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KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code

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With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per
core), whenever a CPU goes idle, we have to pull all the other
hardware threads in the core out of the guest, because the H_CEDE
hcall is handled in the kernel.  This is inefficient.

This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall
in real mode.  When a guest vcpu does an H_CEDE hcall, we now only
exit to the kernel if all the other vcpus in the same core are also
idle.  Otherwise we mark this vcpu as napping, save state that could
be lost in nap mode (mainly GPRs and FPRs), and execute the nap
instruction.  When the thread wakes up, because of a decrementer or
external interrupt, we come back in at kvm_start_guest (from the
system reset interrupt vector), find the `napping' flag set in the
paca, and go to the resume path.

This has some other ramifications.  First, when starting a core, we
now start all the threads, both those that are immediately runnable and
those that are idle.  This is so that we don't have to pull all the
threads out of the guest when an idle thread gets a decrementer interrupt
and wants to start running.  In fact the idle threads will all start
with the H_CEDE hcall returning; being idle they will just do another
H_CEDE immediately and go to nap mode.

This required some changes to kvmppc_run_core() and kvmppc_run_vcpu().
These functions have been restructured to make them simpler and clearer.
We introduce a level of indirection in the wait queue that gets woken
when external and decrementer interrupts get generated for a vcpu, so
that we can have the 4 vcpus in a vcore using the same wait queue.
We need this because the 4 vcpus are being handled by one thread.

Secondly, when we need to exit from the guest to the kernel, we now
have to generate an IPI for any napping threads, because an HDEC
interrupt doesn't wake up a napping thread.

Thirdly, we now need to be able to handle virtual external interrupts
and decrementer interrupts becoming pending while a thread is napping,
and deliver those interrupts to the guest when the thread wakes.
This is done in kvmppc_cede_reentry, just before fast_guest_return.

Finally, since we are not using the generic kvm_vcpu_block for book3s_hv,
and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef
from kvm_arch_vcpu_runnable.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Paul Mackerras 2011-07-23 17:42:46 +10:00 committed by Avi Kivity
parent 0214394760
commit 19ccb76a19
6 changed files with 488 additions and 201 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
arch/powerpc/include/asm/kvm_book3s_asm.h
View file

@ -76,6 +76,7 @@ struct kvmppc_host_state {
ulong scratch1;
u8 in_guest;
u8 restore_hid5;
u8 napping;
#ifdef CONFIG_KVM_BOOK3S_64_HV
struct kvm_vcpu *kvm_vcpu;

19
arch/powerpc/include/asm/kvm_host.h
View file

@ -198,21 +198,29 @@ struct kvm_arch {
*/
struct kvmppc_vcore {
int n_runnable;
int n_blocked;
int n_busy;
int num_threads;
int entry_exit_count;
int n_woken;
int nap_count;
int napping_threads;
u16 pcpu;
u8 vcore_running;
u8 vcore_state;
u8 in_guest;
struct list_head runnable_threads;
spinlock_t lock;
wait_queue_head_t wq;
};
#define VCORE_ENTRY_COUNT(vc) ((vc)->entry_exit_count & 0xff)
#define VCORE_EXIT_COUNT(vc) ((vc)->entry_exit_count >> 8)
/* Values for vcore_state */
#define VCORE_INACTIVE 0
#define VCORE_RUNNING 1
#define VCORE_EXITING 2
#define VCORE_SLEEPING 3
struct kvmppc_pte {
ulong eaddr;
u64 vpage;
@ -403,11 +411,13 @@ struct kvm_vcpu_arch {
struct dtl *dtl;
struct dtl *dtl_end;
wait_queue_head_t *wqp;
struct kvmppc_vcore *vcore;
int ret;
int trap;
int state;
int ptid;
bool timer_running;
wait_queue_head_t cpu_run;
struct kvm_vcpu_arch_shared *shared;
@ -423,8 +433,9 @@ struct kvm_vcpu_arch {
#endif
};
#define KVMPPC_VCPU_BUSY_IN_HOST 0
#define KVMPPC_VCPU_BLOCKED 1
/* Values for vcpu->arch.state */
#define KVMPPC_VCPU_STOPPED 0
#define KVMPPC_VCPU_BUSY_IN_HOST 1
#define KVMPPC_VCPU_RUNNABLE 2
#endif /* __POWERPC_KVM_HOST_H__ */

6
arch/powerpc/kernel/asm-offsets.c
View file

@ -44,6 +44,7 @@
#include <asm/compat.h>
#include <asm/mmu.h>
#include <asm/hvcall.h>
#include <asm/xics.h>
#endif
#ifdef CONFIG_PPC_ISERIES
#include <asm/iseries/alpaca.h>
@ -460,6 +461,8 @@ int main(void)
DEFINE(VCPU_DEC, offsetof(struct kvm_vcpu, arch.dec));
DEFINE(VCPU_DEC_EXPIRES, offsetof(struct kvm_vcpu, arch.dec_expires));
DEFINE(VCPU_PENDING_EXC, offsetof(struct kvm_vcpu, arch.pending_exceptions));
DEFINE(VCPU_CEDED, offsetof(struct kvm_vcpu, arch.ceded));
DEFINE(VCPU_PRODDED, offsetof(struct kvm_vcpu, arch.prodded));
DEFINE(VCPU_VPA, offsetof(struct kvm_vcpu, arch.vpa));
DEFINE(VCPU_MMCR, offsetof(struct kvm_vcpu, arch.mmcr));
DEFINE(VCPU_PMC, offsetof(struct kvm_vcpu, arch.pmc));
@ -475,6 +478,7 @@ int main(void)
DEFINE(VCORE_ENTRY_EXIT, offsetof(struct kvmppc_vcore, entry_exit_count));
DEFINE(VCORE_NAP_COUNT, offsetof(struct kvmppc_vcore, nap_count));
DEFINE(VCORE_IN_GUEST, offsetof(struct kvmppc_vcore, in_guest));
DEFINE(VCORE_NAPPING_THREADS, offsetof(struct kvmppc_vcore, napping_threads));
DEFINE(VCPU_SVCPU, offsetof(struct kvmppc_vcpu_book3s, shadow_vcpu) -
offsetof(struct kvmppc_vcpu_book3s, vcpu));
DEFINE(VCPU_SLB_E, offsetof(struct kvmppc_slb, orige));
@ -532,6 +536,7 @@ int main(void)
HSTATE_FIELD(HSTATE_SCRATCH1, scratch1);
HSTATE_FIELD(HSTATE_IN_GUEST, in_guest);
HSTATE_FIELD(HSTATE_RESTORE_HID5, restore_hid5);
HSTATE_FIELD(HSTATE_NAPPING, napping);
#ifdef CONFIG_KVM_BOOK3S_64_HV
HSTATE_FIELD(HSTATE_KVM_VCPU, kvm_vcpu);
@ -544,6 +549,7 @@ int main(void)
HSTATE_FIELD(HSTATE_DSCR, host_dscr);
HSTATE_FIELD(HSTATE_DABR, dabr);
HSTATE_FIELD(HSTATE_DECEXP, dec_expires);
DEFINE(IPI_PRIORITY, IPI_PRIORITY);
#endif /* CONFIG_KVM_BOOK3S_64_HV */
#else /* CONFIG_PPC_BOOK3S */

345
arch/powerpc/kvm/book3s_hv.c
View file

@ -62,6 +62,8 @@
/* #define EXIT_DEBUG_SIMPLE */
/* #define EXIT_DEBUG_INT */
static void kvmppc_end_cede(struct kvm_vcpu *vcpu);
void kvmppc_core_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
local_paca->kvm_hstate.kvm_vcpu = vcpu;
@ -72,40 +74,10 @@ void kvmppc_core_vcpu_put(struct kvm_vcpu *vcpu)
{
}
static void kvmppc_vcpu_blocked(struct kvm_vcpu *vcpu);
static void kvmppc_vcpu_unblocked(struct kvm_vcpu *vcpu);
void kvmppc_vcpu_block(struct kvm_vcpu *vcpu)
{
u64 now;
unsigned long dec_nsec;
now = get_tb();
if (now >= vcpu->arch.dec_expires && !kvmppc_core_pending_dec(vcpu))
kvmppc_core_queue_dec(vcpu);
if (vcpu->arch.pending_exceptions)
return;
if (vcpu->arch.dec_expires != ~(u64)0) {
dec_nsec = (vcpu->arch.dec_expires - now) * NSEC_PER_SEC /
tb_ticks_per_sec;
hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
HRTIMER_MODE_REL);
}
kvmppc_vcpu_blocked(vcpu);
kvm_vcpu_block(vcpu);
vcpu->stat.halt_wakeup++;
if (vcpu->arch.dec_expires != ~(u64)0)
hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
kvmppc_vcpu_unblocked(vcpu);
}
void kvmppc_set_msr(struct kvm_vcpu *vcpu, u64 msr)
{
vcpu->arch.shregs.msr = msr;
kvmppc_end_cede(vcpu);
}
void kvmppc_set_pvr(struct kvm_vcpu *vcpu, u32 pvr)
@ -257,15 +229,6 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
switch (req) {
case H_CEDE:
vcpu->arch.shregs.msr |= MSR_EE;
vcpu->arch.ceded = 1;
smp_mb();
if (!vcpu->arch.prodded)
kvmppc_vcpu_block(vcpu);
else
vcpu->arch.prodded = 0;
smp_mb();
vcpu->arch.ceded = 0;
break;
case H_PROD:
target = kvmppc_get_gpr(vcpu, 4);
@ -388,20 +351,6 @@ static int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
break;
}
if (!(r & RESUME_HOST)) {
/* To avoid clobbering exit_reason, only check for signals if
* we aren't already exiting to userspace for some other
* reason. */
if (signal_pending(tsk)) {
vcpu->stat.signal_exits++;
run->exit_reason = KVM_EXIT_INTR;
r = -EINTR;
} else {
kvmppc_core_deliver_interrupts(vcpu);
}
}
return r;
}
@ -479,13 +428,9 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
kvmppc_mmu_book3s_hv_init(vcpu);
/*
* Some vcpus may start out in stopped state. If we initialize
* them to busy-in-host state they will stop other vcpus in the
* vcore from running. Instead we initialize them to blocked
* state, effectively considering them to be stopped until we
* see the first run ioctl for them.
* We consider the vcpu stopped until we see the first run ioctl for it.
*/
vcpu->arch.state = KVMPPC_VCPU_BLOCKED;
vcpu->arch.state = KVMPPC_VCPU_STOPPED;
init_waitqueue_head(&vcpu->arch.cpu_run);
@ -496,6 +441,7 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
if (vcore) {
INIT_LIST_HEAD(&vcore->runnable_threads);
spin_lock_init(&vcore->lock);
init_waitqueue_head(&vcore->wq);
}
kvm->arch.vcores[core] = vcore;
}
@ -506,7 +452,6 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
spin_lock(&vcore->lock);
++vcore->num_threads;
++vcore->n_blocked;
spin_unlock(&vcore->lock);
vcpu->arch.vcore = vcore;
@ -527,30 +472,31 @@ void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu)
kfree(vcpu);
}
static void kvmppc_vcpu_blocked(struct kvm_vcpu *vcpu)
static void kvmppc_set_timer(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcore *vc = vcpu->arch.vcore;
unsigned long dec_nsec, now;
spin_lock(&vc->lock);
vcpu->arch.state = KVMPPC_VCPU_BLOCKED;
++vc->n_blocked;
if (vc->n_runnable > 0 &&
vc->n_runnable + vc->n_blocked == vc->num_threads) {
vcpu = list_first_entry(&vc->runnable_threads, struct kvm_vcpu,
arch.run_list);
wake_up(&vcpu->arch.cpu_run);
now = get_tb();
if (now > vcpu->arch.dec_expires) {
/* decrementer has already gone negative */
kvmppc_core_queue_dec(vcpu);
kvmppc_core_deliver_interrupts(vcpu);
return;
}
spin_unlock(&vc->lock);
dec_nsec = (vcpu->arch.dec_expires - now) * NSEC_PER_SEC
/ tb_ticks_per_sec;
hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
HRTIMER_MODE_REL);
vcpu->arch.timer_running = 1;
}
static void kvmppc_vcpu_unblocked(struct kvm_vcpu *vcpu)
static void kvmppc_end_cede(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcore *vc = vcpu->arch.vcore;
spin_lock(&vc->lock);
vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
--vc->n_blocked;
spin_unlock(&vc->lock);
vcpu->arch.ceded = 0;
if (vcpu->arch.timer_running) {
hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
vcpu->arch.timer_running = 0;
}
}
extern int __kvmppc_vcore_entry(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu);
@ -565,6 +511,7 @@ static void kvmppc_remove_runnable(struct kvmppc_vcore *vc,
return;
vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
--vc->n_runnable;
++vc->n_busy;
/* decrement the physical thread id of each following vcpu */
v = vcpu;
list_for_each_entry_continue(v, &vc->runnable_threads, arch.run_list)
@ -578,15 +525,20 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu)
struct paca_struct *tpaca;
struct kvmppc_vcore *vc = vcpu->arch.vcore;
if (vcpu->arch.timer_running) {
hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
vcpu->arch.timer_running = 0;
}
cpu = vc->pcpu + vcpu->arch.ptid;
tpaca = &paca[cpu];
tpaca->kvm_hstate.kvm_vcpu = vcpu;
tpaca->kvm_hstate.kvm_vcore = vc;
tpaca->kvm_hstate.napping = 0;
vcpu->cpu = vc->pcpu;
smp_wmb();
#ifdef CONFIG_PPC_ICP_NATIVE
if (vcpu->arch.ptid) {
tpaca->cpu_start = 0x80;
tpaca->kvm_hstate.in_guest = KVM_GUEST_MODE_GUEST;
wmb();
xics_wake_cpu(cpu);
++vc->n_woken;
@ -634,9 +586,10 @@ static int on_primary_thread(void)
*/
static int kvmppc_run_core(struct kvmppc_vcore *vc)
{
struct kvm_vcpu *vcpu, *vnext;
struct kvm_vcpu *vcpu, *vcpu0, *vnext;
long ret;
u64 now;
int ptid;
/* don't start if any threads have a signal pending */
list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
@ -655,29 +608,50 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
goto out;
}
/*
* Assign physical thread IDs, first to non-ceded vcpus
* and then to ceded ones.
*/
ptid = 0;
vcpu0 = NULL;
list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list) {
if (!vcpu->arch.ceded) {
if (!ptid)
vcpu0 = vcpu;
vcpu->arch.ptid = ptid++;
}
}
if (!vcpu0)
return 0; /* nothing to run */
list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
if (vcpu->arch.ceded)
vcpu->arch.ptid = ptid++;
vc->n_woken = 0;
vc->nap_count = 0;
vc->entry_exit_count = 0;
vc->vcore_running = 1;
vc->vcore_state = VCORE_RUNNING;
vc->in_guest = 0;
vc->pcpu = smp_processor_id();
vc->napping_threads = 0;
list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
kvmppc_start_thread(vcpu);
vcpu = list_first_entry(&vc->runnable_threads, struct kvm_vcpu,
arch.run_list);
spin_unlock(&vc->lock);
preempt_disable();
kvm_guest_enter();
__kvmppc_vcore_entry(NULL, vcpu);
spin_unlock(&vc->lock);
kvm_guest_enter();
__kvmppc_vcore_entry(NULL, vcpu0);
/* wait for secondary threads to finish writing their state to memory */
spin_lock(&vc->lock);
/* disable sending of IPIs on virtual external irqs */
list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
vcpu->cpu = -1;
/* wait for secondary threads to finish writing their state to memory */
if (vc->nap_count < vc->n_woken)
kvmppc_wait_for_nap(vc);
/* prevent other vcpu threads from doing kvmppc_start_thread() now */
vc->vcore_running = 2;
vc->vcore_state = VCORE_EXITING;
spin_unlock(&vc->lock);
/* make sure updates to secondary vcpu structs are visible now */
@ -693,22 +667,26 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
if (now < vcpu->arch.dec_expires &&
kvmppc_core_pending_dec(vcpu))
kvmppc_core_dequeue_dec(vcpu);
if (!vcpu->arch.trap) {
if (signal_pending(vcpu->arch.run_task)) {
vcpu->arch.kvm_run->exit_reason = KVM_EXIT_INTR;
vcpu->arch.ret = -EINTR;
}
continue; /* didn't get to run */
}
ret = kvmppc_handle_exit(vcpu->arch.kvm_run, vcpu,
vcpu->arch.run_task);
ret = RESUME_GUEST;
if (vcpu->arch.trap)
ret = kvmppc_handle_exit(vcpu->arch.kvm_run, vcpu,
vcpu->arch.run_task);
vcpu->arch.ret = ret;
vcpu->arch.trap = 0;
if (vcpu->arch.ceded) {
if (ret != RESUME_GUEST)
kvmppc_end_cede(vcpu);
else
kvmppc_set_timer(vcpu);
}
}
spin_lock(&vc->lock);
out:
vc->vcore_running = 0;
vc->vcore_state = VCORE_INACTIVE;
list_for_each_entry_safe(vcpu, vnext, &vc->runnable_threads,
arch.run_list) {
if (vcpu->arch.ret != RESUME_GUEST) {
@ -720,82 +698,130 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
return 1;
}
static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
/*
* Wait for some other vcpu thread to execute us, and
* wake us up when we need to handle something in the host.
*/
static void kvmppc_wait_for_exec(struct kvm_vcpu *vcpu, int wait_state)
{
int ptid;
int wait_state;
struct kvmppc_vcore *vc;
DEFINE_WAIT(wait);
/* No need to go into the guest when all we do is going out */
if (signal_pending(current)) {
kvm_run->exit_reason = KVM_EXIT_INTR;
return -EINTR;
}
prepare_to_wait(&vcpu->arch.cpu_run, &wait, wait_state);
if (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE)
schedule();
finish_wait(&vcpu->arch.cpu_run, &wait);
}
/* On PPC970, check that we have an RMA region */
if (!vcpu->kvm->arch.rma && cpu_has_feature(CPU_FTR_ARCH_201))
return -EPERM;
/*
* All the vcpus in this vcore are idle, so wait for a decrementer
* or external interrupt to one of the vcpus. vc->lock is held.
*/
static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
{
DEFINE_WAIT(wait);
struct kvm_vcpu *v;
int all_idle = 1;
prepare_to_wait(&vc->wq, &wait, TASK_INTERRUPTIBLE);
vc->vcore_state = VCORE_SLEEPING;
spin_unlock(&vc->lock);
list_for_each_entry(v, &vc->runnable_threads, arch.run_list) {
if (!v->arch.ceded || v->arch.pending_exceptions) {
all_idle = 0;
break;
}
}
if (all_idle)
schedule();
finish_wait(&vc->wq, &wait);
spin_lock(&vc->lock);
vc->vcore_state = VCORE_INACTIVE;
}
static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
{
int n_ceded;
int prev_state;
struct kvmppc_vcore *vc;
struct kvm_vcpu *v, *vn;
kvm_run->exit_reason = 0;
vcpu->arch.ret = RESUME_GUEST;
vcpu->arch.trap = 0;
flush_fp_to_thread(current);
flush_altivec_to_thread(current);
flush_vsx_to_thread(current);
/*
* Synchronize with other threads in this virtual core
*/
vc = vcpu->arch.vcore;
spin_lock(&vc->lock);
/* This happens the first time this is called for a vcpu */
if (vcpu->arch.state == KVMPPC_VCPU_BLOCKED)
--vc->n_blocked;
vcpu->arch.state = KVMPPC_VCPU_RUNNABLE;
ptid = vc->n_runnable;
vcpu->arch.ceded = 0;
vcpu->arch.run_task = current;
vcpu->arch.kvm_run = kvm_run;
vcpu->arch.ptid = ptid;
prev_state = vcpu->arch.state;
vcpu->arch.state = KVMPPC_VCPU_RUNNABLE;
list_add_tail(&vcpu->arch.run_list, &vc->runnable_threads);
++vc->n_runnable;
wait_state = TASK_INTERRUPTIBLE;
while (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE) {
if (signal_pending(current)) {
if (!vc->vcore_running) {
kvm_run->exit_reason = KVM_EXIT_INTR;
vcpu->arch.ret = -EINTR;
break;
}
/* have to wait for vcore to stop executing guest */
wait_state = TASK_UNINTERRUPTIBLE;
smp_send_reschedule(vc->pcpu);
}
if (!vc->vcore_running &&
vc->n_runnable + vc->n_blocked == vc->num_threads) {
/* we can run now */
if (kvmppc_run_core(vc))
continue;
}
if (vc->vcore_running == 1 && VCORE_EXIT_COUNT(vc) == 0)
/*
* This happens the first time this is called for a vcpu.
* If the vcore is already running, we may be able to start
* this thread straight away and have it join in.
*/
if (prev_state == KVMPPC_VCPU_STOPPED) {
if (vc->vcore_state == VCORE_RUNNING &&
VCORE_EXIT_COUNT(vc) == 0) {
vcpu->arch.ptid = vc->n_runnable - 1;
kvmppc_start_thread(vcpu);
}
/* wait for other threads to come in, or wait for vcore */
prepare_to_wait(&vcpu->arch.cpu_run, &wait, wait_state);
spin_unlock(&vc->lock);
schedule();
finish_wait(&vcpu->arch.cpu_run, &wait);
spin_lock(&vc->lock);
} else if (prev_state == KVMPPC_VCPU_BUSY_IN_HOST)
--vc->n_busy;
while (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE &&
!signal_pending(current)) {
if (vc->n_busy || vc->vcore_state != VCORE_INACTIVE) {
spin_unlock(&vc->lock);
kvmppc_wait_for_exec(vcpu, TASK_INTERRUPTIBLE);
spin_lock(&vc->lock);
continue;
}
n_ceded = 0;
list_for_each_entry(v, &vc->runnable_threads, arch.run_list)
n_ceded += v->arch.ceded;
if (n_ceded == vc->n_runnable)
kvmppc_vcore_blocked(vc);
else
kvmppc_run_core(vc);
list_for_each_entry_safe(v, vn, &vc->runnable_threads,
arch.run_list) {
kvmppc_core_deliver_interrupts(v);
if (signal_pending(v->arch.run_task)) {
kvmppc_remove_runnable(vc, v);
v->stat.signal_exits++;
v->arch.kvm_run->exit_reason = KVM_EXIT_INTR;
v->arch.ret = -EINTR;
wake_up(&v->arch.cpu_run);
}
}
}
if (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE)
kvmppc_remove_runnable(vc, vcpu);
spin_unlock(&vc->lock);
if (signal_pending(current)) {
if (vc->vcore_state == VCORE_RUNNING ||
vc->vcore_state == VCORE_EXITING) {
spin_unlock(&vc->lock);
kvmppc_wait_for_exec(vcpu, TASK_UNINTERRUPTIBLE);
spin_lock(&vc->lock);
}
if (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE) {
kvmppc_remove_runnable(vc, vcpu);
vcpu->stat.signal_exits++;
kvm_run->exit_reason = KVM_EXIT_INTR;
vcpu->arch.ret = -EINTR;
}
}
spin_unlock(&vc->lock);
return vcpu->arch.ret;
}
@ -808,6 +834,21 @@ int kvmppc_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
return -EINVAL;
}
/* No need to go into the guest when all we'll do is come back out */
if (signal_pending(current)) {
run->exit_reason = KVM_EXIT_INTR;
return -EINTR;
}
/* On PPC970, check that we have an RMA region */
if (!vcpu->kvm->arch.rma && cpu_has_feature(CPU_FTR_ARCH_201))
return -EPERM;
flush_fp_to_thread(current);
flush_altivec_to_thread(current);
flush_vsx_to_thread(current);
vcpu->arch.wqp = &vcpu->arch.vcore->wq;
do {
r = kvmppc_run_vcpu(run, vcpu);

297
arch/powerpc/kvm/book3s_hv_rmhandlers.S
View file

@ -52,7 +52,7 @@ kvmppc_skip_Hinterrupt:
b .
/*
* Call kvmppc_handler_trampoline_enter in real mode.
* Call kvmppc_hv_entry in real mode.
* Must be called with interrupts hard-disabled.
*
* Input Registers:
@ -92,6 +92,12 @@ _GLOBAL(kvmppc_hv_entry_trampoline)
kvm_start_guest:
ld r1,PACAEMERGSP(r13)
subi r1,r1,STACK_FRAME_OVERHEAD
ld r2,PACATOC(r13)
/* were we napping due to cede? */
lbz r0,HSTATE_NAPPING(r13)
cmpwi r0,0
bne kvm_end_cede
/* get vcpu pointer */
ld r4, HSTATE_KVM_VCPU(r13)
@ -279,15 +285,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
cmpwi r0,0
beq 20b
/* Set LPCR. Set the MER bit if there is a pending external irq. */
/* Set LPCR and RMOR. */
10: ld r8,KVM_LPCR(r9)
ld r0,VCPU_PENDING_EXC(r4)
li r7,(1 << BOOK3S_IRQPRIO_EXTERNAL)
oris r7,r7,(1 << BOOK3S_IRQPRIO_EXTERNAL_LEVEL)@h
and. r0,r0,r7
beq 11f
ori r8,r8,LPCR_MER
11: mtspr SPRN_LPCR,r8
mtspr SPRN_LPCR,r8
ld r8,KVM_RMOR(r9)
mtspr SPRN_RMOR,r8
isync
@ -451,19 +451,50 @@ toc_tlbie_lock:
mtctr r6
mtxer r7
/* Move SRR0 and SRR1 into the respective regs */
kvmppc_cede_reentry: /* r4 = vcpu, r13 = paca */
ld r6, VCPU_SRR0(r4)
ld r7, VCPU_SRR1(r4)
mtspr SPRN_SRR0, r6
mtspr SPRN_SRR1, r7
ld r10, VCPU_PC(r4)
ld r11, VCPU_MSR(r4) /* r11 = vcpu->arch.msr & ~MSR_HV */
ld r11, VCPU_MSR(r4) /* r10 = vcpu->arch.msr & ~MSR_HV */
rldicl r11, r11, 63 - MSR_HV_LG, 1
rotldi r11, r11, 1 + MSR_HV_LG
ori r11, r11, MSR_ME
/* Check if we can deliver an external or decrementer interrupt now */
ld r0,VCPU_PENDING_EXC(r4)
li r8,(1 << BOOK3S_IRQPRIO_EXTERNAL)
oris r8,r8,(1 << BOOK3S_IRQPRIO_EXTERNAL_LEVEL)@h
and r0,r0,r8
cmpdi cr1,r0,0
andi. r0,r11,MSR_EE
beq cr1,11f
BEGIN_FTR_SECTION
mfspr r8,SPRN_LPCR
ori r8,r8,LPCR_MER
mtspr SPRN_LPCR,r8
isync
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
beq 5f
li r0,BOOK3S_INTERRUPT_EXTERNAL
12: mr r6,r10
mr r10,r0
mr r7,r11
li r11,(MSR_ME << 1) | 1 /* synthesize MSR_SF | MSR_ME */
rotldi r11,r11,63
b 5f
11: beq 5f
mfspr r0,SPRN_DEC
cmpwi r0,0
li r0,BOOK3S_INTERRUPT_DECREMENTER
blt 12b
/* Move SRR0 and SRR1 into the respective regs */
5: mtspr SPRN_SRR0, r6
mtspr SPRN_SRR1, r7
li r0,0
stb r0,VCPU_CEDED(r4) /* cancel cede */
fast_guest_return:
mtspr SPRN_HSRR0,r10
mtspr SPRN_HSRR1,r11
@ -577,21 +608,20 @@ kvmppc_interrupt:
/* See if this is something we can handle in real mode */
cmpwi r12,BOOK3S_INTERRUPT_SYSCALL
beq hcall_try_real_mode
hcall_real_cont:
/* Check for mediated interrupts (could be done earlier really ...) */
BEGIN_FTR_SECTION
cmpwi r12,BOOK3S_INTERRUPT_EXTERNAL
bne+ 1f
ld r5,VCPU_KVM(r9)
ld r5,KVM_LPCR(r5)
andi. r0,r11,MSR_EE
beq 1f
mfspr r5,SPRN_LPCR
andi. r0,r5,LPCR_MER
bne bounce_ext_interrupt
1:
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
hcall_real_cont: /* r9 = vcpu, r12 = trap, r13 = paca */
/* Save DEC */
mfspr r5,SPRN_DEC
mftb r6
@ -685,7 +715,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_201)
slbia
ptesync
hdec_soon:
hdec_soon: /* r9 = vcpu, r12 = trap, r13 = paca */
BEGIN_FTR_SECTION
b 32f
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
@ -703,6 +733,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
addi r0,r3,0x100
stwcx. r0,0,r6
bne 41b
lwsync
/*
* At this point we have an interrupt that we have to pass
@ -716,18 +747,39 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
* interrupt, since the other threads will already be on their
* way here in that case.
*/
cmpwi r3,0x100 /* Are we the first here? */
bge 43f
cmpwi r3,1 /* Are any other threads in the guest? */
ble 43f
cmpwi r12,BOOK3S_INTERRUPT_HV_DECREMENTER
beq 40f
cmpwi r3,0x100 /* Are we the first here? */
bge 40f
cmpwi r3,1
ble 40f
li r0,0
mtspr SPRN_HDEC,r0
40:
/*
* Send an IPI to any napping threads, since an HDEC interrupt
* doesn't wake CPUs up from nap.
*/
lwz r3,VCORE_NAPPING_THREADS(r5)
lwz r4,VCPU_PTID(r9)
li r0,1
sldi r0,r0,r4
andc. r3,r3,r0 /* no sense IPI'ing ourselves */
beq 43f
mulli r4,r4,PACA_SIZE /* get paca for thread 0 */
subf r6,r4,r13
42: andi. r0,r3,1
beq 44f
ld r8,HSTATE_XICS_PHYS(r6) /* get thread's XICS reg addr */
li r0,IPI_PRIORITY
li r7,XICS_QIRR
stbcix r0,r7,r8 /* trigger the IPI */
44: srdi. r3,r3,1
addi r6,r6,PACA_SIZE
bne 42b
/* Secondary threads wait for primary to do partition switch */
ld r4,VCPU_KVM(r9) /* pointer to struct kvm */
43: ld r4,VCPU_KVM(r9) /* pointer to struct kvm */
ld r5,HSTATE_KVM_VCORE(r13)
lwz r3,VCPU_PTID(r9)
cmpwi r3,0
@ -1080,7 +1132,6 @@ hcall_try_real_mode:
hcall_real_fallback:
li r12,BOOK3S_INTERRUPT_SYSCALL
ld r9, HSTATE_KVM_VCPU(r13)
ld r11, VCPU_MSR(r9)
b hcall_real_cont
@ -1142,7 +1193,7 @@ hcall_real_table:
.long 0 /* 0xd4 */
.long 0 /* 0xd8 */
.long 0 /* 0xdc */
.long 0 /* 0xe0 */
.long .kvmppc_h_cede - hcall_real_table
.long 0 /* 0xe4 */
.long 0 /* 0xe8 */
.long 0 /* 0xec */
@ -1171,7 +1222,8 @@ bounce_ext_interrupt:
mtspr SPRN_SRR0,r10
mtspr SPRN_SRR1,r11
li r10,BOOK3S_INTERRUPT_EXTERNAL
LOAD_REG_IMMEDIATE(r11,MSR_SF | MSR_ME);
li r11,(MSR_ME << 1) | 1 /* synthesize MSR_SF | MSR_ME */
rotldi r11,r11,63
b fast_guest_return
_GLOBAL(kvmppc_h_set_dabr)
@ -1180,6 +1232,178 @@ _GLOBAL(kvmppc_h_set_dabr)
li r3,0
blr
_GLOBAL(kvmppc_h_cede)
ori r11,r11,MSR_EE
std r11,VCPU_MSR(r3)
li r0,1
stb r0,VCPU_CEDED(r3)
sync /* order setting ceded vs. testing prodded */
lbz r5,VCPU_PRODDED(r3)
cmpwi r5,0
bne 1f
li r0,0 /* set trap to 0 to say hcall is handled */
stw r0,VCPU_TRAP(r3)
li r0,H_SUCCESS
std r0,VCPU_GPR(r3)(r3)
BEGIN_FTR_SECTION
b 2f /* just send it up to host on 970 */
END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206)
/*
* Set our bit in the bitmask of napping threads unless all the
* other threads are already napping, in which case we send this
* up to the host.
*/
ld r5,HSTATE_KVM_VCORE(r13)
lwz r6,VCPU_PTID(r3)
lwz r8,VCORE_ENTRY_EXIT(r5)
clrldi r8,r8,56
li r0,1
sld r0,r0,r6
addi r6,r5,VCORE_NAPPING_THREADS
31: lwarx r4,0,r6
or r4,r4,r0
popcntw r7,r4
cmpw r7,r8
bge 2f
stwcx. r4,0,r6
bne 31b
li r0,1
stb r0,HSTATE_NAPPING(r13)
/* order napping_threads update vs testing entry_exit_count */
lwsync
mr r4,r3
lwz r7,VCORE_ENTRY_EXIT(r5)
cmpwi r7,0x100
bge 33f /* another thread already exiting */
/*
* Although not specifically required by the architecture, POWER7
* preserves the following registers in nap mode, even if an SMT mode
* switch occurs: SLB entries, PURR, SPURR, AMOR, UAMOR, AMR, SPRG0-3,
* DAR, DSISR, DABR, DABRX, DSCR, PMCx, MMCRx, SIAR, SDAR.
*/
/* Save non-volatile GPRs */
std r14, VCPU_GPR(r14)(r3)
std r15, VCPU_GPR(r15)(r3)
std r16, VCPU_GPR(r16)(r3)
std r17, VCPU_GPR(r17)(r3)
std r18, VCPU_GPR(r18)(r3)
std r19, VCPU_GPR(r19)(r3)
std r20, VCPU_GPR(r20)(r3)
std r21, VCPU_GPR(r21)(r3)
std r22, VCPU_GPR(r22)(r3)
std r23, VCPU_GPR(r23)(r3)
std r24, VCPU_GPR(r24)(r3)
std r25, VCPU_GPR(r25)(r3)
std r26, VCPU_GPR(r26)(r3)
std r27, VCPU_GPR(r27)(r3)
std r28, VCPU_GPR(r28)(r3)
std r29, VCPU_GPR(r29)(r3)
std r30, VCPU_GPR(r30)(r3)
std r31, VCPU_GPR(r31)(r3)
/* save FP state */
bl .kvmppc_save_fp
/*
* Take a nap until a decrementer or external interrupt occurs,
* with PECE1 (wake on decr) and PECE0 (wake on external) set in LPCR
*/
li r0,0x80
stb r0,PACAPROCSTART(r13)
mfspr r5,SPRN_LPCR
ori r5,r5,LPCR_PECE0 | LPCR_PECE1
mtspr SPRN_LPCR,r5
isync
li r0, 0
std r0, HSTATE_SCRATCH0(r13)
ptesync
ld r0, HSTATE_SCRATCH0(r13)
1: cmpd r0, r0
bne 1b
nap
b .
kvm_end_cede:
/* Woken by external or decrementer interrupt */
ld r1, HSTATE_HOST_R1(r13)
ld r2, PACATOC(r13)
/* If we're a secondary thread and we got here by an IPI, ack it */
ld r4,HSTATE_KVM_VCPU(r13)
lwz r3,VCPU_PTID(r4)
cmpwi r3,0
beq 27f
mfspr r3,SPRN_SRR1
rlwinm r3,r3,44-31,0x7 /* extract wake reason field */
cmpwi r3,4 /* was it an external interrupt? */
bne 27f
ld r5, HSTATE_XICS_PHYS(r13)
li r0,0xff
li r6,XICS_QIRR
li r7,XICS_XIRR
lwzcix r8,r5,r7 /* ack the interrupt */
sync
stbcix r0,r5,r6 /* clear it */
stwcix r8,r5,r7 /* EOI it */
27:
/* load up FP state */
bl kvmppc_load_fp
/* Load NV GPRS */
ld r14, VCPU_GPR(r14)(r4)
ld r15, VCPU_GPR(r15)(r4)
ld r16, VCPU_GPR(r16)(r4)
ld r17, VCPU_GPR(r17)(r4)
ld r18, VCPU_GPR(r18)(r4)
ld r19, VCPU_GPR(r19)(r4)
ld r20, VCPU_GPR(r20)(r4)
ld r21, VCPU_GPR(r21)(r4)
ld r22, VCPU_GPR(r22)(r4)
ld r23, VCPU_GPR(r23)(r4)
ld r24, VCPU_GPR(r24)(r4)
ld r25, VCPU_GPR(r25)(r4)
ld r26, VCPU_GPR(r26)(r4)
ld r27, VCPU_GPR(r27)(r4)
ld r28, VCPU_GPR(r28)(r4)
ld r29, VCPU_GPR(r29)(r4)
ld r30, VCPU_GPR(r30)(r4)
ld r31, VCPU_GPR(r31)(r4)
/* clear our bit in vcore->napping_threads */
33: ld r5,HSTATE_KVM_VCORE(r13)
lwz r3,VCPU_PTID(r4)
li r0,1
sld r0,r0,r3
addi r6,r5,VCORE_NAPPING_THREADS
32: lwarx r7,0,r6
andc r7,r7,r0
stwcx. r7,0,r6
bne 32b
li r0,0
stb r0,HSTATE_NAPPING(r13)
/* see if any other thread is already exiting */
lwz r0,VCORE_ENTRY_EXIT(r5)
cmpwi r0,0x100
blt kvmppc_cede_reentry /* if not go back to guest */
/* some threads are exiting, so go to the guest exit path */
b hcall_real_fallback
/* cede when already previously prodded case */
1: li r0,0
stb r0,VCPU_PRODDED(r3)
sync /* order testing prodded vs. clearing ceded */
stb r0,VCPU_CEDED(r3)
li r3,H_SUCCESS
blr
/* we've ceded but we want to give control to the host */
2: li r3,H_TOO_HARD
blr
secondary_too_late:
ld r5,HSTATE_KVM_VCORE(r13)
HMT_LOW
@ -1197,14 +1421,20 @@ secondary_too_late:
slbmte r6,r5
1: addi r11,r11,16
.endr
b 50f
secondary_nap:
/* Clear any pending IPI */
50: ld r5, HSTATE_XICS_PHYS(r13)
/* Clear any pending IPI - assume we're a secondary thread */
ld r5, HSTATE_XICS_PHYS(r13)
li r7, XICS_XIRR
lwzcix r3, r5, r7 /* ack any pending interrupt */
rlwinm. r0, r3, 0, 0xffffff /* any pending? */
beq 37f
sync
li r0, 0xff
li r6, XICS_QIRR
stbcix r0, r5, r6
stbcix r0, r5, r6 /* clear the IPI */
stwcix r3, r5, r7 /* EOI it */
37: sync
/* increment the nap count and then go to nap mode */
ld r4, HSTATE_KVM_VCORE(r13)
@ -1214,13 +1444,12 @@ secondary_nap:
addi r3, r3, 1
stwcx. r3, 0, r4
bne 51b
isync
li r3, LPCR_PECE0
mfspr r4, SPRN_LPCR
li r0, LPCR_PECE
andc r4, r4, r0
ori r4, r4, LPCR_PECE0 /* exit nap on interrupt */
rlwimi r4, r3, 0, LPCR_PECE0 | LPCR_PECE1
mtspr SPRN_LPCR, r4
isync
li r0, 0
std r0, HSTATE_SCRATCH0(r13)
ptesync

21
arch/powerpc/kvm/powerpc.c
View file

@ -39,12 +39,8 @@
int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
{
#ifndef CONFIG_KVM_BOOK3S_64_HV
return !(v->arch.shared->msr & MSR_WE) ||
!!(v->arch.pending_exceptions);
#else
return !(v->arch.ceded) || !!(v->arch.pending_exceptions);
#endif
}
int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
@ -285,6 +281,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
{
struct kvm_vcpu *vcpu;
vcpu = kvmppc_core_vcpu_create(kvm, id);
vcpu->arch.wqp = &vcpu->wq;
if (!IS_ERR(vcpu))
kvmppc_create_vcpu_debugfs(vcpu, id);
return vcpu;
@ -316,8 +313,8 @@ static void kvmppc_decrementer_func(unsigned long data)
kvmppc_core_queue_dec(vcpu);
if (waitqueue_active(&vcpu->wq)) {
wake_up_interruptible(&vcpu->wq);
if (waitqueue_active(vcpu->arch.wqp)) {
wake_up_interruptible(vcpu->arch.wqp);
vcpu->stat.halt_wakeup++;
}
}
@ -570,13 +567,15 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
{
if (irq->irq == KVM_INTERRUPT_UNSET)
if (irq->irq == KVM_INTERRUPT_UNSET) {
kvmppc_core_dequeue_external(vcpu, irq);
else
kvmppc_core_queue_external(vcpu, irq);
return 0;
}
if (waitqueue_active(&vcpu->wq)) {
wake_up_interruptible(&vcpu->wq);
kvmppc_core_queue_external(vcpu, irq);
if (waitqueue_active(vcpu->arch.wqp)) {
wake_up_interruptible(vcpu->arch.wqp);
vcpu->stat.halt_wakeup++;
} else if (vcpu->cpu != -1) {
smp_send_reschedule(vcpu->cpu);