[viostor] Introduce Registry read capability

Introduces a Registry read capability:

1. Implemented in VioStorReadRegistryParameter()
2. Requires neo helper CopyBufferToAnsiString()
3. Adds capacity to both detect and read DWORD values in:
   (a) HKLM\SYSTEM\CurrentControlSet\Services\viostor\Paramaters\Device
   (b) HKLM\SYSTEM\CurrentControlSet\Services\viostor\Paramaters\Device(d) NOT WORKING
4. Also supports per-HBA values for \Parameters\Device\Valuename_123
   when the \Parameters\Device(d) key is unavailable (presently broken)
5. Adds TRACE_REGISTRY WPP tracing flag

Signed-off-by: benyamin-codez <[email protected]>

Author: benyamin-codez

viostor/virtio_stor.c

@@ -130,6 +130,229 @@ VOID WppCleanupRoutine(PVOID arg1)
 }
 #endif
 
+USHORT CopyBufferToAnsiString(void *_pDest, const void *_pSrc, const char delimiter, size_t _maxlength)
+{
+    PCHAR dst = (PCHAR)_pDest;
+    PCHAR src = (PCHAR)_pSrc;
+    USHORT _length = _maxlength;
+
+    while (_length && (*src != delimiter))
+    {
+        *dst++ = *src++;
+        --_length;
+    };
+    *dst = '\0';
+    return _length;
+}
+
+BOOLEAN VioStorReadRegistryParameter(IN PVOID DeviceExtension, IN PUCHAR ValueName, IN LONG offset)
+{
+    BOOLEAN bReadResult = FALSE;
+    BOOLEAN bUseAltPerHbaRegRead = FALSE;
+    ULONG pBufferLength = sizeof(ULONG);
+    UCHAR *pBuffer = NULL;
+    PADAPTER_EXTENSION adaptExt = (PADAPTER_EXTENSION)DeviceExtension;
+    ULONG spgspn_rc, i, j;
+    STOR_ADDRESS HwAddress = {0};
+    PSTOR_ADDRESS pHwAddress = &HwAddress;
+    CHAR valname_as_str[64] = {0};
+    CHAR hba_id_as_str[4] = {0};
+    USHORT shAdapterId = (USHORT)adaptExt->slot_number - 1;
+    ULONG value_as_ulong;
+
+    /* Get a clean buffer to store the registry value... */
+    pBuffer = StorPortAllocateRegistryBuffer(DeviceExtension, &pBufferLength);
+    if (pBuffer == NULL)
+    {
+        RhelDbgPrint(TRACE_LEVEL_WARNING, " StorPortAllocateRegistryBuffer failed to allocate buffer\n");
+        return FALSE;
+    }
+    memset(pBuffer, 0, sizeof(ULONG));
+
+    /* Check if we can get a System PortNumber to access the \Parameters\Device(d) subkey to get a per HBA value.
+     * FIXME NOTE
+     *
+     * Regarding StorPortGetSystemPortNumber():
+     *
+     * StorPort always reports STOR_STATUS_INVALID_DEVICE_STATE and does not update pHwAddress->Port.
+     * Calls to StorPortRegistryRead() and StorPortRegistryWrite() only read or write to \Parameters\Device-1,
+     * which appears to be an uninitialized value. Therefore, the alternate per HBA read technique will always be used.
+     *
+     * Please refer to PR #1216 for more details.
+     *
+     * FIXME NOTE END
+     */
+    pHwAddress->Type = STOR_ADDRESS_TYPE_BTL8;
+    pHwAddress->AddressLength = STOR_ADDR_BTL8_ADDRESS_LENGTH;
+    RhelDbgPrint(TRACE_REGISTRY,
+                 " Checking whether the HBA system port number and HBA specific registry are available for reading... "
+                 "\n");
+    spgspn_rc = StorPortGetSystemPortNumber(DeviceExtension, pHwAddress);
+    if (spgspn_rc = STOR_STATUS_INVALID_DEVICE_STATE)
+    {
+        RhelDbgPrint(TRACE_REGISTRY,
+                     " WARNING : !!!...HBA Port not ready yet...!!! Returns : 0x%x (STOR_STATUS_INVALID_DEVICE_STATE) "
+                     "\n",
+                     spgspn_rc);
+        /*
+         * When we are unable to get a valid system PortNumber, we need to
+         * use an alternate per HBA registry read technique. The technique
+         * implemented here uses per HBA registry value names based on the
+         * Storport provided slot_number minus one, padded to hundreds,
+         * e.g. \Parameters\Device\Valuename_123.
+         *
+         * This permits up to 999 HBAs. That ought to be enough... c( O.O )ɔ
+         */
+        bUseAltPerHbaRegRead = TRUE;
+        RhelDbgPrint(TRACE_REGISTRY,
+                     " Using alternate per HBA registry read technique [\\Parameters\\Device\\Value_(ddd)]. \n");
+
+        /* Grab the first 60 characters of the target Registry Value.
+         * Value name limit is 16,383 characters, so this is important.
+         * We leave the last 4 characters for the hba_id_as_str values.
+         * NULL terminator wraps things up. Also used in TRACING.
+         */
+        CopyBufferToAnsiString(&valname_as_str, ValueName, '\0', 60);
+        CopyBufferToAnsiString(&hba_id_as_str, &shAdapterId, '\0', 4);
+
+        /* Convert from integer to padded ASCII numbers. */
+        if (shAdapterId / 100)
+        {
+            j = 0;
+            hba_id_as_str[j] = (UCHAR)(shAdapterId / 100) + 48;
+        }
+        else
+        {
+            hba_id_as_str[0] = 48;
+            if (shAdapterId / 10)
+            {
+                j = 1;
+                hba_id_as_str[j] = (UCHAR)(shAdapterId / 10) + 48;
+            }
+            else
+            {
+                hba_id_as_str[1] = 48;
+                j = 2;
+                hba_id_as_str[j] = (UCHAR)shAdapterId + 48;
+            }
+        }
+        if ((j < 1) && (shAdapterId / 10))
+        {
+            j = 1;
+            hba_id_as_str[j] = (UCHAR)(((shAdapterId - ((shAdapterId / 100) * 100)) / 10) + 48);
+        }
+        else if ((j < 2) && (shAdapterId > 9))
+        {
+            j = 2;
+            hba_id_as_str[j] = (UCHAR)((shAdapterId - ((shAdapterId / 10) * 10)) + 48);
+        }
+        else
+        {
+            j = 1;
+            hba_id_as_str[j] = 48;
+        }
+        if ((j < 2) && (shAdapterId > 0))
+        {
+            j = 2;
+            hba_id_as_str[j] = (UCHAR)((shAdapterId - ((shAdapterId / 10) * 10)) + 48);
+        }
+        else if (j < 2)
+        {
+            j = 2;
+            hba_id_as_str[j] = 48;
+        }
+        /* NULL-terminate the string. */
+        hba_id_as_str[3] = '\0';
+        /* Skip the exisitng ValueName. */
+        for (i = 0; valname_as_str[i] != '\0'; ++i)
+        {
+        }
+        /* Append an underscore. */
+        valname_as_str[i] = '\x5F';
+        /* Append the padded HBA ID and NULL terminator. */
+        for (j = 0; j < 4; ++j)
+        {
+            valname_as_str[i + j + 1] = hba_id_as_str[j];
+        }
+
+        PUCHAR ValueNamePerHba = (UCHAR *)&valname_as_str;
+        bReadResult = StorPortRegistryRead(DeviceExtension,
+                                           ValueNamePerHba,
+                                           1,
+                                           MINIPORT_REG_DWORD,
+                                           pBuffer,
+                                           &pBufferLength);
+    }
+    else
+    {
+        RhelDbgPrint(TRACE_REGISTRY, " HBA Port : %u | Returns : 0x%x \n", pHwAddress->Port, spgspn_rc);
+        RhelDbgPrint(TRACE_REGISTRY, " Using StorPort-based per HBA registry read [\\Parameters\\Device(d)]. \n");
+        /* FIXME : THIS DOES NOT WORK. IT WILL NOT READ \Parameters\Device(d) subkeys...
+         * NOTE  : Only MINIPORT_REG_DWORD values are supported.
+         */
+        bReadResult = StorPortRegistryRead(DeviceExtension, ValueName, 0, MINIPORT_REG_DWORD, pBuffer, &pBufferLength);
+        /* Grab the first 64 characters of the target Registry Value.
+         * Value name limit is 16,383 characters, so this is important.
+         * NULL terminator wraps things up. Used in TRACING.
+         */
+        CopyBufferToAnsiString(&valname_as_str, ValueName, '\0', 64);
+    }
+
+    if ((bReadResult == FALSE) || (pBufferLength == 0))
+    {
+        RhelDbgPrint(TRACE_REGISTRY,
+                     " StorPortRegistryRead was unable to find a per HBA value %s. Attempting to find a global "
+                     "value... \n",
+                     (bUseAltPerHbaRegRead) ? "using \\Parameters\\Device\\Value_(ddd) value names"
+                                            : "at the \\Parameters\\Device(d) subkey");
+        bReadResult = FALSE;
+        pBufferLength = sizeof(ULONG);
+        memset(pBuffer, 0, sizeof(ULONG));
+
+        /* Do a "Global" read of the Parameters\Device subkey...
+         * NOTE : Only MINIPORT_REG_DWORD values are supported.
+         */
+        bReadResult = StorPortRegistryRead(DeviceExtension, ValueName, 1, MINIPORT_REG_DWORD, pBuffer, &pBufferLength);
+        /* Grab the first 64 characters of the target Registry Value.
+         * Value name limit is 16,383 characters, so this is important.
+         * NULL terminator wraps things up. Used in TRACING.
+         */
+        CopyBufferToAnsiString(&valname_as_str, ValueName, '\0', 64);
+    }
+    /* Give me the DWORD Registry Value as a ULONG from the pointer.
+     * Used in TRACING.
+     */
+    memcpy(&value_as_ulong, pBuffer, sizeof(ULONG));
+
+    if ((bReadResult == FALSE) || (pBufferLength == 0))
+    {
+        RhelDbgPrint(TRACE_REGISTRY,
+                     " StorPortRegistryRead of %s returned NOT FOUND or EMPTY, pBufferLength = %d, Possible "
+                     "pBufferLength Hint = 0x%x (%lu) \n",
+                     valname_as_str,
+                     pBufferLength,
+                     value_as_ulong,
+                     value_as_ulong);
+        StorPortFreeRegistryBuffer(DeviceExtension, pBuffer);
+        return FALSE;
+    }
+    else
+    {
+        RhelDbgPrint(TRACE_REGISTRY,
+                     " StorPortRegistryRead of %s returned SUCCESS, pBufferLength = %d, Value = 0x%x (%lu) \n",
+                     valname_as_str,
+                     pBufferLength,
+                     value_as_ulong,
+                     value_as_ulong);
+
+        StorPortCopyMemory((PVOID)((UINT_PTR)adaptExt + offset), (PVOID)pBuffer, sizeof(ULONG));
+
+        StorPortFreeRegistryBuffer(DeviceExtension, pBuffer);
+
+        return TRUE;
+    }
+}
+
 ULONG
 DriverEntry(IN PVOID DriverObject, IN PVOID RegistryPath)
 {

viostor/virtio_stor_trace.h

@@ -90,6 +90,7 @@ extern int nViostorDebugLevel;
         WPP_DEFINE_BIT(TRACE_LEVEL_WARNING)            /* bit  3 = 0x00000008 */ \
         WPP_DEFINE_BIT(TRACE_LEVEL_INFORMATION)        /* bit  4 = 0x00000010 */ \
         WPP_DEFINE_BIT(TRACE_LEVEL_VERBOSE)            /* bit  5 = 0x00000020 */ \
+        WPP_DEFINE_BIT(TRACE_REGISTRY)                 /* bit  6 = 0x00000040 */ \
         )
 
 #define WPP_Flags_LEVEL_LOGGER(Flags, level)                                  \