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8577370fb0
linux_dsm_epyc7002/arch/mips/kvm/mips.c
Marcelo Tosatti 8577370fb0 KVM: Use simple waitqueue for vcpu->wq 
The problem:

On -rt, an emulated LAPIC timer instances has the following path:

1) hard interrupt
2) ksoftirqd is scheduled
3) ksoftirqd wakes up vcpu thread
4) vcpu thread is scheduled

This extra context switch introduces unnecessary latency in the
LAPIC path for a KVM guest.

The solution:

Allow waking up vcpu thread from hardirq context,
thus avoiding the need for ksoftirqd to be scheduled.

Normal waitqueues make use of spinlocks, which on -RT
are sleepable locks. Therefore, waking up a waitqueue
waiter involves locking a sleeping lock, which
is not allowed from hard interrupt context.

cyclictest command line:

This patch reduces the average latency in my tests from 14us to 11us.

Daniel writes:
Paolo asked for numbers from kvm-unit-tests/tscdeadline_latency
benchmark on mainline. The test was run 1000 times on
tip/sched/core 4.4.0-rc8-01134-g0905f04:

  ./x86-run x86/tscdeadline_latency.flat -cpu host

with idle=poll.

The test seems not to deliver really stable numbers though most of
them are smaller. Paolo write:

"Anything above ~10000 cycles means that the host went to C1 or
lower---the number means more or less nothing in that case.

The mean shows an improvement indeed."

Before:

               min             max         mean           std
count  1000.000000     1000.000000  1000.000000   1000.000000
mean   5162.596000  2019270.084000  5824.491541  20681.645558
std      75.431231   622607.723969    89.575700   6492.272062
min    4466.000000    23928.000000  5537.926500    585.864966
25%    5163.000000  1613252.750000  5790.132275  16683.745433
50%    5175.000000  2281919.000000  5834.654000  23151.990026
75%    5190.000000  2382865.750000  5861.412950  24148.206168
max    5228.000000  4175158.000000  6254.827300  46481.048691

After
               min            max         mean           std
count  1000.000000     1000.00000  1000.000000   1000.000000
mean   5143.511000  2076886.10300  5813.312474  21207.357565
std      77.668322   610413.09583    86.541500   6331.915127
min    4427.000000    25103.00000  5529.756600    559.187707
25%    5148.000000  1691272.75000  5784.889825  17473.518244
50%    5160.000000  2308328.50000  5832.025000  23464.837068
75%    5172.000000  2393037.75000  5853.177675  24223.969976
max    5222.000000  3922458.00000  6186.720500  42520.379830

[Patch was originaly based on the swait implementation found in the -rt
 tree. Daniel ported it to mainline's version and gathered the
 benchmark numbers for tscdeadline_latency test.]

Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-rt-users@vger.kernel.org
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1455871601-27484-4-git-send-email-wagi@monom.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-25 11:27:16 +01:00

1664 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: MIPS specific KVM APIs
*
* 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/kdebug.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/bootmem.h>
#include <asm/fpu.h>
#include <asm/page.h>
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <linux/kvm_host.h>
#include "interrupt.h"
#include "commpage.h"
#define CREATE_TRACE_POINTS
#include "trace.h"
#ifndef VECTORSPACING
#define VECTORSPACING 0x100 /* for EI/VI mode */
#endif
#define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x)
struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "wait", VCPU_STAT(wait_exits), KVM_STAT_VCPU },
{ "cache", VCPU_STAT(cache_exits), KVM_STAT_VCPU },
{ "signal", VCPU_STAT(signal_exits), KVM_STAT_VCPU },
{ "interrupt", VCPU_STAT(int_exits), KVM_STAT_VCPU },
{ "cop_unsuable", VCPU_STAT(cop_unusable_exits), KVM_STAT_VCPU },
{ "tlbmod", VCPU_STAT(tlbmod_exits), KVM_STAT_VCPU },
{ "tlbmiss_ld", VCPU_STAT(tlbmiss_ld_exits), KVM_STAT_VCPU },
{ "tlbmiss_st", VCPU_STAT(tlbmiss_st_exits), KVM_STAT_VCPU },
{ "addrerr_st", VCPU_STAT(addrerr_st_exits), KVM_STAT_VCPU },
{ "addrerr_ld", VCPU_STAT(addrerr_ld_exits), KVM_STAT_VCPU },
{ "syscall", VCPU_STAT(syscall_exits), KVM_STAT_VCPU },
{ "resvd_inst", VCPU_STAT(resvd_inst_exits), KVM_STAT_VCPU },
{ "break_inst", VCPU_STAT(break_inst_exits), KVM_STAT_VCPU },
{ "trap_inst", VCPU_STAT(trap_inst_exits), KVM_STAT_VCPU },
{ "msa_fpe", VCPU_STAT(msa_fpe_exits), KVM_STAT_VCPU },
{ "fpe", VCPU_STAT(fpe_exits), KVM_STAT_VCPU },
{ "msa_disabled", VCPU_STAT(msa_disabled_exits), KVM_STAT_VCPU },
{ "flush_dcache", VCPU_STAT(flush_dcache_exits), KVM_STAT_VCPU },
{ "halt_successful_poll", VCPU_STAT(halt_successful_poll), KVM_STAT_VCPU },
{ "halt_attempted_poll", VCPU_STAT(halt_attempted_poll), KVM_STAT_VCPU },
{ "halt_wakeup", VCPU_STAT(halt_wakeup), KVM_STAT_VCPU },
{NULL}
};
static int kvm_mips_reset_vcpu(struct kvm_vcpu *vcpu)
{
int i;
for_each_possible_cpu(i) {
vcpu->arch.guest_kernel_asid[i] = 0;
vcpu->arch.guest_user_asid[i] = 0;
}
return 0;
}
/*
* XXXKYMA: We are simulatoring a processor that has the WII bit set in
* Config7, so we are "runnable" if interrupts are pending
*/
int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
{
return !!(vcpu->arch.pending_exceptions);
}
int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
{
return 1;
}
int kvm_arch_hardware_enable(void)
{
return 0;
}
int kvm_arch_hardware_setup(void)
{
return 0;
}
void kvm_arch_check_processor_compat(void *rtn)
{
*(int *)rtn = 0;
}
static void kvm_mips_init_tlbs(struct kvm *kvm)
{
unsigned long wired;
/*
* Add a wired entry to the TLB, it is used to map the commpage to
* the Guest kernel
*/
wired = read_c0_wired();
write_c0_wired(wired + 1);
mtc0_tlbw_hazard();
kvm->arch.commpage_tlb = wired;
kvm_debug("[%d] commpage TLB: %d\n", smp_processor_id(),
kvm->arch.commpage_tlb);
}
static void kvm_mips_init_vm_percpu(void *arg)
{
struct kvm *kvm = (struct kvm *)arg;
kvm_mips_init_tlbs(kvm);
kvm_mips_callbacks->vm_init(kvm);
}
int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
{
if (atomic_inc_return(&kvm_mips_instance) == 1) {
kvm_debug("%s: 1st KVM instance, setup host TLB parameters\n",
__func__);
on_each_cpu(kvm_mips_init_vm_percpu, kvm, 1);
}
return 0;
}
void kvm_mips_free_vcpus(struct kvm *kvm)
{
unsigned int i;
struct kvm_vcpu *vcpu;
/* Put the pages we reserved for the guest pmap */
for (i = 0; i < kvm->arch.guest_pmap_npages; i++) {
if (kvm->arch.guest_pmap[i] != KVM_INVALID_PAGE)
kvm_mips_release_pfn_clean(kvm->arch.guest_pmap[i]);
}
kfree(kvm->arch.guest_pmap);
kvm_for_each_vcpu(i, vcpu, kvm) {
kvm_arch_vcpu_free(vcpu);
}
mutex_lock(&kvm->lock);
for (i = 0; i < atomic_read(&kvm->online_vcpus); i++)
kvm->vcpus[i] = NULL;
atomic_set(&kvm->online_vcpus, 0);
mutex_unlock(&kvm->lock);
}
static void kvm_mips_uninit_tlbs(void *arg)
{
/* Restore wired count */
write_c0_wired(0);
mtc0_tlbw_hazard();
/* Clear out all the TLBs */
kvm_local_flush_tlb_all();
}
void kvm_arch_destroy_vm(struct kvm *kvm)
{
kvm_mips_free_vcpus(kvm);
/* If this is the last instance, restore wired count */
if (atomic_dec_return(&kvm_mips_instance) == 0) {
kvm_debug("%s: last KVM instance, restoring TLB parameters\n",
__func__);
on_each_cpu(kvm_mips_uninit_tlbs, NULL, 1);
}
}
long kvm_arch_dev_ioctl(struct file *filp, unsigned int ioctl,
unsigned long arg)
{
return -ENOIOCTLCMD;
}
int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
unsigned long npages)
{
return 0;
}
int kvm_arch_prepare_memory_region(struct kvm *kvm,
struct kvm_memory_slot *memslot,
const struct kvm_userspace_memory_region *mem,
enum kvm_mr_change change)
{
return 0;
}
void kvm_arch_commit_memory_region(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem,
const struct kvm_memory_slot *old,
const struct kvm_memory_slot *new,
enum kvm_mr_change change)
{
unsigned long npages = 0;
int i;
kvm_debug("%s: kvm: %p slot: %d, GPA: %llx, size: %llx, QVA: %llx\n",
__func__, kvm, mem->slot, mem->guest_phys_addr,
mem->memory_size, mem->userspace_addr);
/* Setup Guest PMAP table */
if (!kvm->arch.guest_pmap) {
if (mem->slot == 0)
npages = mem->memory_size >> PAGE_SHIFT;
if (npages) {
kvm->arch.guest_pmap_npages = npages;
kvm->arch.guest_pmap =
kzalloc(npages * sizeof(unsigned long), GFP_KERNEL);
if (!kvm->arch.guest_pmap) {
kvm_err("Failed to allocate guest PMAP\n");
return;
}
kvm_debug("Allocated space for Guest PMAP Table (%ld pages) @ %p\n",
npages, kvm->arch.guest_pmap);
/* Now setup the page table */
for (i = 0; i < npages; i++)
kvm->arch.guest_pmap[i] = KVM_INVALID_PAGE;
}
}
}
struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
{
int err, size, offset;
void *gebase;
int i;
struct kvm_vcpu *vcpu = kzalloc(sizeof(struct kvm_vcpu), GFP_KERNEL);
if (!vcpu) {
err = -ENOMEM;
goto out;
}
err = kvm_vcpu_init(vcpu, kvm, id);
if (err)
goto out_free_cpu;
kvm_debug("kvm @ %p: create cpu %d at %p\n", kvm, id, vcpu);
/*
* Allocate space for host mode exception handlers that handle
* guest mode exits
*/
if (cpu_has_veic || cpu_has_vint)
size = 0x200 + VECTORSPACING * 64;
else
size = 0x4000;
/* Save Linux EBASE */
vcpu->arch.host_ebase = (void *)read_c0_ebase();
gebase = kzalloc(ALIGN(size, PAGE_SIZE), GFP_KERNEL);
if (!gebase) {
err = -ENOMEM;
goto out_uninit_cpu;
}
kvm_debug("Allocated %d bytes for KVM Exception Handlers @ %p\n",
ALIGN(size, PAGE_SIZE), gebase);
/* Save new ebase */
vcpu->arch.guest_ebase = gebase;
/* Copy L1 Guest Exception handler to correct offset */
/* TLB Refill, EXL = 0 */
memcpy(gebase, mips32_exception,
mips32_exceptionEnd - mips32_exception);
/* General Exception Entry point */
memcpy(gebase + 0x180, mips32_exception,
mips32_exceptionEnd - mips32_exception);
/* For vectored interrupts poke the exception code @ all offsets 0-7 */
for (i = 0; i < 8; i++) {
kvm_debug("L1 Vectored handler @ %p\n",
gebase + 0x200 + (i * VECTORSPACING));
memcpy(gebase + 0x200 + (i * VECTORSPACING), mips32_exception,
mips32_exceptionEnd - mips32_exception);
}
/* General handler, relocate to unmapped space for sanity's sake */
offset = 0x2000;
kvm_debug("Installing KVM Exception handlers @ %p, %#x bytes\n",
gebase + offset,
mips32_GuestExceptionEnd - mips32_GuestException);
memcpy(gebase + offset, mips32_GuestException,
mips32_GuestExceptionEnd - mips32_GuestException);
/* Invalidate the icache for these ranges */
local_flush_icache_range((unsigned long)gebase,
(unsigned long)gebase + ALIGN(size, PAGE_SIZE));
/*
* Allocate comm page for guest kernel, a TLB will be reserved for
* mapping GVA @ 0xFFFF8000 to this page
*/
vcpu->arch.kseg0_commpage = kzalloc(PAGE_SIZE << 1, GFP_KERNEL);
if (!vcpu->arch.kseg0_commpage) {
err = -ENOMEM;
goto out_free_gebase;
}
kvm_debug("Allocated COMM page @ %p\n", vcpu->arch.kseg0_commpage);
kvm_mips_commpage_init(vcpu);
/* Init */
vcpu->arch.last_sched_cpu = -1;
/* Start off the timer */
kvm_mips_init_count(vcpu);
return vcpu;
out_free_gebase:
kfree(gebase);
out_uninit_cpu:
kvm_vcpu_uninit(vcpu);
out_free_cpu:
kfree(vcpu);
out:
return ERR_PTR(err);
}
void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
{
hrtimer_cancel(&vcpu->arch.comparecount_timer);
kvm_vcpu_uninit(vcpu);
kvm_mips_dump_stats(vcpu);
kfree(vcpu->arch.guest_ebase);
kfree(vcpu->arch.kseg0_commpage);
kfree(vcpu);
}
void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
{
kvm_arch_vcpu_free(vcpu);
}
int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
struct kvm_guest_debug *dbg)
{
return -ENOIOCTLCMD;
}
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
int r = 0;
sigset_t sigsaved;
if (vcpu->sigset_active)
sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
if (vcpu->mmio_needed) {
if (!vcpu->mmio_is_write)
kvm_mips_complete_mmio_load(vcpu, run);
vcpu->mmio_needed = 0;
}
lose_fpu(1);
local_irq_disable();
/* Check if we have any exceptions/interrupts pending */
kvm_mips_deliver_interrupts(vcpu,
kvm_read_c0_guest_cause(vcpu->arch.cop0));
__kvm_guest_enter();
/* Disable hardware page table walking while in guest */
htw_stop();
r = __kvm_mips_vcpu_run(run, vcpu);
/* Re-enable HTW before enabling interrupts */
htw_start();
__kvm_guest_exit();
local_irq_enable();
if (vcpu->sigset_active)
sigprocmask(SIG_SETMASK, &sigsaved, NULL);
return r;
}
int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
struct kvm_mips_interrupt *irq)
{
int intr = (int)irq->irq;
struct kvm_vcpu *dvcpu = NULL;
if (intr == 3 || intr == -3 || intr == 4 || intr == -4)
kvm_debug("%s: CPU: %d, INTR: %d\n", __func__, irq->cpu,
(int)intr);
if (irq->cpu == -1)
dvcpu = vcpu;
else
dvcpu = vcpu->kvm->vcpus[irq->cpu];
if (intr == 2 || intr == 3 || intr == 4) {
kvm_mips_callbacks->queue_io_int(dvcpu, irq);
} else if (intr == -2 || intr == -3 || intr == -4) {
kvm_mips_callbacks->dequeue_io_int(dvcpu, irq);
} else {
kvm_err("%s: invalid interrupt ioctl (%d:%d)\n", __func__,
irq->cpu, irq->irq);
return -EINVAL;
}
dvcpu->arch.wait = 0;
if (swait_active(&dvcpu->wq))
swake_up(&dvcpu->wq);
return 0;
}
int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
return -ENOIOCTLCMD;
}
int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
return -ENOIOCTLCMD;
}
static u64 kvm_mips_get_one_regs[] = {
KVM_REG_MIPS_R0,
KVM_REG_MIPS_R1,
KVM_REG_MIPS_R2,
KVM_REG_MIPS_R3,
KVM_REG_MIPS_R4,
KVM_REG_MIPS_R5,
KVM_REG_MIPS_R6,
KVM_REG_MIPS_R7,
KVM_REG_MIPS_R8,
KVM_REG_MIPS_R9,
KVM_REG_MIPS_R10,
KVM_REG_MIPS_R11,
KVM_REG_MIPS_R12,
KVM_REG_MIPS_R13,
KVM_REG_MIPS_R14,
KVM_REG_MIPS_R15,
KVM_REG_MIPS_R16,
KVM_REG_MIPS_R17,
KVM_REG_MIPS_R18,
KVM_REG_MIPS_R19,
KVM_REG_MIPS_R20,
KVM_REG_MIPS_R21,
KVM_REG_MIPS_R22,
KVM_REG_MIPS_R23,
KVM_REG_MIPS_R24,
KVM_REG_MIPS_R25,
KVM_REG_MIPS_R26,
KVM_REG_MIPS_R27,
KVM_REG_MIPS_R28,
KVM_REG_MIPS_R29,
KVM_REG_MIPS_R30,
KVM_REG_MIPS_R31,
KVM_REG_MIPS_HI,
KVM_REG_MIPS_LO,
KVM_REG_MIPS_PC,
KVM_REG_MIPS_CP0_INDEX,
KVM_REG_MIPS_CP0_CONTEXT,
KVM_REG_MIPS_CP0_USERLOCAL,
KVM_REG_MIPS_CP0_PAGEMASK,
KVM_REG_MIPS_CP0_WIRED,
KVM_REG_MIPS_CP0_HWRENA,
KVM_REG_MIPS_CP0_BADVADDR,
KVM_REG_MIPS_CP0_COUNT,
KVM_REG_MIPS_CP0_ENTRYHI,
KVM_REG_MIPS_CP0_COMPARE,
KVM_REG_MIPS_CP0_STATUS,
KVM_REG_MIPS_CP0_CAUSE,
KVM_REG_MIPS_CP0_EPC,
KVM_REG_MIPS_CP0_PRID,
KVM_REG_MIPS_CP0_CONFIG,
KVM_REG_MIPS_CP0_CONFIG1,
KVM_REG_MIPS_CP0_CONFIG2,
KVM_REG_MIPS_CP0_CONFIG3,
KVM_REG_MIPS_CP0_CONFIG4,
KVM_REG_MIPS_CP0_CONFIG5,
KVM_REG_MIPS_CP0_CONFIG7,
KVM_REG_MIPS_CP0_ERROREPC,
KVM_REG_MIPS_COUNT_CTL,
KVM_REG_MIPS_COUNT_RESUME,
KVM_REG_MIPS_COUNT_HZ,
};
static int kvm_mips_get_reg(struct kvm_vcpu *vcpu,
const struct kvm_one_reg *reg)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct mips_fpu_struct *fpu = &vcpu->arch.fpu;
int ret;
s64 v;
s64 vs[2];
unsigned int idx;
switch (reg->id) {
/* General purpose registers */
case KVM_REG_MIPS_R0 ... KVM_REG_MIPS_R31:
v = (long)vcpu->arch.gprs[reg->id - KVM_REG_MIPS_R0];
break;
case KVM_REG_MIPS_HI:
v = (long)vcpu->arch.hi;
break;
case KVM_REG_MIPS_LO:
v = (long)vcpu->arch.lo;
break;
case KVM_REG_MIPS_PC:
v = (long)vcpu->arch.pc;
break;
/* Floating point registers */
case KVM_REG_MIPS_FPR_32(0) ... KVM_REG_MIPS_FPR_32(31):
if (!kvm_mips_guest_has_fpu(&vcpu->arch))
return -EINVAL;
idx = reg->id - KVM_REG_MIPS_FPR_32(0);
/* Odd singles in top of even double when FR=0 */
if (kvm_read_c0_guest_status(cop0) & ST0_FR)
v = get_fpr32(&fpu->fpr[idx], 0);
else
v = get_fpr32(&fpu->fpr[idx & ~1], idx & 1);
break;
case KVM_REG_MIPS_FPR_64(0) ... KVM_REG_MIPS_FPR_64(31):
if (!kvm_mips_guest_has_fpu(&vcpu->arch))
return -EINVAL;
idx = reg->id - KVM_REG_MIPS_FPR_64(0);
/* Can't access odd doubles in FR=0 mode */
if (idx & 1 && !(kvm_read_c0_guest_status(cop0) & ST0_FR))
return -EINVAL;
v = get_fpr64(&fpu->fpr[idx], 0);
break;
case KVM_REG_MIPS_FCR_IR:
if (!kvm_mips_guest_has_fpu(&vcpu->arch))
return -EINVAL;
v = boot_cpu_data.fpu_id;
break;
case KVM_REG_MIPS_FCR_CSR:
if (!kvm_mips_guest_has_fpu(&vcpu->arch))
return -EINVAL;
v = fpu->fcr31;
break;
/* MIPS SIMD Architecture (MSA) registers */
case KVM_REG_MIPS_VEC_128(0) ... KVM_REG_MIPS_VEC_128(31):
if (!kvm_mips_guest_has_msa(&vcpu->arch))
return -EINVAL;
/* Can't access MSA registers in FR=0 mode */
if (!(kvm_read_c0_guest_status(cop0) & ST0_FR))
return -EINVAL;
idx = reg->id - KVM_REG_MIPS_VEC_128(0);
#ifdef CONFIG_CPU_LITTLE_ENDIAN
/* least significant byte first */
vs[0] = get_fpr64(&fpu->fpr[idx], 0);
vs[1] = get_fpr64(&fpu->fpr[idx], 1);
#else
/* most significant byte first */
vs[0] = get_fpr64(&fpu->fpr[idx], 1);
vs[1] = get_fpr64(&fpu->fpr[idx], 0);
#endif
break;
case KVM_REG_MIPS_MSA_IR:
if (!kvm_mips_guest_has_msa(&vcpu->arch))
return -EINVAL;
v = boot_cpu_data.msa_id;
break;
case KVM_REG_MIPS_MSA_CSR:
if (!kvm_mips_guest_has_msa(&vcpu->arch))
return -EINVAL;
v = fpu->msacsr;
break;
/* Co-processor 0 registers */
case KVM_REG_MIPS_CP0_INDEX:
v = (long)kvm_read_c0_guest_index(cop0);
break;
case KVM_REG_MIPS_CP0_CONTEXT:
v = (long)kvm_read_c0_guest_context(cop0);
break;
case KVM_REG_MIPS_CP0_USERLOCAL:
v = (long)kvm_read_c0_guest_userlocal(cop0);
break;
case KVM_REG_MIPS_CP0_PAGEMASK:
v = (long)kvm_read_c0_guest_pagemask(cop0);
break;
case KVM_REG_MIPS_CP0_WIRED:
v = (long)kvm_read_c0_guest_wired(cop0);
break;
case KVM_REG_MIPS_CP0_HWRENA:
v = (long)kvm_read_c0_guest_hwrena(cop0);
break;
case KVM_REG_MIPS_CP0_BADVADDR:
v = (long)kvm_read_c0_guest_badvaddr(cop0);
break;
case KVM_REG_MIPS_CP0_ENTRYHI:
v = (long)kvm_read_c0_guest_entryhi(cop0);
break;
case KVM_REG_MIPS_CP0_COMPARE:
v = (long)kvm_read_c0_guest_compare(cop0);
break;
case KVM_REG_MIPS_CP0_STATUS:
v = (long)kvm_read_c0_guest_status(cop0);
break;
case KVM_REG_MIPS_CP0_CAUSE:
v = (long)kvm_read_c0_guest_cause(cop0);
break;
case KVM_REG_MIPS_CP0_EPC:
v = (long)kvm_read_c0_guest_epc(cop0);
break;
case KVM_REG_MIPS_CP0_PRID:
v = (long)kvm_read_c0_guest_prid(cop0);
break;
case KVM_REG_MIPS_CP0_CONFIG:
v = (long)kvm_read_c0_guest_config(cop0);
break;
case KVM_REG_MIPS_CP0_CONFIG1:
v = (long)kvm_read_c0_guest_config1(cop0);
break;
case KVM_REG_MIPS_CP0_CONFIG2:
v = (long)kvm_read_c0_guest_config2(cop0);
break;
case KVM_REG_MIPS_CP0_CONFIG3:
v = (long)kvm_read_c0_guest_config3(cop0);
break;
case KVM_REG_MIPS_CP0_CONFIG4:
v = (long)kvm_read_c0_guest_config4(cop0);
break;
case KVM_REG_MIPS_CP0_CONFIG5:
v = (long)kvm_read_c0_guest_config5(cop0);
break;
case KVM_REG_MIPS_CP0_CONFIG7:
v = (long)kvm_read_c0_guest_config7(cop0);
break;
case KVM_REG_MIPS_CP0_ERROREPC:
v = (long)kvm_read_c0_guest_errorepc(cop0);
break;
/* registers to be handled specially */
case KVM_REG_MIPS_CP0_COUNT:
case KVM_REG_MIPS_COUNT_CTL:
case KVM_REG_MIPS_COUNT_RESUME:
case KVM_REG_MIPS_COUNT_HZ:
ret = kvm_mips_callbacks->get_one_reg(vcpu, reg, &v);
if (ret)
return ret;
break;
default:
return -EINVAL;
}
if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U64) {
u64 __user *uaddr64 = (u64 __user *)(long)reg->addr;
return put_user(v, uaddr64);
} else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U32) {
u32 __user *uaddr32 = (u32 __user *)(long)reg->addr;
u32 v32 = (u32)v;
return put_user(v32, uaddr32);
} else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U128) {
void __user *uaddr = (void __user *)(long)reg->addr;
return copy_to_user(uaddr, vs, 16);
} else {
return -EINVAL;
}
}
static int kvm_mips_set_reg(struct kvm_vcpu *vcpu,
const struct kvm_one_reg *reg)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct mips_fpu_struct *fpu = &vcpu->arch.fpu;
s64 v;
s64 vs[2];
unsigned int idx;
if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U64) {
u64 __user *uaddr64 = (u64 __user *)(long)reg->addr;
if (get_user(v, uaddr64) != 0)
return -EFAULT;
} else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U32) {
u32 __user *uaddr32 = (u32 __user *)(long)reg->addr;
s32 v32;
if (get_user(v32, uaddr32) != 0)
return -EFAULT;
v = (s64)v32;
} else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U128) {
void __user *uaddr = (void __user *)(long)reg->addr;
return copy_from_user(vs, uaddr, 16);
} else {
return -EINVAL;
}
switch (reg->id) {
/* General purpose registers */
case KVM_REG_MIPS_R0:
/* Silently ignore requests to set $0 */
break;
case KVM_REG_MIPS_R1 ... KVM_REG_MIPS_R31:
vcpu->arch.gprs[reg->id - KVM_REG_MIPS_R0] = v;
break;
case KVM_REG_MIPS_HI:
vcpu->arch.hi = v;
break;
case KVM_REG_MIPS_LO:
vcpu->arch.lo = v;
break;
case KVM_REG_MIPS_PC:
vcpu->arch.pc = v;
break;
/* Floating point registers */
case KVM_REG_MIPS_FPR_32(0) ... KVM_REG_MIPS_FPR_32(31):
if (!kvm_mips_guest_has_fpu(&vcpu->arch))
return -EINVAL;
idx = reg->id - KVM_REG_MIPS_FPR_32(0);
/* Odd singles in top of even double when FR=0 */
if (kvm_read_c0_guest_status(cop0) & ST0_FR)
set_fpr32(&fpu->fpr[idx], 0, v);
else
set_fpr32(&fpu->fpr[idx & ~1], idx & 1, v);
break;
case KVM_REG_MIPS_FPR_64(0) ... KVM_REG_MIPS_FPR_64(31):
if (!kvm_mips_guest_has_fpu(&vcpu->arch))
return -EINVAL;
idx = reg->id - KVM_REG_MIPS_FPR_64(0);
/* Can't access odd doubles in FR=0 mode */
if (idx & 1 && !(kvm_read_c0_guest_status(cop0) & ST0_FR))
return -EINVAL;
set_fpr64(&fpu->fpr[idx], 0, v);
break;
case KVM_REG_MIPS_FCR_IR:
if (!kvm_mips_guest_has_fpu(&vcpu->arch))
return -EINVAL;
/* Read-only */
break;
case KVM_REG_MIPS_FCR_CSR:
if (!kvm_mips_guest_has_fpu(&vcpu->arch))
return -EINVAL;
fpu->fcr31 = v;
break;
/* MIPS SIMD Architecture (MSA) registers */
case KVM_REG_MIPS_VEC_128(0) ... KVM_REG_MIPS_VEC_128(31):
if (!kvm_mips_guest_has_msa(&vcpu->arch))
return -EINVAL;
idx = reg->id - KVM_REG_MIPS_VEC_128(0);
#ifdef CONFIG_CPU_LITTLE_ENDIAN
/* least significant byte first */
set_fpr64(&fpu->fpr[idx], 0, vs[0]);
set_fpr64(&fpu->fpr[idx], 1, vs[1]);
#else
/* most significant byte first */
set_fpr64(&fpu->fpr[idx], 1, vs[0]);
set_fpr64(&fpu->fpr[idx], 0, vs[1]);
#endif
break;
case KVM_REG_MIPS_MSA_IR:
if (!kvm_mips_guest_has_msa(&vcpu->arch))
return -EINVAL;
/* Read-only */
break;
case KVM_REG_MIPS_MSA_CSR:
if (!kvm_mips_guest_has_msa(&vcpu->arch))
return -EINVAL;
fpu->msacsr = v;
break;
/* Co-processor 0 registers */
case KVM_REG_MIPS_CP0_INDEX:
kvm_write_c0_guest_index(cop0, v);
break;
case KVM_REG_MIPS_CP0_CONTEXT:
kvm_write_c0_guest_context(cop0, v);
break;
case KVM_REG_MIPS_CP0_USERLOCAL:
kvm_write_c0_guest_userlocal(cop0, v);
break;
case KVM_REG_MIPS_CP0_PAGEMASK:
kvm_write_c0_guest_pagemask(cop0, v);
break;
case KVM_REG_MIPS_CP0_WIRED:
kvm_write_c0_guest_wired(cop0, v);
break;
case KVM_REG_MIPS_CP0_HWRENA:
kvm_write_c0_guest_hwrena(cop0, v);
break;
case KVM_REG_MIPS_CP0_BADVADDR:
kvm_write_c0_guest_badvaddr(cop0, v);
break;
case KVM_REG_MIPS_CP0_ENTRYHI:
kvm_write_c0_guest_entryhi(cop0, v);
break;
case KVM_REG_MIPS_CP0_STATUS:
kvm_write_c0_guest_status(cop0, v);
break;
case KVM_REG_MIPS_CP0_EPC:
kvm_write_c0_guest_epc(cop0, v);
break;
case KVM_REG_MIPS_CP0_PRID:
kvm_write_c0_guest_prid(cop0, v);
break;
case KVM_REG_MIPS_CP0_ERROREPC:
kvm_write_c0_guest_errorepc(cop0, v);
break;
/* registers to be handled specially */
case KVM_REG_MIPS_CP0_COUNT:
case KVM_REG_MIPS_CP0_COMPARE:
case KVM_REG_MIPS_CP0_CAUSE:
case KVM_REG_MIPS_CP0_CONFIG:
case KVM_REG_MIPS_CP0_CONFIG1:
case KVM_REG_MIPS_CP0_CONFIG2:
case KVM_REG_MIPS_CP0_CONFIG3:
case KVM_REG_MIPS_CP0_CONFIG4:
case KVM_REG_MIPS_CP0_CONFIG5:
case KVM_REG_MIPS_COUNT_CTL:
case KVM_REG_MIPS_COUNT_RESUME:
case KVM_REG_MIPS_COUNT_HZ:
return kvm_mips_callbacks->set_one_reg(vcpu, reg, v);
default:
return -EINVAL;
}
return 0;
}
static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
struct kvm_enable_cap *cap)
{
int r = 0;
if (!kvm_vm_ioctl_check_extension(vcpu->kvm, cap->cap))
return -EINVAL;
if (cap->flags)
return -EINVAL;
if (cap->args[0])
return -EINVAL;
switch (cap->cap) {
case KVM_CAP_MIPS_FPU:
vcpu->arch.fpu_enabled = true;
break;
case KVM_CAP_MIPS_MSA:
vcpu->arch.msa_enabled = true;
break;
default:
r = -EINVAL;
break;
}
return r;
}
long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl,
unsigned long arg)
{
struct kvm_vcpu *vcpu = filp->private_data;
void __user *argp = (void __user *)arg;
long r;
switch (ioctl) {
case KVM_SET_ONE_REG:
case KVM_GET_ONE_REG: {
struct kvm_one_reg reg;
if (copy_from_user(&reg, argp, sizeof(reg)))
return -EFAULT;
if (ioctl == KVM_SET_ONE_REG)
return kvm_mips_set_reg(vcpu, &reg);
else
return kvm_mips_get_reg(vcpu, &reg);
}
case KVM_GET_REG_LIST: {
struct kvm_reg_list __user *user_list = argp;
u64 __user *reg_dest;
struct kvm_reg_list reg_list;
unsigned n;
if (copy_from_user(&reg_list, user_list, sizeof(reg_list)))
return -EFAULT;
n = reg_list.n;
reg_list.n = ARRAY_SIZE(kvm_mips_get_one_regs);
if (copy_to_user(user_list, &reg_list, sizeof(reg_list)))
return -EFAULT;
if (n < reg_list.n)
return -E2BIG;
reg_dest = user_list->reg;
if (copy_to_user(reg_dest, kvm_mips_get_one_regs,
sizeof(kvm_mips_get_one_regs)))
return -EFAULT;
return 0;
}
case KVM_NMI:
/* Treat the NMI as a CPU reset */
r = kvm_mips_reset_vcpu(vcpu);
break;
case KVM_INTERRUPT:
{
struct kvm_mips_interrupt irq;
r = -EFAULT;
if (copy_from_user(&irq, argp, sizeof(irq)))
goto out;
kvm_debug("[%d] %s: irq: %d\n", vcpu->vcpu_id, __func__,
irq.irq);
r = kvm_vcpu_ioctl_interrupt(vcpu, &irq);
break;
}
case KVM_ENABLE_CAP: {
struct kvm_enable_cap cap;
r = -EFAULT;
if (copy_from_user(&cap, argp, sizeof(cap)))
goto out;
r = kvm_vcpu_ioctl_enable_cap(vcpu, &cap);
break;
}
default:
r = -ENOIOCTLCMD;
}
out:
return r;
}
/* Get (and clear) the dirty memory log for a memory slot. */
int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
{
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
unsigned long ga, ga_end;
int is_dirty = 0;
int r;
unsigned long n;
mutex_lock(&kvm->slots_lock);
r = kvm_get_dirty_log(kvm, log, &is_dirty);
if (r)
goto out;
/* If nothing is dirty, don't bother messing with page tables. */
if (is_dirty) {
slots = kvm_memslots(kvm);
memslot = id_to_memslot(slots, log->slot);
ga = memslot->base_gfn << PAGE_SHIFT;
ga_end = ga + (memslot->npages << PAGE_SHIFT);
kvm_info("%s: dirty, ga: %#lx, ga_end %#lx\n", __func__, ga,
ga_end);
n = kvm_dirty_bitmap_bytes(memslot);
memset(memslot->dirty_bitmap, 0, n);
}
r = 0;
out:
mutex_unlock(&kvm->slots_lock);
return r;
}
long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
{
long r;
switch (ioctl) {
default:
r = -ENOIOCTLCMD;
}
return r;
}
int kvm_arch_init(void *opaque)
{
if (kvm_mips_callbacks) {
kvm_err("kvm: module already exists\n");
return -EEXIST;
}
return kvm_mips_emulation_init(&kvm_mips_callbacks);
}
void kvm_arch_exit(void)
{
kvm_mips_callbacks = NULL;
}
int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
return -ENOIOCTLCMD;
}
int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
return -ENOIOCTLCMD;
}
void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
{
}
int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
return -ENOIOCTLCMD;
}
int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
return -ENOIOCTLCMD;
}
int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
{
return VM_FAULT_SIGBUS;
}
int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
{
int r;
switch (ext) {
case KVM_CAP_ONE_REG:
case KVM_CAP_ENABLE_CAP:
r = 1;
break;
case KVM_CAP_COALESCED_MMIO:
r = KVM_COALESCED_MMIO_PAGE_OFFSET;
break;
case KVM_CAP_MIPS_FPU:
r = !!cpu_has_fpu;
break;
case KVM_CAP_MIPS_MSA:
/*
* We don't support MSA vector partitioning yet:
* 1) It would require explicit support which can't be tested
* yet due to lack of support in current hardware.
* 2) It extends the state that would need to be saved/restored
* by e.g. QEMU for migration.
*
* When vector partitioning hardware becomes available, support
* could be added by requiring a flag when enabling
* KVM_CAP_MIPS_MSA capability to indicate that userland knows
* to save/restore the appropriate extra state.
*/
r = cpu_has_msa && !(boot_cpu_data.msa_id & MSA_IR_WRPF);
break;
default:
r = 0;
break;
}
return r;
}
int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
{
return kvm_mips_pending_timer(vcpu);
}
int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu)
{
int i;
struct mips_coproc *cop0;
if (!vcpu)
return -1;
kvm_debug("VCPU Register Dump:\n");
kvm_debug("\tpc = 0x%08lx\n", vcpu->arch.pc);
kvm_debug("\texceptions: %08lx\n", vcpu->arch.pending_exceptions);
for (i = 0; i < 32; i += 4) {
kvm_debug("\tgpr%02d: %08lx %08lx %08lx %08lx\n", i,
vcpu->arch.gprs[i],
vcpu->arch.gprs[i + 1],
vcpu->arch.gprs[i + 2], vcpu->arch.gprs[i + 3]);
}
kvm_debug("\thi: 0x%08lx\n", vcpu->arch.hi);
kvm_debug("\tlo: 0x%08lx\n", vcpu->arch.lo);
cop0 = vcpu->arch.cop0;
kvm_debug("\tStatus: 0x%08lx, Cause: 0x%08lx\n",
kvm_read_c0_guest_status(cop0),
kvm_read_c0_guest_cause(cop0));
kvm_debug("\tEPC: 0x%08lx\n", kvm_read_c0_guest_epc(cop0));
return 0;
}
int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
int i;
for (i = 1; i < ARRAY_SIZE(vcpu->arch.gprs); i++)
vcpu->arch.gprs[i] = regs->gpr[i];
vcpu->arch.gprs[0] = 0; /* zero is special, and cannot be set. */
vcpu->arch.hi = regs->hi;
vcpu->arch.lo = regs->lo;
vcpu->arch.pc = regs->pc;
return 0;
}
int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
int i;
for (i = 0; i < ARRAY_SIZE(vcpu->arch.gprs); i++)
regs->gpr[i] = vcpu->arch.gprs[i];
regs->hi = vcpu->arch.hi;
regs->lo = vcpu->arch.lo;
regs->pc = vcpu->arch.pc;
return 0;
}
static void kvm_mips_comparecount_func(unsigned long data)
{
struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;
kvm_mips_callbacks->queue_timer_int(vcpu);
vcpu->arch.wait = 0;
if (swait_active(&vcpu->wq))
swake_up(&vcpu->wq);
}
/* low level hrtimer wake routine */
static enum hrtimer_restart kvm_mips_comparecount_wakeup(struct hrtimer *timer)
{
struct kvm_vcpu *vcpu;
vcpu = container_of(timer, struct kvm_vcpu, arch.comparecount_timer);
kvm_mips_comparecount_func((unsigned long) vcpu);
return kvm_mips_count_timeout(vcpu);
}
int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
{
kvm_mips_callbacks->vcpu_init(vcpu);
hrtimer_init(&vcpu->arch.comparecount_timer, CLOCK_MONOTONIC,
HRTIMER_MODE_REL);
vcpu->arch.comparecount_timer.function = kvm_mips_comparecount_wakeup;
return 0;
}
int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
struct kvm_translation *tr)
{
return 0;
}
/* Initial guest state */
int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
{
return kvm_mips_callbacks->vcpu_setup(vcpu);
}
static void kvm_mips_set_c0_status(void)
{
uint32_t status = read_c0_status();
if (cpu_has_dsp)
status |= (ST0_MX);
write_c0_status(status);
ehb();
}
/*
* Return value is in the form (errcode<<2 | RESUME_FLAG_HOST | RESUME_FLAG_NV)
*/
int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
{
uint32_t cause = vcpu->arch.host_cp0_cause;
uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
enum emulation_result er = EMULATE_DONE;
int ret = RESUME_GUEST;
/* re-enable HTW before enabling interrupts */
htw_start();
/* Set a default exit reason */
run->exit_reason = KVM_EXIT_UNKNOWN;
run->ready_for_interrupt_injection = 1;
/*
* Set the appropriate status bits based on host CPU features,
* before we hit the scheduler
*/
kvm_mips_set_c0_status();
local_irq_enable();
kvm_debug("kvm_mips_handle_exit: cause: %#x, PC: %p, kvm_run: %p, kvm_vcpu: %p\n",
cause, opc, run, vcpu);
/*
* Do a privilege check, if in UM most of these exit conditions end up
* causing an exception to be delivered to the Guest Kernel
*/
er = kvm_mips_check_privilege(cause, opc, run, vcpu);
if (er == EMULATE_PRIV_FAIL) {
goto skip_emul;
} else if (er == EMULATE_FAIL) {
run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
ret = RESUME_HOST;
goto skip_emul;
}
switch (exccode) {
case EXCCODE_INT:
kvm_debug("[%d]EXCCODE_INT @ %p\n", vcpu->vcpu_id, opc);
++vcpu->stat.int_exits;
trace_kvm_exit(vcpu, INT_EXITS);
if (need_resched())
cond_resched();
ret = RESUME_GUEST;
break;
case EXCCODE_CPU:
kvm_debug("EXCCODE_CPU: @ PC: %p\n", opc);
++vcpu->stat.cop_unusable_exits;
trace_kvm_exit(vcpu, COP_UNUSABLE_EXITS);
ret = kvm_mips_callbacks->handle_cop_unusable(vcpu);
/* XXXKYMA: Might need to return to user space */
if (run->exit_reason == KVM_EXIT_IRQ_WINDOW_OPEN)
ret = RESUME_HOST;
break;
case EXCCODE_MOD:
++vcpu->stat.tlbmod_exits;
trace_kvm_exit(vcpu, TLBMOD_EXITS);
ret = kvm_mips_callbacks->handle_tlb_mod(vcpu);
break;
case EXCCODE_TLBS:
kvm_debug("TLB ST fault: cause %#x, status %#lx, PC: %p, BadVaddr: %#lx\n",
cause, kvm_read_c0_guest_status(vcpu->arch.cop0), opc,
badvaddr);
++vcpu->stat.tlbmiss_st_exits;
trace_kvm_exit(vcpu, TLBMISS_ST_EXITS);
ret = kvm_mips_callbacks->handle_tlb_st_miss(vcpu);
break;
case EXCCODE_TLBL:
kvm_debug("TLB LD fault: cause %#x, PC: %p, BadVaddr: %#lx\n",
cause, opc, badvaddr);
++vcpu->stat.tlbmiss_ld_exits;
trace_kvm_exit(vcpu, TLBMISS_LD_EXITS);
ret = kvm_mips_callbacks->handle_tlb_ld_miss(vcpu);
break;
case EXCCODE_ADES:
++vcpu->stat.addrerr_st_exits;
trace_kvm_exit(vcpu, ADDRERR_ST_EXITS);
ret = kvm_mips_callbacks->handle_addr_err_st(vcpu);
break;
case EXCCODE_ADEL:
++vcpu->stat.addrerr_ld_exits;
trace_kvm_exit(vcpu, ADDRERR_LD_EXITS);
ret = kvm_mips_callbacks->handle_addr_err_ld(vcpu);
break;
case EXCCODE_SYS:
++vcpu->stat.syscall_exits;
trace_kvm_exit(vcpu, SYSCALL_EXITS);
ret = kvm_mips_callbacks->handle_syscall(vcpu);
break;
case EXCCODE_RI:
++vcpu->stat.resvd_inst_exits;
trace_kvm_exit(vcpu, RESVD_INST_EXITS);
ret = kvm_mips_callbacks->handle_res_inst(vcpu);
break;
case EXCCODE_BP:
++vcpu->stat.break_inst_exits;
trace_kvm_exit(vcpu, BREAK_INST_EXITS);
ret = kvm_mips_callbacks->handle_break(vcpu);
break;
case EXCCODE_TR:
++vcpu->stat.trap_inst_exits;
trace_kvm_exit(vcpu, TRAP_INST_EXITS);
ret = kvm_mips_callbacks->handle_trap(vcpu);
break;
case EXCCODE_MSAFPE:
++vcpu->stat.msa_fpe_exits;
trace_kvm_exit(vcpu, MSA_FPE_EXITS);
ret = kvm_mips_callbacks->handle_msa_fpe(vcpu);
break;
case EXCCODE_FPE:
++vcpu->stat.fpe_exits;
trace_kvm_exit(vcpu, FPE_EXITS);
ret = kvm_mips_callbacks->handle_fpe(vcpu);
break;
case EXCCODE_MSADIS:
++vcpu->stat.msa_disabled_exits;
trace_kvm_exit(vcpu, MSA_DISABLED_EXITS);
ret = kvm_mips_callbacks->handle_msa_disabled(vcpu);
break;
default:
kvm_err("Exception Code: %d, not yet handled, @ PC: %p, inst: 0x%08x BadVaddr: %#lx Status: %#lx\n",
exccode, opc, kvm_get_inst(opc, vcpu), badvaddr,
kvm_read_c0_guest_status(vcpu->arch.cop0));
kvm_arch_vcpu_dump_regs(vcpu);
run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
ret = RESUME_HOST;
break;
}
skip_emul:
local_irq_disable();
if (er == EMULATE_DONE && !(ret & RESUME_HOST))
kvm_mips_deliver_interrupts(vcpu, cause);
if (!(ret & RESUME_HOST)) {
/* Only check for signals if not already exiting to userspace */
if (signal_pending(current)) {
run->exit_reason = KVM_EXIT_INTR;
ret = (-EINTR << 2) | RESUME_HOST;
++vcpu->stat.signal_exits;
trace_kvm_exit(vcpu, SIGNAL_EXITS);
}
}
if (ret == RESUME_GUEST) {
/*
* If FPU / MSA are enabled (i.e. the guest's FPU / MSA context
* is live), restore FCR31 / MSACSR.
*
* This should be before returning to the guest exception
* vector, as it may well cause an [MSA] FP exception if there
* are pending exception bits unmasked. (see
* kvm_mips_csr_die_notifier() for how that is handled).
*/
if (kvm_mips_guest_has_fpu(&vcpu->arch) &&
read_c0_status() & ST0_CU1)
__kvm_restore_fcsr(&vcpu->arch);
if (kvm_mips_guest_has_msa(&vcpu->arch) &&
read_c0_config5() & MIPS_CONF5_MSAEN)
__kvm_restore_msacsr(&vcpu->arch);
}
/* Disable HTW before returning to guest or host */
htw_stop();
return ret;
}
/* Enable FPU for guest and restore context */
void kvm_own_fpu(struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
unsigned int sr, cfg5;
preempt_disable();
sr = kvm_read_c0_guest_status(cop0);
/*
* 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.
*
* In theory we shouldn't ever hit this case since kvm_lose_fpu() should
* get called when guest CU1 is set, however we can't trust the guest
* not to clobber the status register directly via the commpage.
*/
if (cpu_has_msa && sr & ST0_CU1 && !(sr & ST0_FR) &&
vcpu->arch.fpu_inuse & KVM_MIPS_FPU_MSA)
kvm_lose_fpu(vcpu);
/*
* Enable FPU for guest
* We set FR and FRE according to guest context
*/
change_c0_status(ST0_CU1 | ST0_FR, sr);
if (cpu_has_fre) {
cfg5 = kvm_read_c0_guest_config5(cop0);
change_c0_config5(MIPS_CONF5_FRE, cfg5);
}
enable_fpu_hazard();
/* If guest FPU state not active, restore it now */
if (!(vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU)) {
__kvm_restore_fpu(&vcpu->arch);
vcpu->arch.fpu_inuse |= KVM_MIPS_FPU_FPU;
}
preempt_enable();
}
#ifdef CONFIG_CPU_HAS_MSA
/* Enable MSA for guest and restore context */
void kvm_own_msa(struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
unsigned int sr, cfg5;
preempt_disable();
/*
* Enable FPU if enabled in guest, since we're restoring FPU context
* anyway. We set FR and FRE according to guest context.
*/
if (kvm_mips_guest_has_fpu(&vcpu->arch)) {
sr = kvm_read_c0_guest_status(cop0);
/*
* If FR=0 FPU state is already live, it is undefined how it
* interacts with MSA state, so play it safe and save it first.
*/
if (!(sr & ST0_FR) &&
(vcpu->arch.fpu_inuse & (KVM_MIPS_FPU_FPU |
KVM_MIPS_FPU_MSA)) == KVM_MIPS_FPU_FPU)
kvm_lose_fpu(vcpu);
change_c0_status(ST0_CU1 | ST0_FR, sr);
if (sr & ST0_CU1 && cpu_has_fre) {
cfg5 = kvm_read_c0_guest_config5(cop0);
change_c0_config5(MIPS_CONF5_FRE, cfg5);
}
}
/* Enable MSA for guest */
set_c0_config5(MIPS_CONF5_MSAEN);
enable_fpu_hazard();
switch (vcpu->arch.fpu_inuse & (KVM_MIPS_FPU_FPU | KVM_MIPS_FPU_MSA)) {
case KVM_MIPS_FPU_FPU:
/*
* Guest FPU state already loaded, only restore upper MSA state
*/
__kvm_restore_msa_upper(&vcpu->arch);
vcpu->arch.fpu_inuse |= KVM_MIPS_FPU_MSA;
break;
case 0:
/* Neither FPU or MSA already active, restore full MSA state */
__kvm_restore_msa(&vcpu->arch);
vcpu->arch.fpu_inuse |= KVM_MIPS_FPU_MSA;
if (kvm_mips_guest_has_fpu(&vcpu->arch))
vcpu->arch.fpu_inuse |= KVM_MIPS_FPU_FPU;
break;
default:
break;
}
preempt_enable();
}
#endif
/* Drop FPU & MSA without saving it */
void kvm_drop_fpu(struct kvm_vcpu *vcpu)
{
preempt_disable();
if (cpu_has_msa && vcpu->arch.fpu_inuse & KVM_MIPS_FPU_MSA) {
disable_msa();
vcpu->arch.fpu_inuse &= ~KVM_MIPS_FPU_MSA;
}
if (vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU) {
clear_c0_status(ST0_CU1 | ST0_FR);
vcpu->arch.fpu_inuse &= ~KVM_MIPS_FPU_FPU;
}
preempt_enable();
}
/* Save and disable FPU & MSA */
void kvm_lose_fpu(struct kvm_vcpu *vcpu)
{
/*
* FPU & MSA get disabled in root context (hardware) when it is disabled
* in guest context (software), but the register state in the hardware
* may still be in use. This is why we explicitly re-enable the hardware
* before saving.
*/
preempt_disable();
if (cpu_has_msa && vcpu->arch.fpu_inuse & KVM_MIPS_FPU_MSA) {
set_c0_config5(MIPS_CONF5_MSAEN);
enable_fpu_hazard();
__kvm_save_msa(&vcpu->arch);
/* Disable MSA & FPU */
disable_msa();
if (vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU)
clear_c0_status(ST0_CU1 | ST0_FR);
vcpu->arch.fpu_inuse &= ~(KVM_MIPS_FPU_FPU | KVM_MIPS_FPU_MSA);
} else if (vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU) {
set_c0_status(ST0_CU1);
enable_fpu_hazard();
__kvm_save_fpu(&vcpu->arch);
vcpu->arch.fpu_inuse &= ~KVM_MIPS_FPU_FPU;
/* Disable FPU */
clear_c0_status(ST0_CU1 | ST0_FR);
}
preempt_enable();
}
/*
* Step over a specific ctc1 to FCSR and a specific ctcmsa to MSACSR which are
* used to restore guest FCSR/MSACSR state and may trigger a "harmless" FP/MSAFP
* exception if cause bits are set in the value being written.
*/
static int kvm_mips_csr_die_notify(struct notifier_block *self,
unsigned long cmd, void *ptr)
{
struct die_args *args = (struct die_args *)ptr;
struct pt_regs *regs = args->regs;
unsigned long pc;
/* Only interested in FPE and MSAFPE */
if (cmd != DIE_FP && cmd != DIE_MSAFP)
return NOTIFY_DONE;
/* Return immediately if guest context isn't active */
if (!(current->flags & PF_VCPU))
return NOTIFY_DONE;
/* Should never get here from user mode */
BUG_ON(user_mode(regs));
pc = instruction_pointer(regs);
switch (cmd) {
case DIE_FP:
/* match 2nd instruction in __kvm_restore_fcsr */
if (pc != (unsigned long)&__kvm_restore_fcsr + 4)
return NOTIFY_DONE;
break;
case DIE_MSAFP:
/* match 2nd/3rd instruction in __kvm_restore_msacsr */
if (!cpu_has_msa ||
pc < (unsigned long)&__kvm_restore_msacsr + 4 ||
pc > (unsigned long)&__kvm_restore_msacsr + 8)
return NOTIFY_DONE;
break;
}
/* Move PC forward a little and continue executing */
instruction_pointer(regs) += 4;
return NOTIFY_STOP;
}
static struct notifier_block kvm_mips_csr_die_notifier = {
.notifier_call = kvm_mips_csr_die_notify,
};
static int __init kvm_mips_init(void)
{
int ret;
ret = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
if (ret)
return ret;
register_die_notifier(&kvm_mips_csr_die_notifier);
/*
* On MIPS, kernel modules are executed from "mapped space", which
* requires TLBs. The TLB handling code is statically linked with
* the rest of the kernel (tlb.c) to avoid the possibility of
* double faulting. The issue is that the TLB code references
* routines that are part of the the KVM module, which are only
* available once the module is loaded.
*/
kvm_mips_gfn_to_pfn = gfn_to_pfn;
kvm_mips_release_pfn_clean = kvm_release_pfn_clean;
kvm_mips_is_error_pfn = is_error_pfn;
return 0;
}
static void __exit kvm_mips_exit(void)
{
kvm_exit();
kvm_mips_gfn_to_pfn = NULL;
kvm_mips_release_pfn_clean = NULL;
kvm_mips_is_error_pfn = NULL;
unregister_die_notifier(&kvm_mips_csr_die_notifier);
}
module_init(kvm_mips_init);
module_exit(kvm_mips_exit);
EXPORT_TRACEPOINT_SYMBOL(kvm_exit);
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