On Wed, 8 Jan 2020 19:32:16 +0800 Dongjiu Geng <gengdongjiu@xxxxxxxxxx> wrote: > Add APEI/GHES detailed design document > > Signed-off-by: Dongjiu Geng <gengdongjiu@xxxxxxxxxx> > Signed-off-by: Xiang Zheng <zhengxiang9@xxxxxxxxxx> > Reviewed-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Reviewed-by: Igor Mammedov <imammedo@xxxxxxxxxx> > --- > docs/specs/acpi_hest_ghes.rst | 110 ++++++++++++++++++++++++++++++++++++++++++ > docs/specs/index.rst | 1 + > 2 files changed, 111 insertions(+) > create mode 100644 docs/specs/acpi_hest_ghes.rst > > diff --git a/docs/specs/acpi_hest_ghes.rst b/docs/specs/acpi_hest_ghes.rst > new file mode 100644 > index 0000000..7a1aa90 > --- /dev/null > +++ b/docs/specs/acpi_hest_ghes.rst > @@ -0,0 +1,110 @@ > +APEI tables generating and CPER record > +====================================== > + > +.. > + Copyright (c) 2019 HUAWEI TECHNOLOGIES CO., LTD. > + > + This work is licensed under the terms of the GNU GPL, version 2 or later. > + See the COPYING file in the top-level directory. > + > +Design Details > +-------------- > + > +:: > + > + etc/acpi/tables etc/hardware_errors > + ==================== =============================== > + + +--------------------------+ +----------------------------+ > + | | HEST | +--------->| error_block_address1 |------+ > + | +--------------------------+ | +----------------------------+ | > + | | GHES1 | | +------->| error_block_address2 |------+-+ > + | +--------------------------+ | | +----------------------------+ | | > + | | ................. | | | | .............. | | | > + | | error_status_address-----+-+ | -----------------------------+ | | > + | | ................. | | +--->| error_block_addressN |------+-+---+ > + | | read_ack_register--------+-+ | | +----------------------------+ | | | > + | | read_ack_preserve | +-+---+--->| read_ack_register1 | | | | > + | | read_ack_write | | | +----------------------------+ | | | > + + +--------------------------+ | +-+--->| read_ack_register2 | | | | > + | | GHES2 | | | | +----------------------------+ | | | > + + +--------------------------+ | | | | ............. | | | | > + | | ................. | | | | +----------------------------+ | | | > + | | error_status_address-----+---+ | | +->| read_ack_registerN | | | | > + | | ................. | | | | +----------------------------+ | | | > + | | read_ack_register--------+-----+ | | |Generic Error Status Block 1|<-----+ | | > + | | read_ack_preserve | | | |-+------------------------+-+ | | > + | | read_ack_write | | | | | CPER | | | | > + + +--------------------------| | | | | CPER | | | | > + | | ............... | | | | | .... | | | | > + + +--------------------------+ | | | | CPER | | | | > + | | GHESN | | | |-+------------------------+-| | | > + + +--------------------------+ | | |Generic Error Status Block 2|<-------+ | > + | | ................. | | | |-+------------------------+-+ | > + | | error_status_address-----+-------+ | | | CPER | | | > + | | ................. | | | | CPER | | | > + | | read_ack_register--------+---------+ | | .... | | | > + | | read_ack_preserve | | | CPER | | | > + | | read_ack_write | +-+------------------------+-+ | > + + +--------------------------+ | .......... | | > + |----------------------------+ | > + |Generic Error Status Block N |<----------+ > + |-+-------------------------+-+ > + | | CPER | | > + | | CPER | | > + | | .... | | > + | | CPER | | > + +-+-------------------------+-+ > + > + > +(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 types. > + > +(2) A new fw_cfg blob called "etc/hardware_errors" is introduced. QEMU > + also needs to populate this blob. The "etc/hardware_errors" fw_cfg blob > + contains an address registers table and an Error Status Data Block table. > + > +(3) The address registers table contains N Error Block Address entries > + and N Read Ack Register 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 the "etc/hardware_errors" fw_cfg blob is (N * 8 * 2 + N * 4096) bytes. > + N is the number of the kinds of hardware error sources. > + > +(4) QEMU generates the ACPI linker/loader script for the firmware. The > + firmware pre-allocates memory for "etc/acpi/tables", "etc/hardware_errors" > + and copies blob contents there. > + > +(5) QEMU generates N ADD_POINTER commands, which patch addresses in the > + "error_status_address" fields of the HEST table with a pointer to the > + corresponding "address registers" in the "etc/hardware_errors" blob. > + > +(6) QEMU generates N ADD_POINTER commands, which patch addresses in the > + "read_ack_register" fields of the HEST table with a pointer to the > + corresponding "read_ack_register" within the "etc/hardware_errors" blob. > + > +(7) QEMU generates N ADD_POINTER commands for the firmware, which patch > + addresses in the "error_block_address" fields with a pointer to the > + respective "Error Status Data Block" in the "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 command > + for the firmware. The firmware will write back the start address of > + "etc/hardware_errors" blob to the fw_cfg file "etc/hardware_errors_addr". > + > +(9) When QEMU gets a SIGBUS from the kernel, QEMU writes CPER into corresponding > + "Error Status Data Block", guest memory, and then injects platform specific > + interrupt (in case of arm/virt machine it's Synchronous External Abort) as a > + notification which is necessary for notifying the guest. > + > +(10) This notification (in virtual hardware) will be handled by the guest > + kernel, on receiving notification, guest APEI driver could read the CPER error > + and take appropriate action. > + > +(11) kvm_arch_on_sigbus_vcpu() 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" even if guest was > + migrated to a newer QEMU. > diff --git a/docs/specs/index.rst b/docs/specs/index.rst > index 984ba44..3019b9c 100644 > --- a/docs/specs/index.rst > +++ b/docs/specs/index.rst > @@ -13,3 +13,4 @@ Contents: > ppc-xive > ppc-spapr-xive > acpi_hw_reduced_hotplug > + acpi_hest_ghes
