linux/arch/powerpc/kvm/emulate.c

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/*
* 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
*
* 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 <asm/reg.h>
#include <asm/time.h>
#include <asm/byteorder.h>
#include <asm/kvm_ppc.h>
#include <asm/disassemble.h>
#include "timing.h"
#include "trace.h"
#define OP_TRAP 3
#define OP_TRAP_64 2
#define OP_31_XOP_LWZX 23
#define OP_31_XOP_LBZX 87
#define OP_31_XOP_STWX 151
#define OP_31_XOP_STBX 215
#define OP_31_XOP_STBUX 247
#define OP_31_XOP_LHZX 279
#define OP_31_XOP_LHZUX 311
#define OP_31_XOP_MFSPR 339
#define OP_31_XOP_STHX 407
#define OP_31_XOP_STHUX 439
#define OP_31_XOP_MTSPR 467
#define OP_31_XOP_DCBI 470
#define OP_31_XOP_LWBRX 534
#define OP_31_XOP_TLBSYNC 566
#define OP_31_XOP_STWBRX 662
#define OP_31_XOP_LHBRX 790
#define OP_31_XOP_STHBRX 918
#define OP_LWZ 32
#define OP_LWZU 33
#define OP_LBZ 34
#define OP_LBZU 35
#define OP_STW 36
#define OP_STWU 37
#define OP_STB 38
#define OP_STBU 39
#define OP_LHZ 40
#define OP_LHZU 41
#define OP_STH 44
#define OP_STHU 45
#ifdef CONFIG_PPC64
static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
{
return 1;
}
#else
static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
{
return vcpu->arch.tcr & TCR_DIE;
}
#endif
void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
{
unsigned long dec_nsec;
pr_debug("mtDEC: %x\n", vcpu->arch.dec);
#ifdef CONFIG_PPC64
/* mtdec lowers the interrupt line when positive. */
kvmppc_core_dequeue_dec(vcpu);
/* POWER4+ triggers a dec interrupt if the value is < 0 */
if (vcpu->arch.dec & 0x80000000) {
hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
kvmppc_core_queue_dec(vcpu);
return;
}
#endif
if (kvmppc_dec_enabled(vcpu)) {
/* 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. */
hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
dec_nsec = vcpu->arch.dec;
dec_nsec *= 1000;
dec_nsec /= tb_ticks_per_usec;
hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
HRTIMER_MODE_REL);
vcpu->arch.dec_jiffies = get_tb();
} else {
hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
}
}
/* XXX to do:
* lhax
* lhaux
* lswx
* lswi
* stswx
* stswi
* lha
* lhau
* lmw
* stmw
*
* 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 rs;
int rt;
int sprn;
enum emulation_result emulated = EMULATE_DONE;
int advance = 1;
/* this default type might be overwritten by subcategories */
kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
pr_debug(KERN_INFO "Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
/* Try again next time */
if (inst == KVM_INST_FETCH_FAILED)
return EMULATE_DONE;
switch (get_op(inst)) {
case OP_TRAP:
#ifdef CONFIG_PPC64
case OP_TRAP_64:
kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
#else
kvmppc_core_queue_program(vcpu, vcpu->arch.esr | ESR_PTR);
#endif
advance = 0;
break;
case 31:
switch (get_xop(inst)) {
case OP_31_XOP_LWZX:
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
break;
case OP_31_XOP_LBZX:
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
break;
case OP_31_XOP_STWX:
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu,
kvmppc_get_gpr(vcpu, rs),
4, 1);
break;
case OP_31_XOP_STBX:
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu,
kvmppc_get_gpr(vcpu, rs),
1, 1);
break;
case OP_31_XOP_STBUX:
rs = get_rs(inst);
ra = get_ra(inst);
rb = get_rb(inst);
ea = kvmppc_get_gpr(vcpu, rb);
if (ra)
ea += kvmppc_get_gpr(vcpu, ra);
emulated = kvmppc_handle_store(run, vcpu,
kvmppc_get_gpr(vcpu, rs),
1, 1);
kvmppc_set_gpr(vcpu, rs, ea);
break;
case OP_31_XOP_LHZX:
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
break;
case OP_31_XOP_LHZUX:
rt = get_rt(inst);
ra = get_ra(inst);
rb = get_rb(inst);
ea = kvmppc_get_gpr(vcpu, rb);
if (ra)
ea += kvmppc_get_gpr(vcpu, ra);
emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
kvmppc_set_gpr(vcpu, ra, ea);
break;
case OP_31_XOP_MFSPR:
sprn = get_sprn(inst);
rt = get_rt(inst);
switch (sprn) {
case SPRN_SRR0:
kvmppc_set_gpr(vcpu, rt, vcpu->arch.srr0); break;
case SPRN_SRR1:
kvmppc_set_gpr(vcpu, rt, vcpu->arch.srr1); break;
case SPRN_PVR:
kvmppc_set_gpr(vcpu, rt, vcpu->arch.pvr); break;
case SPRN_PIR:
kvmppc_set_gpr(vcpu, rt, vcpu->vcpu_id); break;
case SPRN_MSSSR0:
kvmppc_set_gpr(vcpu, rt, 0); 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:
kvmppc_set_gpr(vcpu, rt, get_tb() >> 32); break;
case SPRN_TBWU:
kvmppc_set_gpr(vcpu, rt, get_tb()); break;
case SPRN_SPRG0:
kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg0); break;
case SPRN_SPRG1:
kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg1); break;
case SPRN_SPRG2:
kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg2); break;
case SPRN_SPRG3:
kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg3); break;
/* Note: SPRG4-7 are user-readable, so we don't get
* a trap. */
case SPRN_DEC:
{
u64 jd = get_tb() - vcpu->arch.dec_jiffies;
kvmppc_set_gpr(vcpu, rt, vcpu->arch.dec - jd);
pr_debug(KERN_INFO "mfDEC: %x - %llx = %lx\n",
vcpu->arch.dec, jd,
kvmppc_get_gpr(vcpu, rt));
break;
}
default:
emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
if (emulated == EMULATE_FAIL) {
printk("mfspr: unknown spr %x\n", sprn);
kvmppc_set_gpr(vcpu, rt, 0);
}
break;
}
break;
case OP_31_XOP_STHX:
rs = get_rs(inst);
ra = get_ra(inst);
rb = get_rb(inst);
emulated = kvmppc_handle_store(run, vcpu,
kvmppc_get_gpr(vcpu, rs),
2, 1);
break;
case OP_31_XOP_STHUX:
rs = get_rs(inst);
ra = get_ra(inst);
rb = get_rb(inst);
ea = kvmppc_get_gpr(vcpu, rb);
if (ra)
ea += kvmppc_get_gpr(vcpu, ra);
emulated = kvmppc_handle_store(run, vcpu,
kvmppc_get_gpr(vcpu, rs),
2, 1);
kvmppc_set_gpr(vcpu, ra, ea);
break;
case OP_31_XOP_MTSPR:
sprn = get_sprn(inst);
rs = get_rs(inst);
switch (sprn) {
case SPRN_SRR0:
vcpu->arch.srr0 = kvmppc_get_gpr(vcpu, rs); break;
case SPRN_SRR1:
vcpu->arch.srr1 = kvmppc_get_gpr(vcpu, rs); break;
/* XXX We need to context-switch the timebase for
* watchdog and FIT. */
case SPRN_TBWL: break;
case SPRN_TBWU: break;
case SPRN_MSSSR0: break;
case SPRN_DEC:
vcpu->arch.dec = kvmppc_get_gpr(vcpu, rs);
kvmppc_emulate_dec(vcpu);
break;
case SPRN_SPRG0:
vcpu->arch.sprg0 = kvmppc_get_gpr(vcpu, rs); break;
case SPRN_SPRG1:
vcpu->arch.sprg1 = kvmppc_get_gpr(vcpu, rs); break;
case SPRN_SPRG2:
vcpu->arch.sprg2 = kvmppc_get_gpr(vcpu, rs); break;
case SPRN_SPRG3:
vcpu->arch.sprg3 = kvmppc_get_gpr(vcpu, rs); break;
default:
emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
if (emulated == EMULATE_FAIL)
printk("mtspr: unknown spr %x\n", sprn);
break;
}
break;
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:
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
break;
case OP_31_XOP_TLBSYNC:
break;
case OP_31_XOP_STWBRX:
rs = get_rs(inst);
ra = get_ra(inst);
rb = get_rb(inst);
emulated = kvmppc_handle_store(run, vcpu,
kvmppc_get_gpr(vcpu, rs),
4, 0);
break;
case OP_31_XOP_LHBRX:
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
break;
case OP_31_XOP_STHBRX:
rs = get_rs(inst);
ra = get_ra(inst);
rb = get_rb(inst);
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:
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
break;
case OP_LWZU:
ra = get_ra(inst);
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
break;
case OP_LBZ:
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
break;
case OP_LBZU:
ra = get_ra(inst);
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
break;
case OP_STW:
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu,
kvmppc_get_gpr(vcpu, rs),
4, 1);
break;
case OP_STWU:
ra = get_ra(inst);
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu,
kvmppc_get_gpr(vcpu, rs),
4, 1);
kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
break;
case OP_STB:
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu,
kvmppc_get_gpr(vcpu, rs),
1, 1);
break;
case OP_STBU:
ra = get_ra(inst);
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu,
kvmppc_get_gpr(vcpu, rs),
1, 1);
kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
break;
case OP_LHZ:
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
break;
case OP_LHZU:
ra = get_ra(inst);
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
break;
case OP_STH:
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu,
kvmppc_get_gpr(vcpu, rs),
2, 1);
break;
case OP_STHU:
ra = get_ra(inst);
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu,
kvmppc_get_gpr(vcpu, rs),
2, 1);
kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
break;
default:
emulated = EMULATE_FAIL;
}
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));
kvmppc_core_queue_program(vcpu, 0);
}
}
trace_kvm_ppc_instr(inst, vcpu->arch.pc, emulated);
if (advance)
vcpu->arch.pc += 4; /* Advance past emulated instruction. */
return emulated;
}