Changeset 90904 in vbox

Timestamp:

Aug 26, 2021 9:49:06 AM (3 years ago)

Author:

vboxsync

Message:

Devices/Security/DevTpm: Allow unaligned reads, Windows loves to access the FIFO status register unaligned, bugref:10075

Location:

trunk/src/VBox/Devices/Security

Files:

• DevTpm.cpp (modified) (2 diffs)
• DrvTpmEmu.cpp (modified) (1 diff)

trunk/src/VBox/Devices/Security/DevTpm.cpp

@@ -1129 +1129 @@
     RT_NOREF(pvUser);
 
-    Assert(!(off & (cb - 1)));
+    RTGCPHYS offAligned = off & ~UINT64_C(0x3);
+    uint8_t cBitsShift  = (off & 0x3) * 8;
 
     VBOXSTRICTRC rc = VINF_SUCCESS;
-    uint32_t uReg = tpmGetRegisterFromOffset(off);
-    uint8_t bLoc = tpmGetLocalityFromOffset(off);
+    uint32_t uReg = tpmGetRegisterFromOffset(offAligned);
+    uint8_t bLoc = tpmGetLocalityFromOffset(offAligned);
     PDEVTPMLOCALITY pLoc = &pThis->aLoc[bLoc];
 
@@ -1148 +1149 @@
         switch (cb)
         {
-            case 1: *(uint8_t *)pv = (uint8_t)u64; break;
-            case 2: *(uint16_t *)pv = (uint16_t)u64; break;
-            case 4: *(uint32_t *)pv = (uint32_t)u64; break;
+            case 1: *(uint8_t *)pv = (uint8_t)(u64 >> cBitsShift); break;
+            case 2: *(uint16_t *)pv = (uint16_t)(u64 >> cBitsShift); break;
+            case 4: *(uint32_t *)pv = (uint32_t)(u64 >> cBitsShift); break;
             case 8: *(uint64_t *)pv = u64; break;
             default: AssertFailedBreakStmt(rc = VERR_INTERNAL_ERROR);

trunk/src/VBox/Devices/Security/DrvTpmEmu.cpp

@@ -617 +617 @@
 
 
-/** @interface_method_impl{PDMITPMCONNECTOR,pfnGetEstablishedFlag} */
+/** @interface_method_impl{PDMITPMCONNECTOR,pfnResetEstablishedFlag} */
 static DECLCALLBACK(int) drvTpmEmuResetEstablishedFlag(PPDMITPMCONNECTOR pInterface, uint8_t bLoc)
 {