diff options
Diffstat (limited to 'docs/specs')
| -rw-r--r-- | docs/specs/acpi_hest_ghes.rst | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/docs/specs/acpi_hest_ghes.rst b/docs/specs/acpi_hest_ghes.rst index c3e9f8d9a7..aaf7b1ad11 100644 --- a/docs/specs/acpi_hest_ghes.rst +++ b/docs/specs/acpi_hest_ghes.rst @@ -89,12 +89,21 @@ Design Details 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". +(8) QEMU defines a third and write-only fw_cfg blob to store the location + where the error block offsets, read ack registers and CPER records are + stored. + + Up to QEMU 9.2, the location was at "etc/hardware_errors_addr", and + contains a GPA for the beginning of "etc/hardware_errors". + + Newer versions place the location at "etc/acpi_table_hest_addr", + pointing to the GPA of the HEST table. + + Using above mentioned 'fw_cfg' files, the firmware can send back the + guest-side allocation addresses to QEMU. They contain a 8-byte entry. + QEMU generates a single WRITE_POINTER command for the firmware. The + firmware will write back the start address of either "etc/hardware_errors" + or HEST table at the corresponding fw_cfg file. (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 @@ -105,8 +114,5 @@ Design Details 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. +(11) kvm_arch_on_sigbus_vcpu() reports RAS errors via a SEA notifications, + when a SIGBUS event is triggered. |