svn commit: r245917 - head/sys/amd64/vmm/intel

[Peter Grehan]

Author: grehan
Date: Fri Jan 25 21:38:31 2013
New Revision: 245917
URL: http://svnweb.freebsd.org/changeset/base/245917

Log:
  Always allow access to the sysenter cs/esp/eip MSRs since they
  are automatically saved and restored in the VMCS.
  
  Reviewed by:	neel
  Obtained from:	NetApp

Modified:
  head/sys/amd64/vmm/intel/vmx.c

Modified: head/sys/amd64/vmm/intel/vmx.c
==============================================================================
--- head/sys/amd64/vmm/intel/vmx.c	Fri Jan 25 20:45:24 2013	(r245916)
+++ head/sys/amd64/vmm/intel/vmx.c	Fri Jan 25 21:38:31 2013	(r245917)
@@ -696,6 +696,10 @@ vmx_vminit(struct vm *vm)
 	 * vm-exit and vm-entry respectively. The host FSBASE and GSBASE are
 	 * always restored from the vmcs host state area on vm-exit.
 	 *
+	 * The SYSENTER_CS/ESP/EIP MSRs are identical to FS/GSBASE in
+	 * how they are saved/restored so can be directly accessed by the
+	 * guest.
+	 *
 	 * Guest KGSBASE is saved and restored in the guest MSR save area.
 	 * Host KGSBASE is restored before returning to userland from the pcb.
 	 * There will be a window of time when we are executing in the host
@@ -708,6 +712,9 @@ vmx_vminit(struct vm *vm)
 	 */
 	if (guest_msr_rw(vmx, MSR_GSBASE) ||
 	    guest_msr_rw(vmx, MSR_FSBASE) ||
+	    guest_msr_rw(vmx, MSR_SYSENTER_CS_MSR) ||
+	    guest_msr_rw(vmx, MSR_SYSENTER_ESP_MSR) ||
+	    guest_msr_rw(vmx, MSR_SYSENTER_EIP_MSR) ||
 	    guest_msr_rw(vmx, MSR_KGSBASE) ||
 	    guest_msr_rw(vmx, MSR_EFER))
 		panic("vmx_vminit: error setting guest msr access");