Re: [PULL 10/23] linux-user: Remove unused handle_vm86_fault

[Thomas Huth <thuth@redhat.com>]

On 04/10/2024 18.03, Michael Tokarev wrote:
> From: "Dr. David Alan Gilbert" <dave@treblig.org>
> 
> handle_vm86_fault has been unused since:
>    1ade5b2fed ("linux-user/i386: Split out maybe_handle_vm86_trap")
> 
> Remove it, and it's local macros.
> 
> Signed-off-by: Dr. David Alan Gilbert <dave@treblig.org>
> Reviewed-by: Thomas Huth <thuth@redhat.com>
> Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
> ---
>   linux-user/user-internals.h |   1 -
>   linux-user/vm86.c           | 136 ------------------------------------
>   2 files changed, 137 deletions(-)
> 
> diff --git a/linux-user/user-internals.h b/linux-user/user-internals.h
> index 5c7f173ceb..46ffc093f4 100644
> --- a/linux-user/user-internals.h
> +++ b/linux-user/user-internals.h
> @@ -102,7 +102,6 @@ int host_to_target_waitstatus(int status);
>   /* vm86.c */
>   void save_v86_state(CPUX86State *env);
>   void handle_vm86_trap(CPUX86State *env, int trapno);
> -void handle_vm86_fault(CPUX86State *env);
>   int do_vm86(CPUX86State *env, long subfunction, abi_ulong v86_addr);
>   #elif defined(TARGET_SPARC64)
>   void sparc64_set_context(CPUSPARCState *env);
> diff --git a/linux-user/vm86.c b/linux-user/vm86.c
> index 9f512a2242..31a2d707cf 100644
> --- a/linux-user/vm86.c
> +++ b/linux-user/vm86.c
> @@ -255,142 +255,6 @@ void handle_vm86_trap(CPUX86State *env, int trapno)
>       }
>   }
>   
> -#define CHECK_IF_IN_TRAP() \
> -      if ((ts->vm86plus.vm86plus.flags & TARGET_vm86dbg_active) && \
> -          (ts->vm86plus.vm86plus.flags & TARGET_vm86dbg_TFpendig)) \
> -                newflags |= TF_MASK
> -
> -#define VM86_FAULT_RETURN \
> -        if ((ts->vm86plus.vm86plus.flags & TARGET_force_return_for_pic) && \
> -            (ts->v86flags & (IF_MASK | VIF_MASK))) \
> -            return_to_32bit(env, TARGET_VM86_PICRETURN); \
> -        return
> -
> -void handle_vm86_fault(CPUX86State *env)
> -{
> -    CPUState *cs = env_cpu(env);
> -    TaskState *ts = get_task_state(cs);
> -    uint32_t csp, ssp;
> -    unsigned int ip, sp, newflags, newip, newcs, opcode, intno;
> -    int data32, pref_done;
> -
> -    csp = env->segs[R_CS].selector << 4;
> -    ip = env->eip & 0xffff;
> -
> -    ssp = env->segs[R_SS].selector << 4;
> -    sp = env->regs[R_ESP] & 0xffff;
> -
> -    LOG_VM86("VM86 exception %04x:%08x\n",
> -             env->segs[R_CS].selector, env->eip);
> -
> -    data32 = 0;
> -    pref_done = 0;
> -    do {
> -        opcode = vm_getb(env, csp, ip);
> -        ADD16(ip, 1);
> -        switch (opcode) {
> -        case 0x66:      /* 32-bit data */     data32=1; break;
> -        case 0x67:      /* 32-bit address */  break;
> -        case 0x2e:      /* CS */              break;
> -        case 0x3e:      /* DS */              break;
> -        case 0x26:      /* ES */              break;
> -        case 0x36:      /* SS */              break;
> -        case 0x65:      /* GS */              break;
> -        case 0x64:      /* FS */              break;
> -        case 0xf2:      /* repnz */	      break;
> -        case 0xf3:      /* rep */             break;
> -        default: pref_done = 1;
> -        }
> -    } while (!pref_done);
> -
> -    /* VM86 mode */
> -    switch(opcode) {
> -    case 0x9c: /* pushf */
> -        if (data32) {
> -            vm_putl(env, ssp, sp - 4, get_vflags(env));
> -            ADD16(env->regs[R_ESP], -4);
> -        } else {
> -            vm_putw(env, ssp, sp - 2, get_vflags(env));
> -            ADD16(env->regs[R_ESP], -2);
> -        }
> -        env->eip = ip;
> -        VM86_FAULT_RETURN;
> -
> -    case 0x9d: /* popf */
> -        if (data32) {
> -            newflags = vm_getl(env, ssp, sp);
> -            ADD16(env->regs[R_ESP], 4);
> -        } else {
> -            newflags = vm_getw(env, ssp, sp);
> -            ADD16(env->regs[R_ESP], 2);
> -        }
> -        env->eip = ip;
> -        CHECK_IF_IN_TRAP();
> -        if (data32) {
> -            if (set_vflags_long(newflags, env))
> -                return;
> -        } else {
> -            if (set_vflags_short(newflags, env))
> -                return;
> -        }
> -        VM86_FAULT_RETURN;
> -
> -    case 0xcd: /* int */
> -        intno = vm_getb(env, csp, ip);
> -        ADD16(ip, 1);
> -        env->eip = ip;
> -        if (ts->vm86plus.vm86plus.flags & TARGET_vm86dbg_active) {
> -            if ( (ts->vm86plus.vm86plus.vm86dbg_intxxtab[intno >> 3] >>
> -                  (intno &7)) & 1) {
> -                return_to_32bit(env, TARGET_VM86_INTx + (intno << 8));
> -                return;
> -            }
> -        }
> -        do_int(env, intno);
> -        break;
> -
> -    case 0xcf: /* iret */
> -        if (data32) {
> -            newip = vm_getl(env, ssp, sp) & 0xffff;
> -            newcs = vm_getl(env, ssp, sp + 4) & 0xffff;
> -            newflags = vm_getl(env, ssp, sp + 8);
> -            ADD16(env->regs[R_ESP], 12);
> -        } else {
> -            newip = vm_getw(env, ssp, sp);
> -            newcs = vm_getw(env, ssp, sp + 2);
> -            newflags = vm_getw(env, ssp, sp + 4);
> -            ADD16(env->regs[R_ESP], 6);
> -        }
> -        env->eip = newip;
> -        cpu_x86_load_seg(env, R_CS, newcs);
> -        CHECK_IF_IN_TRAP();
> -        if (data32) {
> -            if (set_vflags_long(newflags, env))
> -                return;
> -        } else {
> -            if (set_vflags_short(newflags, env))
> -                return;
> -        }
> -        VM86_FAULT_RETURN;
> -
> -    case 0xfa: /* cli */
> -        env->eip = ip;
> -        clear_IF(env);
> -        VM86_FAULT_RETURN;
> -
> -    case 0xfb: /* sti */
> -        env->eip = ip;
> -        if (set_IF(env))
> -            return;
> -        VM86_FAULT_RETURN;
> -
> -    default:
> -        /* real VM86 GPF exception */
> -        return_to_32bit(env, TARGET_VM86_UNKNOWN);
> -        break;
> -    }
> -}

FYI, looks like this broke compiling with Clang:

../../devel/qemu/linux-user/vm86.c:50:20: error: unused function 'vm_putl' 
[-Werror,-Wunused-function]
    50 | static inline void vm_putl(CPUX86State *env, uint32_t segptr,
       |                    ^~~~~~~
../../devel/qemu/linux-user/vm86.c:56:28: error: unused function 'vm_getb' 
[-Werror,-Wunused-function]
    56 | static inline unsigned int vm_getb(CPUX86State *env,
       |                            ^~~~~~~
../../devel/qemu/linux-user/vm86.c:62:28: error: unused function 'vm_getw' 
[-Werror,-Wunused-function]
    62 | static inline unsigned int vm_getw(CPUX86State *env,
       |                            ^~~~~~~
../../devel/qemu/linux-user/vm86.c:68:28: error: unused function 'vm_getl' 
[-Werror,-Wunused-function]
    68 | static inline unsigned int vm_getl(CPUX86State *env,
       |                            ^~~~~~~
../../devel/qemu/linux-user/vm86.c:165:19: error: unused function 
'set_vflags_long' [-Werror,-Wunused-function]
   165 | static inline int set_vflags_long(unsigned long eflags, CPUX86State 
*env)
       |                   ^~~~~~~~~~~~~~~
../../devel/qemu/linux-user/vm86.c:179:19: error: unused function 
'set_vflags_short' [-Werror,-Wunused-function]
   179 | static inline int set_vflags_short(unsigned short flags, 
CPUX86State *env)
       |                   ^~~~~~~~~~~~~~~~
6 errors generated.

Should be easy to fix, I guess..

  Thomas