Changeset 30390 in vbox

Timestamp:

Jun 23, 2010 12:49:37 PM (14 years ago)

Author:

vboxsync

Message:

VT-x: when the guest's FPU state is active, then we no longer care about the FPU related bits. Saves a lot of world switches

File:

• trunk/src/VBox/VMM/VMMR0/HWVMXR0.cpp (modified) (1 diff)

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

@@ -1581 +1581 @@
               | X86_CR0_WP  /* Must monitor this bit (it must always be enabled). */
               | X86_CR0_PG  /* Must monitor this bit (assumptions are made for real mode & protected mode without paging emulation) */
-              | X86_CR0_TS
-              | X86_CR0_ET  /* Bit not restored during VM-exit! */
               | X86_CR0_CD  /* Bit not restored during VM-exit! */
-              | X86_CR0_NW  /* Bit not restored during VM-exit! */
-              | X86_CR0_NE
-              | X86_CR0_MP;
+              | X86_CR0_NW; /* Bit not restored during VM-exit! */
+
+        /* When the guest's FPU state is active, then we no longer care about
+         * the FPU related bits. 
+         */
+        if (CPUMIsGuestFPUStateActive(pVCpu) == false)
+            val |= X86_CR0_TS | X86_CR0_ET | X86_CR0_NE | X86_CR0_MP;
+
         pVCpu->hwaccm.s.vmx.cr0_mask = val;