Add APEI/GHES detailed design document Signed-off-by: Dongjiu Geng <gengdongjiu@xxxxxxxxxx> --- Address Igor's comments to add a doc --- docs/specs/acpi_hest_ghes.txt | 97 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 docs/specs/acpi_hest_ghes.txt diff --git a/docs/specs/acpi_hest_ghes.txt b/docs/specs/acpi_hest_ghes.txt new file mode 100644 index 0000000..fbfc787 --- /dev/null +++ b/docs/specs/acpi_hest_ghes.txt @@ -0,0 +1,97 @@ +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. -- 1.8.3.1
