Commit 59200273 authored by Avi Kivity's avatar Avi Kivity Committed by Marcelo Tosatti
Browse files

KVM: Trace failed msr reads and writes 



Record failed msrs reads and writes, and the fact that they failed as well.

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 6e7d1529

arch/x86/kvm/svm.c

+8 −5
Original line number Diff line number Diff line
@@ -2177,9 +2177,10 @@ static int rdmsr_interception(struct vcpu_svm *svm) 
	u32 ecx = svm->vcpu.arch.regs[VCPU_REGS_RCX];

	u64 data;



	if (svm_get_msr(&svm->vcpu, ecx, &data))

	if (svm_get_msr(&svm->vcpu, ecx, &data)) {

		trace_kvm_msr_read_ex(ecx);

		kvm_inject_gp(&svm->vcpu, 0);

	else {

	} else {

		trace_kvm_msr_read(ecx, data);



		svm->vcpu.arch.regs[VCPU_REGS_RAX] = data & 0xffffffff;
@@ -2271,13 +2272,15 @@ static int wrmsr_interception(struct vcpu_svm *svm) 
	u64 data = (svm->vcpu.arch.regs[VCPU_REGS_RAX] & -1u)

		| ((u64)(svm->vcpu.arch.regs[VCPU_REGS_RDX] & -1u) << 32);



	trace_kvm_msr_write(ecx, data);



	svm->next_rip = kvm_rip_read(&svm->vcpu) + 2;

	if (svm_set_msr(&svm->vcpu, ecx, data))

	if (svm_set_msr(&svm->vcpu, ecx, data)) {

		trace_kvm_msr_write_ex(ecx, data);

		kvm_inject_gp(&svm->vcpu, 0);

	else

	} else {

		trace_kvm_msr_write(ecx, data);

		skip_emulated_instruction(&svm->vcpu);

	}

	return 1;

}

arch/x86/kvm/trace.h

+11 −6
Original line number Diff line number Diff line
@@ -246,28 +246,33 @@ TRACE_EVENT(kvm_page_fault, 
 * Tracepoint for guest MSR access.

 */

TRACE_EVENT(kvm_msr,

	TP_PROTO(unsigned write, u32 ecx, u64 data),

	TP_ARGS(write, ecx, data),

	TP_PROTO(unsigned write, u32 ecx, u64 data, bool exception),

	TP_ARGS(write, ecx, data, exception),



	TP_STRUCT__entry(

		__field(	unsigned,	write		)

		__field(	u32,		ecx		)

		__field(	u64,		data		)

		__field(	u8,		exception	)

	),



	TP_fast_assign(

		__entry->write		= write;

		__entry->ecx		= ecx;

		__entry->data		= data;

		__entry->exception	= exception;

	),



	TP_printk("msr_%s %x = 0x%llx",

	TP_printk("msr_%s %x = 0x%llx%s",

		  __entry->write ? "write" : "read",

		  __entry->ecx, __entry->data)

		  __entry->ecx, __entry->data,

		  __entry->exception ? " (#GP)" : "")

);



#define trace_kvm_msr_read(ecx, data)		trace_kvm_msr(0, ecx, data)

#define trace_kvm_msr_write(ecx, data)		trace_kvm_msr(1, ecx, data)

#define trace_kvm_msr_read(ecx, data)      trace_kvm_msr(0, ecx, data, false)

#define trace_kvm_msr_write(ecx, data)     trace_kvm_msr(1, ecx, data, false)

#define trace_kvm_msr_read_ex(ecx)         trace_kvm_msr(0, ecx, 0, true)

#define trace_kvm_msr_write_ex(ecx, data)  trace_kvm_msr(1, ecx, data, true)



/*

 * Tracepoint for guest CR access.

arch/x86/kvm/vmx.c

+3 −2
Original line number Diff line number Diff line
@@ -3158,6 +3158,7 @@ static int handle_rdmsr(struct kvm_vcpu *vcpu) 
	u64 data;



	if (vmx_get_msr(vcpu, ecx, &data)) {

		trace_kvm_msr_read_ex(ecx);

		kvm_inject_gp(vcpu, 0);

		return 1;

	}
@@ -3177,13 +3178,13 @@ static int handle_wrmsr(struct kvm_vcpu *vcpu) 
	u64 data = (vcpu->arch.regs[VCPU_REGS_RAX] & -1u)

		| ((u64)(vcpu->arch.regs[VCPU_REGS_RDX] & -1u) << 32);



	trace_kvm_msr_write(ecx, data);



	if (vmx_set_msr(vcpu, ecx, data) != 0) {

		trace_kvm_msr_write_ex(ecx, data);

		kvm_inject_gp(vcpu, 0);

		return 1;

	}



	trace_kvm_msr_write(ecx, data);

	skip_emulated_instruction(vcpu);

	return 1;

}