Re: [PATCH] x86/HVM: drop dead assignments from hvmemul_rep_{movs,stos}()

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 27 Jul 2023, Jan Beulich wrote:
> In the latter case the variable altogether is then unused and hence gets
> dropped, eliminating a Misra Rule 5.3 violation. I'm afraid I mistakenly
> introduced both assignments in 57a57465daaf ("x86/HVM: use available
> linear->phys translations in REP MOVS/STOS handling"), likely as a
> result of some re-work on the patch.
> 
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> --- a/xen/arch/x86/hvm/emulate.c
> +++ b/xen/arch/x86/hvm/emulate.c
> @@ -1861,7 +1861,6 @@ static int cf_check hvmemul_rep_movs(
>              return rc;
>      }
>  
> -    bytes = PAGE_SIZE - (daddr & ~PAGE_MASK);
>      if ( hvio->mmio_access.write_access &&
>           (hvio->mmio_gla == (daddr & PAGE_MASK)) &&
>           /* See comment above. */
> @@ -1988,7 +1987,7 @@ static int cf_check hvmemul_rep_stos(
>          container_of(ctxt, struct hvm_emulate_ctxt, ctxt);
>      struct vcpu *curr = current;
>      struct hvm_vcpu_io *hvio = &curr->arch.hvm.hvm_io;
> -    unsigned long addr, bytes;
> +    unsigned long addr;
>      paddr_t gpa;
>      p2m_type_t p2mt;
>      bool_t df = !!(ctxt->regs->eflags & X86_EFLAGS_DF);
> @@ -1998,7 +1997,6 @@ static int cf_check hvmemul_rep_stos(
>      if ( rc != X86EMUL_OKAY )
>          return rc;
>  
> -    bytes = PAGE_SIZE - (addr & ~PAGE_MASK);
>      if ( hvio->mmio_access.write_access &&
>           (hvio->mmio_gla == (addr & PAGE_MASK)) &&
>           /* See respective comment in MOVS processing. */
>