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linux/arch/powerpc/kvm/emulate.c
Hollis Blanchard 75f74f0dbe KVM: ppc: refactor instruction emulation into generic and core-specific pieces 
Cores provide 3 emulation hooks, implemented for example in the new
4xx_emulate.c:
kvmppc_core_emulate_op
kvmppc_core_emulate_mtspr
kvmppc_core_emulate_mfspr

Strictly speaking the last two aren't necessary, but provide for more
informative error reporting ("unknown SPR").

Long term I'd like to have instruction decoding autogenerated from tables of
opcodes, and that way we could aggregate universal, Book E, and core-specific
instructions more easily and without redundant switch statements.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:52:21 +02:00

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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/timer.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>
void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
{
if (vcpu->arch.tcr & TCR_DIE) {
/* 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. */
unsigned long nr_jiffies;
nr_jiffies = vcpu->arch.dec / tb_ticks_per_jiffy;
mod_timer(&vcpu->arch.dec_timer,
get_jiffies_64() + nr_jiffies);
} else {
del_timer(&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;
switch (get_op(inst)) {
case 3: /* trap */
printk("trap!\n");
kvmppc_core_queue_program(vcpu);
advance = 0;
break;
case 31:
switch (get_xop(inst)) {
case 23: /* lwzx */
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
break;
case 87: /* lbzx */
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
break;
case 151: /* stwx */
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu,
vcpu->arch.gpr[rs],
4, 1);
break;
case 215: /* stbx */
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu,
vcpu->arch.gpr[rs],
1, 1);
break;
case 247: /* stbux */
rs = get_rs(inst);
ra = get_ra(inst);
rb = get_rb(inst);
ea = vcpu->arch.gpr[rb];
if (ra)
ea += vcpu->arch.gpr[ra];
emulated = kvmppc_handle_store(run, vcpu,
vcpu->arch.gpr[rs],
1, 1);
vcpu->arch.gpr[rs] = ea;
break;
case 279: /* lhzx */
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
break;
case 311: /* lhzux */
rt = get_rt(inst);
ra = get_ra(inst);
rb = get_rb(inst);
ea = vcpu->arch.gpr[rb];
if (ra)
ea += vcpu->arch.gpr[ra];
emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
vcpu->arch.gpr[ra] = ea;
break;
case 339: /* mfspr */
sprn = get_sprn(inst);
rt = get_rt(inst);
switch (sprn) {
case SPRN_SRR0:
vcpu->arch.gpr[rt] = vcpu->arch.srr0; break;
case SPRN_SRR1:
vcpu->arch.gpr[rt] = vcpu->arch.srr1; break;
case SPRN_PVR:
vcpu->arch.gpr[rt] = vcpu->arch.pvr; 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:
vcpu->arch.gpr[rt] = mftbl(); break;
case SPRN_TBWU:
vcpu->arch.gpr[rt] = mftbu(); break;
case SPRN_SPRG0:
vcpu->arch.gpr[rt] = vcpu->arch.sprg0; break;
case SPRN_SPRG1:
vcpu->arch.gpr[rt] = vcpu->arch.sprg1; break;
case SPRN_SPRG2:
vcpu->arch.gpr[rt] = vcpu->arch.sprg2; break;
case SPRN_SPRG3:
vcpu->arch.gpr[rt] = vcpu->arch.sprg3; break;
/* Note: SPRG4-7 are user-readable, so we don't get
* a trap. */
default:
emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
if (emulated == EMULATE_FAIL) {
printk("mfspr: unknown spr %x\n", sprn);
vcpu->arch.gpr[rt] = 0;
}
break;
}
break;
case 407: /* sthx */
rs = get_rs(inst);
ra = get_ra(inst);
rb = get_rb(inst);
emulated = kvmppc_handle_store(run, vcpu,
vcpu->arch.gpr[rs],
2, 1);
break;
case 439: /* sthux */
rs = get_rs(inst);
ra = get_ra(inst);
rb = get_rb(inst);
ea = vcpu->arch.gpr[rb];
if (ra)
ea += vcpu->arch.gpr[ra];
emulated = kvmppc_handle_store(run, vcpu,
vcpu->arch.gpr[rs],
2, 1);
vcpu->arch.gpr[ra] = ea;
break;
case 467: /* mtspr */
sprn = get_sprn(inst);
rs = get_rs(inst);
switch (sprn) {
case SPRN_SRR0:
vcpu->arch.srr0 = vcpu->arch.gpr[rs]; break;
case SPRN_SRR1:
vcpu->arch.srr1 = vcpu->arch.gpr[rs]; 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 = vcpu->arch.gpr[rs];
kvmppc_emulate_dec(vcpu);
break;
case SPRN_SPRG0:
vcpu->arch.sprg0 = vcpu->arch.gpr[rs]; break;
case SPRN_SPRG1:
vcpu->arch.sprg1 = vcpu->arch.gpr[rs]; break;
case SPRN_SPRG2:
vcpu->arch.sprg2 = vcpu->arch.gpr[rs]; break;
case SPRN_SPRG3:
vcpu->arch.sprg3 = vcpu->arch.gpr[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 470: /* 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 534: /* lwbrx */
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
break;
case 566: /* tlbsync */
break;
case 662: /* stwbrx */
rs = get_rs(inst);
ra = get_ra(inst);
rb = get_rb(inst);
emulated = kvmppc_handle_store(run, vcpu,
vcpu->arch.gpr[rs],
4, 0);
break;
case 790: /* lhbrx */
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
break;
case 918: /* sthbrx */
rs = get_rs(inst);
ra = get_ra(inst);
rb = get_rb(inst);
emulated = kvmppc_handle_store(run, vcpu,
vcpu->arch.gpr[rs],
2, 0);
break;
default:
/* Attempt core-specific emulation below. */
emulated = EMULATE_FAIL;
}
break;
case 32: /* lwz */
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
break;
case 33: /* lwzu */
ra = get_ra(inst);
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
break;
case 34: /* lbz */
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
break;
case 35: /* lbzu */
ra = get_ra(inst);
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
break;
case 36: /* stw */
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
4, 1);
break;
case 37: /* stwu */
ra = get_ra(inst);
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
4, 1);
vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
break;
case 38: /* stb */
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
1, 1);
break;
case 39: /* stbu */
ra = get_ra(inst);
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
1, 1);
vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
break;
case 40: /* lhz */
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
break;
case 41: /* lhzu */
ra = get_ra(inst);
rt = get_rt(inst);
emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
break;
case 44: /* sth */
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
2, 1);
break;
case 45: /* sthu */
ra = get_ra(inst);
rs = get_rs(inst);
emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
2, 1);
vcpu->arch.gpr[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));
}
}
KVMTRACE_3D(PPC_INSTR, vcpu, inst, vcpu->arch.pc, emulated, entryexit);
if (advance)
vcpu->arch.pc += 4; /* Advance past emulated instruction. */
return emulated;
}
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