arch/powerpc/kvm/emulate.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  *
  * 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"

 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
 {
 	unsigned long dec_nsec;
 	unsigned long long dec_time;

 	pr_debug("mtDEC: %lx\n", vcpu->arch.dec);
 	hrtimer_try_to_cancel(&vcpu->arch.dec_timer);

 #ifdef CONFIG_PPC_BOOK3S
 	/* mtdec lowers the interrupt line when positive. */
 	kvmppc_core_dequeue_dec(vcpu);
 #endif

 #ifdef CONFIG_BOOKE
 	/* On BOOKE, DEC = 0 is as good as decrementer not enabled */
 	if (vcpu->arch.dec == 0)
 		return;
 #endif

 	/*
 	 * The decrementer ticks at the same rate as the timebase, so
 	 * that's how we convert the guest DEC value to the number of
 	 * host ticks.
 	 */

 	dec_time = vcpu->arch.dec;
 	/*
 	 * Guest timebase ticks at the same frequency as host timebase.
 	 * So use the host timebase calculations for decrementer emulation.
 	 */
 	dec_time = tb_to_ns(dec_time);
 	dec_nsec = do_div(dec_time, NSEC_PER_SEC);
 	hrtimer_start(&vcpu->arch.dec_timer,
 		ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
 	vcpu->arch.dec_jiffies = get_tb();
 }

 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
 {
 	u64 jd = tb - vcpu->arch.dec_jiffies;

 #ifdef CONFIG_BOOKE
 	if (vcpu->arch.dec < jd)
 		return 0;
 #endif

 	return vcpu->arch.dec - jd;
 }

 static int kvmppc_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
 {
 	enum emulation_result emulated = EMULATE_DONE;
 	ulong spr_val = kvmppc_get_gpr(vcpu, rs);

 	switch (sprn) {
 	case SPRN_SRR0:
 		kvmppc_set_srr0(vcpu, spr_val);
 		break;
 	case SPRN_SRR1:
 		kvmppc_set_srr1(vcpu, spr_val);
 		break;

 	/* XXX We need to context-switch the timebase for
 	 * watchdog and FIT. */
 	case SPRN_TBWL: break;
 	case SPRN_TBWU: break;

 	case SPRN_DEC:
 		vcpu->arch.dec = (u32) spr_val;
 		kvmppc_emulate_dec(vcpu);
 		break;

 	case SPRN_SPRG0:
 		kvmppc_set_sprg0(vcpu, spr_val);
 		break;
 	case SPRN_SPRG1:
 		kvmppc_set_sprg1(vcpu, spr_val);
 		break;
 	case SPRN_SPRG2:
 		kvmppc_set_sprg2(vcpu, spr_val);
 		break;
 	case SPRN_SPRG3:
 		kvmppc_set_sprg3(vcpu, spr_val);
 		break;

 	/* PIR can legally be written, but we ignore it */
 	case SPRN_PIR: break;

 	default:
 		emulated = vcpu->kvm->arch.kvm_ops->emulate_mtspr(vcpu, sprn,
 								  spr_val);
 		if (emulated == EMULATE_FAIL)
 			printk(KERN_INFO "mtspr: unknown spr "
 				"0x%x\n", sprn);
 		break;
 	}

 	kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);

 	return emulated;
 }

 static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
 {
 	enum emulation_result emulated = EMULATE_DONE;
 	ulong spr_val = 0;

 	switch (sprn) {
 	case SPRN_SRR0:
 		spr_val = kvmppc_get_srr0(vcpu);
 		break;
 	case SPRN_SRR1:
 		spr_val = kvmppc_get_srr1(vcpu);
 		break;
 	case SPRN_PVR:
 		spr_val = vcpu->arch.pvr;
 		break;
 	case SPRN_PIR:
 		spr_val = vcpu->vcpu_id;
 		break;

 	/* Note: mftb and TBRL/TBWL are user-accessible, so
 	 * the guest can always access the real TB anyways.
 	 * In fact, we probably will never see these traps. */
 	case SPRN_TBWL:
 		spr_val = get_tb() >> 32;
 		break;
 	case SPRN_TBWU:
 		spr_val = get_tb();
 		break;

 	case SPRN_SPRG0:
 		spr_val = kvmppc_get_sprg0(vcpu);
 		break;
 	case SPRN_SPRG1:
 		spr_val = kvmppc_get_sprg1(vcpu);
 		break;
 	case SPRN_SPRG2:
 		spr_val = kvmppc_get_sprg2(vcpu);
 		break;
 	case SPRN_SPRG3:
 		spr_val = kvmppc_get_sprg3(vcpu);
 		break;
 	/* Note: SPRG4-7 are user-readable, so we don't get
 	 * a trap. */

 	case SPRN_DEC:
 		spr_val = kvmppc_get_dec(vcpu, get_tb());
 		break;
 	default:
 		emulated = vcpu->kvm->arch.kvm_ops->emulate_mfspr(vcpu, sprn,
 								  &spr_val);
 		if (unlikely(emulated == EMULATE_FAIL)) {
 			printk(KERN_INFO "mfspr: unknown spr "
 				"0x%x\n", sprn);
 		}
 		break;
 	}

 	if (emulated == EMULATE_DONE)
 		kvmppc_set_gpr(vcpu, rt, spr_val);
 	kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);

 	return emulated;
 }

 /* XXX Should probably auto-generate instruction decoding for a particular core
  * from opcode tables in the future. */
 int kvmppc_emulate_instruction(struct kvm_vcpu *vcpu)
 {
 	u32 inst;
 	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);
 	if (emulated != EMULATE_DONE)
 		return emulated;

 	pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));

 	rs = get_rs(inst);
 	rt = get_rt(inst);
 	sprn = get_sprn(inst);

 	switch (get_op(inst)) {
 	case OP_TRAP:
 #ifdef CONFIG_PPC_BOOK3S
 	case OP_TRAP_64:
 		kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 #else
 		kvmppc_core_queue_program(vcpu,
 					  vcpu->arch.shared->esr | ESR_PTR);
 #endif
 		advance = 0;
 		break;

 	case 31:
 		switch (get_xop(inst)) {

 		case OP_31_XOP_TRAP:
 #ifdef CONFIG_64BIT
 		case OP_31_XOP_TRAP_64:
 #endif
 #ifdef CONFIG_PPC_BOOK3S
 			kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 #else
 			kvmppc_core_queue_program(vcpu,
 					vcpu->arch.shared->esr | ESR_PTR);
 #endif
 			advance = 0;
 			break;

 		case OP_31_XOP_MFSPR:
 			emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt);
 			if (emulated == EMULATE_AGAIN) {
 				emulated = EMULATE_DONE;
 				advance = 0;
 			}
 			break;

 		case OP_31_XOP_MTSPR:
 			emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs);
 			if (emulated == EMULATE_AGAIN) {
 				emulated = EMULATE_DONE;
 				advance = 0;
 			}
 			break;

 		case OP_31_XOP_TLBSYNC:
 			break;

 		default:
 			/* Attempt core-specific emulation below. */
 			emulated = EMULATE_FAIL;
 		}
 		break;

 	case 0:
 		/*
 		 * Instruction with primary opcode 0. Based on PowerISA
 		 * these are illegal instructions.
 		 */
 		if (inst == KVMPPC_INST_SW_BREAKPOINT) {
 			vcpu->run->exit_reason = KVM_EXIT_DEBUG;
 			vcpu->run->debug.arch.status = 0;
 			vcpu->run->debug.arch.address = kvmppc_get_pc(vcpu);
 			emulated = EMULATE_EXIT_USER;
 			advance = 0;
 		} else
 			emulated = EMULATE_FAIL;

 		break;

 	default:
 		emulated = EMULATE_FAIL;
 	}

 	if (emulated == EMULATE_FAIL) {
 		emulated = vcpu->kvm->arch.kvm_ops->emulate_op(vcpu, inst,
 							       &advance);
 		if (emulated == EMULATE_AGAIN) {
 			advance = 0;
 		} else 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));
 		}
 	}

 	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;
 }
 EXPORT_SYMBOL_GPL(kvmppc_emulate_instruction);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	*
	* 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"

	void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
	{
	unsigned long dec_nsec;
	unsigned long long dec_time;

	pr_debug("mtDEC: %lx\n", vcpu->arch.dec);
	hrtimer_try_to_cancel(&vcpu->arch.dec_timer);

	#ifdef CONFIG_PPC_BOOK3S
	/* mtdec lowers the interrupt line when positive. */
	kvmppc_core_dequeue_dec(vcpu);
	#endif

	#ifdef CONFIG_BOOKE
	/* On BOOKE, DEC = 0 is as good as decrementer not enabled */
	if (vcpu->arch.dec == 0)
	return;
	#endif

	/*
	* The decrementer ticks at the same rate as the timebase, so
	* that's how we convert the guest DEC value to the number of
	* host ticks.
	*/

	dec_time = vcpu->arch.dec;
	/*
	* Guest timebase ticks at the same frequency as host timebase.
	* So use the host timebase calculations for decrementer emulation.
	*/
	dec_time = tb_to_ns(dec_time);
	dec_nsec = do_div(dec_time, NSEC_PER_SEC);
	hrtimer_start(&vcpu->arch.dec_timer,
	ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
	vcpu->arch.dec_jiffies = get_tb();
	}

	u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
	{
	u64 jd = tb - vcpu->arch.dec_jiffies;

	#ifdef CONFIG_BOOKE
	if (vcpu->arch.dec < jd)
	return 0;
	#endif

	return vcpu->arch.dec - jd;
	}

	static int kvmppc_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
	{
	enum emulation_result emulated = EMULATE_DONE;
	ulong spr_val = kvmppc_get_gpr(vcpu, rs);

	switch (sprn) {
	case SPRN_SRR0:
	kvmppc_set_srr0(vcpu, spr_val);
	break;
	case SPRN_SRR1:
	kvmppc_set_srr1(vcpu, spr_val);
	break;

	/* XXX We need to context-switch the timebase for
	* watchdog and FIT. */
	case SPRN_TBWL: break;
	case SPRN_TBWU: break;

	case SPRN_DEC:
	vcpu->arch.dec = (u32) spr_val;
	kvmppc_emulate_dec(vcpu);
	break;

	case SPRN_SPRG0:
	kvmppc_set_sprg0(vcpu, spr_val);
	break;
	case SPRN_SPRG1:
	kvmppc_set_sprg1(vcpu, spr_val);
	break;
	case SPRN_SPRG2:
	kvmppc_set_sprg2(vcpu, spr_val);
	break;
	case SPRN_SPRG3:
	kvmppc_set_sprg3(vcpu, spr_val);
	break;

	/* PIR can legally be written, but we ignore it */
	case SPRN_PIR: break;

	default:
	emulated = vcpu->kvm->arch.kvm_ops->emulate_mtspr(vcpu, sprn,
	spr_val);
	if (emulated == EMULATE_FAIL)
	printk(KERN_INFO "mtspr: unknown spr "
	"0x%x\n", sprn);
	break;
	}

	kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);

	return emulated;
	}

	static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
	{
	enum emulation_result emulated = EMULATE_DONE;
	ulong spr_val = 0;

	switch (sprn) {
	case SPRN_SRR0:
	spr_val = kvmppc_get_srr0(vcpu);
	break;
	case SPRN_SRR1:
	spr_val = kvmppc_get_srr1(vcpu);
	break;
	case SPRN_PVR:
	spr_val = vcpu->arch.pvr;
	break;
	case SPRN_PIR:
	spr_val = vcpu->vcpu_id;
	break;

	/* Note: mftb and TBRL/TBWL are user-accessible, so
	* the guest can always access the real TB anyways.
	* In fact, we probably will never see these traps. */
	case SPRN_TBWL:
	spr_val = get_tb() >> 32;
	break;
	case SPRN_TBWU:
	spr_val = get_tb();
	break;

	case SPRN_SPRG0:
	spr_val = kvmppc_get_sprg0(vcpu);
	break;
	case SPRN_SPRG1:
	spr_val = kvmppc_get_sprg1(vcpu);
	break;
	case SPRN_SPRG2:
	spr_val = kvmppc_get_sprg2(vcpu);
	break;
	case SPRN_SPRG3:
	spr_val = kvmppc_get_sprg3(vcpu);
	break;
	/* Note: SPRG4-7 are user-readable, so we don't get
	* a trap. */

	case SPRN_DEC:
	spr_val = kvmppc_get_dec(vcpu, get_tb());
	break;
	default:
	emulated = vcpu->kvm->arch.kvm_ops->emulate_mfspr(vcpu, sprn,
	&spr_val);
	if (unlikely(emulated == EMULATE_FAIL)) {
	printk(KERN_INFO "mfspr: unknown spr "
	"0x%x\n", sprn);
	}
	break;
	}

	if (emulated == EMULATE_DONE)
	kvmppc_set_gpr(vcpu, rt, spr_val);
	kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);

	return emulated;
	}

	/* XXX Should probably auto-generate instruction decoding for a particular core
	* from opcode tables in the future. */
	int kvmppc_emulate_instruction(struct kvm_vcpu *vcpu)
	{
	u32 inst;
	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);
	if (emulated != EMULATE_DONE)
	return emulated;

	pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));

	rs = get_rs(inst);
	rt = get_rt(inst);
	sprn = get_sprn(inst);

	switch (get_op(inst)) {
	case OP_TRAP:
	#ifdef CONFIG_PPC_BOOK3S
	case OP_TRAP_64:
	kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
	#else
	kvmppc_core_queue_program(vcpu,
	vcpu->arch.shared->esr \| ESR_PTR);
	#endif
	advance = 0;
	break;

	case 31:
	switch (get_xop(inst)) {

	case OP_31_XOP_TRAP:
	#ifdef CONFIG_64BIT
	case OP_31_XOP_TRAP_64:
	#endif
	#ifdef CONFIG_PPC_BOOK3S
	kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
	#else
	kvmppc_core_queue_program(vcpu,
	vcpu->arch.shared->esr \| ESR_PTR);
	#endif
	advance = 0;
	break;

	case OP_31_XOP_MFSPR:
	emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt);
	if (emulated == EMULATE_AGAIN) {
	emulated = EMULATE_DONE;
	advance = 0;
	}
	break;

	case OP_31_XOP_MTSPR:
	emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs);
	if (emulated == EMULATE_AGAIN) {
	emulated = EMULATE_DONE;
	advance = 0;
	}
	break;

	case OP_31_XOP_TLBSYNC:
	break;

	default:
	/* Attempt core-specific emulation below. */
	emulated = EMULATE_FAIL;
	}
	break;

	case 0:
	/*
	* Instruction with primary opcode 0. Based on PowerISA
	* these are illegal instructions.
	*/
	if (inst == KVMPPC_INST_SW_BREAKPOINT) {
	vcpu->run->exit_reason = KVM_EXIT_DEBUG;
	vcpu->run->debug.arch.status = 0;
	vcpu->run->debug.arch.address = kvmppc_get_pc(vcpu);
	emulated = EMULATE_EXIT_USER;
	advance = 0;
	} else
	emulated = EMULATE_FAIL;

	break;

	default:
	emulated = EMULATE_FAIL;
	}

	if (emulated == EMULATE_FAIL) {
	emulated = vcpu->kvm->arch.kvm_ops->emulate_op(vcpu, inst,
	&advance);
	if (emulated == EMULATE_AGAIN) {
	advance = 0;
	} else 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));
	}
	}

	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;
	}
	EXPORT_SYMBOL_GPL(kvmppc_emulate_instruction);