diff options
| author | Wei Huang <wei.huang2@amd.com> | 2021-01-26 03:18:28 -0500 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-02-04 05:27:27 -0500 |
| commit | 4aa2691dcbd38ce1c461188799d863398dd2865d (patch) | |
| tree | c6061aadf5a188296a95c3d7edad8e6edafaa7c5 /arch/x86/kvm/x86.c | |
| parent | 9a3ecd5e2aa10af18d0d5a055122d6cc0b0944c7 (diff) | |
| download | lwn-4aa2691dcbd38ce1c461188799d863398dd2865d.tar.gz lwn-4aa2691dcbd38ce1c461188799d863398dd2865d.zip | |
KVM: x86: Factor out x86 instruction emulation with decoding
Move the instruction decode part out of x86_emulate_instruction() for it
to be used in other places. Also kvm_clear_exception_queue() is moved
inside the if-statement as it doesn't apply when KVM are coming back from
userspace.
Co-developed-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Wei Huang <wei.huang2@amd.com>
Message-Id: <20210126081831.570253-2-wei.huang2@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 62 |
1 files changed, 39 insertions, 23 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index fae4ccbd767b..ae8efb0442cf 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7317,6 +7317,42 @@ static bool is_vmware_backdoor_opcode(struct x86_emulate_ctxt *ctxt) return false; } +/* + * Decode to be emulated instruction. Return EMULATION_OK if success. + */ +int x86_decode_emulated_instruction(struct kvm_vcpu *vcpu, int emulation_type, + void *insn, int insn_len) +{ + int r = EMULATION_OK; + struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt; + + init_emulate_ctxt(vcpu); + + /* + * We will reenter on the same instruction since we do not set + * complete_userspace_io. This does not handle watchpoints yet, + * those would be handled in the emulate_ops. + */ + if (!(emulation_type & EMULTYPE_SKIP) && + kvm_vcpu_check_breakpoint(vcpu, &r)) + return r; + + ctxt->interruptibility = 0; + ctxt->have_exception = false; + ctxt->exception.vector = -1; + ctxt->perm_ok = false; + + ctxt->ud = emulation_type & EMULTYPE_TRAP_UD; + + r = x86_decode_insn(ctxt, insn, insn_len); + + trace_kvm_emulate_insn_start(vcpu); + ++vcpu->stat.insn_emulation; + + return r; +} +EXPORT_SYMBOL_GPL(x86_decode_emulated_instruction); + int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, int emulation_type, void *insn, int insn_len) { @@ -7336,32 +7372,12 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, */ write_fault_to_spt = vcpu->arch.write_fault_to_shadow_pgtable; vcpu->arch.write_fault_to_shadow_pgtable = false; - kvm_clear_exception_queue(vcpu); if (!(emulation_type & EMULTYPE_NO_DECODE)) { - init_emulate_ctxt(vcpu); - - /* - * We will reenter on the same instruction since - * we do not set complete_userspace_io. This does not - * handle watchpoints yet, those would be handled in - * the emulate_ops. - */ - if (!(emulation_type & EMULTYPE_SKIP) && - kvm_vcpu_check_breakpoint(vcpu, &r)) - return r; - - ctxt->interruptibility = 0; - ctxt->have_exception = false; - ctxt->exception.vector = -1; - ctxt->perm_ok = false; - - ctxt->ud = emulation_type & EMULTYPE_TRAP_UD; - - r = x86_decode_insn(ctxt, insn, insn_len); + kvm_clear_exception_queue(vcpu); - trace_kvm_emulate_insn_start(vcpu); - ++vcpu->stat.insn_emulation; + r = x86_decode_emulated_instruction(vcpu, emulation_type, + insn, insn_len); if (r != EMULATION_OK) { if ((emulation_type & EMULTYPE_TRAP_UD) || (emulation_type & EMULTYPE_TRAP_UD_FORCED)) { |