svn commit: r279286 - head/sys/x86/acpica

[Konstantin Belousov]

Author: kib
Date: Wed Feb 25 16:44:07 2015
New Revision: 279286
URL: https://svnweb.freebsd.org/changeset/base/279286

Log:
  For now, disable x2APIC mode when Xen is detected, even if CPU
  declares support for it.  Newer versions of Xen works fine with x2APIC
  code, but e.g. Xen 4.2 delivers GPF on the LAPIC MSR write, despite
  x2APIC mode being known to hypervisor.
  
  Discussed with:	royger
  Sponsored by:	The FreeBSD Foundation

Modified:
  head/sys/x86/acpica/madt.c

Modified: head/sys/x86/acpica/madt.c
==============================================================================
--- head/sys/x86/acpica/madt.c	Wed Feb 25 16:36:44 2015	(r279285)
+++ head/sys/x86/acpica/madt.c	Wed Feb 25 16:44:07 2015	(r279286)
@@ -158,6 +158,8 @@ madt_setup_local(void)
 					printf(
        "x2APIC available but disabled inside VMWare without intr redirection\n");
 			}
+		} else if (vm_guest == VM_GUEST_XEN) {
+			x2apic_mode = 0;
 		}
 		TUNABLE_INT_FETCH("hw.x2apic_enable", &x2apic_mode);
 	}