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+APEI tables generating and CPER record
+=============================
+
+Copyright (C) 2017 HuaWei Corporation.
+
+Design Details:
+-------------------
+
+ etc/acpi/tables etc/hardware_errors
+ ==================== ==========================================
++ +--------------------------+ +-----------------------+
+| | HEST | | address | +--------------+
+| +--------------------------+ | registers | | Error Status |
+| | GHES1 | | +---------------------+ | Data Block 1 |
+| +--------------------------+ +--------->| |error_block_address1 |----------->| +------------+
+| | ................. | | | +---------------------+ | | CPER |
+| | error_status_address-----+-+ +------->| |error_block_address2 |--------+ | | CPER |
+| | ................. | | | +---------------------+ | | | .... |
+| | read_ack_register--------+-+ | | | .............. | | | | CPER |
+| | read_ack_preserve | | | +-----------------------+ | | +------------+
+| | read_ack_write | | | +----->| |error_block_addressN |------+ | | Error Status |
++ +--------------------------+ | | | | +---------------------+ | | | Data Block 2 |
+| | GHES2 | +-+-+----->| |read_ack_register1 | | +-->| +------------+
++ +--------------------------+ | | | +---------------------+ | | | CPER |
+| | ................. | | | +--->| |read_ack_register2 | | | | CPER |
+| | error_status_address-----+---+ | | | +---------------------+ | | | .... |
+| | ................. | | | | | ............. | | | | CPER |
+| | read_ack_register--------+-----+-+ | +---------------------+ | +-+------------+
+| | read_ack_preserve | | +->| |read_ack_registerN | | | |.......... |
+| | read_ack_write | | | | +---------------------+ | | +------------+
++ +--------------------------| | | | | Error Status |
+| | ............... | | | | | Data Block N |
++ +--------------------------+ | | +---->| +------------+
+| | GHESN | | | | | CPER |
++ +--------------------------+ | | | | CPER |
+| | ................. | | | | | .... |
+| | error_status_address-----+-----+ | | | CPER |
+| | ................. | | +-+------------+
+| | read_ack_register--------+---------+
+| | read_ack_preserve |
+| | read_ack_write |
++ +--------------------------+
+
+(1) QEMU generates the ACPI HEST table. This table goes in the current
+ "etc/acpi/tables" fw_cfg blob. Each error source has different
+ notification type.
+
+(2) A new fw_cfg blob called "etc/hardware_errors" is introduced. QEMU
+ also need to populate this blob. The "etc/hardwre_errors" fw_cfg blob
+ contains one address registers table and one Error Status Data Block
+ table, all of which are pre-allocated.
+
+(3) The address registers table contains N Error Block Address entries
+ and N Read Ack Address entries, the size for each entry is 8-byte.
+ The Error Status Data Block table contains N Error Status Data Block
+ entries, the size for each entry is 4096(0x1000) bytes. The total size
+ for "etc/hardware_errors" fw_cfg blob is (N * 8 * 2 + N * 4096) bytes.
+
+(4) QEMU generates the ACPI linker/loader script for the firmware
+
+(4a) The HEST table is part of "etc/acpi/tables", the firmware already
+ allocates the memory for it, because QEMU already generates an ALLOCATE
+ linker/loader command for it
+
+(4b) QEMU creates another ALLOCATE command for the "etc/hardware_errors"
+ blob. The firmware allocates memory for this blob and downloads it.
+
+(5) QEMU generates N ADD_POINTER commands, which patch address in the
+ "error_status_address" fields of the HEST table with a pointer to the
+ corresponding "address registers" in the downloaded "etc/hardware_errors"
+ blob.
+
+(6) QEMU generates N ADD_POINTER commands, which patch address in the
+ "read_ack_register" fields of the HEST table with a pointer to the
+ corresponding "address registers" in the downloaded "etc/hardware_errors" blob.
+
+(7) QEMU generates N ADD_POINTER commands for the firmware, which patch
+ address in the " error_block_address" fields with a pointer to the
+ respective "Error Status Data Block" in the downloaded "etc/hardware_errors"
+ blob.
+
+(8) QEMU Defines a third and write-only fw_cfg blob which is called
+ "etc/hardware_errors_addr". Through that blob, the firmware can send back
+ the guest-side allocation addresses to QEMU. The "etc/hardware_errors_addr"
+ blob contains a 8-byte entry. QEMU generates a single WRITE_POINTER commands
+ for the firmware, the firmware will write back the start address of
+ "etc/hardware_errors" blob to fw_cfg file "etc/hardware_errors_addr". Then
+ Qemu will know the Error Status Data Block for every error source. Each of
+ Error Status Data Block has fixed size which is 4096(0x1000).
+
+(9) When QEMU gets SIGBUS from the kernel, QEMU formats the CPER right into
+ guest memory, and then injects whatever interrupt (or assert whatever GPIO line)
+ as a notification which is necessary for notifying the guest.
+
+(10) This notification (in virtual hardware) will be handled by guest kernel,
+ guest APEI driver will read the CPER which is recorded by QEMU and do the
+ recovery.
Add APEI/GHES detailed design document Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com> --- docs/specs/acpi_hest_ghes.txt | 97 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 docs/specs/acpi_hest_ghes.txt