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Diffstat (limited to 'arch/mips/kvm/emulate.c')
| -rw-r--r-- | arch/mips/kvm/emulate.c | 2324 |
1 files changed, 2324 insertions, 0 deletions
diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c new file mode 100644 index 000000000000..1a6068892e66 --- /dev/null +++ b/arch/mips/kvm/emulate.c @@ -0,0 +1,2324 @@ +/* + * 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 <sanjayl@kymasys.com> + */ + +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/ktime.h> +#include <linux/kvm_host.h> +#include <linux/module.h> +#include <linux/vmalloc.h> +#include <linux/fs.h> +#include <linux/bootmem.h> +#include <linux/random.h> +#include <asm/page.h> +#include <asm/cacheflush.h> +#include <asm/cpu-info.h> +#include <asm/mmu_context.h> +#include <asm/tlbflush.h> +#include <asm/inst.h> + +#undef CONFIG_MIPS_MT +#include <asm/r4kcache.h> +#define CONFIG_MIPS_MT + +#include "opcode.h" +#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. + */ +unsigned long kvm_compute_return_epc(struct kvm_vcpu *vcpu, + unsigned long instpc) +{ + unsigned int dspcontrol; + union mips_instruction insn; + struct kvm_vcpu_arch *arch = &vcpu->arch; + long epc = instpc; + long nextpc = KVM_INVALID_INST; + + if (epc & 3) + goto unaligned; + + /* Read the instruction */ + insn.word = kvm_get_inst((uint32_t *) epc, vcpu); + + if (insn.word == KVM_INVALID_INST) + return KVM_INVALID_INST; + + 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; + } + 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) + goto sigill; + + dspcontrol = rddsp(0x01); + + if (dspcontrol >= 32) + epc = epc + 4 + (insn.i_format.simmediate << 2); + else + epc += 8; + nextpc = epc; + break; + } + 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: /* not really i_format */ + case blezl_op: + /* rt field assumed to be zero */ + 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: + case bgtzl_op: + /* rt field assumed to be zero */ + 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__); + break; + } + + return nextpc; + +unaligned: + kvm_err("%s: unaligned epc\n", __func__); + return nextpc; + +sigill: + kvm_err("%s: DSP branch but not DSP ASE\n", __func__); + return nextpc; +} + +enum emulation_result update_pc(struct kvm_vcpu *vcpu, uint32_t cause) +{ + unsigned long branch_pc; + enum emulation_result er = EMULATE_DONE; + + if (cause & CAUSEF_BD) { + branch_pc = kvm_compute_return_epc(vcpu, vcpu->arch.pc); + if (branch_pc == KVM_INVALID_INST) { + er = EMULATE_FAIL; + } else { + vcpu->arch.pc = branch_pc; + kvm_debug("BD update_pc(): New PC: %#lx\n", + vcpu->arch.pc); + } + } else + vcpu->arch.pc += 4; + + kvm_debug("update_pc(): New PC: %#lx\n", vcpu->arch.pc); + + return er; +} + +/** + * 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 uint32_t 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 uint32_t kvm_mips_read_count_running(struct kvm_vcpu *vcpu, ktime_t now) +{ + ktime_t expires; + int running; + + /* Is the hrtimer pending? */ + expires = hrtimer_get_expires(&vcpu->arch.comparecount_timer); + if (ktime_compare(now, expires) >= 0) { + /* + * 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 the biased and scaled guest CP0_Count */ + return vcpu->arch.count_bias + kvm_mips_ktime_to_count(vcpu, now); +} + +/** + * 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. + */ +uint32_t 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, + uint32_t *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, uint32_t count) +{ + struct mips_coproc *cop0 = vcpu->arch.cop0; + uint32_t compare; + u64 delta; + ktime_t expire; + + /* Calculate timeout (wrap 0 to 2^32) */ + compare = kvm_read_c0_guest_compare(cop0); + delta = (u64)(uint32_t)(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_update_hrtimer() - Update next expiry time of hrtimer. + * @vcpu: Virtual CPU. + * + * Recalculates and updates the expiry time of the hrtimer. This can be used + * after timer parameters have been altered which do not depend on the time that + * the change occurs (in those cases kvm_mips_freeze_hrtimer() and + * kvm_mips_resume_hrtimer() are used directly). + * + * It is guaranteed that no timer interrupts will be lost in the process. + * + * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running). + */ +static void kvm_mips_update_hrtimer(struct kvm_vcpu *vcpu) +{ + ktime_t now; + uint32_t count; + + /* + * freeze_hrtimer takes care of a timer interrupts <= count, and + * resume_hrtimer the hrtimer takes care of a timer interrupts > count. + */ + now = kvm_mips_freeze_hrtimer(vcpu, &count); + kvm_mips_resume_hrtimer(vcpu, now, count); +} + +/** + * 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, uint32_t 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. + * + * Update CP0_Compare to a new value and update the timeout. + */ +void kvm_mips_write_compare(struct kvm_vcpu *vcpu, uint32_t compare) +{ + struct mips_coproc *cop0 = vcpu->arch.cop0; + + /* if unchanged, must just be an ack */ + if (kvm_read_c0_guest_compare(cop0) == compare) + return; + + /* Update compare */ + kvm_write_c0_guest_compare(cop0, compare); + + /* Update timeout if count enabled */ + if (!kvm_mips_count_disabled(vcpu)) + kvm_mips_update_hrtimer(vcpu); +} + +/** + * 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; + uint32_t 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; + uint32_t 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; + uint32_t 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)(uint32_t)(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_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 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 { + 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, WAIT_EXITS); + 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; + uint32_t pc = vcpu->arch.pc; + + kvm_err("[%#x] COP0_TLBR [%ld]\n", pc, kvm_read_c0_guest_index(cop0)); + return EMULATE_FAIL; +} + +/* 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; + uint32_t pc = vcpu->arch.pc; + + if (index < 0 || index >= KVM_MIPS_GUEST_TLB_SIZE) { + kvm_debug("%s: illegal index: %d\n", __func__, index); + kvm_debug("[%#x] 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]; + /* + * Probe the shadow host TLB for the entry being overwritten, if one + * matches, invalidate it + */ + kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi); + + tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0); + tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0); + tlb->tlb_lo0 = kvm_read_c0_guest_entrylo0(cop0); + tlb->tlb_lo1 = kvm_read_c0_guest_entrylo1(cop0); + + kvm_debug("[%#x] 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; + uint32_t pc = vcpu->arch.pc; + int index; + + get_random_bytes(&index, sizeof(index)); + index &= (KVM_MIPS_GUEST_TLB_SIZE - 1); + + if (index < 0 || index >= KVM_MIPS_GUEST_TLB_SIZE) { + kvm_err("%s: illegal index: %d\n", __func__, index); + return EMULATE_FAIL; + } + + tlb = &vcpu->arch.guest_tlb[index]; + + /* + * Probe the shadow host TLB for the entry being overwritten, if one + * matches, invalidate it + */ + kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi); + + tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0); + tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0); + tlb->tlb_lo0 = kvm_read_c0_guest_entrylo0(cop0); + tlb->tlb_lo1 = kvm_read_c0_guest_entrylo1(cop0); + + kvm_debug("[%#x] 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); + uint32_t pc = vcpu->arch.pc; + int index = -1; + + index = kvm_mips_guest_tlb_lookup(vcpu, entryhi); + + kvm_write_c0_guest_index(cop0, index); + + kvm_debug("[%#x] COP0_TLBP (entryhi: %#lx), index: %d\n", pc, entryhi, + index); + + return EMULATE_DONE; +} + +enum emulation_result kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc, + uint32_t cause, struct kvm_run *run, + struct kvm_vcpu *vcpu) +{ + struct mips_coproc *cop0 = vcpu->arch.cop0; + enum emulation_result er = EMULATE_DONE; + int32_t rt, rd, copz, sel, co_bit, op; + uint32_t pc = vcpu->arch.pc; + 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; + + copz = (inst >> 21) & 0x1f; + rt = (inst >> 16) & 0x1f; + rd = (inst >> 11) & 0x1f; + sel = inst & 0x7; + co_bit = (inst >> 25) & 1; + + if (co_bit) { + op = (inst) & 0xff; + + switch (op) { + 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; + break; + case wait_op: + er = kvm_mips_emul_wait(vcpu); + break; + } + } else { + switch (copz) { + 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] = 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] = cop0->reg[rd][sel]; + +#ifdef CONFIG_KVM_MIPS_DYN_TRANS + kvm_mips_trans_mfc0(inst, opc, vcpu); +#endif + } + + kvm_debug + ("[%#x] MFCz[%d][%d], vcpu->arch.gprs[%d]: %#lx\n", + pc, rd, sel, rt, vcpu->arch.gprs[rt]); + + break; + + case dmfc_op: + vcpu->arch.gprs[rt] = cop0->reg[rd][sel]; + break; + + case mtc_op: +#ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS + cop0->stat[rd][sel]++; +#endif + 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) { + uint32_t nasid = + vcpu->arch.gprs[rt] & ASID_MASK; + if ((KSEGX(vcpu->arch.gprs[rt]) != CKSEG0) && + ((kvm_read_c0_guest_entryhi(cop0) & + ASID_MASK) != nasid)) { + kvm_debug("MTCz, change ASID from %#lx to %#lx\n", + kvm_read_c0_guest_entryhi(cop0) + & ASID_MASK, + vcpu->arch.gprs[rt] + & ASID_MASK); + + /* Blow away the shadow host TLBs */ + kvm_mips_flush_host_tlb(1); + } + 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)) { + kvm_debug("[%#x] MTCz, COMPARE %#lx <- %#lx\n", + pc, kvm_read_c0_guest_compare(cop0), + vcpu->arch.gprs[rt]); + + /* If we are writing to COMPARE */ + /* Clear pending timer interrupt, if any */ + kvm_mips_callbacks->dequeue_timer_int(vcpu); + kvm_mips_write_compare(vcpu, + vcpu->arch.gprs[rt]); + } else if ((rd == MIPS_CP0_STATUS) && (sel == 0)) { + kvm_write_c0_guest_status(cop0, + vcpu->arch.gprs[rt]); + /* + * Make sure that CU1 and NMI bits are + * never set + */ + kvm_clear_c0_guest_status(cop0, + (ST0_CU1 | ST0_NMI)); + +#ifdef CONFIG_KVM_MIPS_DYN_TRANS + kvm_mips_trans_mtc0(inst, opc, vcpu); +#endif + } else if ((rd == MIPS_CP0_CAUSE) && (sel == 0)) { + uint32_t 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 { + cop0->reg[rd][sel] = vcpu->arch.gprs[rt]; +#ifdef CONFIG_KVM_MIPS_DYN_TRANS + kvm_mips_trans_mtc0(inst, opc, vcpu); +#endif + } + + kvm_debug("[%#x] MTCz, cop0->reg[%d][%d]: %#lx\n", pc, + rd, sel, cop0->reg[rd][sel]); + break; + + case dmtc_op: + kvm_err("!!!!!!![%#lx]dmtc_op: rt: %d, rd: %d, sel: %d!!!!!!\n", + vcpu->arch.pc, rt, rd, sel); + er = EMULATE_FAIL; + break; + + case mfmcz_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 & 0x20) { + kvm_debug("[%#lx] mfmcz_op: EI\n", + vcpu->arch.pc); + kvm_set_c0_guest_status(cop0, ST0_IE); + } else { + kvm_debug("[%#lx] mfmcz_op: DI\n", + vcpu->arch.pc); + kvm_clear_c0_guest_status(cop0, ST0_IE); + } + + break; + + case wrpgpr_op: + { + uint32_t css = + cop0->reg[MIPS_CP0_STATUS][2] & 0xf; + uint32_t 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, copz); + 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(uint32_t inst, uint32_t cause, + struct kvm_run *run, + struct kvm_vcpu *vcpu) +{ + enum emulation_result er = EMULATE_DO_MMIO; + int32_t op, base, rt, offset; + uint32_t 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 >> 16) & 0x1f; + base = (inst >> 21) & 0x1f; + offset = inst & 0xffff; + op = (inst >> 26) & 0x3f; + + switch (op) { + 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], + *(uint8_t *) 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; + *(uint32_t *) 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], *(uint32_t *) 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; + *(uint16_t *) 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], *(uint32_t *) data); + break; + + default: + kvm_err("Store not yet supported"); + 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(uint32_t inst, uint32_t cause, + struct kvm_run *run, + struct kvm_vcpu *vcpu) +{ + enum emulation_result er = EMULATE_DO_MMIO; + int32_t op, base, rt, offset; + uint32_t bytes; + + rt = (inst >> 16) & 0x1f; + base = (inst >> 21) & 0x1f; + offset = inst & 0xffff; + op = (inst >> 26) & 0x3f; + + vcpu->arch.pending_load_cause = cause; + 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"); + er = EMULATE_FAIL; + break; + } + + return er; +} + +int kvm_mips_sync_icache(unsigned long va, struct kvm_vcpu *vcpu) +{ + unsigned long offset = (va & ~PAGE_MASK); + struct kvm *kvm = vcpu->kvm; + unsigned long pa; + gfn_t gfn; + pfn_t pfn; + + gfn = va >> PAGE_SHIFT; + + if (gfn >= kvm->arch.guest_pmap_npages) { + kvm_err("%s: Invalid gfn: %#llx\n", __func__, gfn); + kvm_mips_dump_host_tlbs(); + kvm_arch_vcpu_dump_regs(vcpu); + return -1; + } + pfn = kvm->arch.guest_pmap[gfn]; + pa = (pfn << PAGE_SHIFT) | offset; + + kvm_debug("%s: va: %#lx, unmapped: %#x\n", __func__, va, + CKSEG0ADDR(pa)); + + local_flush_icache_range(CKSEG0ADDR(pa), 32); + return 0; +} + +#define MIPS_CACHE_OP_INDEX_INV 0x0 +#define MIPS_CACHE_OP_INDEX_LD_TAG 0x1 +#define MIPS_CACHE_OP_INDEX_ST_TAG 0x2 +#define MIPS_CACHE_OP_IMP 0x3 +#define MIPS_CACHE_OP_HIT_INV 0x4 +#define MIPS_CACHE_OP_FILL_WB_INV 0x5 +#define MIPS_CACHE_OP_HIT_HB 0x6 +#define MIPS_CACHE_OP_FETCH_LOCK 0x7 + +#define MIPS_CACHE_ICACHE 0x0 +#define MIPS_CACHE_DCACHE 0x1 +#define MIPS_CACHE_SEC 0x3 + +enum emulation_result kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc, + uint32_t cause, + struct kvm_run *run, + struct kvm_vcpu *vcpu) +{ + struct mips_coproc *cop0 = vcpu->arch.cop0; + enum emulation_result er = EMULATE_DONE; + int32_t offset, cache, op_inst, op, base; + 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 >> 21) & 0x1f; + op_inst = (inst >> 16) & 0x1f; + offset = inst & 0xffff; + cache = (inst >> 16) & 0x3; + op = (inst >> 18) & 0x7; + + 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 == MIPS_CACHE_OP_INDEX_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 == MIPS_CACHE_DCACHE) + r4k_blast_dcache(); + else if (cache == MIPS_CACHE_ICACHE) + 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; + } + + preempt_disable(); + if (KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG0) { + if (kvm_mips_host_tlb_lookup(vcpu, va) < 0) + kvm_mips_handle_kseg0_tlb_fault(va, vcpu); + } else if ((KVM_GUEST_KSEGX(va) < KVM_GUEST_KSEG0) || + KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG23) { + int index; + + /* If an entry already exists then skip */ + if (kvm_mips_host_tlb_lookup(vcpu, va) >= 0) + goto skip_fault; + + /* + * If address not in the guest TLB, then give the guest a fault, + * the resulting handler will do the right thing + */ + index = kvm_mips_guest_tlb_lookup(vcpu, (va & VPN2_MASK) | + (kvm_read_c0_guest_entryhi + (cop0) & ASID_MASK)); + + if (index < 0) { + vcpu->arch.host_cp0_entryhi = (va & VPN2_MASK); + vcpu->arch.host_cp0_badvaddr = va; + er = kvm_mips_emulate_tlbmiss_ld(cause, NULL, run, + vcpu); + preempt_enable(); + goto dont_update_pc; + } 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)) { + er = kvm_mips_emulate_tlbinv_ld(cause, NULL, + run, vcpu); + preempt_enable(); + goto dont_update_pc; + } else { + /* + * We fault an entry from the guest tlb to the + * shadow host TLB + */ + kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, + NULL, + NULL); + } + } + } else { + kvm_err("INVALID CACHE INDEX/ADDRESS (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n", + cache, op, base, arch->gprs[base], offset); + er = EMULATE_FAIL; + preempt_enable(); + goto dont_update_pc; + + } + +skip_fault: + /* XXXKYMA: Only a subset of cache ops are supported, used by Linux */ + if (cache == MIPS_CACHE_DCACHE + && (op == MIPS_CACHE_OP_FILL_WB_INV + || op == MIPS_CACHE_OP_HIT_INV)) { + flush_dcache_line(va); + +#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 == MIPS_CACHE_OP_HIT_INV && cache == MIPS_CACHE_ICACHE) { + flush_dcache_line(va); + flush_icache_line(va); + +#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; + preempt_enable(); + goto dont_update_pc; + } + + preempt_enable(); + +dont_update_pc: + /* Rollback PC */ + vcpu->arch.pc = curr_pc; +done: + return er; +} + +enum emulation_result kvm_mips_emulate_inst(unsigned long cause, uint32_t *opc, + struct kvm_run *run, + struct kvm_vcpu *vcpu) +{ + enum emulation_result er = EMULATE_DONE; + uint32_t inst; + + /* Fetch the instruction. */ + if (cause & CAUSEF_BD) + opc += 1; + + inst = kvm_get_inst(opc, vcpu); + + switch (((union mips_instruction)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; + + case cache_op: + ++vcpu->stat.cache_exits; + trace_kvm_exit(vcpu, CACHE_EXITS); + er = kvm_mips_emulate_cache(inst, opc, cause, run, vcpu); + break; + + default: + kvm_err("Instruction emulation not supported (%p/%#x)\n", opc, + inst); + kvm_arch_vcpu_dump_regs(vcpu); + er = EMULATE_FAIL; + break; + } + + return er; +} + +enum emulation_result kvm_mips_emulate_syscall(unsigned long cause, + uint32_t *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), + (T_SYSCALL << 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(unsigned long cause, + uint32_t *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) & ASID_MASK); + + 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), + (T_TLB_LD_MISS << 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); + /* Blow away the shadow host TLBs */ + kvm_mips_flush_host_tlb(1); + + return EMULATE_DONE; +} + +enum emulation_result kvm_mips_emulate_tlbinv_ld(unsigned long cause, + uint32_t *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) & ASID_MASK); + + 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), + (T_TLB_LD_MISS << 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); + /* Blow away the shadow host TLBs */ + kvm_mips_flush_host_tlb(1); + + return EMULATE_DONE; +} + +enum emulation_result kvm_mips_emulate_tlbmiss_st(unsigned long cause, + uint32_t *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) & ASID_MASK); + + 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), + (T_TLB_ST_MISS << 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); + /* Blow away the shadow host TLBs */ + kvm_mips_flush_host_tlb(1); + + return EMULATE_DONE; +} + +enum emulation_result kvm_mips_emulate_tlbinv_st(unsigned long cause, + uint32_t *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) & ASID_MASK); + + 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), + (T_TLB_ST_MISS << 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); + /* Blow away the shadow host TLBs */ + kvm_mips_flush_host_tlb(1); + + return EMULATE_DONE; +} + +/* TLBMOD: store into address matching TLB with Dirty bit off */ +enum emulation_result kvm_mips_handle_tlbmod(unsigned long cause, uint32_t *opc, + struct kvm_run *run, + struct kvm_vcpu *vcpu) +{ + enum emulation_result er = EMULATE_DONE; +#ifdef DEBUG + struct mips_coproc *cop0 = vcpu->arch.cop0; + unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) | + (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK); + int index; + + /* If address not in the guest TLB, then we are in trouble */ + index = kvm_mips_guest_tlb_lookup(vcpu, entryhi); + if (index < 0) { + /* XXXKYMA Invalidate and retry */ + kvm_mips_host_tlb_inv(vcpu, vcpu->arch.host_cp0_badvaddr); + kvm_err("%s: host got TLBMOD for %#lx but entry not present in Guest TLB\n", + __func__, entryhi); + kvm_mips_dump_guest_tlbs(vcpu); + kvm_mips_dump_host_tlbs(); + return EMULATE_FAIL; + } +#endif + + er = kvm_mips_emulate_tlbmod(cause, opc, run, vcpu); + return er; +} + +enum emulation_result kvm_mips_emulate_tlbmod(unsigned long cause, + uint32_t *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) & ASID_MASK); + 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), (T_TLB_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); + /* Blow away the shadow host TLBs */ + kvm_mips_flush_host_tlb(1); + + return EMULATE_DONE; +} + +enum emulation_result kvm_mips_emulate_fpu_exc(unsigned long cause, + uint32_t *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), + (T_COP_UNUSABLE << CAUSEB_EXCCODE)); + kvm_change_c0_guest_cause(cop0, (CAUSEF_CE), (0x1 << CAUSEB_CE)); + + return EMULATE_DONE; +} + +enum emulation_result kvm_mips_emulate_ri_exc(unsigned long cause, + uint32_t *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), + (T_RES_INST << 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(unsigned long cause, + uint32_t *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), + (T_BREAK << 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; +} + +/* ll/sc, rdhwr, sync emulation */ + +#define OPCODE 0xfc000000 +#define BASE 0x03e00000 +#define RT 0x001f0000 +#define OFFSET 0x0000ffff +#define LL 0xc0000000 +#define SC 0xe0000000 +#define SPEC0 0x00000000 +#define SPEC3 0x7c000000 +#define RD 0x0000f800 +#define FUNC 0x0000003f +#define SYNC 0x0000000f +#define RDHWR 0x0000003b + +enum emulation_result kvm_mips_handle_ri(unsigned long cause, uint32_t *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; + uint32_t inst; + + /* + * 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; + + inst = kvm_get_inst(opc, vcpu); + + if (inst == KVM_INVALID_INST) { + kvm_err("%s: Cannot get inst @ %p\n", __func__, opc); + return EMULATE_FAIL; + } + + if ((inst & OPCODE) == SPEC3 && (inst & FUNC) == RDHWR) { + int usermode = !KVM_GUEST_KERNEL_MODE(vcpu); + int rd = (inst & RD) >> 11; + int rt = (inst & RT) >> 16; + /* 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 0: /* CPU number */ + arch->gprs[rt] = 0; + break; + case 1: /* SYNCI length */ + arch->gprs[rt] = min(current_cpu_data.dcache.linesz, + current_cpu_data.icache.linesz); + break; + case 2: /* Read count register */ + arch->gprs[rt] = kvm_mips_read_count(vcpu); + break; + case 3: /* 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 29: + arch->gprs[rt] = kvm_read_c0_guest_userlocal(cop0); + break; + + default: + kvm_debug("RDHWR %#x not supported @ %p\n", rd, opc); + goto emulate_ri; + } + } else { + kvm_debug("Emulate RI not supported @ %p: %#x\n", opc, inst); + 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; + unsigned long curr_pc; + + if (run->mmio.len > sizeof(*gpr)) { + kvm_err("Bad MMIO length: %d", run->mmio.len); + er = EMULATE_FAIL; + goto done; + } + + /* + * 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, vcpu->arch.pending_load_cause); + if (er == EMULATE_FAIL) + return er; + + switch (run->mmio.len) { + case 4: + *gpr = *(int32_t *) run->mmio.data; + break; + + case 2: + if (vcpu->mmio_needed == 2) + *gpr = *(int16_t *) run->mmio.data; + else + *gpr = *(int16_t *) run->mmio.data; + + break; + case 1: + if (vcpu->mmio_needed == 2) + *gpr = *(int8_t *) run->mmio.data; + else + *gpr = *(u8 *) run->mmio.data; + break; + } + + if (vcpu->arch.pending_load_cause & CAUSEF_BD) + kvm_debug("[%#lx] Completing %d byte BD Load to gpr %d (0x%08lx) type %d\n", + vcpu->arch.pc, run->mmio.len, vcpu->arch.io_gpr, *gpr, + vcpu->mmio_needed); + +done: + return er; +} + +static enum emulation_result kvm_mips_emulate_exc(unsigned long cause, + uint32_t *opc, + struct kvm_run *run, + struct kvm_vcpu *vcpu) +{ + uint32_t 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(unsigned long cause, + uint32_t *opc, + struct kvm_run *run, + struct kvm_vcpu *vcpu) +{ + enum emulation_result er = EMULATE_DONE; + uint32_t 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 T_INT: + case T_SYSCALL: + case T_BREAK: + case T_RES_INST: + break; + + case T_COP_UNUSABLE: + if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 0) + er = EMULATE_PRIV_FAIL; + break; + + case T_TLB_MOD: + break; + + case T_TLB_LD_MISS: + /* + * 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 |= (T_ADDR_ERR_LD << CAUSEB_EXCCODE); + er = EMULATE_PRIV_FAIL; + } + break; + + case T_TLB_ST_MISS: + /* + * 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 |= (T_ADDR_ERR_ST << CAUSEB_EXCCODE); + er = EMULATE_PRIV_FAIL; + } + break; + + case T_ADDR_ERR_ST: + kvm_debug("%s: address error ST @ %#lx\n", __func__, + badvaddr); + if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) { + cause &= ~0xff; + cause |= (T_TLB_ST_MISS << CAUSEB_EXCCODE); + } + er = EMULATE_PRIV_FAIL; + break; + case T_ADDR_ERR_LD: + kvm_debug("%s: address error LD @ %#lx\n", __func__, + badvaddr); + if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) { + cause &= ~0xff; + cause |= (T_TLB_LD_MISS << 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(unsigned long cause, + uint32_t *opc, + struct kvm_run *run, + struct kvm_vcpu *vcpu) +{ + enum emulation_result er = EMULATE_DONE; + uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f; + unsigned long va = vcpu->arch.host_cp0_badvaddr; + int index; + + kvm_debug("kvm_mips_handle_tlbmiss: badvaddr: %#lx, entryhi: %#lx\n", + vcpu->arch.host_cp0_badvaddr, vcpu->arch.host_cp0_entryhi); + + /* + * 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) & ASID_MASK)); + if (index < 0) { + if (exccode == T_TLB_LD_MISS) { + er = kvm_mips_emulate_tlbmiss_ld(cause, opc, run, vcpu); + } else if (exccode == T_TLB_ST_MISS) { + 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 == T_TLB_LD_MISS) { + er = kvm_mips_emulate_tlbinv_ld(cause, opc, run, + vcpu); + } else if (exccode == T_TLB_ST_MISS) { + 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_lo0, tlb->tlb_lo1); + /* + * OK we have a Guest TLB entry, now inject it into the + * shadow host TLB + */ + kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, NULL, + NULL); + } + } + + return er; +} |