KVM: PPC: Make kvmppc_get_last_inst() produce a ppc_inst_t

This changes kvmppc_get_last_inst() so that the instruction it fetches
is returned in a ppc_inst_t variable rather than a u32. This will
allow us to return a 64-bit prefixed instruction on those 64-bit
machines that implement Power ISA v3.1 or later, such as POWER10.
On 32-bit platforms, ppc_inst_t is 32 bits wide, and is turned back
into a u32 by ppc_inst_val, which is an identity operation on those
platforms.

Reviewed-by: Nicholas Piggin <[e-mail]>
Tested-by: Nicholas Piggin <[e-mail]>
Signed-off-by: Paul Mackerras <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>
Link: https://msgid.link/ZAgsiPlL9O7KnlZZ@cleo

arch/powerpc/include/asm/kvm_ppc.h

···
 #include <asm/xive.h>
 #include <asm/cpu_has_feature.h>
 #endif
+#include <asm/inst.h>
 
 /*
  * KVMPPC_INST_SW_BREAKPOINT is debug Instruction
···
 extern struct kvmppc_ops *kvmppc_pr_ops;
 
 static inline int kvmppc_get_last_inst(struct kvm_vcpu *vcpu,
-				enum instruction_fetch_type type, u32 *inst)
+				enum instruction_fetch_type type, ppc_inst_t *inst)
 {
 	int ret = EMULATE_DONE;
 	u32 fetched_inst;
···
 	else
 		fetched_inst = vcpu->arch.last_inst;
 
-	*inst = fetched_inst;
+	*inst = ppc_inst(fetched_inst);
 	return ret;
 }
 

arch/powerpc/kvm/book3s_64_mmu_hv.c

···
  * embodied here.)  If the instruction isn't a load or store, then
  * this doesn't return anything useful.
  */
-static int instruction_is_store(unsigned int instr)
+static int instruction_is_store(ppc_inst_t instr)
 {
 	unsigned int mask;
+	unsigned int suffix;
 
 	mask = 0x10000000;
-	if ((instr & 0xfc000000) == 0x7c000000)
+	suffix = ppc_inst_val(instr);
+	if (ppc_inst_prefixed(instr))
+		suffix = ppc_inst_suffix(instr);
+	else if ((suffix & 0xfc000000) == 0x7c000000)
 		mask = 0x100;		/* major opcode 31 */
-	return (instr & mask) != 0;
+	return (suffix & mask) != 0;
 }
 
 int kvmppc_hv_emulate_mmio(struct kvm_vcpu *vcpu,
 			   unsigned long gpa, gva_t ea, int is_store)
 {
-	u32 last_inst;
+	ppc_inst_t last_inst;
 
 	/*
 	 * Fast path - check if the guest physical address corresponds to a

arch/powerpc/kvm/book3s_hv.c

···
 
 static int kvmppc_emulate_debug_inst(struct kvm_vcpu *vcpu)
 {
-	u32 last_inst;
+	ppc_inst_t last_inst;
 
 	if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) !=
 					EMULATE_DONE) {
···
 		return RESUME_GUEST;
 	}
 
-	if (last_inst == KVMPPC_INST_SW_BREAKPOINT) {
+	if (ppc_inst_val(last_inst) == KVMPPC_INST_SW_BREAKPOINT) {
 		vcpu->run->exit_reason = KVM_EXIT_DEBUG;
 		vcpu->run->debug.arch.address = kvmppc_get_pc(vcpu);
 		return RESUME_HOST;
···
 	unsigned long arg;
 	struct kvm *kvm = vcpu->kvm;
 	struct kvm_vcpu *tvcpu;
+	ppc_inst_t pinst;
 
-	if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst) != EMULATE_DONE)
+	if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &pinst) != EMULATE_DONE)
 		return RESUME_GUEST;
+	inst = ppc_inst_val(pinst);
 	if (get_op(inst) != 31)
 		return EMULATE_FAIL;
 	rb = get_rb(inst);
···
 		 */
 		if (!(vcpu->arch.hfscr_permitted & (1UL << cause)) ||
 				(vcpu->arch.nested_hfscr & (1UL << cause))) {
+			ppc_inst_t pinst;
 			vcpu->arch.trap = BOOK3S_INTERRUPT_H_EMUL_ASSIST;
 
 			/*
 			 * If the fetch failed, return to guest and
 			 * try executing it again.
 			 */
-			r = kvmppc_get_last_inst(vcpu, INST_GENERIC,
-						 &vcpu->arch.emul_inst);
+			r = kvmppc_get_last_inst(vcpu, INST_GENERIC, &pinst);
+			vcpu->arch.emul_inst = ppc_inst_val(pinst);
 			if (r != EMULATE_DONE)
 				r = RESUME_GUEST;
 			else

arch/powerpc/kvm/book3s_paired_singles.c

···
 int kvmppc_emulate_paired_single(struct kvm_vcpu *vcpu)
 {
 	u32 inst;
+	ppc_inst_t pinst;
 	enum emulation_result emulated = EMULATE_DONE;
 	int ax_rd, ax_ra, ax_rb, ax_rc;
 	short full_d;
···
 	int i;
 #endif
 
-	emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst);
+	emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &pinst);
+	inst = ppc_inst_val(pinst);
 	if (emulated != EMULATE_DONE)
 		return emulated;
 

arch/powerpc/kvm/book3s_pr.c

···
 {
 	enum emulation_result er;
 	ulong flags;
-	u32 last_inst;
+	ppc_inst_t last_inst;
 	int emul, r;
 
 	/*
···
 	if (kvmppc_get_msr(vcpu) & MSR_PR) {
 #ifdef EXIT_DEBUG
 		pr_info("Userspace triggered 0x700 exception at\n 0x%lx (0x%x)\n",
-			kvmppc_get_pc(vcpu), last_inst);
+			kvmppc_get_pc(vcpu), ppc_inst_val(last_inst));
 #endif
-		if ((last_inst & 0xff0007ff) != (INS_DCBZ & 0xfffffff7)) {
+		if ((ppc_inst_val(last_inst) & 0xff0007ff) != (INS_DCBZ & 0xfffffff7)) {
 			kvmppc_core_queue_program(vcpu, flags);
 			return RESUME_GUEST;
 		}
···
 		break;
 	case EMULATE_FAIL:
 		pr_crit("%s: emulation at %lx failed (%08x)\n",
-			__func__, kvmppc_get_pc(vcpu), last_inst);
+			__func__, kvmppc_get_pc(vcpu), ppc_inst_val(last_inst));
 		kvmppc_core_queue_program(vcpu, flags);
 		r = RESUME_GUEST;
 		break;
···
 		break;
 	case BOOK3S_INTERRUPT_SYSCALL:
 	{
-		u32 last_sc;
+		ppc_inst_t last_sc;
 		int emul;
 
 		/* Get last sc for papr */
···
 		}
 
 		if (vcpu->arch.papr_enabled &&
-		    (last_sc == 0x44000022) &&
+		    (ppc_inst_val(last_sc) == 0x44000022) &&
 		    !(kvmppc_get_msr(vcpu) & MSR_PR)) {
 			/* SC 1 papr hypercalls */
 			ulong cmd = kvmppc_get_gpr(vcpu, 3);
···
 	{
 		int ext_msr = 0;
 		int emul;
-		u32 last_inst;
+		ppc_inst_t last_inst;
 
 		if (vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE) {
 			/* Do paired single instruction emulation */
···
 	}
 	case BOOK3S_INTERRUPT_ALIGNMENT:
 	{
-		u32 last_inst;
+		ppc_inst_t last_inst;
 		int emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
 
 		if (emul == EMULATE_DONE) {
 			u32 dsisr;
 			u64 dar;
 
-			dsisr = kvmppc_alignment_dsisr(vcpu, last_inst);
-			dar = kvmppc_alignment_dar(vcpu, last_inst);
+			dsisr = kvmppc_alignment_dsisr(vcpu, ppc_inst_val(last_inst));
+			dar = kvmppc_alignment_dar(vcpu, ppc_inst_val(last_inst));
 
 			kvmppc_set_dsisr(vcpu, dsisr);
 			kvmppc_set_dar(vcpu, dar);

arch/powerpc/kvm/booke.c

···
 	int s;
 	int idx;
 	u32 last_inst = KVM_INST_FETCH_FAILED;
+	ppc_inst_t pinst;
 	enum emulation_result emulated = EMULATE_DONE;
 
 	/* Fix irq state (pairs with kvmppc_fix_ee_before_entry()) */
···
 	case BOOKE_INTERRUPT_DATA_STORAGE:
 	case BOOKE_INTERRUPT_DTLB_MISS:
 	case BOOKE_INTERRUPT_HV_PRIV:
-		emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
+		emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &pinst);
+		last_inst = ppc_inst_val(pinst);
 		break;
 	case BOOKE_INTERRUPT_PROGRAM:
 		/* SW breakpoints arrive as illegal instructions on HV */
-		if (vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP)
-			emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
+		if (vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP) {
+			emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &pinst);
+			last_inst = ppc_inst_val(pinst);
+		}
 		break;
 	default:
 		break;

arch/powerpc/kvm/emulate.c

···
 int kvmppc_emulate_instruction(struct kvm_vcpu *vcpu)
 {
 	u32 inst;
+	ppc_inst_t pinst;
 	int rs, rt, sprn;
 	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, INST_GENERIC, &inst);
+	emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &pinst);
+	inst = ppc_inst_val(pinst);
 	if (emulated != EMULATE_DONE)
 		return emulated;
 

arch/powerpc/kvm/emulate_loadstore.c

···
  */
 int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu)
 {
-	u32 inst;
+	ppc_inst_t inst;
 	enum emulation_result emulated = EMULATE_FAIL;
 	struct instruction_op op;
 
···
 
 	emulated = EMULATE_FAIL;
 	vcpu->arch.regs.msr = vcpu->arch.shared->msr;
-	if (analyse_instr(&op, &vcpu->arch.regs, ppc_inst(inst)) == 0) {
+	if (analyse_instr(&op, &vcpu->arch.regs, inst) == 0) {
 		int type = op.type & INSTR_TYPE_MASK;
 		int size = GETSIZE(op.type);
 
···
 		}
 	}
 
-	trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
+	trace_kvm_ppc_instr(ppc_inst_val(inst), kvmppc_get_pc(vcpu), emulated);
 
 	/* Advance past emulated instruction. */
 	if (emulated != EMULATE_FAIL)

arch/powerpc/kvm/powerpc.c

···
 		break;
 	case EMULATE_FAIL:
 	{
-		u32 last_inst;
+		ppc_inst_t last_inst;
 
 		kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
 		kvm_debug_ratelimited("Guest access to device memory using unsupported instruction (opcode: %#08x)\n",
-				      last_inst);
+				      ppc_inst_val(last_inst));
 
 		/*
 		 * Injecting a Data Storage here is a bit more