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| author | Laurent Vivier <Laurent.Vivier@bull.net> | 2007-09-18 11:27:37 +0200 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2008-01-30 17:52:47 +0200 |
| commit | 3427318fd2244737a466a06a93c5fe579852f871 (patch) | |
| tree | 7c6760dbbdd067498c470e6e4f711e5baeef491c /drivers/kvm/kvm_main.c | |
| parent | 1be3aa47182e94944e57b176a5c4ee4e74f1ce33 (diff) | |
| download | lwn-3427318fd2244737a466a06a93c5fe579852f871.tar.gz lwn-3427318fd2244737a466a06a93c5fe579852f871.zip | |
KVM: Call x86_decode_insn() only when needed
Move emulate_ctxt to kvm_vcpu to keep emulate context when we exit from kvm
module. Call x86_decode_insn() only when needed. Modify x86_emulate_insn() to
not modify the context if it must be re-entered.
Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'drivers/kvm/kvm_main.c')
| -rw-r--r-- | drivers/kvm/kvm_main.c | 77 |
1 files changed, 44 insertions, 33 deletions
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 800ab5028ed3..710483669f34 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -1251,45 +1251,56 @@ struct x86_emulate_ops emulate_ops = { int emulate_instruction(struct kvm_vcpu *vcpu, struct kvm_run *run, unsigned long cr2, - u16 error_code) + u16 error_code, + int no_decode) { - struct x86_emulate_ctxt emulate_ctxt; - int r; - int cs_db, cs_l; + int r = 0; vcpu->mmio_fault_cr2 = cr2; kvm_x86_ops->cache_regs(vcpu); - kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l); - - emulate_ctxt.vcpu = vcpu; - emulate_ctxt.eflags = kvm_x86_ops->get_rflags(vcpu); - emulate_ctxt.cr2 = cr2; - emulate_ctxt.mode = (emulate_ctxt.eflags & X86_EFLAGS_VM) - ? X86EMUL_MODE_REAL : cs_l - ? X86EMUL_MODE_PROT64 : cs_db - ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16; - - if (emulate_ctxt.mode == X86EMUL_MODE_PROT64) { - emulate_ctxt.cs_base = 0; - emulate_ctxt.ds_base = 0; - emulate_ctxt.es_base = 0; - emulate_ctxt.ss_base = 0; - } else { - emulate_ctxt.cs_base = get_segment_base(vcpu, VCPU_SREG_CS); - emulate_ctxt.ds_base = get_segment_base(vcpu, VCPU_SREG_DS); - emulate_ctxt.es_base = get_segment_base(vcpu, VCPU_SREG_ES); - emulate_ctxt.ss_base = get_segment_base(vcpu, VCPU_SREG_SS); - } - - emulate_ctxt.gs_base = get_segment_base(vcpu, VCPU_SREG_GS); - emulate_ctxt.fs_base = get_segment_base(vcpu, VCPU_SREG_FS); - vcpu->mmio_is_write = 0; vcpu->pio.string = 0; - r = x86_decode_insn(&emulate_ctxt, &emulate_ops); + + if (!no_decode) { + int cs_db, cs_l; + kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l); + + vcpu->emulate_ctxt.vcpu = vcpu; + vcpu->emulate_ctxt.eflags = kvm_x86_ops->get_rflags(vcpu); + vcpu->emulate_ctxt.cr2 = cr2; + vcpu->emulate_ctxt.mode = + (vcpu->emulate_ctxt.eflags & X86_EFLAGS_VM) + ? X86EMUL_MODE_REAL : cs_l + ? X86EMUL_MODE_PROT64 : cs_db + ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16; + + if (vcpu->emulate_ctxt.mode == X86EMUL_MODE_PROT64) { + vcpu->emulate_ctxt.cs_base = 0; + vcpu->emulate_ctxt.ds_base = 0; + vcpu->emulate_ctxt.es_base = 0; + vcpu->emulate_ctxt.ss_base = 0; + } else { + vcpu->emulate_ctxt.cs_base = + get_segment_base(vcpu, VCPU_SREG_CS); + vcpu->emulate_ctxt.ds_base = + get_segment_base(vcpu, VCPU_SREG_DS); + vcpu->emulate_ctxt.es_base = + get_segment_base(vcpu, VCPU_SREG_ES); + vcpu->emulate_ctxt.ss_base = + get_segment_base(vcpu, VCPU_SREG_SS); + } + + vcpu->emulate_ctxt.gs_base = + get_segment_base(vcpu, VCPU_SREG_GS); + vcpu->emulate_ctxt.fs_base = + get_segment_base(vcpu, VCPU_SREG_FS); + + r = x86_decode_insn(&vcpu->emulate_ctxt, &emulate_ops); + } + if (r == 0) - r = x86_emulate_insn(&emulate_ctxt, &emulate_ops); + r = x86_emulate_insn(&vcpu->emulate_ctxt, &emulate_ops); if (vcpu->pio.string) return EMULATE_DO_MMIO; @@ -1313,7 +1324,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu, } kvm_x86_ops->decache_regs(vcpu); - kvm_x86_ops->set_rflags(vcpu, emulate_ctxt.eflags); + kvm_x86_ops->set_rflags(vcpu, vcpu->emulate_ctxt.eflags); if (vcpu->mmio_is_write) { vcpu->mmio_needed = 0; @@ -2055,7 +2066,7 @@ static int kvm_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) vcpu->mmio_read_completed = 1; vcpu->mmio_needed = 0; r = emulate_instruction(vcpu, kvm_run, - vcpu->mmio_fault_cr2, 0); + vcpu->mmio_fault_cr2, 0, 1); if (r == EMULATE_DO_MMIO) { /* * Read-modify-write. Back to userspace. |