Changeset 87754 in vbox for trunk/src/VBox/VMM/VMMR0

Timestamp:

Feb 13, 2021 5:44:31 PM (4 years ago)

Author:

vboxsync

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

142806

Message:

VMM/HMVMX: Moved the RDTSC in hmR0VmxPostRunGuest to the RESTORE_STATE_VMX assembly macro to get a more accurate value. bugref:9941

Location:

trunk/src/VBox/VMM/VMMR0

Files:

• HMR0A.asm (modified) (2 diffs)
• HMVMXR0.cpp (modified) (4 diffs)

trunk/src/VBox/VMM/VMMR0/HMR0A.asm

@@ -521 +521 @@
  %endif
 
-        ; Save the guest state and restore the non-volatile registers.  We use rax=pGstCtx here.
-        mov     [rsp + cbFrame + frm_guest_rax], rax
-        mov     rax, [rsp + cbFrame + frm_pGstCtx]
-
-        mov     qword [rax + CPUMCTX.ebp], rbp
+        ; Save the guest state and restore the non-volatile registers.  We use rcx=pGstCtx (&pVCpu->cpum.GstCtx) here.
+        mov     [rsp + cbFrame + frm_guest_rcx], rcx
+        mov     rcx, [rsp + cbFrame + frm_pGstCtx]
+
+        mov     qword [rcx + CPUMCTX.eax], rax
+        mov     qword [rcx + CPUMCTX.edx], rdx
+        rdtsc
+        mov     qword [rcx + CPUMCTX.ebp], rbp
         lea     rbp, [rsp + cbFrame]    ; re-establish the frame pointer as early as possible.
-        mov     qword [rax + CPUMCTX.ecx], rcx
-        mov     rcx, SPECTRE_FILLER
-        mov     qword [rax + CPUMCTX.edx], rdx
-        mov     rdx, [rbp + frm_guest_rax]
-        mov     qword [rax + CPUMCTX.eax], rdx
-        mov     rdx, rcx
-        mov     qword [rax + CPUMCTX.r8],  r8
-        mov     r8, rcx
-        mov     qword [rax + CPUMCTX.r9],  r9
-        mov     r9, rcx
-        mov     qword [rax + CPUMCTX.r10], r10
-        mov     r10, rcx
-        mov     qword [rax + CPUMCTX.r11], r11
-        mov     r11, rcx
-        mov     qword [rax + CPUMCTX.esi], rsi
+        shl     rdx, 20h
+        or      rax, rdx                ; TSC value in RAX
+        mov     rdx, [rbp + frm_guest_rcx]
+        mov     qword [rcx + CPUMCTX.ecx], rdx
+        mov     rdx, SPECTRE_FILLER     ; FILLER in RDX
+        mov     qword [rcx + GVMCPU.hmr0 + HMR0PERVCPU.uTscExit - VMCPU.cpum.GstCtx], rax
+        mov     qword [rcx + CPUMCTX.r8],  r8
+        mov     r8, rdx
+        mov     qword [rcx + CPUMCTX.r9],  r9
+        mov     r9, rdx
+        mov     qword [rcx + CPUMCTX.r10], r10
+        mov     r10, rdx
+        mov     qword [rcx + CPUMCTX.r11], r11
+        mov     r11, rdx
+        mov     qword [rcx + CPUMCTX.esi], rsi
  %ifdef ASM_CALL64_MSC
         mov     rsi, [rbp + frm_saved_rsi]
  %else
-        mov     rsi, rcx
- %endif
-        mov     qword [rax + CPUMCTX.edi], rdi
+        mov     rsi, rdx
+ %endif
+        mov     qword [rcx + CPUMCTX.edi], rdi
  %ifdef ASM_CALL64_MSC
         mov     rdi, [rbp + frm_saved_rdi]
  %else
-        mov     rdi, rcx
- %endif
-        mov     qword [rax + CPUMCTX.ebx], rbx
+        mov     rdi, rdx
+ %endif
+        mov     qword [rcx + CPUMCTX.ebx], rbx
         mov     rbx, [rbp + frm_saved_rbx]
-        mov     qword [rax + CPUMCTX.r12], r12
+        mov     qword [rcx + CPUMCTX.r12], r12
         mov     r12,  [rbp + frm_saved_r12]
-        mov     qword [rax + CPUMCTX.r13], r13
+        mov     qword [rcx + CPUMCTX.r13], r13
         mov     r13,  [rbp + frm_saved_r13]
-        mov     qword [rax + CPUMCTX.r14], r14
+        mov     qword [rcx + CPUMCTX.r14], r14
         mov     r14,  [rbp + frm_saved_r14]
-        mov     qword [rax + CPUMCTX.r15], r15
+        mov     qword [rcx + CPUMCTX.r15], r15
         mov     r15,  [rbp + frm_saved_r15]
 
-        mov     rdx, cr2
-        mov     qword [rax + CPUMCTX.cr2], rdx
-        mov     rdx, rcx
+        mov     rax, cr2
+        mov     qword [rcx + CPUMCTX.cr2], rax
+        mov     rax, rdx
 
  %if %4 != 0
         ; Save the context pointer in r8 for the SSE save/restore.
-        mov     r8, rax
+        mov     r8, rcx
  %endif
 
@@ -682 +685 @@
  %define frm_saved_ldtr      -03ch              ; 16-bit: always saved.
  %define frm_rcError         -040h              ; 32-bit: Error status code (not used in the success path)
- %define frm_guest_rax       -048h              ; Temporary storage slot for guest RAX.
+ %define frm_guest_rcx       -048h              ; Temporary storage slot for guest RCX.
  %if %4 = 0
   %assign cbFrame             048h

trunk/src/VBox/VMM/VMMR0/HMVMXR0.cpp

@@ -11153 +11153 @@
 static void hmR0VmxPostRunGuest(PVMCPUCC pVCpu, PVMXTRANSIENT pVmxTransient, int rcVMRun)
 {
-    uint64_t const uHostTsc = ASMReadTSC();                     /** @todo We can do a lot better here, see @bugref{9180#c38}. */
-
     ASMAtomicUoWriteBool(&pVCpu->hm.s.fCheckedTLBFlush, false); /* See HMInvalidatePageOnAllVCpus(): used for TLB flushing. */
     ASMAtomicIncU32(&pVCpu->hmr0.s.cWorldSwitchExits);          /* Initialized in vmR3CreateUVM(): used for EMT poking. */
@@ -11167 +11165 @@
         uint64_t uGstTsc;
         if (!pVmxTransient->fIsNestedGuest)
-            uGstTsc = uHostTsc + pVmcsInfo->u64TscOffset;
+            uGstTsc = pVCpu->hmr0.s.uTscExit + pVmcsInfo->u64TscOffset;
         else
         {
-            uint64_t const uNstGstTsc = uHostTsc + pVmcsInfo->u64TscOffset;
+            uint64_t const uNstGstTsc = pVCpu->hmr0.s.uTscExit + pVmcsInfo->u64TscOffset;
             uGstTsc = CPUMRemoveNestedGuestTscOffset(pVCpu, uNstGstTsc);
         }
@@ -11177 +11175 @@
 
     STAM_PROFILE_ADV_STOP_START(&pVCpu->hm.s.StatInGC, &pVCpu->hm.s.StatPreExit, x);
-    TMNotifyEndOfExecution(pVCpu->CTX_SUFF(pVM), pVCpu, uHostTsc);      /* Notify TM that the guest is no longer running. */
+    TMNotifyEndOfExecution(pVCpu->CTX_SUFF(pVM), pVCpu, pVCpu->hmr0.s.uTscExit); /* Notify TM that the guest is no longer running. */
     VMCPU_SET_STATE(pVCpu, VMCPUSTATE_STARTED_HM);
 
@@ -11258 +11256 @@
          */
         EMHistoryAddExit(pVCpu, EMEXIT_MAKE_FT(EMEXIT_F_KIND_VMX, pVmxTransient->uExitReason & EMEXIT_F_TYPE_MASK),
-                         UINT64_MAX, uHostTsc);
+                         UINT64_MAX, pVCpu->hmr0.s.uTscExit);
 
         if (RT_LIKELY(!pVmxTransient->fVMEntryFailed))