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linux-stable/arch/mips/kvm/mips.c
James Hogan 98e91b8457 MIPS: KVM: Add base guest FPU support 
Add base code for supporting FPU in MIPS KVM guests. The FPU cannot yet
be enabled in the guest, we're just laying the groundwork.

Whether the guest's FPU context is loaded is stored in a bit in the
fpu_inuse vcpu member. This allows the FPU to be disabled when the guest
disables it, but keeping the FPU context loaded so it doesn't have to be
reloaded if the guest re-enables it.

An fpu_enabled vcpu member stores whether userland has enabled the FPU
capability (which will be wired up in a later patch).

New assembly code is added for saving and restoring the FPU context, and
for saving/clearing and restoring FCSR (which can itself cause an FP
exception depending on the value). The FCSR is restored before returning
to the guest if the FPU is already enabled, and a die notifier is
registered to catch the possible FP exception and step over the ctc1
instruction.

The helper function kvm_lose_fpu() is added to save FPU context and
disable the FPU, which is used when saving hardware state before a
context switch or KVM exit (the vcpu_get_regs() callback).

The helper function kvm_own_fpu() is added to enable the FPU and restore
the FPU context if it isn't already loaded, which will be used in a
later patch when the guest attempts to use the FPU for the first time
and triggers a co-processor unusable exception.

The helper function kvm_drop_fpu() is added to discard the FPU context
and disable the FPU, which will be used in a later patch when the FPU
state will become architecturally UNPREDICTABLE (change of FR mode) to
force a reload of [stale] context in the new FR mode.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
2015-03-27 21:25:14 +00:00

1349 lines
31 KiB
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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 },
{ "flush_dcache", VCPU_STAT(flush_dcache_exits), KVM_STAT_VCPU },
{ "halt_successful_poll", VCPU_STAT(halt_successful_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,
struct kvm_userspace_memory_region *mem,
enum kvm_mr_change change)
{
return 0;
}
void kvm_arch_commit_memory_region(struct kvm *kvm,
struct kvm_userspace_memory_region *mem,
const struct kvm_memory_slot *old,
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");
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_free_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_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 (waitqueue_active(&dvcpu->wq))
wake_up_interruptible(&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;
int ret;
s64 v;
switch (reg->id) {
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;
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 {
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;
u64 v;
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 {
return -EINVAL;
}
switch (reg->id) {
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;
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;
}
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;
}
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_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) {
memslot = &kvm->memslots->memslots[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:
r = 1;
break;
case KVM_CAP_COALESCED_MMIO:
r = KVM_COALESCED_MMIO_PAGE_OFFSET;
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 (waitqueue_active(&vcpu->wq))
wake_up_interruptible(&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 T_INT:
kvm_debug("[%d]T_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 T_COP_UNUSABLE:
kvm_debug("T_COP_UNUSABLE: @ 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 T_TLB_MOD:
++vcpu->stat.tlbmod_exits;
trace_kvm_exit(vcpu, TLBMOD_EXITS);
ret = kvm_mips_callbacks->handle_tlb_mod(vcpu);
break;
case T_TLB_ST_MISS:
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 T_TLB_LD_MISS:
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 T_ADDR_ERR_ST:
++vcpu->stat.addrerr_st_exits;
trace_kvm_exit(vcpu, ADDRERR_ST_EXITS);
ret = kvm_mips_callbacks->handle_addr_err_st(vcpu);
break;
case T_ADDR_ERR_LD:
++vcpu->stat.addrerr_ld_exits;
trace_kvm_exit(vcpu, ADDRERR_LD_EXITS);
ret = kvm_mips_callbacks->handle_addr_err_ld(vcpu);
break;
case T_SYSCALL:
++vcpu->stat.syscall_exits;
trace_kvm_exit(vcpu, SYSCALL_EXITS);
ret = kvm_mips_callbacks->handle_syscall(vcpu);
break;
case T_RES_INST:
++vcpu->stat.resvd_inst_exits;
trace_kvm_exit(vcpu, RESVD_INST_EXITS);
ret = kvm_mips_callbacks->handle_res_inst(vcpu);
break;
case T_BREAK:
++vcpu->stat.break_inst_exits;
trace_kvm_exit(vcpu, BREAK_INST_EXITS);
ret = kvm_mips_callbacks->handle_break(vcpu);
break;
case T_TRAP:
++vcpu->stat.trap_inst_exits;
trace_kvm_exit(vcpu, TRAP_INST_EXITS);
ret = kvm_mips_callbacks->handle_trap(vcpu);
break;
case T_MSADIS:
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 is enabled (i.e. the guest's FPU context is live),
* restore FCR31.
*
* This should be before returning to the guest exception
* vector, as it may well cause an 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);
}
/* 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();
/*
* Enable FPU for guest
* We set FR and FRE according to guest context
*/
sr = kvm_read_c0_guest_status(cop0);
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();
}
/* Drop FPU without saving it */
void kvm_drop_fpu(struct kvm_vcpu *vcpu)
{
preempt_disable();
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 */
void kvm_lose_fpu(struct kvm_vcpu *vcpu)
{
/*
* FPU gets 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 (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 which is used to restore guest FCSR state
* and may trigger a "harmless" FP 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 */
if (cmd != DIE_FP)
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;
}
/* 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,
};
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;
}
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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