Changeset 81161 in vbox for trunk/src/VBox/HostDrivers/Support/win

Timestamp:

Oct 8, 2019 3:21:59 PM (5 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

133795

Message:

SUP, VMM: bugref: 9562 Drop SUPR0GetRawModeUsability. No longer required with removal of raw-mode.

File:

• trunk/src/VBox/HostDrivers/Support/win/SUPDrv-win.cpp (modified) (1 diff)

trunk/src/VBox/HostDrivers/Support/win/SUPDrv-win.cpp

@@ -1903 +1903 @@
 
 
-/**
- * Checks whether we're allowed by Hyper-V to modify CR4.
- */
-int  VBOXCALL supdrvOSGetRawModeUsability(void)
-{
-    int rc = VINF_SUCCESS;
-
-#ifdef RT_ARCH_AMD64
-    /*
-     * Broadwell running W10 17083.100:
-     *        CR4: 0x170678
-     *  Evil mask: 0x170638
-     *      X86_CR4_SMEP        - evil
-     *      X86_CR4_FSGSBASE    - evil
-     *      X86_CR4_PCIDE       - evil
-     *      X86_CR4_OSXSAVE     - evil
-     *      X86_CR4_OSFXSR      - evil
-     *      X86_CR4_OSXMMEEXCPT - evil
-     *      X86_CR4_PSE         - evil
-     *      X86_CR4_PAE         - evil
-     *      X86_CR4_MCE         - okay
-     *      X86_CR4_DE          - evil
-     */
-    if (ASMHasCpuId())
-    {
-        uint32_t cStd = ASMCpuId_EAX(0);
-        if (ASMIsValidStdRange(cStd))
-        {
-            uint32_t uIgn         = 0;
-            uint32_t fEdxFeatures = 0;
-            uint32_t fEcxFeatures = 0;
-            ASMCpuIdExSlow(1, 0, 0, 0, &uIgn, &uIgn, &fEcxFeatures, &fEdxFeatures);
-            if (fEcxFeatures & X86_CPUID_FEATURE_ECX_HVP)
-            {
-                RTCCUINTREG  const fOldFlags    = ASMIntDisableFlags();
-                RTCCUINTXREG const fCr4         = ASMGetCR4();
-
-                RTCCUINTXREG const fSafeToClear = X86_CR4_TSD      | X86_CR4_DE     | X86_CR4_PGE  | X86_CR4_PCE
-                                                | X86_CR4_FSGSBASE | X86_CR4_PCIDE  | X86_CR4_SMEP | X86_CR4_SMAP
-                                                | X86_CR4_OSXSAVE  | X86_CR4_OSFXSR | X86_CR4_OSXMMEEXCPT;
-                RTCCUINTXREG       fLoadCr4     = fCr4 & ~fSafeToClear;
-                RTCCUINTXREG const fCleared     = fCr4 & fSafeToClear;
-                if (!(fCleared & X86_CR4_TSD) && (fEdxFeatures & X86_CPUID_FEATURE_EDX_TSC))
-                    fLoadCr4 |= X86_CR4_TSD;
-                if (!(fCleared & X86_CR4_PGE) && (fEdxFeatures & X86_CPUID_FEATURE_EDX_PGE))
-                    fLoadCr4 |= X86_CR4_PGE;
-                __try
-                {
-                    ASMSetCR4(fLoadCr4);
-                }
-                __except(EXCEPTION_EXECUTE_HANDLER)
-                {
-                    rc = VERR_SUPDRV_NO_RAW_MODE_HYPER_V_ROOT;
-                }
-                if (RT_SUCCESS(rc))
-                    ASMSetCR4(fCr4);
-                ASMSetFlags(fOldFlags);
-            }
-        }
-    }
-#endif
-    return rc;
-}
-
-
 #define MY_SystemLoadGdiDriverInSystemSpaceInformation  54
 #define MY_SystemUnloadGdiDriverInformation             27