Changeset 87440 in vbox

Timestamp:

Jan 26, 2021 6:18:57 PM (4 years ago)

Author:

vboxsync

Message:

VMM/HMVMX: More hmR0VmxStartVm work.

File:

• trunk/src/VBox/VMM/VMMR0/HMR0A.asm (modified) (4 diffs)

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

@@ -778 +778 @@
  %define frm_saved_gdtr      -02ah              ; 16+64:  Only used when VMX_SKIP_GDTR isn't defined
  %define frm_saved_tr        -02ch              ; 16-bit: Only used when VMX_SKIP_TR isn't defined
- ;%define frm_fNoRestoreXcr0  -030h              ; 32-bit: Non-zero if we should skip XCR0 restoring.
+ %define frm_MDS_seg         -030h              ; 16-bit: Temporary storage for the MDS flushing.
  %define frm_saved_idtr      -03ah              ; 16+64:  Only used when VMX_SKIP_IDTR isn't defined
  %define frm_saved_ldtr      -03ch              ; 16-bit: always saved.
@@ -888 +888 @@
 .wrote_host_rsp:
 
- %if %3 & CPUMCTX_WSF_IBPB_EXIT
+        ;
         ; Fight spectre and similar. Trashes rax, rcx, and rdx.
-        INDIRECT_BRANCH_PREDICTION_AND_L1_CACHE_BARRIER rdi, CPUMCTX_WSF_IBPB_ENTRY, CPUMCTX_WSF_L1D_ENTRY, CPUMCTX_WSF_MDS_ENTRY
+        ;
+ %if %3 & (CPUMCTX_WSF_IBPB_ENTRY | CPUMCTX_WSF_L1D_ENTRY)  ; The eax:edx value is the same for the first two.
+        AssertCompile(MSR_IA32_PRED_CMD_F_IBPB == MSR_IA32_FLUSH_CMD_F_L1D)
+        mov     eax, MSR_IA32_PRED_CMD_F_IBPB
+        xor     edx, edx
+ %endif
+ %if %3 & CPUMCTX_WSF_IBPB_ENTRY        ; Indirect branch barrier.
+        mov     ecx, MSR_IA32_PRED_CMD
+        wrmsr
+ %endif
+ %if %3 & CPUMCTX_WSF_L1D_ENTRY         ; Level 1 data cache flush.
+        mov     ecx, MSR_IA32_FLUSH_CMD
+        wrmsr
+ %elif %3 & CPUMCTX_WSF_MDS_ENTRY       ; MDS flushing is included in L1D_FLUSH
+        mov     word [rbp + frm_MDS_seg], ds
+        verw    word [rbp + frm_MDS_seg]
  %endif
 
@@ -1018 +1033 @@
         mov     rdx, rcx
 
-  %if %1 = 0 ; Skip this in failure branch (=> guru)
-   %if %3 & CPUMCTX_WSF_IBPB_EXIT
-        ; Fight spectre.
-        INDIRECT_BRANCH_PREDICTION_BARRIER_CTX rax, CPUMCTX_WSF_IBPB_EXIT
+  %if %3 & CPUMCTX_WSF_IBPB_EXIT
+        ; Fight spectre (trashes rax, rdx and rcx).
+   %if %1 = 0 ; Skip this in failure branch (=> guru)
+        mov     ecx, MSR_IA32_PRED_CMD
+        mov     eax, MSR_IA32_PRED_CMD_F_IBPB
+        xor     edx, edx
+        wrmsr
    %endif
   %endif
@@ -1461 +1479 @@
  %endif
 
-        ; Fight spectre.  Note! Trashes rax, rdx and rcx!
  %if %3 & CPUMCTX_WSF_IBPB_EXIT
         ; Fight spectre (trashes rax, rdx and rcx).