KVM: ppc: refactor instruction emulation into generic and core-specific pieces

Cores provide 3 emulation hooks, implemented for example in the new
4xx_emulate.c:
kvmppc_core_emulate_op
kvmppc_core_emulate_mtspr
kvmppc_core_emulate_mfspr

Strictly speaking the last two aren't necessary, but provide for more
informative error reporting ("unknown SPR").

Long term I'd like to have instruction decoding autogenerated from tables of
opcodes, and that way we could aggregate universal, Book E, and core-specific
instructions more easily and without redundant switch statements.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 22 insertions, 250 deletions

diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index 5fd9cf779be5..30a49f8c49b2 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -23,14 +23,13 @@
 #include <linux/string.h>
 #include <linux/kvm_host.h>
 
-#include <asm/dcr.h>
-#include <asm/dcr-regs.h>
+#include <asm/reg.h>
 #include <asm/time.h>
 #include <asm/byteorder.h>
 #include <asm/kvm_ppc.h>
 #include <asm/disassemble.h>
 
-static void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
+void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
 {
 	if (vcpu->arch.tcr & TCR_DIE) {
 		/* The decrementer ticks at the same rate as the timebase, so
@@ -46,12 +45,6 @@ static void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
 	}
 }
 
-static void kvmppc_emul_rfi(struct kvm_vcpu *vcpu)
-{
-	vcpu->arch.pc = vcpu->arch.srr0;
-	kvmppc_set_msr(vcpu, vcpu->arch.srr1);
-}
-
 /* XXX to do:
  * lhax
  * lhaux
@@ -66,18 +59,17 @@ static void kvmppc_emul_rfi(struct kvm_vcpu *vcpu)
  *
  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
  */
+/* XXX Should probably auto-generate instruction decoding for a particular core
+ * from opcode tables in the future. */
 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 {
 	u32 inst = vcpu->arch.last_inst;
 	u32 ea;
 	int ra;
 	int rb;
-	int rc;
 	int rs;
 	int rt;
-	int ws;
 	int sprn;
-	int dcrn;
 	enum emulation_result emulated = EMULATE_DONE;
 	int advance = 1;
 
@@ -88,19 +80,6 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 		advance = 0;
 		break;
 
-	case 19:
-		switch (get_xop(inst)) {
-		case 50:                                        /* rfi */
-			kvmppc_emul_rfi(vcpu);
-			advance = 0;
-			break;
-
-		default:
-			emulated = EMULATE_FAIL;
-			break;
-		}
-		break;
-
 	case 31:
 		switch (get_xop(inst)) {
 
@@ -109,27 +88,11 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 			emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 			break;
 
-		case 83:                                        /* mfmsr */
-			rt = get_rt(inst);
-			vcpu->arch.gpr[rt] = vcpu->arch.msr;
-			break;
-
 		case 87:                                        /* lbzx */
 			rt = get_rt(inst);
 			emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 			break;
 
-		case 131:                                       /* wrtee */
-			rs = get_rs(inst);
-			vcpu->arch.msr = (vcpu->arch.msr & ~MSR_EE)
-			                 | (vcpu->arch.gpr[rs] & MSR_EE);
-			break;
-
-		case 146:                                       /* mtmsr */
-			rs = get_rs(inst);
-			kvmppc_set_msr(vcpu, vcpu->arch.gpr[rs]);
-			break;
-
 		case 151:                                       /* stwx */
 			rs = get_rs(inst);
 			emulated = kvmppc_handle_store(run, vcpu,
@@ -137,11 +100,6 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 			                               4, 1);
 			break;
 
-		case 163:                                       /* wrteei */
-			vcpu->arch.msr = (vcpu->arch.msr & ~MSR_EE)
-			                 | (inst & MSR_EE);
-			break;
-
 		case 215:                                       /* stbx */
 			rs = get_rs(inst);
 			emulated = kvmppc_handle_store(run, vcpu,
@@ -182,42 +140,6 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 			vcpu->arch.gpr[ra] = ea;
 			break;
 
-		case 323:                                       /* mfdcr */
-			dcrn = get_dcrn(inst);
-			rt = get_rt(inst);
-
-			/* 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:
-				vcpu->arch.gpr[rt] = vcpu->arch.cpr0_cfgaddr;
-				break;
-			case DCRN_CPR0_CONFIG_DATA:
-				local_irq_disable();
-				mtdcr(DCRN_CPR0_CONFIG_ADDR,
-				      vcpu->arch.cpr0_cfgaddr);
-				vcpu->arch.gpr[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;
-				emulated = EMULATE_DO_DCR;
-			}
-
-			break;
-
 		case 339:                                       /* mfspr */
 			sprn = get_sprn(inst);
 			rt = get_rt(inst);
@@ -227,26 +149,8 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 				vcpu->arch.gpr[rt] = vcpu->arch.srr0; break;
 			case SPRN_SRR1:
 				vcpu->arch.gpr[rt] = vcpu->arch.srr1; break;
-			case SPRN_MMUCR:
-				vcpu->arch.gpr[rt] = vcpu->arch.mmucr; break;
-			case SPRN_PID:
-				vcpu->arch.gpr[rt] = vcpu->arch.pid; break;
-			case SPRN_IVPR:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivpr; break;
-			case SPRN_CCR0:
-				vcpu->arch.gpr[rt] = vcpu->arch.ccr0; break;
-			case SPRN_CCR1:
-				vcpu->arch.gpr[rt] = vcpu->arch.ccr1; break;
 			case SPRN_PVR:
 				vcpu->arch.gpr[rt] = vcpu->arch.pvr; break;
-			case SPRN_DEAR:
-				vcpu->arch.gpr[rt] = vcpu->arch.dear; break;
-			case SPRN_ESR:
-				vcpu->arch.gpr[rt] = vcpu->arch.esr; break;
-			case SPRN_DBCR0:
-				vcpu->arch.gpr[rt] = vcpu->arch.dbcr0; break;
-			case SPRN_DBCR1:
-				vcpu->arch.gpr[rt] = vcpu->arch.dbcr1; break;
 
 			/* Note: mftb and TBRL/TBWL are user-accessible, so
 			 * the guest can always access the real TB anyways.
@@ -267,42 +171,12 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 			/* Note: SPRG4-7 are user-readable, so we don't get
 			 * a trap. */
 
-			case SPRN_IVOR0:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[0]; break;
-			case SPRN_IVOR1:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[1]; break;
-			case SPRN_IVOR2:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[2]; break;
-			case SPRN_IVOR3:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[3]; break;
-			case SPRN_IVOR4:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[4]; break;
-			case SPRN_IVOR5:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[5]; break;
-			case SPRN_IVOR6:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[6]; break;
-			case SPRN_IVOR7:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[7]; break;
-			case SPRN_IVOR8:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[8]; break;
-			case SPRN_IVOR9:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[9]; break;
-			case SPRN_IVOR10:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[10]; break;
-			case SPRN_IVOR11:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[11]; break;
-			case SPRN_IVOR12:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[12]; break;
-			case SPRN_IVOR13:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[13]; break;
-			case SPRN_IVOR14:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[14]; break;
-			case SPRN_IVOR15:
-				vcpu->arch.gpr[rt] = vcpu->arch.ivor[15]; break;
-
 			default:
-				printk("mfspr: unknown spr %x\n", sprn);
-				vcpu->arch.gpr[rt] = 0;
+				emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
+				if (emulated == EMULATE_FAIL) {
+					printk("mfspr: unknown spr %x\n", sprn);
+					vcpu->arch.gpr[rt] = 0;
+				}
 				break;
 			}
 			break;
@@ -332,25 +206,6 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 			vcpu->arch.gpr[ra] = ea;
 			break;
 
-		case 451:                                       /* mtdcr */
-			dcrn = get_dcrn(inst);
-			rs = get_rs(inst);
-
-			/* emulate some access in kernel */
-			switch (dcrn) {
-			case DCRN_CPR0_CONFIG_ADDR:
-				vcpu->arch.cpr0_cfgaddr = vcpu->arch.gpr[rs];
-				break;
-			default:
-				run->dcr.dcrn = dcrn;
-				run->dcr.data = vcpu->arch.gpr[rs];
-				run->dcr.is_write = 1;
-				vcpu->arch.dcr_needed = 1;
-				emulated = EMULATE_DO_DCR;
-			}
-
-			break;
-
 		case 467:                                       /* mtspr */
 			sprn = get_sprn(inst);
 			rs = get_rs(inst);
@@ -359,22 +214,6 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 				vcpu->arch.srr0 = vcpu->arch.gpr[rs]; break;
 			case SPRN_SRR1:
 				vcpu->arch.srr1 = vcpu->arch.gpr[rs]; break;
-			case SPRN_MMUCR:
-				vcpu->arch.mmucr = vcpu->arch.gpr[rs]; break;
-			case SPRN_PID:
-				kvmppc_set_pid(vcpu, vcpu->arch.gpr[rs]); break;
-			case SPRN_CCR0:
-				vcpu->arch.ccr0 = vcpu->arch.gpr[rs]; break;
-			case SPRN_CCR1:
-				vcpu->arch.ccr1 = vcpu->arch.gpr[rs]; break;
-			case SPRN_DEAR:
-				vcpu->arch.dear = vcpu->arch.gpr[rs]; break;
-			case SPRN_ESR:
-				vcpu->arch.esr = vcpu->arch.gpr[rs]; break;
-			case SPRN_DBCR0:
-				vcpu->arch.dbcr0 = vcpu->arch.gpr[rs]; break;
-			case SPRN_DBCR1:
-				vcpu->arch.dbcr1 = vcpu->arch.gpr[rs]; break;
 
 			/* XXX We need to context-switch the timebase for
 			 * watchdog and FIT. */
@@ -386,14 +225,6 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 				kvmppc_emulate_dec(vcpu);
 				break;
 
-			case SPRN_TSR:
-				vcpu->arch.tsr &= ~vcpu->arch.gpr[rs]; break;
-
-			case SPRN_TCR:
-				vcpu->arch.tcr = vcpu->arch.gpr[rs];
-				kvmppc_emulate_dec(vcpu);
-				break;
-
 			case SPRN_SPRG0:
 				vcpu->arch.sprg0 = vcpu->arch.gpr[rs]; break;
 			case SPRN_SPRG1:
@@ -403,56 +234,10 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 			case SPRN_SPRG3:
 				vcpu->arch.sprg3 = vcpu->arch.gpr[rs]; break;
 
-			/* Note: SPRG4-7 are user-readable. These values are
-			 * loaded into the real SPRGs when resuming the
-			 * guest. */
-			case SPRN_SPRG4:
-				vcpu->arch.sprg4 = vcpu->arch.gpr[rs]; break;
-			case SPRN_SPRG5:
-				vcpu->arch.sprg5 = vcpu->arch.gpr[rs]; break;
-			case SPRN_SPRG6:
-				vcpu->arch.sprg6 = vcpu->arch.gpr[rs]; break;
-			case SPRN_SPRG7:
-				vcpu->arch.sprg7 = vcpu->arch.gpr[rs]; break;
-
-			case SPRN_IVPR:
-				vcpu->arch.ivpr = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR0:
-				vcpu->arch.ivor[0] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR1:
-				vcpu->arch.ivor[1] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR2:
-				vcpu->arch.ivor[2] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR3:
-				vcpu->arch.ivor[3] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR4:
-				vcpu->arch.ivor[4] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR5:
-				vcpu->arch.ivor[5] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR6:
-				vcpu->arch.ivor[6] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR7:
-				vcpu->arch.ivor[7] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR8:
-				vcpu->arch.ivor[8] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR9:
-				vcpu->arch.ivor[9] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR10:
-				vcpu->arch.ivor[10] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR11:
-				vcpu->arch.ivor[11] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR12:
-				vcpu->arch.ivor[12] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR13:
-				vcpu->arch.ivor[13] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR14:
-				vcpu->arch.ivor[14] = vcpu->arch.gpr[rs]; break;
-			case SPRN_IVOR15:
-				vcpu->arch.ivor[15] = vcpu->arch.gpr[rs]; break;
-
 			default:
-				printk("mtspr: unknown spr %x\n", sprn);
-				emulated = EMULATE_FAIL;
+				emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
+				if (emulated == EMULATE_FAIL)
+					printk("mtspr: unknown spr %x\n", sprn);
 				break;
 			}
 			break;
@@ -483,21 +268,6 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 			                               4, 0);
 			break;
 
-		case 978:                                       /* tlbwe */
-			ra = get_ra(inst);
-			rs = get_rs(inst);
-			ws = get_ws(inst);
-			emulated = kvmppc_emul_tlbwe(vcpu, ra, rs, ws);
-			break;
-
-		case 914:                                       /* tlbsx */
-			rt = get_rt(inst);
-			ra = get_ra(inst);
-			rb = get_rb(inst);
-			rc = get_rc(inst);
-			emulated = kvmppc_emul_tlbsx(vcpu, rt, ra, rb, rc);
-			break;
-
 		case 790:                                       /* lhbrx */
 			rt = get_rt(inst);
 			emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
@@ -513,14 +283,9 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 			                               2, 0);
 			break;
 
-		case 966:                                       /* iccci */
-			break;
-
 		default:
-			printk("unknown: op %d xop %d\n", get_op(inst),
-				get_xop(inst));
+			/* Attempt core-specific emulation below. */
 			emulated = EMULATE_FAIL;
-			break;
 		}
 		break;
 
@@ -603,9 +368,16 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 		break;
 
 	default:
-		printk("unknown op %d\n", get_op(inst));
 		emulated = EMULATE_FAIL;
-		break;
+	}
+
+	if (emulated == EMULATE_FAIL) {
+		emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
+		if (emulated == EMULATE_FAIL) {
+			advance = 0;
+			printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
+			       "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
+		}
 	}
 
 	KVMTRACE_3D(PPC_INSTR, vcpu, inst, vcpu->arch.pc, emulated, entryexit);