alistair23-linux/arch/powerpc/kvm/booke_emulate.c
Bharat Bhushan 2f699a59f3 KVM: PPC: BOOKE: Emulate debug registers and exception
This patch emulates debug registers and debug exception
to support guest using debug resource. This enables running
gdb/kgdb etc in guest.

On BOOKE architecture we cannot share debug resources between QEMU and
guest because:
    When QEMU is using debug resources then debug exception must
    be always enabled. To achieve this we set MSR_DE and also set
    MSRP_DEP so guest cannot change MSR_DE.

    When emulating debug resource for guest we want guest
    to control MSR_DE (enable/disable debug interrupt on need).

    So above mentioned two configuration cannot be supported
    at the same time. So the result is that we cannot share
    debug resources between QEMU and Guest on BOOKE architecture.

In the current design QEMU gets priority over guest, this means that if
QEMU is using debug resources then guest cannot use them and if guest is
using debug resource then QEMU can overwrite them.

Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2014-09-22 10:11:33 +02:00

523 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. 2008
* Copyright 2011 Freescale Semiconductor, Inc.
*
* Authors: Hollis Blanchard <hollisb@us.ibm.com>
*/
#include <linux/kvm_host.h>
#include <asm/disassemble.h>
#include "booke.h"
#define OP_19_XOP_RFI 50
#define OP_19_XOP_RFCI 51
#define OP_19_XOP_RFDI 39
#define OP_31_XOP_MFMSR 83
#define OP_31_XOP_WRTEE 131
#define OP_31_XOP_MTMSR 146
#define OP_31_XOP_WRTEEI 163
static void kvmppc_emul_rfi(struct kvm_vcpu *vcpu)
{
vcpu->arch.pc = vcpu->arch.shared->srr0;
kvmppc_set_msr(vcpu, vcpu->arch.shared->srr1);
}
static void kvmppc_emul_rfdi(struct kvm_vcpu *vcpu)
{
vcpu->arch.pc = vcpu->arch.dsrr0;
kvmppc_set_msr(vcpu, vcpu->arch.dsrr1);
}
static void kvmppc_emul_rfci(struct kvm_vcpu *vcpu)
{
vcpu->arch.pc = vcpu->arch.csrr0;
kvmppc_set_msr(vcpu, vcpu->arch.csrr1);
}
int kvmppc_booke_emulate_op(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned int inst, int *advance)
{
int emulated = EMULATE_DONE;
int rs = get_rs(inst);
int rt = get_rt(inst);
switch (get_op(inst)) {
case 19:
switch (get_xop(inst)) {
case OP_19_XOP_RFI:
kvmppc_emul_rfi(vcpu);
kvmppc_set_exit_type(vcpu, EMULATED_RFI_EXITS);
*advance = 0;
break;
case OP_19_XOP_RFCI:
kvmppc_emul_rfci(vcpu);
kvmppc_set_exit_type(vcpu, EMULATED_RFCI_EXITS);
*advance = 0;
break;
case OP_19_XOP_RFDI:
kvmppc_emul_rfdi(vcpu);
kvmppc_set_exit_type(vcpu, EMULATED_RFDI_EXITS);
*advance = 0;
break;
default:
emulated = EMULATE_FAIL;
break;
}
break;
case 31:
switch (get_xop(inst)) {
case OP_31_XOP_MFMSR:
kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->msr);
kvmppc_set_exit_type(vcpu, EMULATED_MFMSR_EXITS);
break;
case OP_31_XOP_MTMSR:
kvmppc_set_exit_type(vcpu, EMULATED_MTMSR_EXITS);
kvmppc_set_msr(vcpu, kvmppc_get_gpr(vcpu, rs));
break;
case OP_31_XOP_WRTEE:
vcpu->arch.shared->msr = (vcpu->arch.shared->msr & ~MSR_EE)
| (kvmppc_get_gpr(vcpu, rs) & MSR_EE);
kvmppc_set_exit_type(vcpu, EMULATED_WRTEE_EXITS);
break;
case OP_31_XOP_WRTEEI:
vcpu->arch.shared->msr = (vcpu->arch.shared->msr & ~MSR_EE)
| (inst & MSR_EE);
kvmppc_set_exit_type(vcpu, EMULATED_WRTEE_EXITS);
break;
default:
emulated = EMULATE_FAIL;
}
break;
default:
emulated = EMULATE_FAIL;
}
return emulated;
}
/*
* NOTE: some of these registers are not emulated on BOOKE_HV (GS-mode).
* Their backing store is in real registers, and these functions
* will return the wrong result if called for them in another context
* (such as debugging).
*/
int kvmppc_booke_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, ulong spr_val)
{
int emulated = EMULATE_DONE;
bool debug_inst = false;
switch (sprn) {
case SPRN_DEAR:
vcpu->arch.shared->dar = spr_val;
break;
case SPRN_ESR:
vcpu->arch.shared->esr = spr_val;
break;
case SPRN_CSRR0:
vcpu->arch.csrr0 = spr_val;
break;
case SPRN_CSRR1:
vcpu->arch.csrr1 = spr_val;
break;
case SPRN_DSRR0:
vcpu->arch.dsrr0 = spr_val;
break;
case SPRN_DSRR1:
vcpu->arch.dsrr1 = spr_val;
break;
case SPRN_IAC1:
/*
* If userspace is debugging guest then guest
* can not access debug registers.
*/
if (vcpu->guest_debug)
break;
debug_inst = true;
vcpu->arch.dbg_reg.iac1 = spr_val;
break;
case SPRN_IAC2:
/*
* If userspace is debugging guest then guest
* can not access debug registers.
*/
if (vcpu->guest_debug)
break;
debug_inst = true;
vcpu->arch.dbg_reg.iac2 = spr_val;
break;
#if CONFIG_PPC_ADV_DEBUG_IACS > 2
case SPRN_IAC3:
/*
* If userspace is debugging guest then guest
* can not access debug registers.
*/
if (vcpu->guest_debug)
break;
debug_inst = true;
vcpu->arch.dbg_reg.iac3 = spr_val;
break;
case SPRN_IAC4:
/*
* If userspace is debugging guest then guest
* can not access debug registers.
*/
if (vcpu->guest_debug)
break;
debug_inst = true;
vcpu->arch.dbg_reg.iac4 = spr_val;
break;
#endif
case SPRN_DAC1:
/*
* If userspace is debugging guest then guest
* can not access debug registers.
*/
if (vcpu->guest_debug)
break;
debug_inst = true;
vcpu->arch.dbg_reg.dac1 = spr_val;
break;
case SPRN_DAC2:
/*
* If userspace is debugging guest then guest
* can not access debug registers.
*/
if (vcpu->guest_debug)
break;
debug_inst = true;
vcpu->arch.dbg_reg.dac2 = spr_val;
break;
case SPRN_DBCR0:
/*
* If userspace is debugging guest then guest
* can not access debug registers.
*/
if (vcpu->guest_debug)
break;
debug_inst = true;
spr_val &= (DBCR0_IDM | DBCR0_IC | DBCR0_BT | DBCR0_TIE |
DBCR0_IAC1 | DBCR0_IAC2 | DBCR0_IAC3 | DBCR0_IAC4 |
DBCR0_DAC1R | DBCR0_DAC1W | DBCR0_DAC2R | DBCR0_DAC2W);
vcpu->arch.dbg_reg.dbcr0 = spr_val;
break;
case SPRN_DBCR1:
/*
* If userspace is debugging guest then guest
* can not access debug registers.
*/
if (vcpu->guest_debug)
break;
debug_inst = true;
vcpu->arch.dbg_reg.dbcr1 = spr_val;
break;
case SPRN_DBCR2:
/*
* If userspace is debugging guest then guest
* can not access debug registers.
*/
if (vcpu->guest_debug)
break;
debug_inst = true;
vcpu->arch.dbg_reg.dbcr2 = spr_val;
break;
case SPRN_DBSR:
/*
* If userspace is debugging guest then guest
* can not access debug registers.
*/
if (vcpu->guest_debug)
break;
vcpu->arch.dbsr &= ~spr_val;
if (!(vcpu->arch.dbsr & ~DBSR_IDE))
kvmppc_core_dequeue_debug(vcpu);
break;
case SPRN_TSR:
kvmppc_clr_tsr_bits(vcpu, spr_val);
break;
case SPRN_TCR:
/*
* WRC is a 2-bit field that is supposed to preserve its
* value once written to non-zero.
*/
if (vcpu->arch.tcr & TCR_WRC_MASK) {
spr_val &= ~TCR_WRC_MASK;
spr_val |= vcpu->arch.tcr & TCR_WRC_MASK;
}
kvmppc_set_tcr(vcpu, spr_val);
break;
case SPRN_DECAR:
vcpu->arch.decar = spr_val;
break;
/*
* Note: SPRG4-7 are user-readable.
* These values are loaded into the real SPRGs when resuming the
* guest (PR-mode only).
*/
case SPRN_SPRG4:
kvmppc_set_sprg4(vcpu, spr_val);
break;
case SPRN_SPRG5:
kvmppc_set_sprg5(vcpu, spr_val);
break;
case SPRN_SPRG6:
kvmppc_set_sprg6(vcpu, spr_val);
break;
case SPRN_SPRG7:
kvmppc_set_sprg7(vcpu, spr_val);
break;
case SPRN_IVPR:
vcpu->arch.ivpr = spr_val;
#ifdef CONFIG_KVM_BOOKE_HV
mtspr(SPRN_GIVPR, spr_val);
#endif
break;
case SPRN_IVOR0:
vcpu->arch.ivor[BOOKE_IRQPRIO_CRITICAL] = spr_val;
break;
case SPRN_IVOR1:
vcpu->arch.ivor[BOOKE_IRQPRIO_MACHINE_CHECK] = spr_val;
break;
case SPRN_IVOR2:
vcpu->arch.ivor[BOOKE_IRQPRIO_DATA_STORAGE] = spr_val;
#ifdef CONFIG_KVM_BOOKE_HV
mtspr(SPRN_GIVOR2, spr_val);
#endif
break;
case SPRN_IVOR3:
vcpu->arch.ivor[BOOKE_IRQPRIO_INST_STORAGE] = spr_val;
break;
case SPRN_IVOR4:
vcpu->arch.ivor[BOOKE_IRQPRIO_EXTERNAL] = spr_val;
break;
case SPRN_IVOR5:
vcpu->arch.ivor[BOOKE_IRQPRIO_ALIGNMENT] = spr_val;
break;
case SPRN_IVOR6:
vcpu->arch.ivor[BOOKE_IRQPRIO_PROGRAM] = spr_val;
break;
case SPRN_IVOR7:
vcpu->arch.ivor[BOOKE_IRQPRIO_FP_UNAVAIL] = spr_val;
break;
case SPRN_IVOR8:
vcpu->arch.ivor[BOOKE_IRQPRIO_SYSCALL] = spr_val;
#ifdef CONFIG_KVM_BOOKE_HV
mtspr(SPRN_GIVOR8, spr_val);
#endif
break;
case SPRN_IVOR9:
vcpu->arch.ivor[BOOKE_IRQPRIO_AP_UNAVAIL] = spr_val;
break;
case SPRN_IVOR10:
vcpu->arch.ivor[BOOKE_IRQPRIO_DECREMENTER] = spr_val;
break;
case SPRN_IVOR11:
vcpu->arch.ivor[BOOKE_IRQPRIO_FIT] = spr_val;
break;
case SPRN_IVOR12:
vcpu->arch.ivor[BOOKE_IRQPRIO_WATCHDOG] = spr_val;
break;
case SPRN_IVOR13:
vcpu->arch.ivor[BOOKE_IRQPRIO_DTLB_MISS] = spr_val;
break;
case SPRN_IVOR14:
vcpu->arch.ivor[BOOKE_IRQPRIO_ITLB_MISS] = spr_val;
break;
case SPRN_IVOR15:
vcpu->arch.ivor[BOOKE_IRQPRIO_DEBUG] = spr_val;
break;
case SPRN_MCSR:
vcpu->arch.mcsr &= ~spr_val;
break;
#if defined(CONFIG_64BIT)
case SPRN_EPCR:
kvmppc_set_epcr(vcpu, spr_val);
#ifdef CONFIG_KVM_BOOKE_HV
mtspr(SPRN_EPCR, vcpu->arch.shadow_epcr);
#endif
break;
#endif
default:
emulated = EMULATE_FAIL;
}
if (debug_inst) {
current->thread.debug = vcpu->arch.dbg_reg;
switch_booke_debug_regs(&vcpu->arch.dbg_reg);
}
return emulated;
}
int kvmppc_booke_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, ulong *spr_val)
{
int emulated = EMULATE_DONE;
switch (sprn) {
case SPRN_IVPR:
*spr_val = vcpu->arch.ivpr;
break;
case SPRN_DEAR:
*spr_val = vcpu->arch.shared->dar;
break;
case SPRN_ESR:
*spr_val = vcpu->arch.shared->esr;
break;
case SPRN_EPR:
*spr_val = vcpu->arch.epr;
break;
case SPRN_CSRR0:
*spr_val = vcpu->arch.csrr0;
break;
case SPRN_CSRR1:
*spr_val = vcpu->arch.csrr1;
break;
case SPRN_DSRR0:
*spr_val = vcpu->arch.dsrr0;
break;
case SPRN_DSRR1:
*spr_val = vcpu->arch.dsrr1;
break;
case SPRN_IAC1:
*spr_val = vcpu->arch.dbg_reg.iac1;
break;
case SPRN_IAC2:
*spr_val = vcpu->arch.dbg_reg.iac2;
break;
#if CONFIG_PPC_ADV_DEBUG_IACS > 2
case SPRN_IAC3:
*spr_val = vcpu->arch.dbg_reg.iac3;
break;
case SPRN_IAC4:
*spr_val = vcpu->arch.dbg_reg.iac4;
break;
#endif
case SPRN_DAC1:
*spr_val = vcpu->arch.dbg_reg.dac1;
break;
case SPRN_DAC2:
*spr_val = vcpu->arch.dbg_reg.dac2;
break;
case SPRN_DBCR0:
*spr_val = vcpu->arch.dbg_reg.dbcr0;
if (vcpu->guest_debug)
*spr_val = *spr_val | DBCR0_EDM;
break;
case SPRN_DBCR1:
*spr_val = vcpu->arch.dbg_reg.dbcr1;
break;
case SPRN_DBCR2:
*spr_val = vcpu->arch.dbg_reg.dbcr2;
break;
case SPRN_DBSR:
*spr_val = vcpu->arch.dbsr;
break;
case SPRN_TSR:
*spr_val = vcpu->arch.tsr;
break;
case SPRN_TCR:
*spr_val = vcpu->arch.tcr;
break;
case SPRN_IVOR0:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_CRITICAL];
break;
case SPRN_IVOR1:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_MACHINE_CHECK];
break;
case SPRN_IVOR2:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_DATA_STORAGE];
break;
case SPRN_IVOR3:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_INST_STORAGE];
break;
case SPRN_IVOR4:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_EXTERNAL];
break;
case SPRN_IVOR5:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_ALIGNMENT];
break;
case SPRN_IVOR6:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_PROGRAM];
break;
case SPRN_IVOR7:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_FP_UNAVAIL];
break;
case SPRN_IVOR8:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_SYSCALL];
break;
case SPRN_IVOR9:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_AP_UNAVAIL];
break;
case SPRN_IVOR10:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_DECREMENTER];
break;
case SPRN_IVOR11:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_FIT];
break;
case SPRN_IVOR12:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_WATCHDOG];
break;
case SPRN_IVOR13:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_DTLB_MISS];
break;
case SPRN_IVOR14:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_ITLB_MISS];
break;
case SPRN_IVOR15:
*spr_val = vcpu->arch.ivor[BOOKE_IRQPRIO_DEBUG];
break;
case SPRN_MCSR:
*spr_val = vcpu->arch.mcsr;
break;
#if defined(CONFIG_64BIT)
case SPRN_EPCR:
*spr_val = vcpu->arch.epcr;
break;
#endif
default:
emulated = EMULATE_FAIL;
}
return emulated;
}