KVM: PPC: Separate loadstore emulation from priv emulation

Today the instruction emulator can get called via 2 separate code paths. It
can either be called by MMIO emulation detection code or by privileged
instruction traps.

This is bad, as both code paths prepare the environment differently. For MMIO
emulation we already know the virtual address we faulted on, so instructions
there don't have to actually fetch that information.

Split out the two separate use cases into separate files.
Signed-off-by: NAlexander Graf <agraf@suse.de>

arch/powerpc/include/asm/kvm_ppc.h

@@ -86,6 +86,7 @@ extern int kvmppc_st(struct kvm_vcpu *vcpu, ulong *eaddr, int size, void *ptr,
 		     bool data);
 extern int kvmppc_emulate_instruction(struct kvm_run *run,
                                       struct kvm_vcpu *vcpu);
+extern int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu);
 extern int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu);
 extern void kvmppc_emulate_dec(struct kvm_vcpu *vcpu);
 extern u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb);

arch/powerpc/kvm/Makefile

@@ -13,8 +13,9 @@ common-objs-y = $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o \
 CFLAGS_e500_mmu.o := -I.
 CFLAGS_e500_mmu_host.o := -I.
 CFLAGS_emulate.o  := -I.
+CFLAGS_emulate_loadstore.o  := -I.
 
-common-objs-y += powerpc.o emulate.o
+common-objs-y += powerpc.o emulate.o emulate_loadstore.o
 obj-$(CONFIG_KVM_EXIT_TIMING) += timing.o
 obj-$(CONFIG_KVM_BOOK3S_HANDLER) += book3s_exports.o
 
@@ -91,6 +92,7 @@ kvm-book3s_64-module-objs += \
 	$(KVM)/eventfd.o \
 	powerpc.o \
 	emulate.o \
+	emulate_loadstore.o \
 	book3s.o \
 	book3s_64_vio.o \
 	book3s_rtas.o \

arch/powerpc/kvm/emulate.c

@@ -207,25 +207,12 @@ static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
 	return emulated;
 }
 
-/* XXX to do:
- * lhax
- * lhaux
- * lswx
- * lswi
- * stswx
- * stswi
- * lha
- * lhau
- * lmw
- * stmw
- *
- */
 /* 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;
-	int ra, rs, rt, sprn;
+	int rs, rt, sprn;
 	enum emulation_result emulated;
 	int advance = 1;
 
@@ -238,7 +225,6 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 
 	pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
 
-	ra = get_ra(inst);
 	rs = get_rs(inst);
 	rt = get_rt(inst);
 	sprn = get_sprn(inst);
@@ -270,200 +256,24 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 #endif
 			advance = 0;
 			break;
-		case OP_31_XOP_LWZX:
-			emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
-			break;
-
-		case OP_31_XOP_LBZX:
-			emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
-			break;
-
-		case OP_31_XOP_LBZUX:
-			emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
-			kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
-			break;
-
-		case OP_31_XOP_STWX:
-			emulated = kvmppc_handle_store(run, vcpu,
-						       kvmppc_get_gpr(vcpu, rs),
-			                               4, 1);
-			break;
-
-		case OP_31_XOP_STBX:
-			emulated = kvmppc_handle_store(run, vcpu,
-						       kvmppc_get_gpr(vcpu, rs),
-			                               1, 1);
-			break;
-
-		case OP_31_XOP_STBUX:
-			emulated = kvmppc_handle_store(run, vcpu,
-						       kvmppc_get_gpr(vcpu, rs),
-			                               1, 1);
-			kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
-			break;
-
-		case OP_31_XOP_LHAX:
-			emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
-			break;
-
-		case OP_31_XOP_LHZX:
-			emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
-			break;
-
-		case OP_31_XOP_LHZUX:
-			emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
-			kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
-			break;
 
 		case OP_31_XOP_MFSPR:
 			emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt);
 			break;
 
-		case OP_31_XOP_STHX:
-			emulated = kvmppc_handle_store(run, vcpu,
-						       kvmppc_get_gpr(vcpu, rs),
-			                               2, 1);
-			break;
-
-		case OP_31_XOP_STHUX:
-			emulated = kvmppc_handle_store(run, vcpu,
-						       kvmppc_get_gpr(vcpu, rs),
-			                               2, 1);
-			kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
-			break;
-
 		case OP_31_XOP_MTSPR:
 			emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs);
 			break;
 
-		case OP_31_XOP_DCBST:
-		case OP_31_XOP_DCBF:
-		case OP_31_XOP_DCBI:
-			/* Do nothing. The guest is performing dcbi because
-			 * hardware DMA is not snooped by the dcache, but
-			 * emulated DMA either goes through the dcache as
-			 * normal writes, or the host kernel has handled dcache
-			 * coherence. */
-			break;
-
-		case OP_31_XOP_LWBRX:
-			emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
-			break;
-
 		case OP_31_XOP_TLBSYNC:
 			break;
 
-		case OP_31_XOP_STWBRX:
-			emulated = kvmppc_handle_store(run, vcpu,
-						       kvmppc_get_gpr(vcpu, rs),
-			                               4, 0);
-			break;
-
-		case OP_31_XOP_LHBRX:
-			emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
-			break;
-
-		case OP_31_XOP_STHBRX:
-			emulated = kvmppc_handle_store(run, vcpu,
-						       kvmppc_get_gpr(vcpu, rs),
-			                               2, 0);
-			break;
-
 		default:
 			/* Attempt core-specific emulation below. */
 			emulated = EMULATE_FAIL;
 		}
 		break;
 
-	case OP_LWZ:
-		emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
-		break;
-
-	/* TBD: Add support for other 64 bit load variants like ldu, ldux, ldx etc. */
-	case OP_LD:
-		rt = get_rt(inst);
-		emulated = kvmppc_handle_load(run, vcpu, rt, 8, 1);
-		break;
-
-	case OP_LWZU:
-		emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
-		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
-		break;
-
-	case OP_LBZ:
-		emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
-		break;
-
-	case OP_LBZU:
-		emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
-		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
-		break;
-
-	case OP_STW:
-		emulated = kvmppc_handle_store(run, vcpu,
-					       kvmppc_get_gpr(vcpu, rs),
-		                               4, 1);
-		break;
-
-	/* TBD: Add support for other 64 bit store variants like stdu, stdux, stdx etc. */
-	case OP_STD:
-		rs = get_rs(inst);
-		emulated = kvmppc_handle_store(run, vcpu,
-					       kvmppc_get_gpr(vcpu, rs),
-		                               8, 1);
-		break;
-
-	case OP_STWU:
-		emulated = kvmppc_handle_store(run, vcpu,
-					       kvmppc_get_gpr(vcpu, rs),
-		                               4, 1);
-		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
-		break;
-
-	case OP_STB:
-		emulated = kvmppc_handle_store(run, vcpu,
-					       kvmppc_get_gpr(vcpu, rs),
-		                               1, 1);
-		break;
-
-	case OP_STBU:
-		emulated = kvmppc_handle_store(run, vcpu,
-					       kvmppc_get_gpr(vcpu, rs),
-		                               1, 1);
-		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
-		break;
-
-	case OP_LHZ:
-		emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
-		break;
-
-	case OP_LHZU:
-		emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
-		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
-		break;
-
-	case OP_LHA:
-		emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
-		break;
-
-	case OP_LHAU:
-		emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
-		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
-		break;
-
-	case OP_STH:
-		emulated = kvmppc_handle_store(run, vcpu,
-					       kvmppc_get_gpr(vcpu, rs),
-		                               2, 1);
-		break;
-
-	case OP_STHU:
-		emulated = kvmppc_handle_store(run, vcpu,
-					       kvmppc_get_gpr(vcpu, rs),
-		                               2, 1);
-		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
-		break;
-
 	default:
 		emulated = EMULATE_FAIL;
 	}

arch/powerpc/kvm/emulate_loadstore.c

+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * Copyright IBM Corp. 2007
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ *
+ * Authors: Hollis Blanchard <hollisb@us.ibm.com>
+ */
+
+#include <linux/jiffies.h>
+#include <linux/hrtimer.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kvm_host.h>
+#include <linux/clockchips.h>
+
+#include <asm/reg.h>
+#include <asm/time.h>
+#include <asm/byteorder.h>
+#include <asm/kvm_ppc.h>
+#include <asm/disassemble.h>
+#include <asm/ppc-opcode.h>
+#include "timing.h"
+#include "trace.h"
+
+/* XXX to do:
+ * lhax
+ * lhaux
+ * lswx
+ * lswi
+ * stswx
+ * stswi
+ * lha
+ * lhau
+ * lmw
+ * stmw
+ *
+ */
+int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu)
+{
+	struct kvm_run *run = vcpu->run;
+	u32 inst;
+	int ra, rs, rt;
+	enum emulation_result emulated;
+	int advance = 1;
+
+	/* this default type might be overwritten by subcategories */
+	kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
+
+	emulated = kvmppc_get_last_inst(vcpu, false, &inst);
+	if (emulated != EMULATE_DONE)
+		return emulated;
+
+	ra = get_ra(inst);
+	rs = get_rs(inst);
+	rt = get_rt(inst);
+
+	switch (get_op(inst)) {
+	case 31:
+		switch (get_xop(inst)) {
+		case OP_31_XOP_LWZX:
+			emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
+			break;
+
+		case OP_31_XOP_LBZX:
+			emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
+			break;
+
+		case OP_31_XOP_LBZUX:
+			emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
+			kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
+			break;
+
+		case OP_31_XOP_STWX:
+			emulated = kvmppc_handle_store(run, vcpu,
+						       kvmppc_get_gpr(vcpu, rs),
+			                               4, 1);
+			break;
+
+		case OP_31_XOP_STBX:
+			emulated = kvmppc_handle_store(run, vcpu,
+						       kvmppc_get_gpr(vcpu, rs),
+			                               1, 1);
+			break;
+
+		case OP_31_XOP_STBUX:
+			emulated = kvmppc_handle_store(run, vcpu,
+						       kvmppc_get_gpr(vcpu, rs),
+			                               1, 1);
+			kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
+			break;
+
+		case OP_31_XOP_LHAX:
+			emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
+			break;
+
+		case OP_31_XOP_LHZX:
+			emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
+			break;
+
+		case OP_31_XOP_LHZUX:
+			emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
+			kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
+			break;
+
+		case OP_31_XOP_STHX:
+			emulated = kvmppc_handle_store(run, vcpu,
+						       kvmppc_get_gpr(vcpu, rs),
+			                               2, 1);
+			break;
+
+		case OP_31_XOP_STHUX:
+			emulated = kvmppc_handle_store(run, vcpu,
+						       kvmppc_get_gpr(vcpu, rs),
+			                               2, 1);
+			kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
+			break;
+
+		case OP_31_XOP_DCBST:
+		case OP_31_XOP_DCBF:
+		case OP_31_XOP_DCBI:
+			/* Do nothing. The guest is performing dcbi because
+			 * hardware DMA is not snooped by the dcache, but
+			 * emulated DMA either goes through the dcache as
+			 * normal writes, or the host kernel has handled dcache
+			 * coherence. */
+			break;
+
+		case OP_31_XOP_LWBRX:
+			emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
+			break;
+
+		case OP_31_XOP_STWBRX:
+			emulated = kvmppc_handle_store(run, vcpu,
+						       kvmppc_get_gpr(vcpu, rs),
+			                               4, 0);
+			break;
+
+		case OP_31_XOP_LHBRX:
+			emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
+			break;
+
+		case OP_31_XOP_STHBRX:
+			emulated = kvmppc_handle_store(run, vcpu,
+						       kvmppc_get_gpr(vcpu, rs),
+			                               2, 0);
+			break;
+
+		default:
+			emulated = EMULATE_FAIL;
+			break;
+		}
+		break;
+
+	case OP_LWZ:
+		emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
+		break;
+
+	/* TBD: Add support for other 64 bit load variants like ldu, ldux, ldx etc. */
+	case OP_LD:
+		rt = get_rt(inst);
+		emulated = kvmppc_handle_load(run, vcpu, rt, 8, 1);
+		break;
+
+	case OP_LWZU:
+		emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
+		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
+		break;
+
+	case OP_LBZ:
+		emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
+		break;
+
+	case OP_LBZU:
+		emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
+		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
+		break;
+
+	case OP_STW:
+		emulated = kvmppc_handle_store(run, vcpu,
+					       kvmppc_get_gpr(vcpu, rs),
+		                               4, 1);
+		break;
+
+	/* TBD: Add support for other 64 bit store variants like stdu, stdux, stdx etc. */
+	case OP_STD:
+		rs = get_rs(inst);
+		emulated = kvmppc_handle_store(run, vcpu,
+					       kvmppc_get_gpr(vcpu, rs),
+		                               8, 1);
+		break;
+
+	case OP_STWU:
+		emulated = kvmppc_handle_store(run, vcpu,
+					       kvmppc_get_gpr(vcpu, rs),
+		                               4, 1);
+		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
+		break;
+
+	case OP_STB:
+		emulated = kvmppc_handle_store(run, vcpu,
+					       kvmppc_get_gpr(vcpu, rs),
+		                               1, 1);
+		break;
+
+	case OP_STBU:
+		emulated = kvmppc_handle_store(run, vcpu,
+					       kvmppc_get_gpr(vcpu, rs),
+		                               1, 1);
+		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
+		break;
+
+	case OP_LHZ:
+		emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
+		break;
+
+	case OP_LHZU:
+		emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
+		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
+		break;
+
+	case OP_LHA:
+		emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
+		break;
+
+	case OP_LHAU:
+		emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
+		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
+		break;
+
+	case OP_STH:
+		emulated = kvmppc_handle_store(run, vcpu,
+					       kvmppc_get_gpr(vcpu, rs),
+		                               2, 1);
+		break;
+
+	case OP_STHU:
+		emulated = kvmppc_handle_store(run, vcpu,
+					       kvmppc_get_gpr(vcpu, rs),
+		                               2, 1);
+		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
+		break;
+
+	default:
+		emulated = EMULATE_FAIL;
+		break;
+	}
+
+	if (emulated == EMULATE_FAIL) {
+		advance = 0;
+		kvmppc_core_queue_program(vcpu, 0);
+	}
+
+	trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
+
+	/* Advance past emulated instruction. */
+	if (advance)
+		kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
+
+	return emulated;
+}

arch/powerpc/kvm/powerpc.c

@@ -272,7 +272,7 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
 	enum emulation_result er;
 	int r;
 
-	er = kvmppc_emulate_instruction(run, vcpu);
+	er = kvmppc_emulate_loadstore(vcpu);
 	switch (er) {
 	case EMULATE_DONE:
 		/* Future optimization: only reload non-volatiles if they were