Changeset 10647 in vbox for trunk/src/VBox/VMM/VMMR0

Timestamp:

Jul 15, 2008 12:07:24 PM (17 years ago)

Author:

vboxsync

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

33357

Message:

Manual saving of XMM registers.
Use new FPU/MMX/XMM state saving for VT-x and AMD-V.

Location:

trunk/src/VBox/VMM/VMMR0

Files:

• CPUMR0.cpp (modified) (3 diffs)
• HWACCMR0.cpp (modified) (1 diff)
• HWSVMR0.cpp (modified) (1 diff)
• HWVMXR0.cpp (modified) (1 diff)

trunk/src/VBox/VMM/VMMR0/CPUMR0.cpp

@@ -119 +119 @@
 {
     Assert(pVM->cpum.s.CPUFeatures.edx.u1FXSR);
+    Assert(ASMGetCR4() & X86_CR4_OSFSXR);
 
     /* If the FPU state has already been loaded, then it's a guest trap. */
@@ -163 +164 @@
     }
     CPUMLoadFPUAsm(pCtx);
+
+    /* The MSR_K6_EFER_FFXSR feature is AMD only so far, but check the cpuid just in case Intel adds it in the future.
+     *
+     * MSR_K6_EFER_FFXSR changes the behaviour of fxsave and fxrstore: the XMM state isn't saved/restored
+     *
+     * If the guest uses the MSR_K6_EFER_FFXSR as well, then it has to manually restore the XMM state. 
+     * In that case we don't care.
+     *
+     * We would end up saving/restoring too much if the guest has it enabled, but the host hasn't.
+     */
+    if (    (pVM->cpum.s.aGuestCpuIdExt[1].edx & X86_CPUID_AMD_FEATURE_EDX_FFXSR) /* 0x80000001 */
+        &&  !(pCtx->msrEFER & MSR_K6_EFER_FFXSR))
+    {
+        /* @todo Do we really need to read this every time?? The host could change this on the fly though. */
+        uint64_t msrEFERHost = ASMRdMsr(MSR_K6_EFER);
+
+        if (msrEFERHost & MSR_K6_EFER_FFXSR)
+        {
+            /* fxrstor doesn't restore the XMM state! */
+            CPUMLoadXMMAsm(pCtx);
+            pVM->cpum.s.fUseFlags |= CPUM_MANUAL_XMM_RESTORE;
+        }
+    }
+
     pVM->cpum.s.fUseFlags |= CPUM_USED_FPU;
     return VINF_SUCCESS;
@@ -178 +203 @@
 {
     Assert(pVM->cpum.s.CPUFeatures.edx.u1FXSR);
+    Assert(ASMGetCR4() & X86_CR4_OSFSXR);
     AssertReturn((pVM->cpum.s.fUseFlags & CPUM_USED_FPU), VINF_SUCCESS);
 
     CPUMSaveFPUAsm(pCtx);
-    pVM->cpum.s.fUseFlags &= ~CPUM_USED_FPU;
+    if (pVM->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
+    {
+        /* fxsave doesn't save the XMM state! */
+        CPUMSaveXMMAsm(pCtx);
+    }
+    pVM->cpum.s.fUseFlags &= ~(CPUM_USED_FPU|CPUM_MANUAL_XMM_RESTORE);
     return VINF_SUCCESS;
 }

trunk/src/VBox/VMM/VMMR0/HWACCMR0.cpp

@@ -774 +774 @@
     if (CPUMIsGuestFPUStateActive(pVM))
     {
-        Log2(("CPUMRestoreHostFPUState\n"));
-        /** @note CPUMRestoreHostFPUState keeps the current CR0 intact. */
-        CPUMRestoreHostFPUState(pVM);
+        Log2(("CPUMR0SaveGuestFPU\n"));
+        CPUMR0SaveGuestFPU(pVM, pCtx);
 
         pVM->hwaccm.s.fContextUseFlags |= HWACCM_CHANGED_GUEST_CR0;

trunk/src/VBox/VMM/VMMR0/HWSVMR0.cpp

@@ -1226 +1226 @@
         case X86_XCPT_NM:
         {
-            uint32_t oldCR0;
-
             Log(("#NM fault at %VGv\n", pCtx->rip));
 
             /** @todo don't intercept #NM exceptions anymore when we've activated the guest FPU state. */
-            oldCR0 = ASMGetCR0();
             /* If we sync the FPU/XMM state on-demand, then we can continue execution as if nothing has happened. */
-            rc = CPUMHandleLazyFPU(pVM);
+            rc = CPUMR0LoadGuestFPU(pVM, pCtx);
             if (rc == VINF_SUCCESS)
             {
                 Assert(CPUMIsGuestFPUStateActive(pVM));
-
-                /* CPUMHandleLazyFPU could have changed CR0; restore it. */
-                ASMSetCR0(oldCR0);
-
                 STAM_COUNTER_INC(&pVM->hwaccm.s.StatExitShadowNM);
 

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

@@ -1556 +1556 @@
             case X86_XCPT_NM:
             {
-                uint32_t oldCR0;
-
                 Log(("#NM fault at %VGv error code %x\n", pCtx->rip, errCode));
 
                 /** @todo don't intercept #NM exceptions anymore when we've activated the guest FPU state. */
-                oldCR0 = ASMGetCR0();
                 /* If we sync the FPU/XMM state on-demand, then we can continue execution as if nothing has happened. */
-                rc = CPUMHandleLazyFPU(pVM);
+                rc = CPUMR0LoadGuestFPU(pVM, pCtx);
                 if (rc == VINF_SUCCESS)
                 {
                     Assert(CPUMIsGuestFPUStateActive(pVM));
-
-                    /* CPUMHandleLazyFPU could have changed CR0; restore it. */
-                    ASMSetCR0(oldCR0);
 
                     STAM_COUNTER_INC(&pVM->hwaccm.s.StatExitShadowNM);