KVM: PPC: Remove DCR handling

DCR handling was only needed for 440 KVM. Since we removed it, we can also
remove handling of DCR accesses.

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

Documentation/virtual/kvm/api.txt

@@ -2613,8 +2613,8 @@ The 'data' member contains, in its first 'len' bytes, the value as it would
 appear if the VCPU performed a load or store of the appropriate width directly
 to the byte array.
 
-NOTE: For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_DCR,
-      KVM_EXIT_PAPR and KVM_EXIT_EPR the corresponding
+NOTE: For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI KVM_EXIT_PAPR and
+      KVM_EXIT_EPR the corresponding
 operations are complete (and guest state is consistent) only after userspace
 has re-entered the kernel with KVM_RUN.  The kernel side will first finish
 incomplete operations and then check for pending signals.  Userspace
@@ -2685,7 +2685,7 @@ Principles of Operation Book in the Chapter for Dynamic Address Translation
 			__u8  is_write;
 		} dcr;
 
-powerpc specific.
+Deprecated - was used for 440 KVM.
 
 		/* KVM_EXIT_OSI */
 		struct {

arch/powerpc/include/asm/kvm_host.h

@@ -94,7 +94,6 @@ struct kvm_vm_stat {
 struct kvm_vcpu_stat {
 	u32 sum_exits;
 	u32 mmio_exits;
-	u32 dcr_exits;
 	u32 signal_exits;
 	u32 light_exits;
 	/* Account for special types of light exits: */
@@ -126,7 +125,6 @@ struct kvm_vcpu_stat {
 
 enum kvm_exit_types {
 	MMIO_EXITS,
-	DCR_EXITS,
 	SIGNAL_EXITS,
 	ITLB_REAL_MISS_EXITS,
 	ITLB_VIRT_MISS_EXITS,
@@ -601,8 +599,6 @@ struct kvm_vcpu_arch {
 	u8 io_gpr; /* GPR used as IO source/target */
 	u8 mmio_is_bigendian;
 	u8 mmio_sign_extend;
-	u8 dcr_needed;
-	u8 dcr_is_write;
 	u8 osi_needed;
 	u8 osi_enabled;
 	u8 papr_enabled;

arch/powerpc/include/asm/kvm_ppc.h

@@ -41,7 +41,6 @@
 enum emulation_result {
 	EMULATE_DONE,         /* no further processing */
 	EMULATE_DO_MMIO,      /* kvm_run filled with MMIO request */
-	EMULATE_DO_DCR,       /* kvm_run filled with DCR request */
 	EMULATE_FAIL,         /* can't emulate this instruction */
 	EMULATE_AGAIN,        /* something went wrong. go again */
 	EMULATE_EXIT_USER,    /* emulation requires exit to user-space */

arch/powerpc/kvm/booke.c

@@ -51,7 +51,6 @@ unsigned long kvmppc_booke_handlers;
 
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	{ "mmio",       VCPU_STAT(mmio_exits) },
-	{ "dcr",        VCPU_STAT(dcr_exits) },
 	{ "sig",        VCPU_STAT(signal_exits) },
 	{ "itlb_r",     VCPU_STAT(itlb_real_miss_exits) },
 	{ "itlb_v",     VCPU_STAT(itlb_virt_miss_exits) },
@@ -709,10 +708,6 @@ static int emulation_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
 	case EMULATE_AGAIN:
 		return RESUME_GUEST;
 
-	case EMULATE_DO_DCR:
-		run->exit_reason = KVM_EXIT_DCR;
-		return RESUME_HOST;
-
 	case EMULATE_FAIL:
 		printk(KERN_CRIT "%s: emulation at %lx failed (%08x)\n",
 		       __func__, vcpu->arch.pc, vcpu->arch.last_inst);

arch/powerpc/kvm/powerpc.c

@@ -743,12 +743,6 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 #endif
 }
 
-static void kvmppc_complete_dcr_load(struct kvm_vcpu *vcpu,
-                                     struct kvm_run *run)
-{
-	kvmppc_set_gpr(vcpu, vcpu->arch.io_gpr, run->dcr.data);
-}
-
 static void kvmppc_complete_mmio_load(struct kvm_vcpu *vcpu,
                                       struct kvm_run *run)
 {
@@ -945,10 +939,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		if (!vcpu->mmio_is_write)
 			kvmppc_complete_mmio_load(vcpu, run);
 		vcpu->mmio_needed = 0;
-	} else if (vcpu->arch.dcr_needed) {
-		if (!vcpu->arch.dcr_is_write)
-			kvmppc_complete_dcr_load(vcpu, run);
-		vcpu->arch.dcr_needed = 0;
 	} else if (vcpu->arch.osi_needed) {
 		u64 *gprs = run->osi.gprs;
 		int i;

arch/powerpc/kvm/timing.c

@@ -110,7 +110,6 @@ void kvmppc_update_timing_stats(struct kvm_vcpu *vcpu)
 
 static const char *kvm_exit_names[__NUMBER_OF_KVM_EXIT_TYPES] = {
 	[MMIO_EXITS] =              "MMIO",
-	[DCR_EXITS] =               "DCR",
 	[SIGNAL_EXITS] =            "SIGNAL",
 	[ITLB_REAL_MISS_EXITS] =    "ITLBREAL",
 	[ITLB_VIRT_MISS_EXITS] =    "ITLBVIRT",

arch/powerpc/kvm/timing.h

@@ -63,9 +63,6 @@ static inline void kvmppc_account_exit_stat(struct kvm_vcpu *vcpu, int type)
 	case EMULATED_INST_EXITS:
 		vcpu->stat.emulated_inst_exits++;
 		break;
-	case DCR_EXITS:
-		vcpu->stat.dcr_exits++;
-		break;
 	case DSI_EXITS:
 		vcpu->stat.dsi_exits++;
 		break;

include/uapi/linux/kvm.h

@@ -162,7 +162,7 @@ struct kvm_pit_config {
 #define KVM_EXIT_TPR_ACCESS       12
 #define KVM_EXIT_S390_SIEIC       13
 #define KVM_EXIT_S390_RESET       14
-#define KVM_EXIT_DCR              15
+#define KVM_EXIT_DCR              15 /* deprecated */
 #define KVM_EXIT_NMI              16
 #define KVM_EXIT_INTERNAL_ERROR   17
 #define KVM_EXIT_OSI              18
@@ -268,7 +268,7 @@ struct kvm_run {
 			__u64 trans_exc_code;
 			__u32 pgm_code;
 		} s390_ucontrol;
-		/* KVM_EXIT_DCR */
+		/* KVM_EXIT_DCR (deprecated) */
 		struct {
 			__u32 dcrn;
 			__u32 data;