From e46479f852adab6027e4950d69400d967bf7bc6f Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Sun, 11 Apr 2010 13:05:16 +0300 Subject: [PATCH] KVM: Trace emulated instructions Log emulated instructions in ftrace, especially if they failed. Signed-off-by: Avi Kivity Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/trace.h | 86 ++++++++++++++++++++++++++++++++++++++++++++ arch/x86/kvm/x86.c | 4 +++ 2 files changed, 90 insertions(+) diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h index 32c912c40bf8..a6544b8e7c0f 100644 --- a/arch/x86/kvm/trace.h +++ b/arch/x86/kvm/trace.h @@ -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 diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 247e805a041e..33a40c544c7a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -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; }