diff options
| -rw-r--r-- | usr/src/uts/i86pc/io/pcplusmp/apic_common.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/usr/src/uts/i86pc/io/pcplusmp/apic_common.c b/usr/src/uts/i86pc/io/pcplusmp/apic_common.c index 12368abf89..5d642e6bd4 100644 --- a/usr/src/uts/i86pc/io/pcplusmp/apic_common.c +++ b/usr/src/uts/i86pc/io/pcplusmp/apic_common.c @@ -1499,13 +1499,26 @@ apic_intrmap_init(int apic_mode) { int suppress_brdcst_eoi = 0; + /* + * Intel Software Developer's Manual 3A, 10.12.7: + * + * Routing of device interrupts to local APIC units operating in + * x2APIC mode requires use of the interrupt-remapping architecture + * specified in the Intel Virtualization Technology for Directed + * I/O, Revision 1.3. Because of this, BIOS must enumerate support + * for and software must enable this interrupt remapping with + * Extended Interrupt Mode Enabled before it enabling x2APIC mode in + * the local APIC units. + * + * + * In other words, to use the APIC in x2APIC mode, we need interrupt + * remapping. Since we don't start up the IOMMU by default, we + * won't be able to do any interrupt remapping and therefore have to + * use the APIC in traditional 'local APIC' mode with memory mapped + * I/O. + */ + if (psm_vt_ops != NULL) { - /* - * Since X2APIC requires the use of interrupt remapping - * (though this is not documented explicitly in the Intel - * documentation (yet)), initialize interrupt remapping - * support before initializing the X2APIC unit. - */ if (((apic_intrmap_ops_t *)psm_vt_ops)-> apic_intrmap_init(apic_mode) == DDI_SUCCESS) { |