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| author |   Avi Kivity <avi@qumranet.com> | 2008-06-22 16:22:51 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2008-07-20 12:42:35 +0300 |
| commit | 7a5b56dfd3a682a51fc84682290d5147872a8e99 (patch) | |
| tree | f7b6f0e746df3c43ab8317d1c4b585334808e5fb /arch/x86/kvm/x86.c | |
| parent | KVM: x86 emulator: avoid segment base adjust for lea (diff) | |
| download | linux-dev-7a5b56dfd3a682a51fc84682290d5147872a8e99.tar.xz linux-dev-7a5b56dfd3a682a51fc84682290d5147872a8e99.zip | |
KVM: x86 emulator: lazily evaluate segment registers
Instead of prefetching all segment bases before emulation, read them at the
last moment. Since most of them are unneeded, we save some cycles on
Intel machines where this is a bit expensive.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 21 |
1 files changed, 0 insertions, 21 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d1db5aa5c7f4..f726ba79fd3a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2126,27 +2126,6 @@ int emulate_instruction(struct kvm_vcpu *vcpu, ? X86EMUL_MODE_PROT64 : cs_db ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16; - if (vcpu->arch.emulate_ctxt.mode == X86EMUL_MODE_PROT64) { - vcpu->arch.emulate_ctxt.cs_base = 0; - vcpu->arch.emulate_ctxt.ds_base = 0; - vcpu->arch.emulate_ctxt.es_base = 0; - vcpu->arch.emulate_ctxt.ss_base = 0; - } else { - vcpu->arch.emulate_ctxt.cs_base = - get_segment_base(vcpu, VCPU_SREG_CS); - vcpu->arch.emulate_ctxt.ds_base = - get_segment_base(vcpu, VCPU_SREG_DS); - vcpu->arch.emulate_ctxt.es_base = - get_segment_base(vcpu, VCPU_SREG_ES); - vcpu->arch.emulate_ctxt.ss_base = - get_segment_base(vcpu, VCPU_SREG_SS); - } - - vcpu->arch.emulate_ctxt.gs_base = - get_segment_base(vcpu, VCPU_SREG_GS); - vcpu->arch.emulate_ctxt.fs_base = - get_segment_base(vcpu, VCPU_SREG_FS); - r = x86_decode_insn(&vcpu->arch.emulate_ctxt, &emulate_ops); /* Reject the instructions other than VMCALL/VMMCALL when |