// SPDX-License-Identifier: GPL-2.0-only
/*
*
* Copyright IBM Corp. 2007
* Copyright 2011 Freescale Semiconductor, Inc.
*
* Authors: Hollis Blanchard <[email protected]>
*/
#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;
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, &pinst);
inst = ppc_inst_val(pinst);
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 this ever handles prefixed instructions, the 4
* will need to become ppc_inst_len(pinst) instead.
*/
if (advance)
kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
return emulated;
}
EXPORT_SYMBOL_GPL(kvmppc_emulate_instruction);
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