Multi-bit ECC error */
+    mem_err->validation_bits |= cpu_to_le32(UEFI_CPER_MEM_VALID_ERROR_TYPE);
+    mem_err->error_type = cpu_to_le32(UEFI_CPER_MEM_ERROR_TYPE_MULTI_ECC);
+
+    /* Record the physical address at which the memory error occurred */
+    mem_err->validation_bits |= cpu_to_le32(UEFI_CPER_MEM_VALID_PA);
+    mem_err->physical_addr = cpu_to_le32(error_physical_addr);
+
+    /* Write back the Generic Error Data Entry to guest memory */
+    cpu_physical_memory_write(error_block_address + current_block_length,
+        buffer, sizeof(AcpiGenericErrorData) + sizeof(UefiCperSecMemErr));
+
+    g_free(buffer);
+    return GHES_CPER_OK;
+}
+
+void ghes_build_acpi(GArray *table_data, GArray *hardware_error,
+                                            BIOSLinker *linker)
+{
+    GArray *buffer;
+    uint32_t address_registers_offset;
+    AcpiHardwareErrorSourceTable *error_source_table;
+    AcpiGenericHardwareErrorSource *error_source;
+    int i;
+    /*
+     * The block_req_size stands for one address and one
+     * generic error status block
+      +---------+
+      | address | --------+-> +---------+
+      +---------+             |  CPER   |
+                              |  CPER   |
+                              |  CPER   |
+                              |  CPER   |
+                              |  ....   |
+                              +---------+
+     */
+    int block_req_size = sizeof(uint64_t) + GHES_MAX_RAW_DATA_LENGTH;
+
+    /* The total size for address of data structure and
+     * error status data block
+     */
+    g_array_set_size(hardware_error, GHES_ACPI_HEST_NOTIFY_RESERVED *
+                                                block_req_size);
+
+    buffer = g_array_new(false, true /* clear */, 1);
+    address_registers_offset = table_data->len +
+        sizeof(AcpiHardwareErrorSourceTable) +
+        offsetof(AcpiGenericHardwareErrorSource, error_status_address) +
+        offsetof(struct AcpiGenericAddress, address);
+
+    /* Reserve space for HEST table size */
+    acpi_data_push(buffer, sizeof(AcpiHardwareErrorSourceTable) +
+                                GHES_ACPI_HEST_NOTIFY_RESERVED *
+                                sizeof(AcpiGenericHardwareErrorSource));
+
+    g_array_append_vals(table_data, buffer->data, buffer->len);
+    /* Allocate guest memory for the Data fw_cfg blob */
+    bios_linker_loader_alloc(linker, GHES_ERRORS_FW_CFG_FILE, hardware_error,
+                            4096, false /* page boundary, high memory */);
+
+    error_source_table = (AcpiHardwareErrorSourceTable *)(table_data->data
+                        + table_data->len - buffer->len);
+    error_source_table->error_source_count = GHES_ACPI_HEST_NOTIFY_RESERVED;
+    error_source = (AcpiGenericHardwareErrorSource *)
+        ((AcpiHardwareErrorSourceTable *)error_source_table + 1);
+
+    bios_linker_loader_write_pointer(linker, GHES_DATA_ADDR_FW_CFG_FILE,
+        0, sizeof(uint64_t), GHES_ERRORS_FW_CFG_FILE,
+        GHES_ACPI_HEST_NOTIFY_RESERVED * sizeof(uint64_t));
+
+    for (i = 0; i < GHES_ACPI_HEST_NOTIFY_RESERVED; i++) {
+        error_source->type = ACPI_HEST_SOURCE_GENERIC_ERROR;
+        error_source->source_id = cpu_to_le16(i);
+        error_source->related_source_id = 0xffff;
+        error_source->flags = 0;
+        error_source->enabled = 1;
+        /* The number of error status block per Generic Hardware Error Source */
+        error_source->number_of_records = 1;
+        error_source->max_sections_per_record = 1;
+        error_source->max_raw_data_length = GHES_MAX_RAW_DATA_LENGTH;
+        error_source->error_status_address.space_id =
+                                    AML_SYSTEM_MEMORY;
+        error_source->error_status_address.bit_width = 64;
+        error_source->error_status_address.bit_offset = 0;
+        error_source->error_status_address.access_width = 4;
+        error_source->notify.type = i;
+        error_source->notify.length = sizeof(AcpiHestNotify);
+
+        error_source->error_status_block_length = GHES_MAX_RAW_DATA_LENGTH;
+
+        bios_linker_loader_add_pointer(linker,
+            ACPI_BUILD_TABLE_FILE, address_registers_offset + i *
+            sizeof(AcpiGenericHardwareErrorSource), sizeof(uint64_t),
+            GHES_ERRORS_FW_CFG_FILE, i * sizeof(uint64_t));
+
+        error_source++;
+    }
+
+    for (i = 0; i < GHES_ACPI_HEST_NOTIFY_RESERVED; i++) {
+        bios_linker_loader_add_pointer(linker,
+            GHES_ERRORS_FW_CFG_FILE, sizeof(uint64_t) * i, sizeof(uint64_t),
+            GHES_ERRORS_FW_CFG_FILE, GHES_ACPI_HEST_NOTIFY_RESERVED *
+            sizeof(uint64_t) + i * GHES_MAX_RAW_DATA_LENGTH);
+    }
+
+    build_header(linker, table_data,
+        (void *)error_source_table, "HEST", buffer->len, 1, NULL, "GHES");
+
+    g_array_free(buffer, true);
+}
+
+static GhesState ges;
+void ghes_add_fw_cfg(FWCfgState *s, GArray *hardware_error)
+{
+
+    size_t request_block_size = sizeof(uint64_t) + GHES_MAX_RAW_DATA_LENGTH;
+    size_t size = GHES_ACPI_HEST_NOTIFY_RESERVED * request_block_size;
+
+    /* Create a read-only fw_cfg file for GHES */
+    fw_cfg_add_file(s, GHES_ERRORS_FW_CFG_FILE, hardware_error->data,
+                    size);
+    /* Create a read-write fw_cfg file for Address */
+    fw_cfg_add_file_callback(s, GHES_DATA_ADDR_FW_CFG_FILE, NULL, NULL,
+        &ges.ghes_addr_le, sizeof(ges.ghes_addr_le), false);
+}
+
+bool ghes_update_guest(uint32_t notify, uint64_t physical_address)
+{
+    uint64_t error_block_addr;
+
+    if (physical_address && notify < GHES_ACPI_HEST_NOTIFY_RESERVED) {
+        error_block_addr = ges.ghes_addr_le + notify * GHES_MAX_RAW_DATA_LENGTH;
+        error_block_addr = le32_to_cpu(error_block_addr);
+
+        /* A zero value in ghes_addr means that BIOS has not yet written
+         * the address
+         */
+        if (error_block_addr) {
+            return ghes_record_cper(error_block_addr, physical_address);
+        }
+    }
+
+    return GHES_CPER_FAIL;
+}
diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 0835e59..5c97016 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -45,6 +45,7 @@
 #include "hw/arm/virt.h"
 #include "sysemu/numa.h"
 #include "kvm_arm.h"
+#include "hw/acpi/hest_ghes.h"
 
 #define ARM_SPI_BASE 32
 #define ACPI_POWER_BUTTON_DEVICE "PWRB"
@@ -778,6 +779,9 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
     acpi_add_table(table_offsets, tables_blob);
     build_spcr(tables_blob, tables->linker, vms);
 
+    acpi_add_table(table_offsets, tables_blob);
+    ghes_build_acpi(tables_blob, tables->hardware_errors, tables->linker);
+
     if (nb_numa_nodes > 0) {
         acpi_add_table(table_offsets, tables_blob);
         build_srat(tables_blob, tables->linker, vms);
@@ -890,6 +894,8 @@ void virt_acpi_setup(VirtMachineState *vms)
     fw_cfg_add_file(vms->fw_cfg, ACPI_BUILD_TPMLOG_FILE, tables.tcpalog->data,
                     acpi_data_len(tables.tcpalog));
 
+    ghes_add_fw_cfg(vms->fw_cfg, tables.hardware_errors);
+
     build_state->rsdp_mr = acpi_add_rom_blob(build_state, tables.rsdp,
                                               ACPI_BUILD_RSDP_FILE, 0);
 
