[PATCH 2/3] KVM: PPC: 440: Implement mfdcrx

[Alexander Graf <agraf@suse.de>]

We need mfdcrx to execute properly on 460 cores.

Signed-off-by: Alexander Graf <agraf@suse.de>

---

v1 -> v2:

  - rework mfdcr into a function
---
 arch/powerpc/kvm/44x_emulate.c |   74 +++++++++++++++++++++++-----------------
 1 files changed, 43 insertions(+), 31 deletions(-)

diff --git a/arch/powerpc/kvm/44x_emulate.c b/arch/powerpc/kvm/44x_emulate.c
index 3843a75..1a793c4 100644
--- a/arch/powerpc/kvm/44x_emulate.c
+++ b/arch/powerpc/kvm/44x_emulate.c
@@ -27,6 +27,7 @@
 #include "booke.h"
 #include "44x_tlb.h"
 
+#define XOP_MFDCRX  259
 #define XOP_MFDCR   323
 #define XOP_MTDCRX  387
 #define XOP_MTDCR   451
@@ -51,6 +52,43 @@ static int emulate_mtdcr(struct kvm_vcpu *vcpu, int rs, int dcrn)
 	}
 }
 
+static int emulate_mfdcr(struct kvm_vcpu *vcpu, int rt, int dcrn)
+{
+	/* The guest may access CPR0 registers to determine the timebase
+	 * frequency, and it must know the real host frequency because it
+	 * can directly access the timebase registers.
+	 *
+	 * It would be possible to emulate those accesses in userspace,
+	 * but userspace can really only figure out the end frequency.
+	 * We could decompose that into the factors that compute it, but
+	 * that's tricky math, and it's easier to just report the real
+	 * CPR0 values.
+	 */
+	switch (dcrn) {
+	case DCRN_CPR0_CONFIG_ADDR:
+		kvmppc_set_gpr(vcpu, rt, vcpu->arch.cpr0_cfgaddr);
+		break;
+	case DCRN_CPR0_CONFIG_DATA:
+		local_irq_disable();
+		mtdcr(DCRN_CPR0_CONFIG_ADDR,
+			  vcpu->arch.cpr0_cfgaddr);
+		kvmppc_set_gpr(vcpu, rt,
+			       mfdcr(DCRN_CPR0_CONFIG_DATA));
+		local_irq_enable();
+		break;
+	default:
+		vcpu->run->dcr.dcrn = dcrn;
+		vcpu->run->dcr.data =  0;
+		vcpu->run->dcr.is_write = 0;
+		vcpu->arch.io_gpr = rt;
+		vcpu->arch.dcr_needed = 1;
+		kvmppc_account_exit(vcpu, DCR_EXITS);
+		return EMULATE_DO_DCR;
+	}
+
+	return EMULATE_DONE;
+}
+
 int kvmppc_core_emulate_op(struct kvm_run *run, struct kvm_vcpu *vcpu,
                            unsigned int inst, int *advance)
 {
@@ -68,38 +106,12 @@ int kvmppc_core_emulate_op(struct kvm_run *run, struct kvm_vcpu *vcpu,
 		switch (get_xop(inst)) {
 
 		case XOP_MFDCR:
-			/* The guest may access CPR0 registers to determine the timebase
-			 * frequency, and it must know the real host frequency because it
-			 * can directly access the timebase registers.
-			 *
-			 * It would be possible to emulate those accesses in userspace,
-			 * but userspace can really only figure out the end frequency.
-			 * We could decompose that into the factors that compute it, but
-			 * that's tricky math, and it's easier to just report the real
-			 * CPR0 values.
-			 */
-			switch (dcrn) {
-			case DCRN_CPR0_CONFIG_ADDR:
-				kvmppc_set_gpr(vcpu, rt, vcpu->arch.cpr0_cfgaddr);
-				break;
-			case DCRN_CPR0_CONFIG_DATA:
-				local_irq_disable();
-				mtdcr(DCRN_CPR0_CONFIG_ADDR,
-					  vcpu->arch.cpr0_cfgaddr);
-				kvmppc_set_gpr(vcpu, rt,
-					       mfdcr(DCRN_CPR0_CONFIG_DATA));
-				local_irq_enable();
-				break;
-			default:
-				run->dcr.dcrn = dcrn;
-				run->dcr.data =  0;
-				run->dcr.is_write = 0;
-				vcpu->arch.io_gpr = rt;
-				vcpu->arch.dcr_needed = 1;
-				kvmppc_account_exit(vcpu, DCR_EXITS);
-				emulated = EMULATE_DO_DCR;
-			}
+			emulated = emulate_mfdcr(vcpu, rt, dcrn);
+			break;
 
+		case XOP_MFDCRX:
+			emulated = emulate_mfdcr(vcpu, rt,
+					kvmppc_get_gpr(vcpu, ra));
 			break;
 
 		case XOP_MTDCR:
-- 
1.6.0.2