Changeset 9814 in vbox

Timestamp:

Jun 19, 2008 11:09:21 AM (17 years ago)

Author:

vboxsync

Message:

FS & GS base msr fixes

Location:

trunk/src/VBox/VMM/VMMR0

Files:

• HWACCMR0A.asm (modified) (1 diff)
• HWVMXR0.cpp (modified) (2 diffs)

trunk/src/VBox/VMM/VMMR0/HWACCMR0A.asm

@@ -459 +459 @@
     LOADGUESTMSR MSR_K8_KERNEL_GS_BASE, CPUMCTX.msrKERNELGSBASE
 
+    ; Load the guest MSRs for FS & GS base (saved in MYPUSHSEGS)
+    mov     rcx, MSR_K8_FS_BASE
+    mov     rax, qword [xSI + CPUMCTX.msrFSBASE]
+    wrmsr
+
+    mov     rcx, MSR_K8_GS_BASE
+    mov     rax, qword [xSI + CPUMCTX.msrGSBASE]
+    wrmsr
+
     ; Save the pCtx pointer
     push    xSI

trunk/src/VBox/VMM/VMMR0/HWVMXR0.cpp

@@ -969 +969 @@
         pVM->hwaccm.s.vmx.pfnStartVM  = VMXR0StartVM64;
 #endif
-        rc = VMXWriteVMCS(VMX_VMCS_GUEST_FS_BASE, pCtx->msrFSBASE);
-        AssertRC(rc);
-        rc = VMXWriteVMCS(VMX_VMCS_GUEST_GS_BASE, pCtx->msrGSBASE);
-        AssertRC(rc);
     }
     else
@@ -2095 +2091 @@
         VMXReadVMCS(VMX_VMCS_GUEST_SYSENTER_ESP,     &val);
         pCtx->SysEnter.esp      = val;
-
-        /* 64 bits guest mode? */
-        if (pCtx->msrEFER & MSR_K6_EFER_LMA)
-        {
-            /* Note: we assume that either you can't rely on fs/gs base staying intact when switching in and out of 64 bits mode or that in
-             *       reality it really doesn't matter (as the guest OS restores them manually).
-             */
-            VMXReadVMCS(VMX_VMCS_GUEST_FS_BASE, &val);
-            pCtx->msrFSBASE = val;
-            VMXReadVMCS(VMX_VMCS_GUEST_GS_BASE, &val);
-            pCtx->msrGSBASE = val;
-        }
     }