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KVM: Trace emulated instructions 

Log emulated instructions in ftrace, especially if they failed.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
hifive-unleashed-5.1
Avi Kivity 2010-04-11 13:05:16 +03:00
parent 2fb53ad811
commit e46479f852
2 changed files with 90 additions and 0 deletions
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86
arch/x86/kvm/trace.h
View File

@ -603,6 +603,92 @@ TRACE_EVENT(kvm_skinit,
__entry->rip, __entry->slb)
);
#define __print_insn(insn, ilen) ({ \
int i; \
const char *ret = p->buffer + p->len; \
\
for (i = 0; i < ilen; ++i) \
trace_seq_printf(p, " %02x", insn[i]); \
trace_seq_printf(p, "%c", 0); \
ret; \
})
#define KVM_EMUL_INSN_F_CR0_PE (1 << 0)
#define KVM_EMUL_INSN_F_EFL_VM (1 << 1)
#define KVM_EMUL_INSN_F_CS_D (1 << 2)
#define KVM_EMUL_INSN_F_CS_L (1 << 3)
#define kvm_trace_symbol_emul_flags \
{ 0, "real" }, \
{ KVM_EMUL_INSN_F_CR0_PE \
| KVM_EMUL_INSN_F_EFL_VM, "vm16" }, \
{ KVM_EMUL_INSN_F_CR0_PE, "prot16" }, \
{ KVM_EMUL_INSN_F_CR0_PE \
| KVM_EMUL_INSN_F_CS_D, "prot32" }, \
{ KVM_EMUL_INSN_F_CR0_PE \
| KVM_EMUL_INSN_F_CS_L, "prot64" }
#define kei_decode_mode(mode) ({ \
u8 flags = 0xff; \
switch (mode) { \
case X86EMUL_MODE_REAL: \
flags = 0; \
break; \
case X86EMUL_MODE_VM86: \
flags = KVM_EMUL_INSN_F_EFL_VM; \
break; \
case X86EMUL_MODE_PROT16: \
flags = KVM_EMUL_INSN_F_CR0_PE; \
break; \
case X86EMUL_MODE_PROT32: \
flags = KVM_EMUL_INSN_F_CR0_PE \
| KVM_EMUL_INSN_F_CS_D; \
break; \
case X86EMUL_MODE_PROT64: \
flags = KVM_EMUL_INSN_F_CR0_PE \
| KVM_EMUL_INSN_F_CS_L; \
break; \
} \
flags; \
})
TRACE_EVENT(kvm_emulate_insn,
TP_PROTO(struct kvm_vcpu *vcpu, __u8 failed),
TP_ARGS(vcpu, failed),
TP_STRUCT__entry(
__field( __u64, rip )
__field( __u32, csbase )
__field( __u8, len )
__array( __u8, insn, 15 )
__field( __u8, flags )
__field( __u8, failed )
),
TP_fast_assign(
__entry->rip = vcpu->arch.emulate_ctxt.decode.fetch.start;
__entry->csbase = kvm_x86_ops->get_segment_base(vcpu, VCPU_SREG_CS);
__entry->len = vcpu->arch.emulate_ctxt.decode.eip
- vcpu->arch.emulate_ctxt.decode.fetch.start;
memcpy(__entry->insn,
vcpu->arch.emulate_ctxt.decode.fetch.data,
15);
__entry->flags = kei_decode_mode(vcpu->arch.emulate_ctxt.mode);
__entry->failed = failed;
),
TP_printk("%x:%llx:%s (%s)%s",
__entry->csbase, __entry->rip,
__print_insn(__entry->insn, __entry->len),
__print_symbolic(__entry->flags,
kvm_trace_symbol_emul_flags),
__entry->failed ? " failed" : ""
)
);
#define trace_kvm_emulate_insn_start(vcpu) trace_kvm_emulate_insn(vcpu, 0)
#define trace_kvm_emulate_insn_failed(vcpu) trace_kvm_emulate_insn(vcpu, 1)
#endif /* _TRACE_KVM_H */
#undef TRACE_INCLUDE_PATH

4
arch/x86/kvm/x86.c
View File

@ -3718,6 +3718,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;
r = x86_decode_insn(&vcpu->arch.emulate_ctxt, &emulate_ops);
trace_kvm_emulate_insn_start(vcpu);
/* Only allow emulation of specific instructions on #UD
* (namely VMMCALL, sysenter, sysexit, syscall)*/
@ -3750,6 +3751,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
++vcpu->stat.insn_emulation;
if (r) {
++vcpu->stat.insn_emulation_fail;
trace_kvm_emulate_insn_failed(vcpu);
if (kvm_mmu_unprotect_page_virt(vcpu, cr2))
return EMULATE_DONE;
return EMULATE_FAIL;
@ -3786,6 +3788,8 @@ restart:
if (kvm_mmu_unprotect_page_virt(vcpu, cr2))
goto done;
if (!vcpu->mmio_needed) {
++vcpu->stat.insn_emulation_fail;
trace_kvm_emulate_insn_failed(vcpu);
kvm_report_emulation_failure(vcpu, "mmio");
return EMULATE_FAIL;
}