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linux/arch/mips/kvm/emulate.c
Paul Burton e6331a321a
MIPS: KVM: Use prandom_u32_max() to generate tlbwr index 
Emulation of the tlbwr instruction, which writes a TLB entry to a random
index in the TLB, currently uses get_random_bytes() to generate a 4 byte
random number which we then mask to form the index. This is overkill in
a couple of ways:

  - We don't need 4 bytes here since we mask the value to form a 6 bit
    number anyway, so we waste /dev/random entropy generating 3 random
    bytes that are unused.

  - We don't need crypto-grade randomness here - the architecture spec
    allows implementations to use any algorithm & merely encourages that
    some pseudo-randomness be used rather than a simple counter. The
    fast prandom_u32() function fits that criteria well.

So rather than using get_random_bytes() & consuming /dev/random entropy,
switch to using the faster prandom_u32_max() which provides what we need
here whilst also performing the masking/modulo for us.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Reported-by: George Spelvin <lkml@sdf.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
2019-03-25 14:02:12 -07:00

2828 lines
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/*
* 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/vmalloc.h>
#include <linux/fs.h>
#include <linux/memblock.h>
#include <linux/random.h>
#include <asm/page.h>
#include <asm/cacheflush.h>
#include <asm/cacheops.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 "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).
*/
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.
*/
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_restore_hrtimer() - Restore hrtimer after a gap, updating expiry.
* @vcpu: Virtual CPU.
* @before: Time before Count was saved, lower bound of drift calculation.
* @count: CP0_Count at point of restore.
* @min_drift: Minimum amount of drift permitted before correction.
* Must be <= 0.
*
* Restores the timer from a particular @count, accounting for drift. This can
* be used in conjunction with kvm_mips_freeze_timer() when a hardware timer is
* to be used for a period of time, but the exact ktime corresponding to the
* final Count that must be restored is not known.
*
* It is gauranteed that a timer interrupt immediately after restore will be
* handled, but not if CP0_Compare is exactly at @count. That case should
* already be handled when the hardware timer state is saved.
*
* Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is not
* stopped).
*
* Returns: Amount of correction to count_bias due to drift.
*/
int kvm_mips_restore_hrtimer(struct kvm_vcpu *vcpu, ktime_t before,
u32 count, int min_drift)
{
ktime_t now, count_time;
u32 now_count, before_count;
u64 delta;
int drift, ret = 0;
/* Calculate expected count at before */
before_count = vcpu->arch.count_bias +
kvm_mips_ktime_to_count(vcpu, before);
/*
* Detect significantly negative drift, where count is lower than
* expected. Some negative drift is expected when hardware counter is
* set after kvm_mips_freeze_timer(), and it is harmless to allow the
* time to jump forwards a little, within reason. If the drift is too
* significant, adjust the bias to avoid a big Guest.CP0_Count jump.
*/
drift = count - before_count;
if (drift < min_drift) {
count_time = before;
vcpu->arch.count_bias += drift;
ret = drift;
goto resume;
}
/* Calculate expected count right now */
now = ktime_get();
now_count = vcpu->arch.count_bias + kvm_mips_ktime_to_count(vcpu, now);
/*
* Detect positive drift, where count is higher than expected, and
* adjust the bias to avoid guest time going backwards.
*/
drift = count - now_count;
if (drift > 0) {
count_time = now;
vcpu->arch.count_bias += drift;
ret = drift;
goto resume;
}
/* Subtract nanosecond delta to find ktime when count was read */
delta = (u64)(u32)(now_count - count);
delta = div_u64(delta * NSEC_PER_SEC, vcpu->arch.count_hz);
count_time = ktime_sub_ns(now, delta);
resume:
/* Resume using the calculated ktime */
kvm_mips_resume_hrtimer(vcpu, count_time, count);
return ret;
}
/**
* 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.
* @count_hz: Frequency of timer.
*
* Initialise the timer to the specified frequency, zero it, and set it going if
* it's enabled.
*/
void kvm_mips_init_count(struct kvm_vcpu *vcpu, unsigned long count_hz)
{
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;
/* 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);
s32 delta = compare - old_compare;
u32 cause;
ktime_t now = ktime_set(0, 0); /* silence bogus GCC warning */
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;
}
/*
* If guest CP0_Compare moves forward, CP0_GTOffset should be adjusted
* too to prevent guest CP0_Count hitting guest CP0_Compare.
*
* The new GTOffset corresponds to the new value of CP0_Compare, and is
* set prior to it being written into the guest context. We disable
* preemption until the new value is written to prevent restore of a
* GTOffset corresponding to the old CP0_Compare value.
*/
if (IS_ENABLED(CONFIG_KVM_MIPS_VZ) && delta > 0) {
preempt_disable();
write_c0_gtoffset(compare - read_c0_count());
back_to_back_c0_hazard();
}
/* 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);
else if (IS_ENABLED(CONFIG_KVM_MIPS_VZ))
/*
* With VZ, writing CP0_Compare acks (clears) CP0_Cause.TI, so
* preserve guest CP0_Cause.TI if we don't want to ack it.
*/
cause = kvm_read_c0_guest_cause(cop0);
kvm_write_c0_guest_compare(cop0, compare);
if (IS_ENABLED(CONFIG_KVM_MIPS_VZ)) {
if (delta > 0)
preempt_enable();
back_to_back_c0_hazard();
if (!ack && cause & CAUSEF_TI)
kvm_write_c0_guest_cause(cop0, cause);
}
/* resume_hrtimer() takes care of timer interrupts > count */
if (!dc)
kvm_mips_resume_hrtimer(vcpu, now, count);
/*
* If guest CP0_Compare is moving backward, we delay CP0_GTOffset change
* until after the new CP0_Compare is written, otherwise new guest
* CP0_Count could hit new guest CP0_Compare.
*/
if (IS_ENABLED(CONFIG_KVM_MIPS_VZ) && delta <= 0)
write_c0_gtoffset(compare - read_c0_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) {
kvm_vz_lose_htimer(vcpu);
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)) {
kvm_clear_request(KVM_REQ_UNHALT, vcpu);
vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
}
}
return EMULATE_DONE;
}
static void kvm_mips_change_entryhi(struct kvm_vcpu *vcpu,
unsigned long entryhi)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
int cpu, i;
u32 nasid = entryhi & 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);
for_each_possible_cpu(i)
if (i != cpu)
set_cpu_context(i, kern_mm, 0);
preempt_enable();
}
kvm_write_c0_guest_entryhi(cop0, entryhi);
}
enum emulation_result kvm_mips_emul_tlbr(struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_mips_tlb *tlb;
unsigned long pc = vcpu->arch.pc;
int index;
index = kvm_read_c0_guest_index(cop0);
if (index < 0 || index >= KVM_MIPS_GUEST_TLB_SIZE) {
/* UNDEFINED */
kvm_debug("[%#lx] TLBR Index %#x out of range\n", pc, index);
index &= KVM_MIPS_GUEST_TLB_SIZE - 1;
}
tlb = &vcpu->arch.guest_tlb[index];
kvm_write_c0_guest_pagemask(cop0, tlb->tlb_mask);
kvm_write_c0_guest_entrylo0(cop0, tlb->tlb_lo[0]);
kvm_write_c0_guest_entrylo1(cop0, tlb->tlb_lo[1]);
kvm_mips_change_entryhi(vcpu, tlb->tlb_hi);
return EMULATE_DONE;
}
/**
* 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)
set_cpu_context(i, user_mm, 0);
set_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;
index = prandom_u32_max(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_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 |= 0xfc << MIPS_CONF4_KSCREXIST_SHIFT;
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;
enum emulation_result er = EMULATE_DONE;
u32 rt, rd, sel;
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;
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;
case hypcall_op:
er = kvm_mips_emul_hypcall(vcpu, inst);
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;
}
if ((rd == MIPS_CP0_PRID) && (sel == 1)) {
/*
* Preserve core number, and keep the exception
* base in guest KSeg0.
*/
kvm_change_c0_guest_ebase(cop0, 0x1ffff000,
vcpu->arch.gprs[rt]);
} else if (rd == MIPS_CP0_TLB_HI && sel == 0) {
kvm_mips_change_entryhi(vcpu,
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;
u32 rt;
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;
run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(
vcpu->arch.host_cp0_badvaddr);
if (run->mmio.phys_addr == KVM_INVALID_ADDR)
goto out_fail;
switch (inst.i_format.opcode) {
#if defined(CONFIG_64BIT) && defined(CONFIG_KVM_MIPS_VZ)
case sd_op:
run->mmio.len = 8;
*(u64 *)data = vcpu->arch.gprs[rt];
kvm_debug("[%#lx] OP_SD: eaddr: %#lx, gpr: %#lx, data: %#llx\n",
vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
vcpu->arch.gprs[rt], *(u64 *)data);
break;
#endif
case sw_op:
run->mmio.len = 4;
*(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:
run->mmio.len = 2;
*(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], *(u16 *)data);
break;
case sb_op:
run->mmio.len = 1;
*(u8 *)data = vcpu->arch.gprs[rt];
kvm_debug("[%#lx] OP_SB: eaddr: %#lx, gpr: %#lx, data: %#x\n",
vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
vcpu->arch.gprs[rt], *(u8 *)data);
break;
default:
kvm_err("Store not yet supported (inst=0x%08x)\n",
inst.word);
goto out_fail;
}
run->mmio.is_write = 1;
vcpu->mmio_needed = 1;
vcpu->mmio_is_write = 1;
return EMULATE_DO_MMIO;
out_fail:
/* Rollback PC if emulation was unsuccessful */
vcpu->arch.pc = curr_pc;
return EMULATE_FAIL;
}
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;
unsigned long curr_pc;
u32 op, rt;
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;
run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(
vcpu->arch.host_cp0_badvaddr);
if (run->mmio.phys_addr == KVM_INVALID_ADDR)
return EMULATE_FAIL;
vcpu->mmio_needed = 2; /* signed */
switch (op) {
#if defined(CONFIG_64BIT) && defined(CONFIG_KVM_MIPS_VZ)
case ld_op:
run->mmio.len = 8;
break;
case lwu_op:
vcpu->mmio_needed = 1; /* unsigned */
/* fall through */
#endif
case lw_op:
run->mmio.len = 4;
break;
case lhu_op:
vcpu->mmio_needed = 1; /* unsigned */
/* fall through */
case lh_op:
run->mmio.len = 2;
break;
case lbu_op:
vcpu->mmio_needed = 1; /* unsigned */
/* fall through */
case lb_op:
run->mmio.len = 1;
break;
default:
kvm_err("Load not yet supported (inst=0x%08x)\n",
inst.word);
vcpu->mmio_needed = 0;
return EMULATE_FAIL;
}
run->mmio.is_write = 0;
vcpu->mmio_is_write = 0;
return EMULATE_DO_MMIO;
}
#ifndef CONFIG_KVM_MIPS_VZ
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) {
#ifdef CONFIG_CPU_R4K_CACHE_TLB
r4k_blast_dcache();
#else
switch (boot_cpu_type()) {
case CPU_CAVIUM_OCTEON3:
/* locally flush icache */
local_flush_icache_range(0, 0);
break;
default:
__flush_cache_all();
break;
}
#endif
} else if (cache == Cache_I) {
#ifdef CONFIG_CPU_R4K_CACHE_TLB
r4k_blast_icache();
#else
switch (boot_cpu_type()) {
case CPU_CAVIUM_OCTEON3:
/* locally flush icache */
local_flush_icache_range(0, 0);
break;
default:
flush_icache_all();
break;
}
#endif
} 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;
#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;
}
#endif /* CONFIG_KVM_MIPS_VZ */
/**
* kvm_mips_guest_exception_base() - Find guest exception vector base address.
*
* Returns: The base address of the current guest exception vector, taking
* both Guest.CP0_Status.BEV and Guest.CP0_EBase into account.
*/
long kvm_mips_guest_exception_base(struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
if (kvm_read_c0_guest_status(cop0) & ST0_BEV)
return KVM_GUEST_CKSEG1ADDR(0x1fc00200);
else
return kvm_read_c0_guest_ebase(cop0) & MIPS_EBASE_BASE;
}
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_mips_guest_exception_base(vcpu) + 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_mips_guest_exception_base(vcpu) + 0x0;
} else {
kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
arch->pc);
arch->pc = kvm_mips_guest_exception_base(vcpu) + 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);
} else {
kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
arch->pc);
}
/* set pc to the exception entry point */
arch->pc = kvm_mips_guest_exception_base(vcpu) + 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_mips_guest_exception_base(vcpu) + 0x0;
} else {
kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
arch->pc);
arch->pc = kvm_mips_guest_exception_base(vcpu) + 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);
} else {
kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
arch->pc);
}
/* Set PC to the exception entry point */
arch->pc = kvm_mips_guest_exception_base(vcpu) + 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);
} else {
kvm_debug("[EXL == 1] Delivering TLB MOD @ pc %#lx\n",
arch->pc);
}
arch->pc = kvm_mips_guest_exception_base(vcpu) + 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_mips_guest_exception_base(vcpu) + 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_mips_guest_exception_base(vcpu) + 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_mips_guest_exception_base(vcpu) + 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_mips_guest_exception_base(vcpu) + 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_mips_guest_exception_base(vcpu) + 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_mips_guest_exception_base(vcpu) + 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_mips_guest_exception_base(vcpu) + 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 8:
*gpr = *(s64 *)run->mmio.data;
break;
case 4:
if (vcpu->mmio_needed == 2)
*gpr = *(s32 *)run->mmio.data;
else
*gpr = *(u32 *)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_mips_guest_exception_base(vcpu) + 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;
}
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