Changeset 26989 in vbox for trunk/src/VBox

Timestamp:

Mar 3, 2010 1:50:05 PM (15 years ago)

Author:

vboxsync

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

58296

Message:

Extra comment for the backdoor config bytes

File:

• trunk/src/VBox/Devices/Bus/DevPCI.cpp (modified) (1 diff)

trunk/src/VBox/Devices/Bus/DevPCI.cpp ¶

@@ -653 +653 @@
     uint8_t    *pbCfg = pGlobals->PIIX3State.dev.config;
     const bool  fIsAcpiDevice = pPciDev->config[2] == 0x13 && pPciDev->config[3] == 0x71;
+    /* These two configuration space bytes enable a backdoor to trigger the irq directly on the io-apic; e.g. 64 bit Linux guests use it. */
     const bool  fIsApicEnabled = pGlobals->fUseIoApic && pbCfg[0xde] == 0xbe && pbCfg[0xad] == 0xef;
     int pic_irq, pic_level;