forked from mirrors/linux
c43befca86
This changes the KVM code that emulates the decrementer function to do the conversion of decrementer values to time intervals in nanoseconds by calling the tb_to_ns() function exported by the powerpc timer code, in preference to open-coded arithmetic using values from the decrementer_clockevent struct. Similarly, the HV-KVM code that did the same conversion using arithmetic on tb_ticks_per_sec also now uses tb_to_ns(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
317 lines
7.3 KiB
C
317 lines
7.3 KiB
C
/*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* Copyright IBM Corp. 2007
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* Copyright 2011 Freescale Semiconductor, Inc.
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*
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* Authors: Hollis Blanchard <hollisb@us.ibm.com>
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*/
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#include <linux/jiffies.h>
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#include <linux/hrtimer.h>
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#include <linux/types.h>
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#include <linux/string.h>
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#include <linux/kvm_host.h>
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#include <linux/clockchips.h>
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#include <asm/reg.h>
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#include <asm/time.h>
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#include <asm/byteorder.h>
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#include <asm/kvm_ppc.h>
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#include <asm/disassemble.h>
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#include <asm/ppc-opcode.h>
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#include "timing.h"
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#include "trace.h"
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void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
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{
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unsigned long dec_nsec;
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unsigned long long dec_time;
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pr_debug("mtDEC: %lx\n", vcpu->arch.dec);
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hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
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#ifdef CONFIG_PPC_BOOK3S
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/* mtdec lowers the interrupt line when positive. */
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kvmppc_core_dequeue_dec(vcpu);
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#endif
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#ifdef CONFIG_BOOKE
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/* On BOOKE, DEC = 0 is as good as decrementer not enabled */
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if (vcpu->arch.dec == 0)
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return;
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#endif
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/*
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* The decrementer ticks at the same rate as the timebase, so
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* that's how we convert the guest DEC value to the number of
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* host ticks.
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*/
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dec_time = vcpu->arch.dec;
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/*
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* Guest timebase ticks at the same frequency as host timebase.
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* So use the host timebase calculations for decrementer emulation.
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*/
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dec_time = tb_to_ns(dec_time);
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dec_nsec = do_div(dec_time, NSEC_PER_SEC);
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hrtimer_start(&vcpu->arch.dec_timer,
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ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
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vcpu->arch.dec_jiffies = get_tb();
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}
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u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
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{
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u64 jd = tb - vcpu->arch.dec_jiffies;
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#ifdef CONFIG_BOOKE
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if (vcpu->arch.dec < jd)
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return 0;
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#endif
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return vcpu->arch.dec - jd;
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}
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static int kvmppc_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
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{
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enum emulation_result emulated = EMULATE_DONE;
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ulong spr_val = kvmppc_get_gpr(vcpu, rs);
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switch (sprn) {
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case SPRN_SRR0:
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kvmppc_set_srr0(vcpu, spr_val);
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break;
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case SPRN_SRR1:
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kvmppc_set_srr1(vcpu, spr_val);
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break;
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/* XXX We need to context-switch the timebase for
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* watchdog and FIT. */
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case SPRN_TBWL: break;
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case SPRN_TBWU: break;
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case SPRN_DEC:
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vcpu->arch.dec = (u32) spr_val;
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kvmppc_emulate_dec(vcpu);
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break;
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case SPRN_SPRG0:
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kvmppc_set_sprg0(vcpu, spr_val);
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break;
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case SPRN_SPRG1:
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kvmppc_set_sprg1(vcpu, spr_val);
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break;
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case SPRN_SPRG2:
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kvmppc_set_sprg2(vcpu, spr_val);
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break;
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case SPRN_SPRG3:
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kvmppc_set_sprg3(vcpu, spr_val);
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break;
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/* PIR can legally be written, but we ignore it */
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case SPRN_PIR: break;
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default:
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emulated = vcpu->kvm->arch.kvm_ops->emulate_mtspr(vcpu, sprn,
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spr_val);
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if (emulated == EMULATE_FAIL)
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printk(KERN_INFO "mtspr: unknown spr "
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"0x%x\n", sprn);
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break;
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}
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kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
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return emulated;
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}
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static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
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{
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enum emulation_result emulated = EMULATE_DONE;
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ulong spr_val = 0;
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switch (sprn) {
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case SPRN_SRR0:
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spr_val = kvmppc_get_srr0(vcpu);
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break;
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case SPRN_SRR1:
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spr_val = kvmppc_get_srr1(vcpu);
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break;
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case SPRN_PVR:
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spr_val = vcpu->arch.pvr;
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break;
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case SPRN_PIR:
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spr_val = vcpu->vcpu_id;
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break;
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/* Note: mftb and TBRL/TBWL are user-accessible, so
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* the guest can always access the real TB anyways.
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* In fact, we probably will never see these traps. */
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case SPRN_TBWL:
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spr_val = get_tb() >> 32;
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break;
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case SPRN_TBWU:
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spr_val = get_tb();
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break;
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case SPRN_SPRG0:
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spr_val = kvmppc_get_sprg0(vcpu);
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break;
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case SPRN_SPRG1:
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spr_val = kvmppc_get_sprg1(vcpu);
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break;
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case SPRN_SPRG2:
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spr_val = kvmppc_get_sprg2(vcpu);
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break;
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case SPRN_SPRG3:
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spr_val = kvmppc_get_sprg3(vcpu);
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break;
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/* Note: SPRG4-7 are user-readable, so we don't get
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* a trap. */
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case SPRN_DEC:
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spr_val = kvmppc_get_dec(vcpu, get_tb());
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break;
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default:
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emulated = vcpu->kvm->arch.kvm_ops->emulate_mfspr(vcpu, sprn,
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&spr_val);
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if (unlikely(emulated == EMULATE_FAIL)) {
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printk(KERN_INFO "mfspr: unknown spr "
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"0x%x\n", sprn);
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}
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break;
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}
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if (emulated == EMULATE_DONE)
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kvmppc_set_gpr(vcpu, rt, spr_val);
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kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
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return emulated;
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}
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/* XXX Should probably auto-generate instruction decoding for a particular core
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* from opcode tables in the future. */
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int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
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{
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u32 inst;
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int rs, rt, sprn;
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enum emulation_result emulated;
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int advance = 1;
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/* this default type might be overwritten by subcategories */
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kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
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emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst);
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if (emulated != EMULATE_DONE)
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return emulated;
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pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
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rs = get_rs(inst);
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rt = get_rt(inst);
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sprn = get_sprn(inst);
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switch (get_op(inst)) {
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case OP_TRAP:
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#ifdef CONFIG_PPC_BOOK3S
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case OP_TRAP_64:
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kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
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#else
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kvmppc_core_queue_program(vcpu,
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vcpu->arch.shared->esr | ESR_PTR);
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#endif
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advance = 0;
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break;
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case 31:
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switch (get_xop(inst)) {
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case OP_31_XOP_TRAP:
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#ifdef CONFIG_64BIT
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case OP_31_XOP_TRAP_64:
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#endif
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#ifdef CONFIG_PPC_BOOK3S
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kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
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#else
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kvmppc_core_queue_program(vcpu,
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vcpu->arch.shared->esr | ESR_PTR);
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#endif
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advance = 0;
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break;
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case OP_31_XOP_MFSPR:
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emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt);
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if (emulated == EMULATE_AGAIN) {
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emulated = EMULATE_DONE;
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advance = 0;
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}
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break;
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case OP_31_XOP_MTSPR:
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emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs);
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if (emulated == EMULATE_AGAIN) {
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emulated = EMULATE_DONE;
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advance = 0;
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}
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break;
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case OP_31_XOP_TLBSYNC:
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break;
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default:
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/* Attempt core-specific emulation below. */
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emulated = EMULATE_FAIL;
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}
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break;
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case 0:
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/*
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* Instruction with primary opcode 0. Based on PowerISA
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* these are illegal instructions.
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*/
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if (inst == KVMPPC_INST_SW_BREAKPOINT) {
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run->exit_reason = KVM_EXIT_DEBUG;
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run->debug.arch.address = kvmppc_get_pc(vcpu);
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emulated = EMULATE_EXIT_USER;
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advance = 0;
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} else
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emulated = EMULATE_FAIL;
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break;
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default:
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emulated = EMULATE_FAIL;
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}
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if (emulated == EMULATE_FAIL) {
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emulated = vcpu->kvm->arch.kvm_ops->emulate_op(run, vcpu, inst,
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&advance);
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if (emulated == EMULATE_AGAIN) {
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advance = 0;
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} else if (emulated == EMULATE_FAIL) {
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advance = 0;
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printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
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"(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
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}
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}
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trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
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/* Advance past emulated instruction. */
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if (advance)
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kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
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return emulated;
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}
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EXPORT_SYMBOL_GPL(kvmppc_emulate_instruction);
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