/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * KVM/MIPS: Instruction/Exception emulation * * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved. * Authors: Sanjay Lal */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #undef CONFIG_MIPS_MT #include #define CONFIG_MIPS_MT #include "interrupt.h" #include "commpage.h" #include "trace.h" /* * Compute the return address and do emulate branch simulation, if required. * This function should be called only in branch delay slot active. */ static int kvm_compute_return_epc(struct kvm_vcpu *vcpu, unsigned long instpc, unsigned long *out) { unsigned int dspcontrol; union mips_instruction insn; struct kvm_vcpu_arch *arch = &vcpu->arch; long epc = instpc; long nextpc; int err; if (epc & 3) { kvm_err("%s: unaligned epc\n", __func__); return -EINVAL; } /* Read the instruction */ err = kvm_get_badinstrp((u32 *)epc, vcpu, &insn.word); if (err) return err; switch (insn.i_format.opcode) { /* jr and jalr are in r_format format. */ case spec_op: switch (insn.r_format.func) { case jalr_op: arch->gprs[insn.r_format.rd] = epc + 8; /* Fall through */ case jr_op: nextpc = arch->gprs[insn.r_format.rs]; break; default: return -EINVAL; } break; /* * This group contains: * bltz_op, bgez_op, bltzl_op, bgezl_op, * bltzal_op, bgezal_op, bltzall_op, bgezall_op. */ case bcond_op: switch (insn.i_format.rt) { case bltz_op: case bltzl_op: if ((long)arch->gprs[insn.i_format.rs] < 0) epc = epc + 4 + (insn.i_format.simmediate << 2); else epc += 8; nextpc = epc; break; case bgez_op: case bgezl_op: if ((long)arch->gprs[insn.i_format.rs] >= 0) epc = epc + 4 + (insn.i_format.simmediate << 2); else epc += 8; nextpc = epc; break; case bltzal_op: case bltzall_op: arch->gprs[31] = epc + 8; if ((long)arch->gprs[insn.i_format.rs] < 0) epc = epc + 4 + (insn.i_format.simmediate << 2); else epc += 8; nextpc = epc; break; case bgezal_op: case bgezall_op: arch->gprs[31] = epc + 8; if ((long)arch->gprs[insn.i_format.rs] >= 0) epc = epc + 4 + (insn.i_format.simmediate << 2); else epc += 8; nextpc = epc; break; case bposge32_op: if (!cpu_has_dsp) { kvm_err("%s: DSP branch but not DSP ASE\n", __func__); return -EINVAL; } dspcontrol = rddsp(0x01); if (dspcontrol >= 32) epc = epc + 4 + (insn.i_format.simmediate << 2); else epc += 8; nextpc = epc; break; default: return -EINVAL; } break; /* These are unconditional and in j_format. */ case jal_op: arch->gprs[31] = instpc + 8; case j_op: epc += 4; epc >>= 28; epc <<= 28; epc |= (insn.j_format.target << 2); nextpc = epc; break; /* These are conditional and in i_format. */ case beq_op: case beql_op: if (arch->gprs[insn.i_format.rs] == arch->gprs[insn.i_format.rt]) epc = epc + 4 + (insn.i_format.simmediate << 2); else epc += 8; nextpc = epc; break; case bne_op: case bnel_op: if (arch->gprs[insn.i_format.rs] != arch->gprs[insn.i_format.rt]) epc = epc + 4 + (insn.i_format.simmediate << 2); else epc += 8; nextpc = epc; break; case blez_op: /* POP06 */ #ifndef CONFIG_CPU_MIPSR6 case blezl_op: /* removed in R6 */ #endif if (insn.i_format.rt != 0) goto compact_branch; if ((long)arch->gprs[insn.i_format.rs] <= 0) epc = epc + 4 + (insn.i_format.simmediate << 2); else epc += 8; nextpc = epc; break; case bgtz_op: /* POP07 */ #ifndef CONFIG_CPU_MIPSR6 case bgtzl_op: /* removed in R6 */ #endif if (insn.i_format.rt != 0) goto compact_branch; if ((long)arch->gprs[insn.i_format.rs] > 0) epc = epc + 4 + (insn.i_format.simmediate << 2); else epc += 8; nextpc = epc; break; /* And now the FPA/cp1 branch instructions. */ case cop1_op: kvm_err("%s: unsupported cop1_op\n", __func__); return -EINVAL; #ifdef CONFIG_CPU_MIPSR6 /* R6 added the following compact branches with forbidden slots */ case blezl_op: /* POP26 */ case bgtzl_op: /* POP27 */ /* only rt == 0 isn't compact branch */ if (insn.i_format.rt != 0) goto compact_branch; return -EINVAL; case pop10_op: case pop30_op: /* only rs == rt == 0 is reserved, rest are compact branches */ if (insn.i_format.rs != 0 || insn.i_format.rt != 0) goto compact_branch; return -EINVAL; case pop66_op: case pop76_op: /* only rs == 0 isn't compact branch */ if (insn.i_format.rs != 0) goto compact_branch; return -EINVAL; compact_branch: /* * If we've hit an exception on the forbidden slot, then * the branch must not have been taken. */ epc += 8; nextpc = epc; break; #else compact_branch: /* Fall through - Compact branches not supported before R6 */ #endif default: return -EINVAL; } *out = nextpc; return 0; } enum emulation_result update_pc(struct kvm_vcpu *vcpu, u32 cause) { int err; if (cause & CAUSEF_BD) { err = kvm_compute_return_epc(vcpu, vcpu->arch.pc, &vcpu->arch.pc); if (err) return EMULATE_FAIL; } else { vcpu->arch.pc += 4; } kvm_debug("update_pc(): New PC: %#lx\n", vcpu->arch.pc); return EMULATE_DONE; } /** * kvm_get_badinstr() - Get bad instruction encoding. * @opc: Guest pointer to faulting instruction. * @vcpu: KVM VCPU information. * * Gets the instruction encoding of the faulting instruction, using the saved * BadInstr register value if it exists, otherwise falling back to reading guest * memory at @opc. * * Returns: The instruction encoding of the faulting instruction. */ int kvm_get_badinstr(u32 *opc, struct kvm_vcpu *vcpu, u32 *out) { if (cpu_has_badinstr) { *out = vcpu->arch.host_cp0_badinstr; return 0; } else { return kvm_get_inst(opc, vcpu, out); } } /** * kvm_get_badinstrp() - Get bad prior instruction encoding. * @opc: Guest pointer to prior faulting instruction. * @vcpu: KVM VCPU information. * * Gets the instruction encoding of the prior faulting instruction (the branch * containing the delay slot which faulted), using the saved BadInstrP register * value if it exists, otherwise falling back to reading guest memory at @opc. * * Returns: The instruction encoding of the prior faulting instruction. */ int kvm_get_badinstrp(u32 *opc, struct kvm_vcpu *vcpu, u32 *out) { if (cpu_has_badinstrp) { *out = vcpu->arch.host_cp0_badinstrp; return 0; } else { return kvm_get_inst(opc, vcpu, out); } } /** * kvm_mips_count_disabled() - Find whether the CP0_Count timer is disabled. * @vcpu: Virtual CPU. * * Returns: 1 if the CP0_Count timer is disabled by either the guest * CP0_Cause.DC bit or the count_ctl.DC bit. * 0 otherwise (in which case CP0_Count timer is running). */ static inline int kvm_mips_count_disabled(struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; return (vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC) || (kvm_read_c0_guest_cause(cop0) & CAUSEF_DC); } /** * kvm_mips_ktime_to_count() - Scale ktime_t to a 32-bit count. * * Caches the dynamic nanosecond bias in vcpu->arch.count_dyn_bias. * * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running). */ static u32 kvm_mips_ktime_to_count(struct kvm_vcpu *vcpu, ktime_t now) { s64 now_ns, periods; u64 delta; now_ns = ktime_to_ns(now); delta = now_ns + vcpu->arch.count_dyn_bias; if (delta >= vcpu->arch.count_period) { /* If delta is out of safe range the bias needs adjusting */ periods = div64_s64(now_ns, vcpu->arch.count_period); vcpu->arch.count_dyn_bias = -periods * vcpu->arch.count_period; /* Recalculate delta with new bias */ delta = now_ns + vcpu->arch.count_dyn_bias; } /* * We've ensured that: * delta < count_period * * Therefore the intermediate delta*count_hz will never overflow since * at the boundary condition: * delta = count_period * delta = NSEC_PER_SEC * 2^32 / count_hz * delta * count_hz = NSEC_PER_SEC * 2^32 */ return div_u64(delta * vcpu->arch.count_hz, NSEC_PER_SEC); } /** * kvm_mips_count_time() - Get effective current time. * @vcpu: Virtual CPU. * * Get effective monotonic ktime. This is usually a straightforward ktime_get(), * except when the master disable bit is set in count_ctl, in which case it is * count_resume, i.e. the time that the count was disabled. * * Returns: Effective monotonic ktime for CP0_Count. */ static inline ktime_t kvm_mips_count_time(struct kvm_vcpu *vcpu) { if (unlikely(vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC)) return vcpu->arch.count_resume; return ktime_get(); } /** * kvm_mips_read_count_running() - Read the current count value as if running. * @vcpu: Virtual CPU. * @now: Kernel time to read CP0_Count at. * * Returns the current guest CP0_Count register at time @now and handles if the * timer interrupt is pending and hasn't been handled yet. * * Returns: The current value of the guest CP0_Count register. */ static u32 kvm_mips_read_count_running(struct kvm_vcpu *vcpu, ktime_t now) { struct mips_coproc *cop0 = vcpu->arch.cop0; ktime_t expires, threshold; u32 count, compare; int running; /* Calculate the biased and scaled guest CP0_Count */ count = vcpu->arch.count_bias + kvm_mips_ktime_to_count(vcpu, now); compare = kvm_read_c0_guest_compare(cop0); /* * Find whether CP0_Count has reached the closest timer interrupt. If * not, we shouldn't inject it. */ if ((s32)(count - compare) < 0) return count; /* * The CP0_Count we're going to return has already reached the closest * timer interrupt. Quickly check if it really is a new interrupt by * looking at whether the interval until the hrtimer expiry time is * less than 1/4 of the timer period. */ expires = hrtimer_get_expires(&vcpu->arch.comparecount_timer); threshold = ktime_add_ns(now, vcpu->arch.count_period / 4); if (ktime_before(expires, threshold)) { /* * Cancel it while we handle it so there's no chance of * interference with the timeout handler. */ running = hrtimer_cancel(&vcpu->arch.comparecount_timer); /* Nothing should be waiting on the timeout */ kvm_mips_callbacks->queue_timer_int(vcpu); /* * Restart the timer if it was running based on the expiry time * we read, so that we don't push it back 2 periods. */ if (running) { expires = ktime_add_ns(expires, vcpu->arch.count_period); hrtimer_start(&vcpu->arch.comparecount_timer, expires, HRTIMER_MODE_ABS); } } return count; } /** * kvm_mips_read_count() - Read the current count value. * @vcpu: Virtual CPU. * * Read the current guest CP0_Count value, taking into account whether the timer * is stopped. * * Returns: The current guest CP0_Count value. */ u32 kvm_mips_read_count(struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; /* If count disabled just read static copy of count */ if (kvm_mips_count_disabled(vcpu)) return kvm_read_c0_guest_count(cop0); return kvm_mips_read_count_running(vcpu, ktime_get()); } /** * kvm_mips_freeze_hrtimer() - Safely stop the hrtimer. * @vcpu: Virtual CPU. * @count: Output pointer for CP0_Count value at point of freeze. * * Freeze the hrtimer safely and return both the ktime and the CP0_Count value * at the point it was frozen. It is guaranteed that any pending interrupts at * the point it was frozen are handled, and none after that point. * * This is useful where the time/CP0_Count is needed in the calculation of the * new parameters. * * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running). * * Returns: The ktime at the point of freeze. */ static ktime_t kvm_mips_freeze_hrtimer(struct kvm_vcpu *vcpu, u32 *count) { ktime_t now; /* stop hrtimer before finding time */ hrtimer_cancel(&vcpu->arch.comparecount_timer); now = ktime_get(); /* find count at this point and handle pending hrtimer */ *count = kvm_mips_read_count_running(vcpu, now); return now; } /** * kvm_mips_resume_hrtimer() - Resume hrtimer, updating expiry. * @vcpu: Virtual CPU. * @now: ktime at point of resume. * @count: CP0_Count at point of resume. * * Resumes the timer and updates the timer expiry based on @now and @count. * This can be used in conjunction with kvm_mips_freeze_timer() when timer * parameters need to be changed. * * It is guaranteed that a timer interrupt immediately after resume will be * handled, but not if CP_Compare is exactly at @count. That case is already * handled by kvm_mips_freeze_timer(). * * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running). */ static void kvm_mips_resume_hrtimer(struct kvm_vcpu *vcpu, ktime_t now, u32 count) { struct mips_coproc *cop0 = vcpu->arch.cop0; u32 compare; u64 delta; ktime_t expire; /* Calculate timeout (wrap 0 to 2^32) */ compare = kvm_read_c0_guest_compare(cop0); delta = (u64)(u32)(compare - count - 1) + 1; delta = div_u64(delta * NSEC_PER_SEC, vcpu->arch.count_hz); expire = ktime_add_ns(now, delta); /* Update hrtimer to use new timeout */ hrtimer_cancel(&vcpu->arch.comparecount_timer); hrtimer_start(&vcpu->arch.comparecount_timer, expire, HRTIMER_MODE_ABS); } /** * kvm_mips_write_count() - Modify the count and update timer. * @vcpu: Virtual CPU. * @count: Guest CP0_Count value to set. * * Sets the CP0_Count value and updates the timer accordingly. */ void kvm_mips_write_count(struct kvm_vcpu *vcpu, u32 count) { struct mips_coproc *cop0 = vcpu->arch.cop0; ktime_t now; /* Calculate bias */ now = kvm_mips_count_time(vcpu); vcpu->arch.count_bias = count - kvm_mips_ktime_to_count(vcpu, now); if (kvm_mips_count_disabled(vcpu)) /* The timer's disabled, adjust the static count */ kvm_write_c0_guest_count(cop0, count); else /* Update timeout */ kvm_mips_resume_hrtimer(vcpu, now, count); } /** * kvm_mips_init_count() - Initialise timer. * @vcpu: Virtual CPU. * * Initialise the timer to a sensible frequency, namely 100MHz, zero it, and set * it going if it's enabled. */ void kvm_mips_init_count(struct kvm_vcpu *vcpu) { /* 100 MHz */ vcpu->arch.count_hz = 100*1000*1000; vcpu->arch.count_period = div_u64((u64)NSEC_PER_SEC << 32, vcpu->arch.count_hz); vcpu->arch.count_dyn_bias = 0; /* Starting at 0 */ kvm_mips_write_count(vcpu, 0); } /** * kvm_mips_set_count_hz() - Update the frequency of the timer. * @vcpu: Virtual CPU. * @count_hz: Frequency of CP0_Count timer in Hz. * * Change the frequency of the CP0_Count timer. This is done atomically so that * CP0_Count is continuous and no timer interrupt is lost. * * Returns: -EINVAL if @count_hz is out of range. * 0 on success. */ int kvm_mips_set_count_hz(struct kvm_vcpu *vcpu, s64 count_hz) { struct mips_coproc *cop0 = vcpu->arch.cop0; int dc; ktime_t now; u32 count; /* ensure the frequency is in a sensible range... */ if (count_hz <= 0 || count_hz > NSEC_PER_SEC) return -EINVAL; /* ... and has actually changed */ if (vcpu->arch.count_hz == count_hz) return 0; /* Safely freeze timer so we can keep it continuous */ dc = kvm_mips_count_disabled(vcpu); if (dc) { now = kvm_mips_count_time(vcpu); count = kvm_read_c0_guest_count(cop0); } else { now = kvm_mips_freeze_hrtimer(vcpu, &count); } /* Update the frequency */ vcpu->arch.count_hz = count_hz; vcpu->arch.count_period = div_u64((u64)NSEC_PER_SEC << 32, count_hz); vcpu->arch.count_dyn_bias = 0; /* Calculate adjusted bias so dynamic count is unchanged */ vcpu->arch.count_bias = count - kvm_mips_ktime_to_count(vcpu, now); /* Update and resume hrtimer */ if (!dc) kvm_mips_resume_hrtimer(vcpu, now, count); return 0; } /** * kvm_mips_write_compare() - Modify compare and update timer. * @vcpu: Virtual CPU. * @compare: New CP0_Compare value. * @ack: Whether to acknowledge timer interrupt. * * Update CP0_Compare to a new value and update the timeout. * If @ack, atomically acknowledge any pending timer interrupt, otherwise ensure * any pending timer interrupt is preserved. */ void kvm_mips_write_compare(struct kvm_vcpu *vcpu, u32 compare, bool ack) { struct mips_coproc *cop0 = vcpu->arch.cop0; int dc; u32 old_compare = kvm_read_c0_guest_compare(cop0); ktime_t now; u32 count; /* if unchanged, must just be an ack */ if (old_compare == compare) { if (!ack) return; kvm_mips_callbacks->dequeue_timer_int(vcpu); kvm_write_c0_guest_compare(cop0, compare); return; } /* freeze_hrtimer() takes care of timer interrupts <= count */ dc = kvm_mips_count_disabled(vcpu); if (!dc) now = kvm_mips_freeze_hrtimer(vcpu, &count); if (ack) kvm_mips_callbacks->dequeue_timer_int(vcpu); kvm_write_c0_guest_compare(cop0, compare); /* resume_hrtimer() takes care of timer interrupts > count */ if (!dc) kvm_mips_resume_hrtimer(vcpu, now, count); } /** * kvm_mips_count_disable() - Disable count. * @vcpu: Virtual CPU. * * Disable the CP0_Count timer. A timer interrupt on or before the final stop * time will be handled but not after. * * Assumes CP0_Count was previously enabled but now Guest.CP0_Cause.DC or * count_ctl.DC has been set (count disabled). * * Returns: The time that the timer was stopped. */ static ktime_t kvm_mips_count_disable(struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; u32 count; ktime_t now; /* Stop hrtimer */ hrtimer_cancel(&vcpu->arch.comparecount_timer); /* Set the static count from the dynamic count, handling pending TI */ now = ktime_get(); count = kvm_mips_read_count_running(vcpu, now); kvm_write_c0_guest_count(cop0, count); return now; } /** * kvm_mips_count_disable_cause() - Disable count using CP0_Cause.DC. * @vcpu: Virtual CPU. * * Disable the CP0_Count timer and set CP0_Cause.DC. A timer interrupt on or * before the final stop time will be handled if the timer isn't disabled by * count_ctl.DC, but not after. * * Assumes CP0_Cause.DC is clear (count enabled). */ void kvm_mips_count_disable_cause(struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; kvm_set_c0_guest_cause(cop0, CAUSEF_DC); if (!(vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC)) kvm_mips_count_disable(vcpu); } /** * kvm_mips_count_enable_cause() - Enable count using CP0_Cause.DC. * @vcpu: Virtual CPU. * * Enable the CP0_Count timer and clear CP0_Cause.DC. A timer interrupt after * the start time will be handled if the timer isn't disabled by count_ctl.DC, * potentially before even returning, so the caller should be careful with * ordering of CP0_Cause modifications so as not to lose it. * * Assumes CP0_Cause.DC is set (count disabled). */ void kvm_mips_count_enable_cause(struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; u32 count; kvm_clear_c0_guest_cause(cop0, CAUSEF_DC); /* * Set the dynamic count to match the static count. * This starts the hrtimer if count_ctl.DC allows it. * Otherwise it conveniently updates the biases. */ count = kvm_read_c0_guest_count(cop0); kvm_mips_write_count(vcpu, count); } /** * kvm_mips_set_count_ctl() - Update the count control KVM register. * @vcpu: Virtual CPU. * @count_ctl: Count control register new value. * * Set the count control KVM register. The timer is updated accordingly. * * Returns: -EINVAL if reserved bits are set. * 0 on success. */ int kvm_mips_set_count_ctl(struct kvm_vcpu *vcpu, s64 count_ctl) { struct mips_coproc *cop0 = vcpu->arch.cop0; s64 changed = count_ctl ^ vcpu->arch.count_ctl; s64 delta; ktime_t expire, now; u32 count, compare; /* Only allow defined bits to be changed */ if (changed & ~(s64)(KVM_REG_MIPS_COUNT_CTL_DC)) return -EINVAL; /* Apply new value */ vcpu->arch.count_ctl = count_ctl; /* Master CP0_Count disable */ if (changed & KVM_REG_MIPS_COUNT_CTL_DC) { /* Is CP0_Cause.DC already disabling CP0_Count? */ if (kvm_read_c0_guest_cause(cop0) & CAUSEF_DC) { if (count_ctl & KVM_REG_MIPS_COUNT_CTL_DC) /* Just record the current time */ vcpu->arch.count_resume = ktime_get(); } else if (count_ctl & KVM_REG_MIPS_COUNT_CTL_DC) { /* disable timer and record current time */ vcpu->arch.count_resume = kvm_mips_count_disable(vcpu); } else { /* * Calculate timeout relative to static count at resume * time (wrap 0 to 2^32). */ count = kvm_read_c0_guest_count(cop0); compare = kvm_read_c0_guest_compare(cop0); delta = (u64)(u32)(compare - count - 1) + 1; delta = div_u64(delta * NSEC_PER_SEC, vcpu->arch.count_hz); expire = ktime_add_ns(vcpu->arch.count_resume, delta); /* Handle pending interrupt */ now = ktime_get(); if (ktime_compare(now, expire) >= 0) /* Nothing should be waiting on the timeout */ kvm_mips_callbacks->queue_timer_int(vcpu); /* Resume hrtimer without changing bias */ count = kvm_mips_read_count_running(vcpu, now); kvm_mips_resume_hrtimer(vcpu, now, count); } } return 0; } /** * kvm_mips_set_count_resume() - Update the count resume KVM register. * @vcpu: Virtual CPU. * @count_resume: Count resume register new value. * * Set the count resume KVM register. * * Returns: -EINVAL if out of valid range (0..now). * 0 on success. */ int kvm_mips_set_count_resume(struct kvm_vcpu *vcpu, s64 count_resume) { /* * It doesn't make sense for the resume time to be in the future, as it * would be possible for the next interrupt to be more than a full * period in the future. */ if (count_resume < 0 || count_resume > ktime_to_ns(ktime_get())) return -EINVAL; vcpu->arch.count_resume = ns_to_ktime(count_resume); return 0; } /** * kvm_mips_count_timeout() - Push timer forward on timeout. * @vcpu: Virtual CPU. * * Handle an hrtimer event by push the hrtimer forward a period. * * Returns: The hrtimer_restart value to return to the hrtimer subsystem. */ enum hrtimer_restart kvm_mips_count_timeout(struct kvm_vcpu *vcpu) { /* Add the Count period to the current expiry time */ hrtimer_add_expires_ns(&vcpu->arch.comparecount_timer, vcpu->arch.count_period); return HRTIMER_RESTART; } enum emulation_result kvm_mips_emul_eret(struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; enum emulation_result er = EMULATE_DONE; if (kvm_read_c0_guest_status(cop0) & ST0_ERL) { kvm_clear_c0_guest_status(cop0, ST0_ERL); vcpu->arch.pc = kvm_read_c0_guest_errorepc(cop0); } else if (kvm_read_c0_guest_status(cop0) & ST0_EXL) { kvm_debug("[%#lx] ERET to %#lx\n", vcpu->arch.pc, kvm_read_c0_guest_epc(cop0)); kvm_clear_c0_guest_status(cop0, ST0_EXL); vcpu->arch.pc = kvm_read_c0_guest_epc(cop0); } else { kvm_err("[%#lx] ERET when MIPS_SR_EXL|MIPS_SR_ERL == 0\n", vcpu->arch.pc); er = EMULATE_FAIL; } return er; } enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu) { kvm_debug("[%#lx] !!!WAIT!!! (%#lx)\n", vcpu->arch.pc, vcpu->arch.pending_exceptions); ++vcpu->stat.wait_exits; trace_kvm_exit(vcpu, KVM_TRACE_EXIT_WAIT); if (!vcpu->arch.pending_exceptions) { vcpu->arch.wait = 1; kvm_vcpu_block(vcpu); /* * We we are runnable, then definitely go off to user space to * check if any I/O interrupts are pending. */ if (kvm_check_request(KVM_REQ_UNHALT, vcpu)) { clear_bit(KVM_REQ_UNHALT, &vcpu->requests); vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN; } } return EMULATE_DONE; } /* * XXXKYMA: Linux doesn't seem to use TLBR, return EMULATE_FAIL for now so that * we can catch this, if things ever change */ enum emulation_result kvm_mips_emul_tlbr(struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; unsigned long pc = vcpu->arch.pc; kvm_err("[%#lx] COP0_TLBR [%ld]\n", pc, kvm_read_c0_guest_index(cop0)); return EMULATE_FAIL; } /** * kvm_mips_invalidate_guest_tlb() - Indicates a change in guest MMU map. * @vcpu: VCPU with changed mappings. * @tlb: TLB entry being removed. * * This is called to indicate a single change in guest MMU mappings, so that we * can arrange TLB flushes on this and other CPUs. */ static void kvm_mips_invalidate_guest_tlb(struct kvm_vcpu *vcpu, struct kvm_mips_tlb *tlb) { struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm; struct mm_struct *user_mm = &vcpu->arch.guest_user_mm; int cpu, i; bool user; /* No need to flush for entries which are already invalid */ if (!((tlb->tlb_lo[0] | tlb->tlb_lo[1]) & ENTRYLO_V)) return; /* Don't touch host kernel page tables or TLB mappings */ if ((unsigned long)tlb->tlb_hi > 0x7fffffff) return; /* User address space doesn't need flushing for KSeg2/3 changes */ user = tlb->tlb_hi < KVM_GUEST_KSEG0; preempt_disable(); /* Invalidate page table entries */ kvm_trap_emul_invalidate_gva(vcpu, tlb->tlb_hi & VPN2_MASK, user); /* * Probe the shadow host TLB for the entry being overwritten, if one * matches, invalidate it */ kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi, user, true); /* Invalidate the whole ASID on other CPUs */ cpu = smp_processor_id(); for_each_possible_cpu(i) { if (i == cpu) continue; if (user) cpu_context(i, user_mm) = 0; cpu_context(i, kern_mm) = 0; } preempt_enable(); } /* Write Guest TLB Entry @ Index */ enum emulation_result kvm_mips_emul_tlbwi(struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; int index = kvm_read_c0_guest_index(cop0); struct kvm_mips_tlb *tlb = NULL; unsigned long pc = vcpu->arch.pc; if (index < 0 || index >= KVM_MIPS_GUEST_TLB_SIZE) { kvm_debug("%s: illegal index: %d\n", __func__, index); kvm_debug("[%#lx] COP0_TLBWI [%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx, mask: %#lx)\n", pc, index, kvm_read_c0_guest_entryhi(cop0), kvm_read_c0_guest_entrylo0(cop0), kvm_read_c0_guest_entrylo1(cop0), kvm_read_c0_guest_pagemask(cop0)); index = (index & ~0x80000000) % KVM_MIPS_GUEST_TLB_SIZE; } tlb = &vcpu->arch.guest_tlb[index]; kvm_mips_invalidate_guest_tlb(vcpu, tlb); tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0); tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0); tlb->tlb_lo[0] = kvm_read_c0_guest_entrylo0(cop0); tlb->tlb_lo[1] = kvm_read_c0_guest_entrylo1(cop0); kvm_debug("[%#lx] COP0_TLBWI [%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx, mask: %#lx)\n", pc, index, kvm_read_c0_guest_entryhi(cop0), kvm_read_c0_guest_entrylo0(cop0), kvm_read_c0_guest_entrylo1(cop0), kvm_read_c0_guest_pagemask(cop0)); return EMULATE_DONE; } /* Write Guest TLB Entry @ Random Index */ enum emulation_result kvm_mips_emul_tlbwr(struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_mips_tlb *tlb = NULL; unsigned long pc = vcpu->arch.pc; int index; get_random_bytes(&index, sizeof(index)); index &= (KVM_MIPS_GUEST_TLB_SIZE - 1); tlb = &vcpu->arch.guest_tlb[index]; kvm_mips_invalidate_guest_tlb(vcpu, tlb); tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0); tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0); tlb->tlb_lo[0] = kvm_read_c0_guest_entrylo0(cop0); tlb->tlb_lo[1] = kvm_read_c0_guest_entrylo1(cop0); kvm_debug("[%#lx] COP0_TLBWR[%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx)\n", pc, index, kvm_read_c0_guest_entryhi(cop0), kvm_read_c0_guest_entrylo0(cop0), kvm_read_c0_guest_entrylo1(cop0)); return EMULATE_DONE; } enum emulation_result kvm_mips_emul_tlbp(struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; long entryhi = kvm_read_c0_guest_entryhi(cop0); unsigned long pc = vcpu->arch.pc; int index = -1; index = kvm_mips_guest_tlb_lookup(vcpu, entryhi); kvm_write_c0_guest_index(cop0, index); kvm_debug("[%#lx] COP0_TLBP (entryhi: %#lx), index: %d\n", pc, entryhi, index); return EMULATE_DONE; } /** * kvm_mips_config1_wrmask() - Find mask of writable bits in guest Config1 * @vcpu: Virtual CPU. * * Finds the mask of bits which are writable in the guest's Config1 CP0 * register, by userland (currently read-only to the guest). */ unsigned int kvm_mips_config1_wrmask(struct kvm_vcpu *vcpu) { unsigned int mask = 0; /* Permit FPU to be present if FPU is supported */ if (kvm_mips_guest_can_have_fpu(&vcpu->arch)) mask |= MIPS_CONF1_FP; return mask; } /** * kvm_mips_config3_wrmask() - Find mask of writable bits in guest Config3 * @vcpu: Virtual CPU. * * Finds the mask of bits which are writable in the guest's Config3 CP0 * register, by userland (currently read-only to the guest). */ unsigned int kvm_mips_config3_wrmask(struct kvm_vcpu *vcpu) { /* Config4 and ULRI are optional */ unsigned int mask = MIPS_CONF_M | MIPS_CONF3_ULRI; /* Permit MSA to be present if MSA is supported */ if (kvm_mips_guest_can_have_msa(&vcpu->arch)) mask |= MIPS_CONF3_MSA; return mask; } /** * kvm_mips_config4_wrmask() - Find mask of writable bits in guest Config4 * @vcpu: Virtual CPU. * * Finds the mask of bits which are writable in the guest's Config4 CP0 * register, by userland (currently read-only to the guest). */ unsigned int kvm_mips_config4_wrmask(struct kvm_vcpu *vcpu) { /* Config5 is optional */ unsigned int mask = MIPS_CONF_M; /* KScrExist */ mask |= (unsigned int)vcpu->arch.kscratch_enabled << 16; return mask; } /** * kvm_mips_config5_wrmask() - Find mask of writable bits in guest Config5 * @vcpu: Virtual CPU. * * Finds the mask of bits which are writable in the guest's Config5 CP0 * register, by the guest itself. */ unsigned int kvm_mips_config5_wrmask(struct kvm_vcpu *vcpu) { unsigned int mask = 0; /* Permit MSAEn changes if MSA supported and enabled */ if (kvm_mips_guest_has_msa(&vcpu->arch)) mask |= MIPS_CONF5_MSAEN; /* * Permit guest FPU mode changes if FPU is enabled and the relevant * feature exists according to FIR register. */ if (kvm_mips_guest_has_fpu(&vcpu->arch)) { if (cpu_has_fre) mask |= MIPS_CONF5_FRE; /* We don't support UFR or UFE */ } return mask; } enum emulation_result kvm_mips_emulate_CP0(union mips_instruction inst, u32 *opc, u32 cause, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm; enum emulation_result er = EMULATE_DONE; u32 rt, rd, sel; unsigned long curr_pc; int cpu, i; /* * Update PC and hold onto current PC in case there is * an error and we want to rollback the PC */ curr_pc = vcpu->arch.pc; er = update_pc(vcpu, cause); if (er == EMULATE_FAIL) return er; if (inst.co_format.co) { switch (inst.co_format.func) { case tlbr_op: /* Read indexed TLB entry */ er = kvm_mips_emul_tlbr(vcpu); break; case tlbwi_op: /* Write indexed */ er = kvm_mips_emul_tlbwi(vcpu); break; case tlbwr_op: /* Write random */ er = kvm_mips_emul_tlbwr(vcpu); break; case tlbp_op: /* TLB Probe */ er = kvm_mips_emul_tlbp(vcpu); break; case rfe_op: kvm_err("!!!COP0_RFE!!!\n"); break; case eret_op: er = kvm_mips_emul_eret(vcpu); goto dont_update_pc; case wait_op: er = kvm_mips_emul_wait(vcpu); break; } } else { rt = inst.c0r_format.rt; rd = inst.c0r_format.rd; sel = inst.c0r_format.sel; switch (inst.c0r_format.rs) { case mfc_op: #ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS cop0->stat[rd][sel]++; #endif /* Get reg */ if ((rd == MIPS_CP0_COUNT) && (sel == 0)) { vcpu->arch.gprs[rt] = (s32)kvm_mips_read_count(vcpu); } else if ((rd == MIPS_CP0_ERRCTL) && (sel == 0)) { vcpu->arch.gprs[rt] = 0x0; #ifdef CONFIG_KVM_MIPS_DYN_TRANS kvm_mips_trans_mfc0(inst, opc, vcpu); #endif } else { vcpu->arch.gprs[rt] = (s32)cop0->reg[rd][sel]; #ifdef CONFIG_KVM_MIPS_DYN_TRANS kvm_mips_trans_mfc0(inst, opc, vcpu); #endif } trace_kvm_hwr(vcpu, KVM_TRACE_MFC0, KVM_TRACE_COP0(rd, sel), vcpu->arch.gprs[rt]); break; case dmfc_op: vcpu->arch.gprs[rt] = cop0->reg[rd][sel]; trace_kvm_hwr(vcpu, KVM_TRACE_DMFC0, KVM_TRACE_COP0(rd, sel), vcpu->arch.gprs[rt]); break; case mtc_op: #ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS cop0->stat[rd][sel]++; #endif trace_kvm_hwr(vcpu, KVM_TRACE_MTC0, KVM_TRACE_COP0(rd, sel), vcpu->arch.gprs[rt]); if ((rd == MIPS_CP0_TLB_INDEX) && (vcpu->arch.gprs[rt] >= KVM_MIPS_GUEST_TLB_SIZE)) { kvm_err("Invalid TLB Index: %ld", vcpu->arch.gprs[rt]); er = EMULATE_FAIL; break; } #define C0_EBASE_CORE_MASK 0xff if ((rd == MIPS_CP0_PRID) && (sel == 1)) { /* Preserve CORE number */ kvm_change_c0_guest_ebase(cop0, ~(C0_EBASE_CORE_MASK), vcpu->arch.gprs[rt]); kvm_err("MTCz, cop0->reg[EBASE]: %#lx\n", kvm_read_c0_guest_ebase(cop0)); } else if (rd == MIPS_CP0_TLB_HI && sel == 0) { u32 nasid = vcpu->arch.gprs[rt] & KVM_ENTRYHI_ASID; if (((kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID) != nasid)) { trace_kvm_asid_change(vcpu, kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID, nasid); /* * Flush entries from the GVA page * tables. * Guest user page table will get * flushed lazily on re-entry to guest * user if the guest ASID actually * changes. */ kvm_mips_flush_gva_pt(kern_mm->pgd, KMF_KERN); /* * Regenerate/invalidate kernel MMU * context. * The user MMU context will be * regenerated lazily on re-entry to * guest user if the guest ASID actually * changes. */ preempt_disable(); cpu = smp_processor_id(); get_new_mmu_context(kern_mm, cpu); for_each_possible_cpu(i) if (i != cpu) cpu_context(i, kern_mm) = 0; preempt_enable(); } kvm_write_c0_guest_entryhi(cop0, vcpu->arch.gprs[rt]); } /* Are we writing to COUNT */ else if ((rd == MIPS_CP0_COUNT) && (sel == 0)) { kvm_mips_write_count(vcpu, vcpu->arch.gprs[rt]); goto done; } else if ((rd == MIPS_CP0_COMPARE) && (sel == 0)) { /* If we are writing to COMPARE */ /* Clear pending timer interrupt, if any */ kvm_mips_write_compare(vcpu, vcpu->arch.gprs[rt], true); } else if ((rd == MIPS_CP0_STATUS) && (sel == 0)) { unsigned int old_val, val, change; old_val = kvm_read_c0_guest_status(cop0); val = vcpu->arch.gprs[rt]; change = val ^ old_val; /* Make sure that the NMI bit is never set */ val &= ~ST0_NMI; /* * Don't allow CU1 or FR to be set unless FPU * capability enabled and exists in guest * configuration. */ if (!kvm_mips_guest_has_fpu(&vcpu->arch)) val &= ~(ST0_CU1 | ST0_FR); /* * Also don't allow FR to be set if host doesn't * support it. */ if (!(current_cpu_data.fpu_id & MIPS_FPIR_F64)) val &= ~ST0_FR; /* Handle changes in FPU mode */ preempt_disable(); /* * FPU and Vector register state is made * UNPREDICTABLE by a change of FR, so don't * even bother saving it. */ if (change & ST0_FR) kvm_drop_fpu(vcpu); /* * If MSA state is already live, it is undefined * how it interacts with FR=0 FPU state, and we * don't want to hit reserved instruction * exceptions trying to save the MSA state later * when CU=1 && FR=1, so play it safe and save * it first. */ if (change & ST0_CU1 && !(val & ST0_FR) && vcpu->arch.aux_inuse & KVM_MIPS_AUX_MSA) kvm_lose_fpu(vcpu); /* * Propagate CU1 (FPU enable) changes * immediately if the FPU context is already * loaded. When disabling we leave the context * loaded so it can be quickly enabled again in * the near future. */ if (change & ST0_CU1 && vcpu->arch.aux_inuse & KVM_MIPS_AUX_FPU) change_c0_status(ST0_CU1, val); preempt_enable(); kvm_write_c0_guest_status(cop0, val); #ifdef CONFIG_KVM_MIPS_DYN_TRANS /* * If FPU present, we need CU1/FR bits to take * effect fairly soon. */ if (!kvm_mips_guest_has_fpu(&vcpu->arch)) kvm_mips_trans_mtc0(inst, opc, vcpu); #endif } else if ((rd == MIPS_CP0_CONFIG) && (sel == 5)) { unsigned int old_val, val, change, wrmask; old_val = kvm_read_c0_guest_config5(cop0); val = vcpu->arch.gprs[rt]; /* Only a few bits are writable in Config5 */ wrmask = kvm_mips_config5_wrmask(vcpu); change = (val ^ old_val) & wrmask; val = old_val ^ change; /* Handle changes in FPU/MSA modes */ preempt_disable(); /* * Propagate FRE changes immediately if the FPU * context is already loaded. */ if (change & MIPS_CONF5_FRE && vcpu->arch.aux_inuse & KVM_MIPS_AUX_FPU) change_c0_config5(MIPS_CONF5_FRE, val); /* * Propagate MSAEn changes immediately if the * MSA context is already loaded. When disabling * we leave the context loaded so it can be * quickly enabled again in the near future. */ if (change & MIPS_CONF5_MSAEN && vcpu->arch.aux_inuse & KVM_MIPS_AUX_MSA) change_c0_config5(MIPS_CONF5_MSAEN, val); preempt_enable(); kvm_write_c0_guest_config5(cop0, val); } else if ((rd == MIPS_CP0_CAUSE) && (sel == 0)) { u32 old_cause, new_cause; old_cause = kvm_read_c0_guest_cause(cop0); new_cause = vcpu->arch.gprs[rt]; /* Update R/W bits */ kvm_change_c0_guest_cause(cop0, 0x08800300, new_cause); /* DC bit enabling/disabling timer? */ if ((old_cause ^ new_cause) & CAUSEF_DC) { if (new_cause & CAUSEF_DC) kvm_mips_count_disable_cause(vcpu); else kvm_mips_count_enable_cause(vcpu); } } else if ((rd == MIPS_CP0_HWRENA) && (sel == 0)) { u32 mask = MIPS_HWRENA_CPUNUM | MIPS_HWRENA_SYNCISTEP | MIPS_HWRENA_CC | MIPS_HWRENA_CCRES; if (kvm_read_c0_guest_config3(cop0) & MIPS_CONF3_ULRI) mask |= MIPS_HWRENA_ULR; cop0->reg[rd][sel] = vcpu->arch.gprs[rt] & mask; } else { cop0->reg[rd][sel] = vcpu->arch.gprs[rt]; #ifdef CONFIG_KVM_MIPS_DYN_TRANS kvm_mips_trans_mtc0(inst, opc, vcpu); #endif } break; case dmtc_op: kvm_err("!!!!!!![%#lx]dmtc_op: rt: %d, rd: %d, sel: %d!!!!!!\n", vcpu->arch.pc, rt, rd, sel); trace_kvm_hwr(vcpu, KVM_TRACE_DMTC0, KVM_TRACE_COP0(rd, sel), vcpu->arch.gprs[rt]); er = EMULATE_FAIL; break; case mfmc0_op: #ifdef KVM_MIPS_DEBUG_COP0_COUNTERS cop0->stat[MIPS_CP0_STATUS][0]++; #endif if (rt != 0) vcpu->arch.gprs[rt] = kvm_read_c0_guest_status(cop0); /* EI */ if (inst.mfmc0_format.sc) { kvm_debug("[%#lx] mfmc0_op: EI\n", vcpu->arch.pc); kvm_set_c0_guest_status(cop0, ST0_IE); } else { kvm_debug("[%#lx] mfmc0_op: DI\n", vcpu->arch.pc); kvm_clear_c0_guest_status(cop0, ST0_IE); } break; case wrpgpr_op: { u32 css = cop0->reg[MIPS_CP0_STATUS][2] & 0xf; u32 pss = (cop0->reg[MIPS_CP0_STATUS][2] >> 6) & 0xf; /* * We don't support any shadow register sets, so * SRSCtl[PSS] == SRSCtl[CSS] = 0 */ if (css || pss) { er = EMULATE_FAIL; break; } kvm_debug("WRPGPR[%d][%d] = %#lx\n", pss, rd, vcpu->arch.gprs[rt]); vcpu->arch.gprs[rd] = vcpu->arch.gprs[rt]; } break; default: kvm_err("[%#lx]MachEmulateCP0: unsupported COP0, copz: 0x%x\n", vcpu->arch.pc, inst.c0r_format.rs); er = EMULATE_FAIL; break; } } done: /* Rollback PC only if emulation was unsuccessful */ if (er == EMULATE_FAIL) vcpu->arch.pc = curr_pc; dont_update_pc: /* * This is for special instructions whose emulation * updates the PC, so do not overwrite the PC under * any circumstances */ return er; } enum emulation_result kvm_mips_emulate_store(union mips_instruction inst, u32 cause, struct kvm_run *run, struct kvm_vcpu *vcpu) { enum emulation_result er = EMULATE_DO_MMIO; u32 rt; u32 bytes; void *data = run->mmio.data; unsigned long curr_pc; /* * Update PC and hold onto current PC in case there is * an error and we want to rollback the PC */ curr_pc = vcpu->arch.pc; er = update_pc(vcpu, cause); if (er == EMULATE_FAIL) return er; rt = inst.i_format.rt; switch (inst.i_format.opcode) { case sb_op: bytes = 1; if (bytes > sizeof(run->mmio.data)) { kvm_err("%s: bad MMIO length: %d\n", __func__, run->mmio.len); } run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(vcpu->arch. host_cp0_badvaddr); if (run->mmio.phys_addr == KVM_INVALID_ADDR) { er = EMULATE_FAIL; break; } run->mmio.len = bytes; run->mmio.is_write = 1; vcpu->mmio_needed = 1; vcpu->mmio_is_write = 1; *(u8 *) data = vcpu->arch.gprs[rt]; kvm_debug("OP_SB: eaddr: %#lx, gpr: %#lx, data: %#x\n", vcpu->arch.host_cp0_badvaddr, vcpu->arch.gprs[rt], *(u8 *) data); break; case sw_op: bytes = 4; if (bytes > sizeof(run->mmio.data)) { kvm_err("%s: bad MMIO length: %d\n", __func__, run->mmio.len); } run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(vcpu->arch. host_cp0_badvaddr); if (run->mmio.phys_addr == KVM_INVALID_ADDR) { er = EMULATE_FAIL; break; } run->mmio.len = bytes; run->mmio.is_write = 1; vcpu->mmio_needed = 1; vcpu->mmio_is_write = 1; *(u32 *) data = vcpu->arch.gprs[rt]; kvm_debug("[%#lx] OP_SW: eaddr: %#lx, gpr: %#lx, data: %#x\n", vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr, vcpu->arch.gprs[rt], *(u32 *) data); break; case sh_op: bytes = 2; if (bytes > sizeof(run->mmio.data)) { kvm_err("%s: bad MMIO length: %d\n", __func__, run->mmio.len); } run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(vcpu->arch. host_cp0_badvaddr); if (run->mmio.phys_addr == KVM_INVALID_ADDR) { er = EMULATE_FAIL; break; } run->mmio.len = bytes; run->mmio.is_write = 1; vcpu->mmio_needed = 1; vcpu->mmio_is_write = 1; *(u16 *) data = vcpu->arch.gprs[rt]; kvm_debug("[%#lx] OP_SH: eaddr: %#lx, gpr: %#lx, data: %#x\n", vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr, vcpu->arch.gprs[rt], *(u32 *) data); break; default: kvm_err("Store not yet supported (inst=0x%08x)\n", inst.word); er = EMULATE_FAIL; break; } /* Rollback PC if emulation was unsuccessful */ if (er == EMULATE_FAIL) vcpu->arch.pc = curr_pc; return er; } enum emulation_result kvm_mips_emulate_load(union mips_instruction inst, u32 cause, struct kvm_run *run, struct kvm_vcpu *vcpu) { enum emulation_result er = EMULATE_DO_MMIO; unsigned long curr_pc; u32 op, rt; u32 bytes; rt = inst.i_format.rt; op = inst.i_format.opcode; /* * Find the resume PC now while we have safe and easy access to the * prior branch instruction, and save it for * kvm_mips_complete_mmio_load() to restore later. */ curr_pc = vcpu->arch.pc; er = update_pc(vcpu, cause); if (er == EMULATE_FAIL) return er; vcpu->arch.io_pc = vcpu->arch.pc; vcpu->arch.pc = curr_pc; vcpu->arch.io_gpr = rt; switch (op) { case lw_op: bytes = 4; if (bytes > sizeof(run->mmio.data)) { kvm_err("%s: bad MMIO length: %d\n", __func__, run->mmio.len); er = EMULATE_FAIL; break; } run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(vcpu->arch. host_cp0_badvaddr); if (run->mmio.phys_addr == KVM_INVALID_ADDR) { er = EMULATE_FAIL; break; } run->mmio.len = bytes; run->mmio.is_write = 0; vcpu->mmio_needed = 1; vcpu->mmio_is_write = 0; break; case lh_op: case lhu_op: bytes = 2; if (bytes > sizeof(run->mmio.data)) { kvm_err("%s: bad MMIO length: %d\n", __func__, run->mmio.len); er = EMULATE_FAIL; break; } run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(vcpu->arch. host_cp0_badvaddr); if (run->mmio.phys_addr == KVM_INVALID_ADDR) { er = EMULATE_FAIL; break; } run->mmio.len = bytes; run->mmio.is_write = 0; vcpu->mmio_needed = 1; vcpu->mmio_is_write = 0; if (op == lh_op) vcpu->mmio_needed = 2; else vcpu->mmio_needed = 1; break; case lbu_op: case lb_op: bytes = 1; if (bytes > sizeof(run->mmio.data)) { kvm_err("%s: bad MMIO length: %d\n", __func__, run->mmio.len); er = EMULATE_FAIL; break; } run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(vcpu->arch. host_cp0_badvaddr); if (run->mmio.phys_addr == KVM_INVALID_ADDR) { er = EMULATE_FAIL; break; } run->mmio.len = bytes; run->mmio.is_write = 0; vcpu->mmio_is_write = 0; if (op == lb_op) vcpu->mmio_needed = 2; else vcpu->mmio_needed = 1; break; default: kvm_err("Load not yet supported (inst=0x%08x)\n", inst.word); er = EMULATE_FAIL; break; } return er; } static enum emulation_result kvm_mips_guest_cache_op(int (*fn)(unsigned long), unsigned long curr_pc, unsigned long addr, struct kvm_run *run, struct kvm_vcpu *vcpu, u32 cause) { int err; for (;;) { /* Carefully attempt the cache operation */ kvm_trap_emul_gva_lockless_begin(vcpu); err = fn(addr); kvm_trap_emul_gva_lockless_end(vcpu); if (likely(!err)) return EMULATE_DONE; /* * Try to handle the fault and retry, maybe we just raced with a * GVA invalidation. */ switch (kvm_trap_emul_gva_fault(vcpu, addr, false)) { case KVM_MIPS_GVA: case KVM_MIPS_GPA: /* bad virtual or physical address */ return EMULATE_FAIL; case KVM_MIPS_TLB: /* no matching guest TLB */ vcpu->arch.host_cp0_badvaddr = addr; vcpu->arch.pc = curr_pc; kvm_mips_emulate_tlbmiss_ld(cause, NULL, run, vcpu); return EMULATE_EXCEPT; case KVM_MIPS_TLBINV: /* invalid matching guest TLB */ vcpu->arch.host_cp0_badvaddr = addr; vcpu->arch.pc = curr_pc; kvm_mips_emulate_tlbinv_ld(cause, NULL, run, vcpu); return EMULATE_EXCEPT; default: break; }; } } enum emulation_result kvm_mips_emulate_cache(union mips_instruction inst, u32 *opc, u32 cause, struct kvm_run *run, struct kvm_vcpu *vcpu) { enum emulation_result er = EMULATE_DONE; u32 cache, op_inst, op, base; s16 offset; struct kvm_vcpu_arch *arch = &vcpu->arch; unsigned long va; unsigned long curr_pc; /* * Update PC and hold onto current PC in case there is * an error and we want to rollback the PC */ curr_pc = vcpu->arch.pc; er = update_pc(vcpu, cause); if (er == EMULATE_FAIL) return er; base = inst.i_format.rs; op_inst = inst.i_format.rt; if (cpu_has_mips_r6) offset = inst.spec3_format.simmediate; else offset = inst.i_format.simmediate; cache = op_inst & CacheOp_Cache; op = op_inst & CacheOp_Op; va = arch->gprs[base] + offset; kvm_debug("CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n", cache, op, base, arch->gprs[base], offset); /* * Treat INDEX_INV as a nop, basically issued by Linux on startup to * invalidate the caches entirely by stepping through all the * ways/indexes */ if (op == Index_Writeback_Inv) { kvm_debug("@ %#lx/%#lx CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n", vcpu->arch.pc, vcpu->arch.gprs[31], cache, op, base, arch->gprs[base], offset); if (cache == Cache_D) r4k_blast_dcache(); else if (cache == Cache_I) r4k_blast_icache(); else { kvm_err("%s: unsupported CACHE INDEX operation\n", __func__); return EMULATE_FAIL; } #ifdef CONFIG_KVM_MIPS_DYN_TRANS kvm_mips_trans_cache_index(inst, opc, vcpu); #endif goto done; } /* XXXKYMA: Only a subset of cache ops are supported, used by Linux */ if (op_inst == Hit_Writeback_Inv_D || op_inst == Hit_Invalidate_D) { /* * Perform the dcache part of icache synchronisation on the * guest's behalf. */ er = kvm_mips_guest_cache_op(protected_writeback_dcache_line, curr_pc, va, run, vcpu, cause); if (er != EMULATE_DONE) goto done; #ifdef CONFIG_KVM_MIPS_DYN_TRANS /* * Replace the CACHE instruction, with a SYNCI, not the same, * but avoids a trap */ kvm_mips_trans_cache_va(inst, opc, vcpu); #endif } else if (op_inst == Hit_Invalidate_I) { /* Perform the icache synchronisation on the guest's behalf */ er = kvm_mips_guest_cache_op(protected_writeback_dcache_line, curr_pc, va, run, vcpu, cause); if (er != EMULATE_DONE) goto done; er = kvm_mips_guest_cache_op(protected_flush_icache_line, curr_pc, va, run, vcpu, cause); if (er != EMULATE_DONE) goto done; #ifdef CONFIG_KVM_MIPS_DYN_TRANS /* Replace the CACHE instruction, with a SYNCI */ kvm_mips_trans_cache_va(inst, opc, vcpu); #endif } else { kvm_err("NO-OP CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n", cache, op, base, arch->gprs[base], offset); er = EMULATE_FAIL; } done: /* Rollback PC only if emulation was unsuccessful */ if (er == EMULATE_FAIL) vcpu->arch.pc = curr_pc; /* Guest exception needs guest to resume */ if (er == EMULATE_EXCEPT) er = EMULATE_DONE; return er; } enum emulation_result kvm_mips_emulate_inst(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { union mips_instruction inst; enum emulation_result er = EMULATE_DONE; int err; /* Fetch the instruction. */ if (cause & CAUSEF_BD) opc += 1; err = kvm_get_badinstr(opc, vcpu, &inst.word); if (err) return EMULATE_FAIL; switch (inst.r_format.opcode) { case cop0_op: er = kvm_mips_emulate_CP0(inst, opc, cause, run, vcpu); break; case sb_op: case sh_op: case sw_op: er = kvm_mips_emulate_store(inst, cause, run, vcpu); break; case lb_op: case lbu_op: case lhu_op: case lh_op: case lw_op: er = kvm_mips_emulate_load(inst, cause, run, vcpu); break; #ifndef CONFIG_CPU_MIPSR6 case cache_op: ++vcpu->stat.cache_exits; trace_kvm_exit(vcpu, KVM_TRACE_EXIT_CACHE); er = kvm_mips_emulate_cache(inst, opc, cause, run, vcpu); break; #else case spec3_op: switch (inst.spec3_format.func) { case cache6_op: ++vcpu->stat.cache_exits; trace_kvm_exit(vcpu, KVM_TRACE_EXIT_CACHE); er = kvm_mips_emulate_cache(inst, opc, cause, run, vcpu); break; default: goto unknown; }; break; unknown: #endif default: kvm_err("Instruction emulation not supported (%p/%#x)\n", opc, inst.word); kvm_arch_vcpu_dump_regs(vcpu); er = EMULATE_FAIL; break; } return er; } enum emulation_result kvm_mips_emulate_syscall(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_vcpu_arch *arch = &vcpu->arch; enum emulation_result er = EMULATE_DONE; if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) { /* save old pc */ kvm_write_c0_guest_epc(cop0, arch->pc); kvm_set_c0_guest_status(cop0, ST0_EXL); if (cause & CAUSEF_BD) kvm_set_c0_guest_cause(cop0, CAUSEF_BD); else kvm_clear_c0_guest_cause(cop0, CAUSEF_BD); kvm_debug("Delivering SYSCALL @ pc %#lx\n", arch->pc); kvm_change_c0_guest_cause(cop0, (0xff), (EXCCODE_SYS << CAUSEB_EXCCODE)); /* Set PC to the exception entry point */ arch->pc = KVM_GUEST_KSEG0 + 0x180; } else { kvm_err("Trying to deliver SYSCALL when EXL is already set\n"); er = EMULATE_FAIL; } return er; } enum emulation_result kvm_mips_emulate_tlbmiss_ld(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_vcpu_arch *arch = &vcpu->arch; unsigned long entryhi = (vcpu->arch. host_cp0_badvaddr & VPN2_MASK) | (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID); if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) { /* save old pc */ kvm_write_c0_guest_epc(cop0, arch->pc); kvm_set_c0_guest_status(cop0, ST0_EXL); if (cause & CAUSEF_BD) kvm_set_c0_guest_cause(cop0, CAUSEF_BD); else kvm_clear_c0_guest_cause(cop0, CAUSEF_BD); kvm_debug("[EXL == 0] delivering TLB MISS @ pc %#lx\n", arch->pc); /* set pc to the exception entry point */ arch->pc = KVM_GUEST_KSEG0 + 0x0; } else { kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n", arch->pc); arch->pc = KVM_GUEST_KSEG0 + 0x180; } kvm_change_c0_guest_cause(cop0, (0xff), (EXCCODE_TLBL << CAUSEB_EXCCODE)); /* setup badvaddr, context and entryhi registers for the guest */ kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr); /* XXXKYMA: is the context register used by linux??? */ kvm_write_c0_guest_entryhi(cop0, entryhi); return EMULATE_DONE; } enum emulation_result kvm_mips_emulate_tlbinv_ld(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_vcpu_arch *arch = &vcpu->arch; unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) | (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID); if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) { /* save old pc */ kvm_write_c0_guest_epc(cop0, arch->pc); kvm_set_c0_guest_status(cop0, ST0_EXL); if (cause & CAUSEF_BD) kvm_set_c0_guest_cause(cop0, CAUSEF_BD); else kvm_clear_c0_guest_cause(cop0, CAUSEF_BD); kvm_debug("[EXL == 0] delivering TLB INV @ pc %#lx\n", arch->pc); /* set pc to the exception entry point */ arch->pc = KVM_GUEST_KSEG0 + 0x180; } else { kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n", arch->pc); arch->pc = KVM_GUEST_KSEG0 + 0x180; } kvm_change_c0_guest_cause(cop0, (0xff), (EXCCODE_TLBL << CAUSEB_EXCCODE)); /* setup badvaddr, context and entryhi registers for the guest */ kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr); /* XXXKYMA: is the context register used by linux??? */ kvm_write_c0_guest_entryhi(cop0, entryhi); return EMULATE_DONE; } enum emulation_result kvm_mips_emulate_tlbmiss_st(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_vcpu_arch *arch = &vcpu->arch; unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) | (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID); if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) { /* save old pc */ kvm_write_c0_guest_epc(cop0, arch->pc); kvm_set_c0_guest_status(cop0, ST0_EXL); if (cause & CAUSEF_BD) kvm_set_c0_guest_cause(cop0, CAUSEF_BD); else kvm_clear_c0_guest_cause(cop0, CAUSEF_BD); kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n", arch->pc); /* Set PC to the exception entry point */ arch->pc = KVM_GUEST_KSEG0 + 0x0; } else { kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n", arch->pc); arch->pc = KVM_GUEST_KSEG0 + 0x180; } kvm_change_c0_guest_cause(cop0, (0xff), (EXCCODE_TLBS << CAUSEB_EXCCODE)); /* setup badvaddr, context and entryhi registers for the guest */ kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr); /* XXXKYMA: is the context register used by linux??? */ kvm_write_c0_guest_entryhi(cop0, entryhi); return EMULATE_DONE; } enum emulation_result kvm_mips_emulate_tlbinv_st(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_vcpu_arch *arch = &vcpu->arch; unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) | (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID); if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) { /* save old pc */ kvm_write_c0_guest_epc(cop0, arch->pc); kvm_set_c0_guest_status(cop0, ST0_EXL); if (cause & CAUSEF_BD) kvm_set_c0_guest_cause(cop0, CAUSEF_BD); else kvm_clear_c0_guest_cause(cop0, CAUSEF_BD); kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n", arch->pc); /* Set PC to the exception entry point */ arch->pc = KVM_GUEST_KSEG0 + 0x180; } else { kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n", arch->pc); arch->pc = KVM_GUEST_KSEG0 + 0x180; } kvm_change_c0_guest_cause(cop0, (0xff), (EXCCODE_TLBS << CAUSEB_EXCCODE)); /* setup badvaddr, context and entryhi registers for the guest */ kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr); /* XXXKYMA: is the context register used by linux??? */ kvm_write_c0_guest_entryhi(cop0, entryhi); return EMULATE_DONE; } enum emulation_result kvm_mips_emulate_tlbmod(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) | (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID); struct kvm_vcpu_arch *arch = &vcpu->arch; if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) { /* save old pc */ kvm_write_c0_guest_epc(cop0, arch->pc); kvm_set_c0_guest_status(cop0, ST0_EXL); if (cause & CAUSEF_BD) kvm_set_c0_guest_cause(cop0, CAUSEF_BD); else kvm_clear_c0_guest_cause(cop0, CAUSEF_BD); kvm_debug("[EXL == 0] Delivering TLB MOD @ pc %#lx\n", arch->pc); arch->pc = KVM_GUEST_KSEG0 + 0x180; } else { kvm_debug("[EXL == 1] Delivering TLB MOD @ pc %#lx\n", arch->pc); arch->pc = KVM_GUEST_KSEG0 + 0x180; } kvm_change_c0_guest_cause(cop0, (0xff), (EXCCODE_MOD << CAUSEB_EXCCODE)); /* setup badvaddr, context and entryhi registers for the guest */ kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr); /* XXXKYMA: is the context register used by linux??? */ kvm_write_c0_guest_entryhi(cop0, entryhi); return EMULATE_DONE; } enum emulation_result kvm_mips_emulate_fpu_exc(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_vcpu_arch *arch = &vcpu->arch; if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) { /* save old pc */ kvm_write_c0_guest_epc(cop0, arch->pc); kvm_set_c0_guest_status(cop0, ST0_EXL); if (cause & CAUSEF_BD) kvm_set_c0_guest_cause(cop0, CAUSEF_BD); else kvm_clear_c0_guest_cause(cop0, CAUSEF_BD); } arch->pc = KVM_GUEST_KSEG0 + 0x180; kvm_change_c0_guest_cause(cop0, (0xff), (EXCCODE_CPU << CAUSEB_EXCCODE)); kvm_change_c0_guest_cause(cop0, (CAUSEF_CE), (0x1 << CAUSEB_CE)); return EMULATE_DONE; } enum emulation_result kvm_mips_emulate_ri_exc(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_vcpu_arch *arch = &vcpu->arch; enum emulation_result er = EMULATE_DONE; if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) { /* save old pc */ kvm_write_c0_guest_epc(cop0, arch->pc); kvm_set_c0_guest_status(cop0, ST0_EXL); if (cause & CAUSEF_BD) kvm_set_c0_guest_cause(cop0, CAUSEF_BD); else kvm_clear_c0_guest_cause(cop0, CAUSEF_BD); kvm_debug("Delivering RI @ pc %#lx\n", arch->pc); kvm_change_c0_guest_cause(cop0, (0xff), (EXCCODE_RI << CAUSEB_EXCCODE)); /* Set PC to the exception entry point */ arch->pc = KVM_GUEST_KSEG0 + 0x180; } else { kvm_err("Trying to deliver RI when EXL is already set\n"); er = EMULATE_FAIL; } return er; } enum emulation_result kvm_mips_emulate_bp_exc(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_vcpu_arch *arch = &vcpu->arch; enum emulation_result er = EMULATE_DONE; if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) { /* save old pc */ kvm_write_c0_guest_epc(cop0, arch->pc); kvm_set_c0_guest_status(cop0, ST0_EXL); if (cause & CAUSEF_BD) kvm_set_c0_guest_cause(cop0, CAUSEF_BD); else kvm_clear_c0_guest_cause(cop0, CAUSEF_BD); kvm_debug("Delivering BP @ pc %#lx\n", arch->pc); kvm_change_c0_guest_cause(cop0, (0xff), (EXCCODE_BP << CAUSEB_EXCCODE)); /* Set PC to the exception entry point */ arch->pc = KVM_GUEST_KSEG0 + 0x180; } else { kvm_err("Trying to deliver BP when EXL is already set\n"); er = EMULATE_FAIL; } return er; } enum emulation_result kvm_mips_emulate_trap_exc(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_vcpu_arch *arch = &vcpu->arch; enum emulation_result er = EMULATE_DONE; if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) { /* save old pc */ kvm_write_c0_guest_epc(cop0, arch->pc); kvm_set_c0_guest_status(cop0, ST0_EXL); if (cause & CAUSEF_BD) kvm_set_c0_guest_cause(cop0, CAUSEF_BD); else kvm_clear_c0_guest_cause(cop0, CAUSEF_BD); kvm_debug("Delivering TRAP @ pc %#lx\n", arch->pc); kvm_change_c0_guest_cause(cop0, (0xff), (EXCCODE_TR << CAUSEB_EXCCODE)); /* Set PC to the exception entry point */ arch->pc = KVM_GUEST_KSEG0 + 0x180; } else { kvm_err("Trying to deliver TRAP when EXL is already set\n"); er = EMULATE_FAIL; } return er; } enum emulation_result kvm_mips_emulate_msafpe_exc(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_vcpu_arch *arch = &vcpu->arch; enum emulation_result er = EMULATE_DONE; if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) { /* save old pc */ kvm_write_c0_guest_epc(cop0, arch->pc); kvm_set_c0_guest_status(cop0, ST0_EXL); if (cause & CAUSEF_BD) kvm_set_c0_guest_cause(cop0, CAUSEF_BD); else kvm_clear_c0_guest_cause(cop0, CAUSEF_BD); kvm_debug("Delivering MSAFPE @ pc %#lx\n", arch->pc); kvm_change_c0_guest_cause(cop0, (0xff), (EXCCODE_MSAFPE << CAUSEB_EXCCODE)); /* Set PC to the exception entry point */ arch->pc = KVM_GUEST_KSEG0 + 0x180; } else { kvm_err("Trying to deliver MSAFPE when EXL is already set\n"); er = EMULATE_FAIL; } return er; } enum emulation_result kvm_mips_emulate_fpe_exc(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_vcpu_arch *arch = &vcpu->arch; enum emulation_result er = EMULATE_DONE; if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) { /* save old pc */ kvm_write_c0_guest_epc(cop0, arch->pc); kvm_set_c0_guest_status(cop0, ST0_EXL); if (cause & CAUSEF_BD) kvm_set_c0_guest_cause(cop0, CAUSEF_BD); else kvm_clear_c0_guest_cause(cop0, CAUSEF_BD); kvm_debug("Delivering FPE @ pc %#lx\n", arch->pc); kvm_change_c0_guest_cause(cop0, (0xff), (EXCCODE_FPE << CAUSEB_EXCCODE)); /* Set PC to the exception entry point */ arch->pc = KVM_GUEST_KSEG0 + 0x180; } else { kvm_err("Trying to deliver FPE when EXL is already set\n"); er = EMULATE_FAIL; } return er; } enum emulation_result kvm_mips_emulate_msadis_exc(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_vcpu_arch *arch = &vcpu->arch; enum emulation_result er = EMULATE_DONE; if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) { /* save old pc */ kvm_write_c0_guest_epc(cop0, arch->pc); kvm_set_c0_guest_status(cop0, ST0_EXL); if (cause & CAUSEF_BD) kvm_set_c0_guest_cause(cop0, CAUSEF_BD); else kvm_clear_c0_guest_cause(cop0, CAUSEF_BD); kvm_debug("Delivering MSADIS @ pc %#lx\n", arch->pc); kvm_change_c0_guest_cause(cop0, (0xff), (EXCCODE_MSADIS << CAUSEB_EXCCODE)); /* Set PC to the exception entry point */ arch->pc = KVM_GUEST_KSEG0 + 0x180; } else { kvm_err("Trying to deliver MSADIS when EXL is already set\n"); er = EMULATE_FAIL; } return er; } enum emulation_result kvm_mips_handle_ri(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_vcpu_arch *arch = &vcpu->arch; enum emulation_result er = EMULATE_DONE; unsigned long curr_pc; union mips_instruction inst; int err; /* * Update PC and hold onto current PC in case there is * an error and we want to rollback the PC */ curr_pc = vcpu->arch.pc; er = update_pc(vcpu, cause); if (er == EMULATE_FAIL) return er; /* Fetch the instruction. */ if (cause & CAUSEF_BD) opc += 1; err = kvm_get_badinstr(opc, vcpu, &inst.word); if (err) { kvm_err("%s: Cannot get inst @ %p (%d)\n", __func__, opc, err); return EMULATE_FAIL; } if (inst.r_format.opcode == spec3_op && inst.r_format.func == rdhwr_op && inst.r_format.rs == 0 && (inst.r_format.re >> 3) == 0) { int usermode = !KVM_GUEST_KERNEL_MODE(vcpu); int rd = inst.r_format.rd; int rt = inst.r_format.rt; int sel = inst.r_format.re & 0x7; /* If usermode, check RDHWR rd is allowed by guest HWREna */ if (usermode && !(kvm_read_c0_guest_hwrena(cop0) & BIT(rd))) { kvm_debug("RDHWR %#x disallowed by HWREna @ %p\n", rd, opc); goto emulate_ri; } switch (rd) { case MIPS_HWR_CPUNUM: /* CPU number */ arch->gprs[rt] = vcpu->vcpu_id; break; case MIPS_HWR_SYNCISTEP: /* SYNCI length */ arch->gprs[rt] = min(current_cpu_data.dcache.linesz, current_cpu_data.icache.linesz); break; case MIPS_HWR_CC: /* Read count register */ arch->gprs[rt] = (s32)kvm_mips_read_count(vcpu); break; case MIPS_HWR_CCRES: /* Count register resolution */ switch (current_cpu_data.cputype) { case CPU_20KC: case CPU_25KF: arch->gprs[rt] = 1; break; default: arch->gprs[rt] = 2; } break; case MIPS_HWR_ULR: /* Read UserLocal register */ arch->gprs[rt] = kvm_read_c0_guest_userlocal(cop0); break; default: kvm_debug("RDHWR %#x not supported @ %p\n", rd, opc); goto emulate_ri; } trace_kvm_hwr(vcpu, KVM_TRACE_RDHWR, KVM_TRACE_HWR(rd, sel), vcpu->arch.gprs[rt]); } else { kvm_debug("Emulate RI not supported @ %p: %#x\n", opc, inst.word); goto emulate_ri; } return EMULATE_DONE; emulate_ri: /* * Rollback PC (if in branch delay slot then the PC already points to * branch target), and pass the RI exception to the guest OS. */ vcpu->arch.pc = curr_pc; return kvm_mips_emulate_ri_exc(cause, opc, run, vcpu); } enum emulation_result kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu, struct kvm_run *run) { unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr]; enum emulation_result er = EMULATE_DONE; if (run->mmio.len > sizeof(*gpr)) { kvm_err("Bad MMIO length: %d", run->mmio.len); er = EMULATE_FAIL; goto done; } /* Restore saved resume PC */ vcpu->arch.pc = vcpu->arch.io_pc; switch (run->mmio.len) { case 4: *gpr = *(s32 *) run->mmio.data; break; case 2: if (vcpu->mmio_needed == 2) *gpr = *(s16 *) run->mmio.data; else *gpr = *(u16 *)run->mmio.data; break; case 1: if (vcpu->mmio_needed == 2) *gpr = *(s8 *) run->mmio.data; else *gpr = *(u8 *) run->mmio.data; break; } done: return er; } static enum emulation_result kvm_mips_emulate_exc(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { u32 exccode = (cause >> CAUSEB_EXCCODE) & 0x1f; struct mips_coproc *cop0 = vcpu->arch.cop0; struct kvm_vcpu_arch *arch = &vcpu->arch; enum emulation_result er = EMULATE_DONE; if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) { /* save old pc */ kvm_write_c0_guest_epc(cop0, arch->pc); kvm_set_c0_guest_status(cop0, ST0_EXL); if (cause & CAUSEF_BD) kvm_set_c0_guest_cause(cop0, CAUSEF_BD); else kvm_clear_c0_guest_cause(cop0, CAUSEF_BD); kvm_change_c0_guest_cause(cop0, (0xff), (exccode << CAUSEB_EXCCODE)); /* Set PC to the exception entry point */ arch->pc = KVM_GUEST_KSEG0 + 0x180; kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr); kvm_debug("Delivering EXC %d @ pc %#lx, badVaddr: %#lx\n", exccode, kvm_read_c0_guest_epc(cop0), kvm_read_c0_guest_badvaddr(cop0)); } else { kvm_err("Trying to deliver EXC when EXL is already set\n"); er = EMULATE_FAIL; } return er; } enum emulation_result kvm_mips_check_privilege(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu) { enum emulation_result er = EMULATE_DONE; u32 exccode = (cause >> CAUSEB_EXCCODE) & 0x1f; unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr; int usermode = !KVM_GUEST_KERNEL_MODE(vcpu); if (usermode) { switch (exccode) { case EXCCODE_INT: case EXCCODE_SYS: case EXCCODE_BP: case EXCCODE_RI: case EXCCODE_TR: case EXCCODE_MSAFPE: case EXCCODE_FPE: case EXCCODE_MSADIS: break; case EXCCODE_CPU: if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 0) er = EMULATE_PRIV_FAIL; break; case EXCCODE_MOD: break; case EXCCODE_TLBL: /* * We we are accessing Guest kernel space, then send an * address error exception to the guest */ if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) { kvm_debug("%s: LD MISS @ %#lx\n", __func__, badvaddr); cause &= ~0xff; cause |= (EXCCODE_ADEL << CAUSEB_EXCCODE); er = EMULATE_PRIV_FAIL; } break; case EXCCODE_TLBS: /* * We we are accessing Guest kernel space, then send an * address error exception to the guest */ if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) { kvm_debug("%s: ST MISS @ %#lx\n", __func__, badvaddr); cause &= ~0xff; cause |= (EXCCODE_ADES << CAUSEB_EXCCODE); er = EMULATE_PRIV_FAIL; } break; case EXCCODE_ADES: kvm_debug("%s: address error ST @ %#lx\n", __func__, badvaddr); if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) { cause &= ~0xff; cause |= (EXCCODE_TLBS << CAUSEB_EXCCODE); } er = EMULATE_PRIV_FAIL; break; case EXCCODE_ADEL: kvm_debug("%s: address error LD @ %#lx\n", __func__, badvaddr); if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) { cause &= ~0xff; cause |= (EXCCODE_TLBL << CAUSEB_EXCCODE); } er = EMULATE_PRIV_FAIL; break; default: er = EMULATE_PRIV_FAIL; break; } } if (er == EMULATE_PRIV_FAIL) kvm_mips_emulate_exc(cause, opc, run, vcpu); return er; } /* * User Address (UA) fault, this could happen if * (1) TLB entry not present/valid in both Guest and shadow host TLBs, in this * case we pass on the fault to the guest kernel and let it handle it. * (2) TLB entry is present in the Guest TLB but not in the shadow, in this * case we inject the TLB from the Guest TLB into the shadow host TLB */ enum emulation_result kvm_mips_handle_tlbmiss(u32 cause, u32 *opc, struct kvm_run *run, struct kvm_vcpu *vcpu, bool write_fault) { enum emulation_result er = EMULATE_DONE; u32 exccode = (cause >> CAUSEB_EXCCODE) & 0x1f; unsigned long va = vcpu->arch.host_cp0_badvaddr; int index; kvm_debug("kvm_mips_handle_tlbmiss: badvaddr: %#lx\n", vcpu->arch.host_cp0_badvaddr); /* * KVM would not have got the exception if this entry was valid in the * shadow host TLB. Check the Guest TLB, if the entry is not there then * send the guest an exception. The guest exc handler should then inject * an entry into the guest TLB. */ index = kvm_mips_guest_tlb_lookup(vcpu, (va & VPN2_MASK) | (kvm_read_c0_guest_entryhi(vcpu->arch.cop0) & KVM_ENTRYHI_ASID)); if (index < 0) { if (exccode == EXCCODE_TLBL) { er = kvm_mips_emulate_tlbmiss_ld(cause, opc, run, vcpu); } else if (exccode == EXCCODE_TLBS) { er = kvm_mips_emulate_tlbmiss_st(cause, opc, run, vcpu); } else { kvm_err("%s: invalid exc code: %d\n", __func__, exccode); er = EMULATE_FAIL; } } else { struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index]; /* * Check if the entry is valid, if not then setup a TLB invalid * exception to the guest */ if (!TLB_IS_VALID(*tlb, va)) { if (exccode == EXCCODE_TLBL) { er = kvm_mips_emulate_tlbinv_ld(cause, opc, run, vcpu); } else if (exccode == EXCCODE_TLBS) { er = kvm_mips_emulate_tlbinv_st(cause, opc, run, vcpu); } else { kvm_err("%s: invalid exc code: %d\n", __func__, exccode); er = EMULATE_FAIL; } } else { kvm_debug("Injecting hi: %#lx, lo0: %#lx, lo1: %#lx into shadow host TLB\n", tlb->tlb_hi, tlb->tlb_lo[0], tlb->tlb_lo[1]); /* * OK we have a Guest TLB entry, now inject it into the * shadow host TLB */ if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, va, write_fault)) { kvm_err("%s: handling mapped seg tlb fault for %lx, index: %u, vcpu: %p, ASID: %#lx\n", __func__, va, index, vcpu, read_c0_entryhi()); er = EMULATE_FAIL; } } } return er; }