[PATCH 07/16] per-vcpu lguest timers

Glauber de Oliveira Costa
2008-01-07T13:08:16Z

Here, I introduce per-vcpu timers. With this, we can have
local expiries, needed for accounting time in smp guests

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
---
drivers/lguest/hypercalls.c | 2 +-
drivers/lguest/interrupts_and_traps.c | 20 ++++++++++----------
drivers/lguest/lg.h | 10 +++++-----
drivers/lguest/lguest_user.c | 12 +++++++-----
4 files changed, 23 insertions(+), 21 deletions(-)

diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c
index 9417601..1bf133e 100644
--- a/drivers/lguest/hypercalls.c
+++ b/drivers/lguest/hypercalls.c
@@ -78,7 +78,7 @@ static void do_hcall(struct lg_vcpu *vcpu, struct hcall_args *args)
guest_set_pmd(lg, args->arg1, args->arg2);
break;
case LHCALL_SET_CLOCKEVENT:
- guest_set_clockevent(lg, args->arg1);
+ guest_set_clockevent(vcpu, args->arg1);
break;
case LHCALL_TS:
/* This sets the TS flag, as we saw used in run_guest(). */
diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c
index 2b66f79..3be18a6 100644
--- a/drivers/lguest/interrupts_and_traps.c
+++ b/drivers/lguest/interrupts_and_traps.c
@@ -470,13 +470,13 @@ void copy_traps(const struct lguest *lg, struct desc_struct *idt,
* infrastructure to set a callback at that time.
*
* 0 means "turn off the clock". */
-void guest_set_clockevent(struct lguest *lg, unsigned long delta)
+void guest_set_clockevent(struct lg_vcpu *vcpu, unsigned long delta)
{
ktime_t expires;

if (unlikely(delta == 0)) {
/* Clock event device is shutting down. */
- hrtimer_cancel(&lg->hrt);
+ hrtimer_cancel(&vcpu->hrt);
return;
}

@@ -484,25 +484,25 @@ void guest_set_clockevent(struct lguest *lg, unsigned long delta)
* all the time between now and the timer interrupt it asked for. This
* is almost always the right thing to do. */
expires = ktime_add_ns(ktime_get_real(), delta);
- hrtimer_start(&lg->hrt, expires, HRTIMER_MODE_ABS);
+ hrtimer_start(&vcpu->hrt, expires, HRTIMER_MODE_ABS);
}

/* This is the function called when the Guest's timer expires. */
static enum hrtimer_restart clockdev_fn(struct hrtimer *timer)
{
- struct lguest *lg = container_of(timer, struct lguest, hrt);
+ struct lg_vcpu *vcpu = container_of(timer, struct lg_vcpu, hrt);

/* Remember the first interrupt is the timer interrupt. */
- set_bit(0, lg->irqs_pending);
+ set_bit(0, vcpu->lg->irqs_pending);
/* If the Guest is actually stopped, we need to wake it up. */
- if (lg->halted)
- wake_up_process(lg->tsk);
+ if (vcpu->lg->halted)
+ wake_up_process(vcpu->lg->tsk);
return HRTIMER_NORESTART;
}

/* This sets up the timer for this Guest. */
-void init_clockdev(struct lguest *lg)
+void init_clockdev(struct lg_vcpu *vcpu)
{
- hrtimer_init(&lg->hrt, CLOCK_REALTIME, HRTIMER_MODE_ABS);
- lg->hrt.function = clockdev_fn;
+ hrtimer_init(&vcpu->hrt, CLOCK_REALTIME, HRTIMER_MODE_ABS);
+ vcpu->hrt.function = clockdev_fn;
}
diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
index 13a991a..9c90fd3 100644
--- a/drivers/lguest/lg.h
+++ b/drivers/lguest/lg.h
@@ -47,6 +47,9 @@ struct lg_vcpu {
/* If a hypercall was asked for, this points to the arguments. */
struct hcall_args *hcall;
u32 next_hcall;
+
+ /* Virtual clock device */
+ struct hrtimer hrt;
};

/* The private info the thread maintains about the guest. */
@@ -95,9 +98,6 @@ struct lguest

struct lguest_arch arch;

- /* Virtual clock device */
- struct hrtimer hrt;
-
/* Pending virtual interrupts */
DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
};
@@ -145,8 +145,8 @@ void setup_default_idt_entries(struct lguest_ro_state *state,
const unsigned long *def);
void copy_traps(const struct lguest *lg, struct desc_struct *idt,
const unsigned long *def);
-void guest_set_clockevent(struct lguest *lg, unsigned long delta);
-void init_clockdev(struct lguest *lg);
+void guest_set_clockevent(struct lg_vcpu *vcpu, unsigned long delta);
+void init_clockdev(struct lg_vcpu *vcpu);
bool check_syscall_vector(struct lguest *lg);
int init_interrupts(void);
void free_interrupts(void);
diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c
index d176004..cd2b0bf 100644
--- a/drivers/lguest/lguest_user.c
+++ b/drivers/lguest/lguest_user.c
@@ -104,6 +104,9 @@ static int vcpu_start(struct lg_vcpu *vcpu, int vcpu_id,

vcpu->vcpu_id = vcpu_id;

+ /* The timer for lguest's clock needs initialization. */
+ init_clockdev(vcpu);
+
vcpu->lg = container_of((vcpu - vcpu_id), struct lguest, vcpus[0]);
vcpu->lg->nr_vcpus++;

@@ -183,9 +186,6 @@ static int initialize(struct file *file, const unsigned long __user *input)
* address. */
lguest_arch_setup_regs(lg, args[3]);

- /* The timer for lguest's clock needs initialization. */
- init_clockdev(lg);
-
/* We keep a pointer to the Launcher task (ie. current task) for when
* other Guests want to wake this one (inter-Guest I/O). */
lg->tsk = current;
@@ -276,6 +276,7 @@ static ssize_t write(struct file *file, const char __user *in,
static int close(struct inode *inode, struct file *file)
{
struct lguest *lg = file->private_data;
+ int i;

/* If we never successfully initialized, there's nothing to clean up */
if (!lg)
@@ -284,8 +285,9 @@ static int close(struct inode *inode, struct file *file)
/* We need the big lock, to protect from inter-guest I/O and other
* Launchers initializing guests. */
mutex_lock(&lguest_lock);
- /* Cancels the hrtimer set via LHCALL_SET_CLOCKEVENT. */
- hrtimer_cancel(&lg->hrt);
+ for (i = 0; i < lg->nr_vcpus; i++)
+ /* Cancels the hrtimer set via LHCALL_SET_CLOCKEVENT. */
+ hrtimer_cancel(&lg->vcpus[i].hrt);
/* Free up the shadow page tables for the Guest. */
free_guest_pagetable(lg);
/* Now all the memory cleanups are done, it's safe to release the
--
1.5.0.6