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| -rw-r--r-- | src/VBox/VMM/VMMR3/GCM.cpp | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/src/VBox/VMM/VMMR3/GCM.cpp b/src/VBox/VMM/VMMR3/GCM.cpp new file mode 100644 index 00000000..45b93d02 --- /dev/null +++ b/src/VBox/VMM/VMMR3/GCM.cpp @@ -0,0 +1,259 @@ +/** @file + * GCM - Guest Compatibility Manager. + */ + +/* + * Copyright (C) 2022 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, in version 3 of the + * License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <https://www.gnu.org/licenses>. + * + * SPDX-License-Identifier: GPL-3.0-only + */ + +/** @page pg_gcm GCM - The Guest Compatibility Manager + * + * The Guest Compatibility Manager provides run-time compatibility fixes + * for certain known guest bugs. + * + * @see grp_gcm + * + * + * @section sec_gcm_fixer Fixers + * + * A GCM fixer implements a collection of run-time helpers/patches suitable for + * a specific guest type. Several fixers can be active at the same time; for + * example OS/2 or Windows 9x need their own fixers, but can also runs DOS + * applications which need DOS-specific fixers. + * + * The concept of fixers exists to reduce the number of false positives to a + * minimum. Heuristics are used to decide whether a particular fix should be + * applied or not; restricting the number of applicable fixes minimizes the + * chance that a fix could be misapplied. + * + * The fixers are invisible to a guest. A common problem is division by zero + * caused by a software timing loop which cannot deal with fast CPUs (where + * "fast" very much depends on the era when the software was written). A fixer + * intercepts division by zero, recognizes known register contents and code + * sequence, modifies one or more registers to avoid a divide error, and + * restarts the instruction. + * + * It is not expected that the set of active fixers would be changed during + * the lifetime of the VM. + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#define LOG_GROUP LOG_GROUP_GIM +#include <VBox/vmm/gcm.h> +#include <VBox/vmm/hm.h> +#include <VBox/vmm/ssm.h> +#include <VBox/vmm/pdmdev.h> +#include "GCMInternal.h" +#include <VBox/vmm/vm.h> + +#include <VBox/log.h> + +#include <iprt/err.h> +#include <iprt/semaphore.h> +#include <iprt/string.h> + + +/********************************************************************************************************************************* +* Internal Functions * +*********************************************************************************************************************************/ +static FNSSMINTSAVEEXEC gcmR3Save; +static FNSSMINTLOADEXEC gcmR3Load; + + +/** + * Initializes the GCM. + * + * @returns VBox status code. + * @param pVM The cross context VM structure. + */ +VMMR3_INT_DECL(int) GCMR3Init(PVM pVM) +{ + LogFlow(("GCMR3Init\n")); + + /* + * Assert alignment and sizes. + */ + AssertCompile(sizeof(pVM->gcm.s) <= sizeof(pVM->gcm.padding)); + + /* + * Register the saved state data unit. + */ + int rc = SSMR3RegisterInternal(pVM, "GCM", 0 /* uInstance */, GCM_SAVED_STATE_VERSION, sizeof(GCM), + NULL /* pfnLivePrep */, NULL /* pfnLiveExec */, NULL /* pfnLiveVote*/, + NULL /* pfnSavePrep */, gcmR3Save, NULL /* pfnSaveDone */, + NULL /* pfnLoadPrep */, gcmR3Load, NULL /* pfnLoadDone */); + if (RT_FAILURE(rc)) + return rc; + + /* + * Read configuration. + */ + PCFGMNODE pCfgNode = CFGMR3GetChild(CFGMR3GetRoot(pVM), "GCM/"); + + /* + * Validate the GCM settings. + */ + rc = CFGMR3ValidateConfig(pCfgNode, "/GCM/", /* pszNode */ + "FixerSet", /* pszValidValues */ + "", /* pszValidNodes */ + "GCM", /* pszWho */ + 0); /* uInstance */ + if (RT_FAILURE(rc)) + return rc; + +#if 1 + /** @cfgm{/GCM/FixerSet, uint32_t, 0} + * The set (bit mask) of enabled fixers. See GCMFIXERID. + */ + uint32_t u32FixerIds; + rc = CFGMR3QueryU32Def(pCfgNode, "FixerSet", &u32FixerIds, 0); + AssertRCReturn(rc, rc); + + /* Check for unknown bits. */ + uint32_t u32BadBits = u32FixerIds & ~(GCMFIXER_DBZ_DOS | GCMFIXER_DBZ_OS2 | GCMFIXER_DBZ_WIN9X); + + if (u32BadBits) + { + rc = VMR3SetError(pVM->pUVM, VERR_CFGM_CONFIG_UNKNOWN_VALUE, RT_SRC_POS, "Unsupported GCM fixer bits (%#x) set.", u32BadBits); + } + else + { + pVM->gcm.s.enmFixerIds = u32FixerIds; + } +#else + pVM->gcm.s.enmFixerIds = GCMFIXER_DBZ_OS2 | GCMFIXER_DBZ_DOS | GCMFIXER_DBZ_WIN9X; +#endif + LogRel(("GCM: Initialized (fixer bits: %#x)\n", u32FixerIds)); + + return rc; +} + + +/** + * Finalize the GCM initialization. + * + * This is called after initializing HM and most other VMM components. + * + * @returns VBox status code. + * @param pVM The cross context VM structure. + * @thread EMT(0) + */ +VMMR3_INT_DECL(int) GCMR3InitCompleted(PVM pVM) +{ + RT_NOREF(pVM); + return VINF_SUCCESS; +} + + +/** + * @callback_method_impl{FNSSMINTSAVEEXEC} + */ +static DECLCALLBACK(int) gcmR3Save(PVM pVM, PSSMHANDLE pSSM) +{ + AssertReturn(pVM, VERR_INVALID_PARAMETER); + AssertReturn(pSSM, VERR_SSM_INVALID_STATE); + + int rc = VINF_SUCCESS; + + /* + * Save per-VM data. + */ + SSMR3PutU32(pSSM, pVM->gcm.s.enmFixerIds); + + return rc; +} + + +/** + * @callback_method_impl{FNSSMINTLOADEXEC} + */ +static DECLCALLBACK(int) gcmR3Load(PVM pVM, PSSMHANDLE pSSM, uint32_t uVersion, uint32_t uPass) +{ + if (uPass != SSM_PASS_FINAL) + return VINF_SUCCESS; + if (uVersion != GCM_SAVED_STATE_VERSION) + return VERR_SSM_UNSUPPORTED_DATA_UNIT_VERSION; + + int rc; + + /* + * Load per-VM data. + */ + uint32_t uFixerIds; + + rc = SSMR3GetU32(pSSM, &uFixerIds); + AssertRCReturn(rc, rc); + + if ((GCMFIXERID)uFixerIds != pVM->gcm.s.enmFixerIds) + return SSMR3SetCfgError(pSSM, RT_SRC_POS, N_("Saved GCM fixer set %#X differs from the configured one (%#X)."), + uFixerIds, pVM->gcm.s.enmFixerIds); + + return VINF_SUCCESS; +} + + +/** + * Terminates the GCM. + * + * Termination means cleaning up and freeing all resources, + * the VM itself is, at this point, powered off or suspended. + * + * @returns VBox status code. + * @param pVM The cross context VM structure. + */ +VMMR3_INT_DECL(int) GCMR3Term(PVM pVM) +{ + RT_NOREF(pVM); + return VINF_SUCCESS; +} + + +/** + * Applies relocations to data and code managed by this + * component. This function will be called at init and + * whenever the VMM need to relocate itself inside the GC. + * + * @param pVM The cross context VM structure. + * @param offDelta Relocation delta relative to old location. + */ +VMMR3_INT_DECL(void) GCMR3Relocate(PVM pVM, RTGCINTPTR offDelta) +{ + RT_NOREF(pVM); + RT_NOREF(offDelta); +} + + +/** + * The VM is being reset. + * + * Do whatever fixer-specific resetting that needs to be done. + * + * @returns VBox status code. + * @param pVM The cross context VM structure. + */ +VMMR3_INT_DECL(void) GCMR3Reset(PVM pVM) +{ + RT_NOREF(pVM); +} + |