f7060ac4e7
It will generate WDAT table [1] customized for TCO watchdog.
This allows Windows guests (Windows Server 2008/Vista+) to
use TCO watchdog using built-in generic driver, which
alleviates need to install vendor specific drivers.
Given that enabling it might change guest behaviour
(both Windows/Linux) the feature is disabled by default.
Users that need it can enable the feature with
following CLI option.
-machine wdat=on
1)
"Hardware Watchdog Timers Design Specification"
https://uefi.org/acpi 'Watchdog Action Table (WDAT)'
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Ani Sinha <anisinha@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20260303092532.2410177-4-imammedo@redhat.com>
91 lines
3.7 KiB
C
91 lines
3.7 KiB
C
/*
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* TCO Watchdog Action Table (WDAT)
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*
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* Copyright Red Hat, Inc. 2026
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* Author(s): Igor Mammedov <imammedo@redhat.com>
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*
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* SPDX-License-Identifier: GPL-2.0-or-later
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*/
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#include "qemu/osdep.h"
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#include "hw/acpi/wdat.h"
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#include "hw/acpi/wdat-ich9.h"
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#include "hw/southbridge/ich9.h"
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#define TCO_REG(base, reg_offset, reg_width) { .space_id = AML_AS_SYSTEM_IO, \
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.address = base + reg_offset, .bit_width = reg_width, \
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.access_width = AML_WORD_ACC, };
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/*
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* "Hardware Watchdog Timers Design Specification"
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* https://uefi.org/acpi 'Watchdog Action Table (WDAT)'
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*
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* ICH9 specific implementation.
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*/
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void build_ich9_wdat(GArray *table_data, BIOSLinker *linker, const char *oem_id,
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const char *oem_table_id, uint64_t tco_base)
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{
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AcpiTable table = { .sig = "WDAT", .rev = 1, .oem_id = oem_id,
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.oem_table_id = oem_table_id };
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struct AcpiGenericAddress tco_rld = TCO_REG(tco_base, 0x0, 16);
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struct AcpiGenericAddress tco2_sts = TCO_REG(tco_base, 0x6, 16);
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struct AcpiGenericAddress tco1_cnt = TCO_REG(tco_base, 0x8, 16);
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struct AcpiGenericAddress tco_tmr = TCO_REG(tco_base, 0x12, 16);
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acpi_table_begin(&table, table_data);
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build_append_int_noprefix(table_data, 0x20, 4); /* Watchdog Header Length */
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build_append_int_noprefix(table_data, 0xff, 2); /* PCI Segment */
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build_append_int_noprefix(table_data, 0xff, 1); /* PCI Bus Number */
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build_append_int_noprefix(table_data, 0xff, 1); /* PCI Device Number */
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build_append_int_noprefix(table_data, 0xff, 1); /* PCI Function Number */
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build_append_int_noprefix(table_data, 0, 3); /* Reserved */
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/*
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* limits/resolution are defined by ICH9 TCO spec
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*/
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build_append_int_noprefix(table_data, 0x258, 4);/* Timer Period, ms */
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build_append_int_noprefix(table_data, 0x3ff, 4);/* Maximum Count */
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build_append_int_noprefix(table_data, 0x4, 4); /* Minimum Count */
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/*
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* WATCHDOG_ENABLED & WATCHDOG_STOPPED_IN_SLEEP_STATE
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*/
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build_append_int_noprefix(table_data, 0x81, 1); /* Watchdog Flags */
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build_append_int_noprefix(table_data, 0, 3); /* Reserved */
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/*
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* watchdog instruction entries
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*/
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build_append_int_noprefix(table_data, 10 /* # of actions below */, 4);
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/* Action table */
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build_append_wdat_ins(table_data, WDAT_ACTION_RESET,
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WDAT_INS_WRITE_VALUE,
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tco_rld, 0x1, 0x1ff);
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build_append_wdat_ins(table_data, WDAT_ACTION_QUERY_RUNNING_STATE,
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WDAT_INS_READ_VALUE,
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tco1_cnt, 0x0, 0x800);
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build_append_wdat_ins(table_data, WDAT_ACTION_SET_RUNNING_STATE,
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WDAT_INS_WRITE_VALUE | WDAT_INS_PRESERVE_REGISTER,
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tco1_cnt, 0, 0x800);
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build_append_wdat_ins(table_data, WDAT_ACTION_QUERY_STOPPED_STATE,
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WDAT_INS_READ_VALUE,
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tco1_cnt, 0x800, 0x800);
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build_append_wdat_ins(table_data, WDAT_ACTION_SET_STOPPED_STATE,
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WDAT_INS_WRITE_VALUE | WDAT_INS_PRESERVE_REGISTER,
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tco1_cnt, 0x800, 0x800);
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build_append_wdat_ins(table_data, WDAT_ACTION_SET_COUNTDOWN_PERIOD,
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WDAT_INS_WRITE_COUNTDOWN,
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tco_tmr, 0x0, 0x3FF);
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build_append_wdat_ins(table_data, WDAT_ACTION_QUERY_COUNTDOWN_PERIOD,
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WDAT_INS_READ_COUNTDOWN,
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tco_tmr, 0x0, 0x3FF);
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build_append_wdat_ins(table_data, WDAT_ACTION_QUERY_WATCHDOG_STATUS,
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WDAT_INS_READ_VALUE,
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tco2_sts, 0x2, 0x2);
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build_append_wdat_ins(table_data, WDAT_ACTION_SET_WATCHDOG_STATUS,
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WDAT_INS_WRITE_VALUE | WDAT_INS_PRESERVE_REGISTER,
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tco2_sts, 0x2, 0x2);
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build_append_wdat_ins(table_data, WDAT_ACTION_SET_WATCHDOG_STATUS,
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WDAT_INS_WRITE_VALUE | WDAT_INS_PRESERVE_REGISTER,
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tco2_sts, 0x4, 0x4);
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acpi_table_end(linker, &table);
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}
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