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linux-next/arch/powerpc/kvm/emulate.c
Alexander Graf 3587d5348c KVM: PPC: Teach MMIO Signedness
The guest I was trying to get to run uses the LHA and LHAU instructions.
Those instructions basically do a load, but also sign extend the result.

Since we need to fill our registers by hand when doing MMIO, we also need
to sign extend manually.

This patch implements sign extended MMIO and the LHA(U) instructions.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-25 12:34:44 +03:00

504 lines
12 KiB
C

/*
* 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_LHA 42
#define OP_LHAU 43
#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_LHA:
rt = get_rt(inst);
emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
break;
case OP_LHAU:
ra = get_ra(inst);
rt = get_rt(inst);
emulated = kvmppc_handle_loads(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;
}