| Message ID | 1397174612-17373-4-git-send-email-bsd@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Il 10/04/2014 20:03, Bandan Das ha scritto: > - if (ctxt->rex_prefix) { > - ctxt->modrm_reg = (ctxt->rex_prefix & 4) << 1; /* REX.R */ > - index_reg = (ctxt->rex_prefix & 2) << 2; /* REX.X */ > - ctxt->modrm_rm = base_reg = (ctxt->rex_prefix & 1) << 3; /* REG.B */ > - } > + index_reg = (ctxt->rex_prefix << 2) & 8; /* REX.X */ > + base_reg = (ctxt->rex_prefix << 3) & 8; /* REG.B */ This is REX.B (preexisting typo), and please leave REX.R here too for clarity. Also, the function is "decode_modrm", not "decode_rm" (in the commit message). Otherwise the series seems okay from a somewhat cursory review. Paolo > > - ctxt->modrm_mod |= (ctxt->modrm & 0xc0) >> 6; > - ctxt->modrm_reg |= (ctxt->modrm & 0x38) >> 3; > - ctxt->modrm_rm |= (ctxt->modrm & 0x07); > + ctxt->modrm_mod = (ctxt->modrm & 0xc0) >> 6; > + ctxt->modrm_reg = ((ctxt->rex_prefix << 1) & 8) | /* REX.R */ > + ((ctxt->modrm & 0x38) >> 3); > + ctxt->modrm_rm = base_reg | (ctxt->modrm & 0x07); > ctxt->modrm_seg = VCPU_SREG_DS; > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index a6d9892..9cbaba2 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1064,19 +1064,17 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, struct operand *op) { u8 sib; - int index_reg = 0, base_reg = 0, scale; + int index_reg, base_reg, scale; int rc = X86EMUL_CONTINUE; ulong modrm_ea = 0; - if (ctxt->rex_prefix) { - ctxt->modrm_reg = (ctxt->rex_prefix & 4) << 1; /* REX.R */ - index_reg = (ctxt->rex_prefix & 2) << 2; /* REX.X */ - ctxt->modrm_rm = base_reg = (ctxt->rex_prefix & 1) << 3; /* REG.B */ - } + index_reg = (ctxt->rex_prefix << 2) & 8; /* REX.X */ + base_reg = (ctxt->rex_prefix << 3) & 8; /* REG.B */ - ctxt->modrm_mod |= (ctxt->modrm & 0xc0) >> 6; - ctxt->modrm_reg |= (ctxt->modrm & 0x38) >> 3; - ctxt->modrm_rm |= (ctxt->modrm & 0x07); + ctxt->modrm_mod = (ctxt->modrm & 0xc0) >> 6; + ctxt->modrm_reg = ((ctxt->rex_prefix << 1) & 8) | /* REX.R */ + ((ctxt->modrm & 0x38) >> 3); + ctxt->modrm_rm = base_reg | (ctxt->modrm & 0x07); ctxt->modrm_seg = VCPU_SREG_DS; if (ctxt->modrm_mod == 3) {
Remove the if conditional - that will help us avoid an "else initialize to 0" Also, rearrange operators for slightly better code. Signed-off-by: Bandan Das <bsd@redhat.com> --- arch/x86/kvm/emulate.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-)