[PATCH 1/3] KVM: trace mmio read event properly

[Xiao Guangrong]

In current code, we use KVM_TRACE_MMIO_READ to trace mmio read event which
only can be completed immediately, instead of it, we trace the time when
read event occur, then cooperate with then later patch, we can know the time
of mmio read emulation

Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx>
---
 arch/x86/kvm/x86.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c95ca2d..0d41cfc 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3432,7 +3432,6 @@ static int vcpu_mmio_read(struct kvm_vcpu *vcpu, gpa_t addr, int len, void *v)
 		      !kvm_iodevice_read(&vcpu->arch.apic->dev, addr, n, v))
 		    && kvm_io_bus_read(vcpu->kvm, KVM_MMIO_BUS, addr, n, v))
 			break;
-		trace_kvm_mmio(KVM_TRACE_MMIO_READ, n, addr, *(u64 *)v);
 		handled += n;
 		addr += n;
 		len -= n;
@@ -3658,8 +3657,6 @@ static int read_prepare(struct kvm_vcpu *vcpu, void *val, int bytes)
 {
 	if (vcpu->mmio_read_completed) {
 		memcpy(val, vcpu->mmio_data, bytes);
-		trace_kvm_mmio(KVM_TRACE_MMIO_READ, bytes,
-			       vcpu->mmio_phys_addr, *(u64 *)val);
 		vcpu->mmio_read_completed = 0;
 		return 1;
 	}
@@ -3681,7 +3678,6 @@ static int write_emulate(struct kvm_vcpu *vcpu, gpa_t gpa,

 static int write_mmio(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes, void *val)
 {
-	trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, bytes, gpa, *(u64 *)val);
 	return vcpu_mmio_write(vcpu, gpa, bytes, val);
 }

@@ -3744,6 +3740,8 @@ mmio:
 	/*
 	 * Is this MMIO handled locally?
 	 */
+	trace_kvm_mmio(write ? KVM_TRACE_MMIO_WRITE : KVM_TRACE_MMIO_READ,
+			bytes, gpa, *(u64 *)val);
 	handled = ops->read_write_mmio(vcpu, gpa, bytes, val);
 	if (handled == bytes)
 		return X86EMUL_CONTINUE;
-- 
1.7.7.5

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