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KVM: PPC: booke: Add watchdog emulation

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This patch adds the watchdog emulation in KVM. The watchdog
emulation is enabled by KVM_ENABLE_CAP(KVM_CAP_PPC_BOOKE_WATCHDOG) ioctl.
The kernel timer are used for watchdog emulation and emulates
h/w watchdog state machine. On watchdog timer expiry, it exit to QEMU
if TCR.WRC is non ZERO. QEMU can reset/shutdown etc depending upon how
it is configured.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
[bharat.bhushan@freescale.com: reworked patch]
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
[agraf: adjust to new request framework]
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Bharat Bhushan 2012-08-08 20:38:19 +00:00 committed by Alexander Graf
parent 7c973a2ebb
commit f61c94bb99
9 changed files with 199 additions and 2 deletions
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3
arch/powerpc/include/asm/kvm_host.h
View file

@ -471,6 +471,8 @@ struct kvm_vcpu_arch {
ulong fault_esr;
ulong queued_dear;
ulong queued_esr;
spinlock_t wdt_lock;
struct timer_list wdt_timer;
u32 tlbcfg[4];
u32 mmucfg;
u32 epr;
@ -486,6 +488,7 @@ struct kvm_vcpu_arch {
u8 osi_needed;
u8 osi_enabled;
u8 papr_enabled;
u8 watchdog_enabled;
u8 sane;
u8 cpu_type;
u8 hcall_needed;

2
arch/powerpc/include/asm/kvm_ppc.h
View file

@ -68,6 +68,8 @@ extern void kvmppc_emulate_dec(struct kvm_vcpu *vcpu);
extern u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb);
extern void kvmppc_decrementer_func(unsigned long data);
extern int kvmppc_sanity_check(struct kvm_vcpu *vcpu);
extern int kvmppc_subarch_vcpu_init(struct kvm_vcpu *vcpu);
extern void kvmppc_subarch_vcpu_uninit(struct kvm_vcpu *vcpu);
/* Core-specific hooks */

7
arch/powerpc/include/asm/reg_booke.h
View file

@ -539,6 +539,13 @@
#define TCR_FIE 0x00800000 /* FIT Interrupt Enable */
#define TCR_ARE 0x00400000 /* Auto Reload Enable */
#ifdef CONFIG_E500
#define TCR_GET_WP(tcr) ((((tcr) & 0xC0000000) >> 30) | \
(((tcr) & 0x1E0000) >> 15))
#else
#define TCR_GET_WP(tcr) (((tcr) & 0xC0000000) >> 30)
#endif
/* Bit definitions for the TSR. */
#define TSR_ENW 0x80000000 /* Enable Next Watchdog */
#define TSR_WIS 0x40000000 /* WDT Interrupt Status */

9
arch/powerpc/kvm/book3s.c
View file

@ -411,6 +411,15 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
return 0;
}
int kvmppc_subarch_vcpu_init(struct kvm_vcpu *vcpu)
{
return 0;
}
void kvmppc_subarch_vcpu_uninit(struct kvm_vcpu *vcpu)
{
}
int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
int i;

155
arch/powerpc/kvm/booke.c
View file

@ -209,6 +209,16 @@ void kvmppc_core_dequeue_external(struct kvm_vcpu *vcpu,
clear_bit(BOOKE_IRQPRIO_EXTERNAL_LEVEL, &vcpu->arch.pending_exceptions);
}
static void kvmppc_core_queue_watchdog(struct kvm_vcpu *vcpu)
{
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_WATCHDOG);
}
static void kvmppc_core_dequeue_watchdog(struct kvm_vcpu *vcpu)
{
clear_bit(BOOKE_IRQPRIO_WATCHDOG, &vcpu->arch.pending_exceptions);
}
static void set_guest_srr(struct kvm_vcpu *vcpu, unsigned long srr0, u32 srr1)
{
#ifdef CONFIG_KVM_BOOKE_HV
@ -328,6 +338,7 @@ static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
msr_mask = MSR_CE | MSR_ME | MSR_DE;
int_class = INT_CLASS_NONCRIT;
break;
case BOOKE_IRQPRIO_WATCHDOG:
case BOOKE_IRQPRIO_CRITICAL:
case BOOKE_IRQPRIO_DBELL_CRIT:
allowed = vcpu->arch.shared->msr & MSR_CE;
@ -407,12 +418,121 @@ static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
return allowed;
}
/*
* Return the number of jiffies until the next timeout. If the timeout is
* longer than the NEXT_TIMER_MAX_DELTA, then return NEXT_TIMER_MAX_DELTA
* because the larger value can break the timer APIs.
*/
static unsigned long watchdog_next_timeout(struct kvm_vcpu *vcpu)
{
u64 tb, wdt_tb, wdt_ticks = 0;
u64 nr_jiffies = 0;
u32 period = TCR_GET_WP(vcpu->arch.tcr);
wdt_tb = 1ULL << (63 - period);
tb = get_tb();
/*
* The watchdog timeout will hapeen when TB bit corresponding
* to watchdog will toggle from 0 to 1.
*/
if (tb & wdt_tb)
wdt_ticks = wdt_tb;
wdt_ticks += wdt_tb - (tb & (wdt_tb - 1));
/* Convert timebase ticks to jiffies */
nr_jiffies = wdt_ticks;
if (do_div(nr_jiffies, tb_ticks_per_jiffy))
nr_jiffies++;
return min_t(unsigned long long, nr_jiffies, NEXT_TIMER_MAX_DELTA);
}
static void arm_next_watchdog(struct kvm_vcpu *vcpu)
{
unsigned long nr_jiffies;
unsigned long flags;
/*
* If TSR_ENW and TSR_WIS are not set then no need to exit to
* userspace, so clear the KVM_REQ_WATCHDOG request.
*/
if ((vcpu->arch.tsr & (TSR_ENW | TSR_WIS)) != (TSR_ENW | TSR_WIS))
clear_bit(KVM_REQ_WATCHDOG, &vcpu->requests);
spin_lock_irqsave(&vcpu->arch.wdt_lock, flags);
nr_jiffies = watchdog_next_timeout(vcpu);
/*
* If the number of jiffies of watchdog timer >= NEXT_TIMER_MAX_DELTA
* then do not run the watchdog timer as this can break timer APIs.
*/
if (nr_jiffies < NEXT_TIMER_MAX_DELTA)
mod_timer(&vcpu->arch.wdt_timer, jiffies + nr_jiffies);
else
del_timer(&vcpu->arch.wdt_timer);
spin_unlock_irqrestore(&vcpu->arch.wdt_lock, flags);
}
void kvmppc_watchdog_func(unsigned long data)
{
struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;
u32 tsr, new_tsr;
int final;
do {
new_tsr = tsr = vcpu->arch.tsr;
final = 0;
/* Time out event */
if (tsr & TSR_ENW) {
if (tsr & TSR_WIS)
final = 1;
else
new_tsr = tsr | TSR_WIS;
} else {
new_tsr = tsr | TSR_ENW;
}
} while (cmpxchg(&vcpu->arch.tsr, tsr, new_tsr) != tsr);
if (new_tsr & TSR_WIS) {
smp_wmb();
kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
kvm_vcpu_kick(vcpu);
}
/*
* If this is final watchdog expiry and some action is required
* then exit to userspace.
*/
if (final && (vcpu->arch.tcr & TCR_WRC_MASK) &&
vcpu->arch.watchdog_enabled) {
smp_wmb();
kvm_make_request(KVM_REQ_WATCHDOG, vcpu);
kvm_vcpu_kick(vcpu);
}
/*
* Stop running the watchdog timer after final expiration to
* prevent the host from being flooded with timers if the
* guest sets a short period.
* Timers will resume when TSR/TCR is updated next time.
*/
if (!final)
arm_next_watchdog(vcpu);
}
static void update_timer_ints(struct kvm_vcpu *vcpu)
{
if ((vcpu->arch.tcr & TCR_DIE) && (vcpu->arch.tsr & TSR_DIS))
kvmppc_core_queue_dec(vcpu);
else
kvmppc_core_dequeue_dec(vcpu);
if ((vcpu->arch.tcr & TCR_WIE) && (vcpu->arch.tsr & TSR_WIS))
kvmppc_core_queue_watchdog(vcpu);
else
kvmppc_core_dequeue_watchdog(vcpu);
}
static void kvmppc_core_check_exceptions(struct kvm_vcpu *vcpu)
@ -466,6 +586,11 @@ int kvmppc_core_check_requests(struct kvm_vcpu *vcpu)
kvmppc_core_flush_tlb(vcpu);
#endif
if (kvm_check_request(KVM_REQ_WATCHDOG, vcpu)) {
vcpu->run->exit_reason = KVM_EXIT_WATCHDOG;
r = 0;
}
return r;
}
@ -995,6 +1120,21 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
return r;
}
int kvmppc_subarch_vcpu_init(struct kvm_vcpu *vcpu)
{
/* setup watchdog timer once */
spin_lock_init(&vcpu->arch.wdt_lock);
setup_timer(&vcpu->arch.wdt_timer, kvmppc_watchdog_func,
(unsigned long)vcpu);
return 0;
}
void kvmppc_subarch_vcpu_uninit(struct kvm_vcpu *vcpu)
{
del_timer_sync(&vcpu->arch.wdt_timer);
}
int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
int i;
@ -1090,7 +1230,13 @@ static int set_sregs_base(struct kvm_vcpu *vcpu,
}
if (sregs->u.e.update_special & KVM_SREGS_E_UPDATE_TSR) {
u32 old_tsr = vcpu->arch.tsr;
vcpu->arch.tsr = sregs->u.e.tsr;
if ((old_tsr ^ vcpu->arch.tsr) & (TSR_ENW | TSR_WIS))
arm_next_watchdog(vcpu);
update_timer_ints(vcpu);
}
@ -1251,6 +1397,7 @@ void kvmppc_core_commit_memory_region(struct kvm *kvm,
void kvmppc_set_tcr(struct kvm_vcpu *vcpu, u32 new_tcr)
{
vcpu->arch.tcr = new_tcr;
arm_next_watchdog(vcpu);
update_timer_ints(vcpu);
}
@ -1265,6 +1412,14 @@ void kvmppc_set_tsr_bits(struct kvm_vcpu *vcpu, u32 tsr_bits)
void kvmppc_clr_tsr_bits(struct kvm_vcpu *vcpu, u32 tsr_bits)
{
clear_bits(tsr_bits, &vcpu->arch.tsr);
/*
* We may have stopped the watchdog due to
* being stuck on final expiration.
*/
if (tsr_bits & (TSR_ENW | TSR_WIS))
arm_next_watchdog(vcpu);
update_timer_ints(vcpu);
}

8
arch/powerpc/kvm/booke_emulate.c
View file

@ -145,6 +145,14 @@ int kvmppc_booke_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, ulong spr_val)
kvmppc_clr_tsr_bits(vcpu, spr_val);
break;
case SPRN_TCR:
/*
* WRC is a 2-bit field that is supposed to preserve its
* value once written to non-zero.
*/
if (vcpu->arch.tcr & TCR_WRC_MASK) {
spr_val &= ~TCR_WRC_MASK;
spr_val |= vcpu->arch.tcr & TCR_WRC_MASK;
}
kvmppc_set_tcr(vcpu, spr_val);
break;

14
arch/powerpc/kvm/powerpc.c
View file

@ -300,6 +300,7 @@ int kvm_dev_ioctl_check_extension(long ext)
switch (ext) {
#ifdef CONFIG_BOOKE
case KVM_CAP_PPC_BOOKE_SREGS:
case KVM_CAP_PPC_BOOKE_WATCHDOG:
#else
case KVM_CAP_PPC_SEGSTATE:
case KVM_CAP_PPC_HIOR:
@ -476,6 +477,8 @@ enum hrtimer_restart kvmppc_decrementer_wakeup(struct hrtimer *timer)
int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
{
int ret;
hrtimer_init(&vcpu->arch.dec_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
tasklet_init(&vcpu->arch.tasklet, kvmppc_decrementer_func, (ulong)vcpu);
vcpu->arch.dec_timer.function = kvmppc_decrementer_wakeup;
@ -484,13 +487,14 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
#ifdef CONFIG_KVM_EXIT_TIMING
mutex_init(&vcpu->arch.exit_timing_lock);
#endif
return 0;
ret = kvmppc_subarch_vcpu_init(vcpu);
return ret;
}
void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
{
kvmppc_mmu_destroy(vcpu);
kvmppc_subarch_vcpu_uninit(vcpu);
}
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
@ -735,6 +739,12 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
r = 0;
vcpu->arch.papr_enabled = true;
break;
#ifdef CONFIG_BOOKE
case KVM_CAP_PPC_BOOKE_WATCHDOG:
r = 0;
vcpu->arch.watchdog_enabled = true;
break;
#endif
#if defined(CONFIG_KVM_E500V2) || defined(CONFIG_KVM_E500MC)
case KVM_CAP_SW_TLB: {
struct kvm_config_tlb cfg;

2
include/linux/kvm.h
View file

@ -167,6 +167,7 @@ struct kvm_pit_config {
#define KVM_EXIT_OSI 18
#define KVM_EXIT_PAPR_HCALL 19
#define KVM_EXIT_S390_UCONTROL 20
#define KVM_EXIT_WATCHDOG 21
/* For KVM_EXIT_INTERNAL_ERROR */
#define KVM_INTERNAL_ERROR_EMULATION 1
@ -628,6 +629,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_READONLY_MEM 81
#endif
#define KVM_CAP_IRQFD_RESAMPLE 82
#define KVM_CAP_PPC_BOOKE_WATCHDOG 83
#ifdef KVM_CAP_IRQ_ROUTING

1
include/linux/kvm_host.h
View file

@ -118,6 +118,7 @@ static inline bool is_error_page(struct page *page)
#define KVM_REQ_IMMEDIATE_EXIT 15
#define KVM_REQ_PMU 16
#define KVM_REQ_PMI 17
#define KVM_REQ_WATCHDOG 18
#define KVM_USERSPACE_IRQ_SOURCE_ID 0
#define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID 1