Changeset 47660 in vbox for trunk/src/VBox/VMM/VMMSwitcher

Timestamp:

Aug 12, 2013 12:37:34 AM (12 years ago)

Author:

vboxsync

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

87863

Message:

VMM: Debug register handling redo. (only partly tested on AMD-V so far.)

Location:

trunk/src/VBox/VMM/VMMSwitcher

Files:

• AMD64andLegacy.mac (modified) (12 diffs)
• LegacyandAMD64.mac (modified) (4 diffs)
• PAEand32Bit.mac (modified) (9 diffs)

trunk/src/VBox/VMM/VMMSwitcher/AMD64andLegacy.mac

@@ -5 +5 @@
 
 ;
-; Copyright (C) 2006-2012 Oracle Corporation
+; Copyright (C) 2006-2013 Oracle Corporation
 ;
 ; This file is part of VirtualBox Open Source Edition (OSE), as
@@ -355 +355 @@
 
     ; debug registers.
-    test    esi, CPUM_USE_DEBUG_REGS | CPUM_USE_DEBUG_REGS_HOST
-    jz      htg_debug_regs_no
-    jmp     htg_debug_regs_save
+    test    esi, CPUM_USE_DEBUG_REGS_HYPER | CPUM_USE_DEBUG_REGS_HOST
+    jnz     htg_debug_regs_save
 htg_debug_regs_no:
     DEBUG_CHAR('a')                     ; trashes esi
@@ -439 +438 @@
     mov     rax, dr7                    ; not sure, but if I read the docs right this will trap if GD is set. FIXME!!!
     mov     [rdx + r8 + CPUMCPU.Host.dr7], rax
-    xor     eax, eax                    ; clear everything. (bit 12? is read as 1...)
-    mov     dr7, rax
+    mov     ecx, X86_DR7_INIT_VAL
+    cmp     eax, ecx
+    je      .htg_debug_regs_dr7_disabled
+    mov     dr7, rcx
+.htg_debug_regs_dr7_disabled:
     mov     rax, dr6                    ; just in case we save the state register too.
     mov     [rdx + r8 + CPUMCPU.Host.dr6], rax
     ; save host DR0-3?
-    test    esi, CPUM_USE_DEBUG_REGS
-    jz near htg_debug_regs_no
+    test    esi, CPUM_USE_DEBUG_REGS_HYPER
+    jz      htg_debug_regs_no
 DEBUG_S_CHAR('S');
     mov     rax, dr0
@@ -455 +457 @@
     mov     rax, dr3
     mov     [rdx + r8 + CPUMCPU.Host.dr3], rax
+    or      dword [rdx + r8 + CPUMCPU.fUseFlags], CPUM_USED_DEBUG_REGS_HOST
     jmp     htg_debug_regs_no
 
@@ -513 +516 @@
 GLOBALNAME JmpGCTarget
     DEBUG_CHAR('-')
-;mov eax, 0ffff0000h
-;.delay_loop:
-;nop
-;dec eax
-;nop
-;jnz .delay_loop
     ; load final cr3 and do far jump to load cs.
     mov     cr3, ebp                ; ebp set above
@@ -565 +562 @@
 
     ; debug registers
-    test    esi, CPUM_USE_DEBUG_REGS
+    test    esi, CPUM_USE_DEBUG_REGS_HYPER
     jnz     htg_debug_regs_guest
 htg_debug_regs_guest_done:
@@ -622 +619 @@
     mov     ebx, [edx + CPUMCPU.Hyper.dr + 8*3]
     mov     dr3, ebx
-    ;mov     eax, [edx + CPUMCPU.Hyper.dr + 8*6]
-    mov     ecx, 0ffff0ff0h
+    mov     ecx, X86_DR6_INIT_VAL
     mov     dr6, ecx
     mov     eax, [edx + CPUMCPU.Hyper.dr + 8*7]
     mov     dr7, eax
+    or      dword [edx + CPUMCPU.fUseFlags], CPUM_USED_DEBUG_REGS_HYPER
     jmp     htg_debug_regs_guest_done
 
@@ -793 +790 @@
     ; FPU context is saved before restore of host saving (another) branch.
 
+    ; Disable debug registers if active so they cannot trigger while switching.
+    test    dword [edi + CPUMCPU.fUseFlags], CPUM_USED_DEBUG_REGS_HYPER
+    jz      .gth_disabled_dr7
+    mov     eax, X86_DR7_INIT_VAL
+    mov     dr7, eax
+.gth_disabled_dr7:
 
     ;;
@@ -991 +994 @@
     ;mov     cr2, rcx
 
-    ; restore debug registers (if modified) (esi must still be fUseFlags!)
-    ; (must be done after cr4 reload because of the debug extension.)
-    test    esi, CPUM_USE_DEBUG_REGS | CPUM_USE_DEBUG_REGS_HOST
-    jz short gth_debug_regs_no
-    jmp     gth_debug_regs_restore
-gth_debug_regs_no:
-
     ; Restore MSRs
     mov     rbx, rdx
@@ -1014 +1010 @@
     mov     rdx, rbx
 
-    ; restore general registers.
+    ; Restore debug registers (if modified). (ESI must still be fUseFlags! Must be done late, at least after CR4!)
+    test    esi, CPUM_USE_DEBUG_REGS_HOST | CPUM_USED_DEBUG_REGS_HOST | CPUM_USE_DEBUG_REGS_HYPER
+    jnz     gth_debug_regs_restore
+gth_debug_regs_done:
+    and     dword [edx + CPUMCPU.fUseFlags], ~(CPUM_USED_DEBUG_REGS_HOST | CPUM_USED_DEBUG_REGS_HYPER)
+
+    ; Restore general registers.
     mov     eax, edi                    ; restore return code. eax = return code !!
     ; mov     rax, [rdx + r8 + CPUMCPU.Host.rax] - scratch + return code
@@ -1049 +1051 @@
 gth_debug_regs_restore:
     DEBUG_S_CHAR('d')
-    xor     eax, eax
-    mov     dr7, rax                    ; paranoia or not?
-    test    esi, CPUM_USE_DEBUG_REGS
-    jz short gth_debug_regs_dr7
+    mov     rax, dr7                    ; Some DR7 paranoia first...
+    mov     ecx, X86_DR7_INIT_VAL
+    cmp     rax, rcx
+    je      .gth_debug_skip_dr7_disabling
+    mov     dr7, rcx
+.gth_debug_skip_dr7_disabling:
+    test    esi, CPUM_USED_DEBUG_REGS_HOST
+    jz      .gth_debug_regs_dr7
+
     DEBUG_S_CHAR('r')
     mov     rax, [rdx + r8 + CPUMCPU.Host.dr0]
@@ -1062 +1069 @@
     mov     rax, [rdx + r8 + CPUMCPU.Host.dr3]
     mov     dr3, rax
-gth_debug_regs_dr7:
+.gth_debug_regs_dr7:
     mov     rbx, [rdx + r8 + CPUMCPU.Host.dr6]
     mov     dr6, rbx
     mov     rcx, [rdx + r8 + CPUMCPU.Host.dr7]
     mov     dr7, rcx
-    jmp     gth_debug_regs_no
+
+    ; We clear the USED flags in the main code path.
+    jmp     gth_debug_regs_done
 
 ENDPROC vmmRCToHostAsm

trunk/src/VBox/VMM/VMMSwitcher/LegacyandAMD64.mac

@@ -445 +445 @@
     mov     esi, [rdx + CPUMCPU.fUseFlags] ; esi == use flags.
     test    esi, CPUM_SYNC_FPU_STATE
-    jz      near gth_fpu_no
+    jz      near htg_fpu_no
 
 %ifdef VBOX_WITH_CRASHDUMP_MAGIC
@@ -460 +460 @@
     and     dword [rdx + CPUMCPU.fUseFlags], ~CPUM_SYNC_FPU_STATE
 
-gth_fpu_no:
+htg_fpu_no:
     ; Check if we need to restore the guest debug state
-    test    esi, CPUM_SYNC_DEBUG_STATE
-    jz      near gth_debug_no
+    test    esi, CPUM_SYNC_DEBUG_REGS_GUEST | CPUM_SYNC_DEBUG_REGS_HYPER
+    jz      htg_debug_done
 
 %ifdef VBOX_WITH_CRASHDUMP_MAGIC
     mov dword [rdx + CPUMCPU.Guest.dr + 4*8], 8
 %endif
-
+    test    esi, CPUM_SYNC_DEBUG_REGS_HYPER
+    jnz     htg_debug_hyper
+
+    ; Guest values in DRx, letting the guest access them directly.
     mov     rax, qword [rdx + CPUMCPU.Guest.dr + 0*8]
     mov     dr0, rax
@@ -480 +483 @@
     mov     dr6, rax    ; not required for AMD-V
 
-    and     dword [rdx + CPUMCPU.fUseFlags], ~CPUM_SYNC_DEBUG_STATE
-
-gth_debug_no:
+    and     dword [rdx + CPUMCPU.fUseFlags], ~CPUM_SYNC_DEBUG_REGS_GUEST
+    or      dword [rdx + CPUMCPU.fUseFlags], CPUM_USED_DEBUG_REGS_GUEST
+    jmp     htg_debug_done
+
+htg_debug_hyper:
+    ; Combined values in DRx, intercepting all accesses.
+    mov     rax, qword [rdx + CPUMCPU.Hyper.dr + 0*8]
+    mov     dr0, rax
+    mov     rax, qword [rdx + CPUMCPU.Hyper.dr + 1*8]
+    mov     dr1, rax
+    mov     rax, qword [rdx + CPUMCPU.Hyper.dr + 2*8]
+    mov     dr2, rax
+    mov     rax, qword [rdx + CPUMCPU.Hyper.dr + 3*8]
+    mov     dr3, rax
+    mov     rax, qword [rdx + CPUMCPU.Hyper.dr + 6*8]
+    mov     dr6, rax    ; not required for AMD-V
+
+    and     dword [rdx + CPUMCPU.fUseFlags], ~CPUM_SYNC_DEBUG_REGS_HYPER
+    or      dword [rdx + CPUMCPU.fUseFlags], CPUM_USED_DEBUG_REGS_HYPER
+
+htg_debug_done:
 
 %ifdef VBOX_WITH_CRASHDUMP_MAGIC
     mov dword [rdx + CPUMCPU.Guest.dr + 4*8], 9
 %endif
+
+    ;
+    ; "Call" the specified helper function.
+    ;
 
     ; parameter for all helper functions (pCtx)
     DEBUG64_CHAR('9')
     lea     rsi, [rdx + CPUMCPU.Guest.fpu]
-    lea     rax, [gth_return wrt rip]
+    lea     rax, [htg_return wrt rip]
     push    rax                         ; return address
 
@@ -505 +530 @@
     jz      NAME(HMRCTestSwitcher64)
     mov     eax, VERR_HM_INVALID_HM64ON32OP
-gth_return:
+htg_return:
     DEBUG64_CHAR('r')
 

trunk/src/VBox/VMM/VMMSwitcher/PAEand32Bit.mac

@@ -5 +5 @@
 
 ;
-; Copyright (C) 2006-2012 Oracle Corporation
+; Copyright (C) 2006-2013 Oracle Corporation
 ;
 ; This file is part of VirtualBox Open Source Edition (OSE), as
@@ -256 +256 @@
 
     ; debug registers.
-    test    esi, CPUM_USE_DEBUG_REGS | CPUM_USE_DEBUG_REGS_HOST
+    test    esi, CPUM_USE_DEBUG_REGS_HYPER | CPUM_USE_DEBUG_REGS_HOST
     jnz     htg_debug_regs_save_dr7and6
 htg_debug_regs_no:
@@ -407 +407 @@
 
     ; debug registers
-    test    esi, CPUM_USE_DEBUG_REGS
+    test    esi, CPUM_USE_DEBUG_REGS_HYPER
     jnz     htg_debug_regs_guest
 htg_debug_regs_guest_done:
@@ -515 +515 @@
     mov     eax, dr3
     mov     [edx + CPUMCPU.Host.dr3], eax
+    or      dword [edi + CPUMCPU.fUseFlags], CPUM_USED_DEBUG_REGS_HOST
 
     ; load hyper DR0-7
@@ -525 +526 @@
     mov     ebx, [edx + CPUMCPU.Hyper.dr + 8*3]
     mov     dr3, ebx
-    ;mov     eax, [edx + CPUMCPU.Hyper.dr + 8*6]
-    mov     ecx, 0ffff0ff0h
+    mov     ecx, X86_DR6_INIT_VAL
     mov     dr6, ecx
     mov     eax, [edx + CPUMCPU.Hyper.dr + 8*7]
     mov     dr7, eax
+    or      dword [edi + CPUMCPU.fUseFlags], CPUM_USED_DEBUG_REGS_HYPER
     jmp     htg_debug_regs_guest_done
 
@@ -686 +687 @@
     ; No need to save CRx here. They are set dynamically according to Guest/Host requirements.
     ; FPU context is saved before restore of host saving (another) branch.
+
+    ; Disable debug regsiters if active so they cannot trigger while switching.
+    test    dword [edi + CPUMCPU.fUseFlags], CPUM_USED_DEBUG_REGS_HYPER
+    jz      .gth_disabled_dr7
+    mov     eax, X86_DR7_INIT_VAL
+    mov     dr7, eax
+.gth_disabled_dr7:
 
 %ifdef VBOX_WITH_NMI
@@ -887 +895 @@
     ; restore debug registers (if modified) (esi must still be fUseFlags!)
     ; (must be done after cr4 reload because of the debug extension.)
-    test    esi, CPUM_USE_DEBUG_REGS | CPUM_USE_DEBUG_REGS_HOST
-    jz short gth_debug_regs_no
-    jmp     gth_debug_regs_restore
-gth_debug_regs_no:
+    test    esi, CPUM_USE_DEBUG_REGS_HYPER | CPUM_USE_DEBUG_REGS_HOST | CPUM_USED_DEBUG_REGS_HOST
+    jnz     gth_debug_regs_restore
+gth_debug_regs_done:
 
     ; restore general registers.
@@ -911 +918 @@
 gth_debug_regs_restore:
     DEBUG_S_CHAR('d')
-    xor     eax, eax
-    mov     dr7, eax                    ; paranoia or not?
-    test    esi, CPUM_USE_DEBUG_REGS
-    jz short gth_debug_regs_dr7
+    mov     eax, dr7                    ; Some DR7 paranoia first...
+    mov     ecx, X86_DR7_INIT_VAL
+    cmp     eax, ecx
+    je      .gth_debug_skip_dr7_disabling
+    mov     dr7, ecx
+.gth_debug_skip_dr7_disabling:
+    test    esi, CPUM_USED_DEBUG_REGS_HOST
+    jz      .gth_debug_regs_dr7
+
     DEBUG_S_CHAR('r')
     mov     eax, [edx + CPUMCPU.Host.dr0]
@@ -924 +936 @@
     mov     eax, [edx + CPUMCPU.Host.dr3]
     mov     dr3, eax
-gth_debug_regs_dr7:
+.gth_debug_regs_dr7:
     mov     ebx, [edx + CPUMCPU.Host.dr6]
     mov     dr6, ebx
     mov     ecx, [edx + CPUMCPU.Host.dr7]
     mov     dr7, ecx
-    jmp     gth_debug_regs_no
+
+    and     dword [edx + CPUMCPU.fUseFlags], ~(CPUM_USED_DEBUG_REGS_HOST | CPUM_USED_DEBUG_REGS_HYPER)
+    jmp     gth_debug_regs_done
 
 ENDPROC vmmRCToHostAsm