On Thu, Sep 08, 2022, Liam Ni wrote:
> From: Liam Ni <zhiguangni01@xxxxxxxxx>
>
> Refactor decode_register_operand() to get the ModR/M register if and
> only if the instruction uses a ModR/M encoding to make it more obvious
> how the register operand is retrieved.
>
> Signed-off-by: Liam Ni <zhiguangni01@xxxxxxxxx>
> ---
Pushed to branch `for_paolo/6.1` at:
https://github.com/sean-jc/linux.git
with the below nit sqaushed. Unless you hear otherwise, it will make its way to
kvm/queue "soon".
Note, the commit IDs are not guaranteed to be stable.
> arch/x86/kvm/emulate.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
> index f092c54d1a2f..879b52af763a 100644
> --- a/arch/x86/kvm/emulate.c
> +++ b/arch/x86/kvm/emulate.c
> @@ -1137,9 +1137,11 @@ static int em_fnstsw(struct x86_emulate_ctxt *ctxt)
> static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
> struct operand *op)
> {
> - unsigned reg = ctxt->modrm_reg;
> + unsigned int reg;
>
> - if (!(ctxt->d & ModRM))
> + if ((ctxt->d & ModRM))
Only need one set of parentheses.
> + reg = ctxt->modrm_reg;
> + else
> reg = (ctxt->b & 7) | ((ctxt->rex_prefix & 1) << 3);
>
> if (ctxt->d & Sse) {
> --
> 2.34.1
>
