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authorBandan Das <bsd@redhat.com>2014-04-16 12:46:14 -0400
committerPaolo Bonzini <pbonzini@redhat.com>2014-07-11 09:14:01 +0200
commit41061cdb98a0bec464278b4db8e894a3121671f5 (patch)
treeda1cd3e8f52f23fe8dd614b38474065f5b9f3ca1 /arch/x86/kvm
parent573e80fe04db1aa44e8303037f65716ba5c3a343 (diff)
downloadlinux-41061cdb98a0bec464278b4db8e894a3121671f5.tar.gz
KVM: emulate: do not initialize memopp
rip_relative is only set if decode_modrm runs, and if you have ModRM you will also have a memopp. We can then access memopp unconditionally. Note that rip_relative cannot be hoisted up to decode_modrm, or you break "mov $0, xyz(%rip)". Also, move typecast on "out of range value" of mem.ea to decode_modrm. Together, all these optimizations save about 50 cycles on each emulated instructions (4-6%). Signed-off-by: Bandan Das <bsd@redhat.com> [Fix immediate operands with rip-relative addressing. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r--arch/x86/kvm/emulate.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 08badf638fb..390400a54a9 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1177,6 +1177,9 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt,
}
}
op->addr.mem.ea = modrm_ea;
+ if (ctxt->ad_bytes != 8)
+ ctxt->memop.addr.mem.ea = (u32)ctxt->memop.addr.mem.ea;
+
done:
return rc;
}
@@ -4425,9 +4428,6 @@ done_prefixes:
ctxt->memop.addr.mem.seg = ctxt->seg_override;
- if (ctxt->memop.type == OP_MEM && ctxt->ad_bytes != 8)
- ctxt->memop.addr.mem.ea = (u32)ctxt->memop.addr.mem.ea;
-
/*
* Decode and fetch the source operand: register, memory
* or immediate.
@@ -4448,7 +4448,7 @@ done_prefixes:
rc = decode_operand(ctxt, &ctxt->dst, (ctxt->d >> DstShift) & OpMask);
done:
- if (ctxt->memopp && ctxt->memopp->type == OP_MEM && ctxt->rip_relative)
+ if (ctxt->rip_relative)
ctxt->memopp->addr.mem.ea += ctxt->_eip;
return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK;