Change emulate_rdmsr() and emulate_wrmsr() to return 0 on sucess and errno on

failure. The conversion from the return value to HANDLED or UNHANDLED can be
done locally in vmx_exit_process().

Obtained from: NetApp

3 files changed, 37 insertions, 65 deletions

diff --git a/sys/amd64/vmm/intel/vmx.c b/sys/amd64/vmm/intel/vmx.c
index b185c57..af4a03f 100644
--- a/sys/amd64/vmm/intel/vmx.c
+++ b/sys/amd64/vmm/intel/vmx.c
@@ -1214,23 +1214,25 @@ vmx_exit_process(struct vmx *vmx, int vcpu, struct vm_exit *vmexit)
 		break;
 	case EXIT_REASON_RDMSR:
 		ecx = vmxctx->guest_rcx;
-		handled = emulate_rdmsr(vmx->vm, vcpu, ecx);
-		if (!handled) {
+		error = emulate_rdmsr(vmx->vm, vcpu, ecx);
+		if (error) {
 			vmexit->exitcode = VM_EXITCODE_RDMSR;
 			vmexit->u.msr.code = ecx;
-		}
+		} else
+			handled = 1;
 		break;
 	case EXIT_REASON_WRMSR:
 		eax = vmxctx->guest_rax;
 		ecx = vmxctx->guest_rcx;
 		edx = vmxctx->guest_rdx;
-		handled = emulate_wrmsr(vmx->vm, vcpu, ecx,
+		error = emulate_wrmsr(vmx->vm, vcpu, ecx,
 					(uint64_t)edx << 32 | eax);
-		if (!handled) {
+		if (error) {
 			vmexit->exitcode = VM_EXITCODE_WRMSR;
 			vmexit->u.msr.code = ecx;
 			vmexit->u.msr.wval = (uint64_t)edx << 32 | eax;
-		}
+		} else
+			handled = 1;
 		break;
 	case EXIT_REASON_HLT:
 		vmm_stat_incr(vmx->vm, vcpu, VMEXIT_HLT, 1);
diff --git a/sys/amd64/vmm/vmm_lapic.c b/sys/amd64/vmm/vmm_lapic.c
index dabcf06..d024b71 100644
--- a/sys/amd64/vmm/vmm_lapic.c
+++ b/sys/amd64/vmm/vmm_lapic.c
@@ -41,32 +41,6 @@ __FBSDID("$FreeBSD$");
 #include "vmm_lapic.h"
 #include "vlapic.h"
 
-static int
-lapic_write(struct vlapic *vlapic, u_int offset, uint64_t val)
-{
-	int handled;
-
-	if (vlapic_op_mem_write(vlapic, offset, DWORD, val) == 0)
-		handled = 1;
-	else
-		handled = 0;
-
-	return (handled);
-}
-
-static int
-lapic_read(struct vlapic *vlapic, u_int offset, uint64_t *rv)
-{
-	int handled;
-
-	if (vlapic_op_mem_read(vlapic, offset, DWORD, rv) == 0)
-		handled = 1;
-	else
-		handled = 0;
-
-	return (handled);
-}
-
 int
 lapic_pending_intr(struct vm *vm, int cpu)
 {
@@ -145,35 +119,41 @@ lapic_msr(u_int msr)
 int
 lapic_rdmsr(struct vm *vm, int cpu, u_int msr, uint64_t *rval)
 {
-	int handled;
+	int error;
+	u_int offset;
 	struct vlapic *vlapic;
 
 	vlapic = vm_lapic(vm, cpu);
 
 	if (msr == MSR_APICBASE) {
 		*rval = vlapic_get_apicbase(vlapic);
-		handled = 1;
-	} else
-		handled = lapic_read(vlapic, x2apic_msr_to_regoff(msr), rval);
+		error = 0;
+	} else {
+		offset = x2apic_msr_to_regoff(msr);
+		error = vlapic_op_mem_read(vlapic, offset, DWORD, rval);
+	}
 
-	return (handled);
+	return (error);
 }
 
 int
 lapic_wrmsr(struct vm *vm, int cpu, u_int msr, uint64_t val)
 {
-	int handled;
+	int error;
+	u_int offset;
 	struct vlapic *vlapic;
 
 	vlapic = vm_lapic(vm, cpu);
 
 	if (msr == MSR_APICBASE) {
 		vlapic_set_apicbase(vlapic, val);
-		handled = 1;
-	} else
-		handled = lapic_write(vlapic, x2apic_msr_to_regoff(msr), val);
+		error = 0;
+	} else {
+		offset = x2apic_msr_to_regoff(msr);
+		error = vlapic_op_mem_write(vlapic, offset, DWORD, val);
+	}
 
-	return (handled);
+	return (error);
 }
 
 int
diff --git a/sys/amd64/vmm/vmm_msr.c b/sys/amd64/vmm/vmm_msr.c
index bc67f98..d97c819 100644
--- a/sys/amd64/vmm/vmm_msr.c
+++ b/sys/amd64/vmm/vmm_msr.c
@@ -41,7 +41,7 @@ __FBSDID("$FreeBSD$");
 
 #define	VMM_MSR_F_EMULATE	0x01
 #define	VMM_MSR_F_READONLY	0x02
-#define VMM_MSR_F_INVALID	0x04
+#define VMM_MSR_F_INVALID	0x04  /* guest_msr_valid() can override this */
 
 struct vmm_msr {
 	int		num;
@@ -137,20 +137,15 @@ msr_num_to_idx(u_int num)
 int
 emulate_wrmsr(struct vm *vm, int cpu, u_int num, uint64_t val)
 {
-	int handled, idx;
+	int idx;
 	uint64_t *guest_msrs;
 
-	handled = 0;
-
 	if (lapic_msr(num))
 		return (lapic_wrmsr(vm, cpu, num, val));
 
 	idx = msr_num_to_idx(num);
-	if (idx < 0)
-		goto done;
-
-	if (invalid_msr(idx))
-		goto done;
+	if (idx < 0 || invalid_msr(idx))
+		return (EINVAL);
 
 	if (!readonly_msr(idx)) {
 		guest_msrs = vm_guest_msrs(vm, cpu);
@@ -163,31 +158,26 @@ emulate_wrmsr(struct vm *vm, int cpu, u_int num, uint64_t val)
 			wrmsr(vmm_msr[idx].num, val);
 	}
 
-	handled = 1;
-done:
-	return (handled);
+	return (0);
 }
 
 int
 emulate_rdmsr(struct vm *vm, int cpu, u_int num)
 {
-	int error, handled, idx;
+	int error, idx;
 	uint32_t eax, edx;
 	uint64_t result, *guest_msrs;
 
-	handled = 0;
-
 	if (lapic_msr(num)) {
-		handled = lapic_rdmsr(vm, cpu, num, &result);
+		error = lapic_rdmsr(vm, cpu, num, &result);
 		goto done;
 	}
 
 	idx = msr_num_to_idx(num);
-	if (idx < 0)
-		goto done;
-
-	if (invalid_msr(idx))
+	if (idx < 0 || invalid_msr(idx)) {
+		error = EINVAL;
 		goto done;
+	}
 
 	guest_msrs = vm_guest_msrs(vm, cpu);
 	result = guest_msrs[idx];
@@ -202,10 +192,10 @@ emulate_rdmsr(struct vm *vm, int cpu, u_int num)
 		      result, rdmsr(num));
 	}
 
-	handled = 1;
+	error = 0;
 
 done:
-	if (handled) {
+	if (error == 0) {
 		eax = result;
 		edx = result >> 32;
 		error = vm_set_register(vm, cpu, VM_REG_GUEST_RAX, eax);
@@ -215,7 +205,7 @@ done:
 		if (error)
 			panic("vm_set_register(rdx) error %d", error);
 	}
-	return (handled);
+	return (error);
 }
 
 void