Changeset 48539 in vbox for trunk

Timestamp:

Sep 19, 2013 3:31:53 PM (12 years ago)

Author:

vboxsync

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

89084

Message:

VMM/CPUMR0A.asm: Yasm requires explicit REX prefix for fxsave/rstor. Don't corrupt the FPU state for 64-bit guests.

File:

• trunk/src/VBox/VMM/VMMR0/CPUMR0A.asm (modified) (3 diffs)

trunk/src/VBox/VMM/VMMR0/CPUMR0A.asm

@@ -104 +104 @@
 %endif ; VBOX_WITH_HYBRID_32BIT_KERNEL
 
-    fxsave  [xDX + CPUMCPU.Host.fpu]    ; ASSUMES that all VT-x/AMD-V boxes sports fxsave/fxrstor (safe assumption)
+%ifdef RT_ARCH_AMD64
+    ; Use explicit REX prefix. See @bugref{6398}.
+    o64 fxsave  [xDX + CPUMCPU.Host.fpu]    ; ASSUMES that all VT-x/AMD-V boxes sports fxsave/fxrstor (safe assumption)
+    o64 fxrstor [xDX + CPUMCPU.Guest.fpu]
+%else
+    fxsave  [xDX + CPUMCPU.Host.fpu]        ; ASSUMES that all VT-x/AMD-V boxes sports fxsave/fxrstor (safe assumption)
     fxrstor [xDX + CPUMCPU.Guest.fpu]
+%endif
 
 %ifdef VBOX_WITH_KERNEL_USING_XMM
@@ -133 +139 @@
 .sixtyfourbit_mode:
     and     edx, 0ffffffffh
-    fxsave  [rdx + CPUMCPU.Host.fpu]
-    fxrstor [rdx + CPUMCPU.Guest.fpu]
+    o64 fxsave  [rdx + CPUMCPU.Host.fpu]
+    o64 fxrstor [rdx + CPUMCPU.Guest.fpu]
     jmp far [.fpret wrt rip]
 .fpret:                                 ; 16:32 Pointer to .the_end.
@@ -217 +223 @@
 %endif ; VBOX_WITH_HYBRID_32BIT_KERNEL
 
-    fxsave  [xDX + CPUMCPU.Guest.fpu]   ; ASSUMES that all VT-x/AMD-V boxes support fxsave/fxrstor (safe assumption)
+%ifdef RT_ARCH_AMD64
+    ; Use explicit REX prefix. See @bugref{6398}.
+    o64 fxsave  [xDX + CPUMCPU.Guest.fpu]   ; ASSUMES that all VT-x/AMD-V boxes support fxsave/fxrstor (safe assumption)
+    o64 fxrstor [xDX + CPUMCPU.Host.fpu]
+%else
+    fxsave  [xDX + CPUMCPU.Guest.fpu]       ; ASSUMES that all VT-x/AMD-V boxes support fxsave/fxrstor (safe assumption)
     fxrstor [xDX + CPUMCPU.Host.fpu]
+%endif
 
 .done: