Changelog:
v2:
* ditch generic '-machine acpi-watchdog' option in favor of
board specific variants:
x86/q35: -machine wdat={on|off}
arm/virt: -device sbsa_gwdt,wdat={on|off}
* arm/virt: add FDT and GTDT ACPI entries for GWDT when it's present
and hide GDTD one when WDAT is enabled.
* arm/virt: add test case for GTDT
* [18-21] optional GWDT cleanup/fixes in handling WCV register update,
make QEMU behave according to spec (at least the way I read it and
it appears MS also read it that way). It fixes Windows 11 reboots when
GWDT is present (without WDAT). With that fixed it's up to MS to fix
their driver to set sane timeout as with the current one wdatchdog
will never trigger.
Windows doesn't ship built-in TCO watchdog driver, and users are
forced to install vendor specific driver(s) if such exists.
However the OS provides a generic watchdog driver that uses
ACPI WDAT table [1] to abstract actual hardware behind it.
The same applies to ARM version of Windows.
This series adds
* WDAT table tailored for TCO watchdog that Q35 already
has as part of ICH9 chipset and a knob to enable it.
* SBSA GWDT to arm/virt machine with WDAT table tailored
for it and necessary tweaks to GWDT to make usable
with WDAT driver.
* in addition to WDAT, it also adds native variant
with GWDT described in FDT and DTDT
(broken on Windows/works on linux).
Guest OS WDAT support is present since Windows Vista and Linux since 2016[2].
One can test it launching VM with following options:
* x86:
-machine q35,wdat=on
* arm/virt:
-device sbsa_gwdt,wdat=on
to trace access to TCO registers one can add to CLI:
-trace "tco_*"
to trace access to GWDT registers one can add to CLI:
-trace "sbsa_gwdt*"
To verify that guest uses WDAT (both Windows and Linux would use it if present),
* on linux make sure that watchdog service is configured/enabled
(use wdctl to check what watchdog device is in use) and then
trigger kernel panic with command:
echo c > /proc/sysrq-trigger
* on Windows kill svchost process, running cmd in admin mode:
taskkill /f /im svchost.exe
Tested with WS2025 & RHEL9.6 & Fedora 43 (aarch64)
git tree at: https://gitlab.com/imammedo/qemu/-/commits/gwdt_v2
1) http://msdn.microsoft.com/en-us/windows/hardware/gg463320.aspx
2) https://lwn.net/Articles/700524/
PS:
previous revision:
https://patchew.org/QEMU/[email protected]/
Igor Mammedov (21):
acpi: add API to build WDAT instructions
x86: q35: add 'wdat' property
x86: q35: generate WDAT ACPI table
tests: acpi: x86/q35: whitelist new WDAT table
tests: acpi: x86/q35: add WDAT table test case
tests: acpi: x86/q35: update expected WDAT blob
arm: sbsa_gwdt: fixup default "clock-frequency"
arm: add tracing events to sbsa_gwdt
arm: virt: create sbsa_gwdt watchdog
arm: sbsa_gwdt: add 'wdat' option
arm: virt: add support for WDAT based watchdog
tests: acpi: arm/virt: whitelist new WDAT table
tests: acpi: arm/virt: add WDAT table test case
tests: acpi: arm/virt: update expected WDAT blob
tests: acpi: arm/virt: whitelist GTDT table
tests: acpi: arm/virt: add GTDT watchdog table test case
tests: acpi: arm/virt: update expected GTDT blob
sbsa_gwdt: reduce code ident
sbsa_gwdt: move all foo_REFRESH logic under REFRESH condition
sbsa_gwdt: reschedule timer on direct WCV load
sbsa_gwdt: limit compare_value to INT64_MAX
include/hw/acpi/wdat-gwdt.h | 19 ++++
include/hw/acpi/wdat-ich9.h | 15 ++++
include/hw/acpi/wdat.h | 118 +++++++++++++++++++++++++
include/hw/i386/pc.h | 1 +
include/hw/watchdog/sbsa_gwdt.h | 1 +
hw/acpi/aml-build.c | 14 +++
hw/acpi/meson.build | 5 +-
hw/acpi/wdat-gwdt-stub.c | 16 ++++
hw/acpi/wdat-gwdt.c | 92 +++++++++++++++++++
hw/acpi/wdat-ich9-stub.c | 15 ++++
hw/acpi/wdat-ich9.c | 90 +++++++++++++++++++
hw/arm/Kconfig | 1 +
hw/arm/virt-acpi-build.c | 65 +++++++++++++-
hw/arm/virt.c | 2 +
hw/core/sysbus-fdt.c | 32 +++++++
hw/i386/acpi-build.c | 12 +++
hw/i386/pc_q35.c | 18 ++++
hw/watchdog/sbsa_gwdt.c | 65 +++++++++-----
hw/watchdog/trace-events | 9 ++
tests/data/acpi/aarch64/virt/GTDT.gwdt | Bin 0 -> 132 bytes
tests/data/acpi/aarch64/virt/WDAT.wdat | Bin 0 -> 260 bytes
tests/data/acpi/x86/q35/WDAT.wdat | Bin 0 -> 308 bytes
tests/qtest/bios-tables-test.c | 54 +++++++++++
23 files changed, 618 insertions(+), 26 deletions(-)
create mode 100644 include/hw/acpi/wdat-gwdt.h
create mode 100644 include/hw/acpi/wdat-ich9.h
create mode 100644 include/hw/acpi/wdat.h
create mode 100644 hw/acpi/wdat-gwdt-stub.c
create mode 100644 hw/acpi/wdat-gwdt.c
create mode 100644 hw/acpi/wdat-ich9-stub.c
create mode 100644 hw/acpi/wdat-ich9.c
create mode 100644 tests/data/acpi/aarch64/virt/GTDT.gwdt
create mode 100644 tests/data/acpi/aarch64/virt/WDAT.wdat
create mode 100644 tests/data/acpi/x86/q35/WDAT.wdat
--
2.47.3
