|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v2 6/8] xen: arm: supporting routing a PPI to the current vcpu.
That is whichever vcpu is resident when the interrupt fires. An
interrupt is in this state when both IRQ_GUEST and IRQ_PER_CPU are set
in the descriptor status. Only PPIs can be in this mode.
This requires some peripheral specific code to make use of the
previously introduced functionality to save and restore the PPI state.
The vtimer driver will do so shortly.
Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
xen/arch/arm/gic.c | 24 ++++++++++++++
xen/arch/arm/irq.c | 84 +++++++++++++++++++++++++++++++++++++++++------
xen/include/asm-arm/gic.h | 2 ++
xen/include/asm-arm/irq.h | 2 +-
4 files changed, 101 insertions(+), 11 deletions(-)
diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index e294e89..aea913b 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -177,6 +177,30 @@ void gic_route_irq_to_xen(struct irq_desc *desc, const
cpumask_t *cpu_mask,
gic_set_irq_properties(desc, cpu_mask, priority);
}
+/* Program the GIC to route an interrupt to the current guest
+ *
+ * That is the IRQ is delivered to whichever VCPU happens to be
+ * resident on the PCPU when the interrupt arrives.
+ *
+ * Currently the interrupt *must* be a PPI and the code responsible
+ * for the related hardware must save and restore the PPI with
+ * gic_save_and_mask_hwppi/gic_restore_hwppi.
+ */
+int gic_route_irq_to_current_guest(struct irq_desc *desc,
+ unsigned int priority)
+{
+ ASSERT(spin_is_locked(&desc->lock));
+ ASSERT(desc->irq >= 16 && desc->irq < 32);
+
+ desc->handler = gic_hw_ops->gic_guest_irq_type;
+ set_bit(_IRQ_GUEST, &desc->status);
+ set_bit(_IRQ_PER_CPU, &desc->status);
+
+ gic_set_irq_properties(desc, cpumask_of(smp_processor_id()), GIC_PRI_IRQ);
+
+ return 0;
+}
+
/* Program the GIC to route an interrupt to a guest
* - desc.lock must be held
*/
diff --git a/xen/arch/arm/irq.c b/xen/arch/arm/irq.c
index 95be10e..ca18403 100644
--- a/xen/arch/arm/irq.c
+++ b/xen/arch/arm/irq.c
@@ -229,12 +229,15 @@ void do_IRQ(struct cpu_user_regs *regs, unsigned int irq,
int is_fiq)
set_bit(_IRQ_INPROGRESS, &desc->status);
/*
- * The irq cannot be a PPI, we only support delivery of SPIs to
- * guests.
+ * A PPI exposed to a guest must always be in IRQ_GUEST|IRQ_PER_CPU
+ * mode ("route to active VCPU"), so we use current.
+ *
+ * For SPI we look up the required target as normal.
*/
- v = vgic_get_target_vcpu(info->d->vcpu[0], info->virq);
- vgic_vcpu_inject_irq(v, info->virq);
+ v = test_bit(_IRQ_PER_CPU, &desc->status) ? current :
+ vgic_get_target_vcpu(info->d->vcpu[0], info->virq);
+ vgic_vcpu_inject_irq(v, info->virq);
goto out_no_end;
}
@@ -363,11 +366,15 @@ int setup_irq(unsigned int irq, unsigned int irqflags,
struct irqaction *new)
if ( test_bit(_IRQ_GUEST, &desc->status) )
{
- struct domain *d = irq_get_domain(desc);
+ struct irq_guest *info = irq_get_guest_info(desc);
spin_unlock_irqrestore(&desc->lock, flags);
- printk(XENLOG_ERR "ERROR: IRQ %u is already in use by the domain %u\n",
- irq, d->domain_id);
+ if ( !test_bit(_IRQ_PER_CPU, &desc->status) )
+ printk(XENLOG_ERR "ERROR: IRQ %u is already in use by domain %u\n",
+ irq, info->d->domain_id);
+ else
+ printk(XENLOG_ERR
+ "ERROR: IRQ %u is already in use by <current-vcpu>\n", irq);
return -EBUSY;
}
@@ -410,7 +417,7 @@ static int setup_guest_irq(struct irq_desc *desc, unsigned
int virq,
{
const unsigned irq = desc->irq;
struct irqaction *action;
- int retval = 0;
+ int retval;
ASSERT(spin_is_locked(&desc->lock));
@@ -451,12 +458,21 @@ static int setup_guest_irq(struct irq_desc *desc,
unsigned int virq,
d->domain_id, irq, irq_get_guest_info(desc)->virq);
retval = -EBUSY;
}
+ else
+ retval = 0;
goto out;
}
if ( test_bit(_IRQ_GUEST, &desc->status) )
- printk(XENLOG_G_ERR "IRQ %u is already used by domain %u\n",
- irq, ad->domain_id);
+ {
+ if ( !test_bit(_IRQ_PER_CPU, &desc->status) )
+ printk(XENLOG_ERR
+ "ERROR: IRQ %u is already used by domain %u\n",
+ irq, ad->domain_id);
+ else
+ printk(XENLOG_ERR
+ "ERROR: IRQ %u is already used by <current-vcpu>\n",
irq);
+ }
else
printk(XENLOG_G_ERR "IRQ %u is already used by Xen\n", irq);
retval = -EBUSY;
@@ -542,6 +558,54 @@ free_info:
return retval;
}
+/*
+ * Route a PPI such that it is always delivered to the current vcpu on
+ * the pcpu. The driver for the peripheral must use
+ * gic_{save_and_mask,restore}_hwppi as part of the context switch.
+ */
+int route_hwppi_to_current_vcpu(unsigned int irq, const char *devname)
+{
+ struct irq_guest *info;
+ struct irq_desc *desc;
+ unsigned long flags;
+ int retval = 0;
+
+ /* Can only route PPIs to current VCPU */
+ if ( irq < 16 || irq >= 32 )
+ return -EINVAL;
+
+ desc = irq_to_desc(irq);
+
+ info = xmalloc(struct irq_guest);
+ if ( !info )
+ return -ENOMEM;
+
+ info->d = NULL; /* Routed to current vcpu, so no specific domain */
+ /* info->virq is set by gic_restore_hwppi. */
+
+ spin_lock_irqsave(&desc->lock, flags);
+
+ retval = setup_guest_irq(desc, irq, flags, info, devname);
+ if ( retval )
+ {
+ xfree(info);
+ return retval;
+ }
+
+ retval = gic_route_irq_to_current_guest(desc, GIC_PRI_IRQ);
+
+ spin_unlock_irqrestore(&desc->lock, flags);
+
+ if ( retval )
+ {
+ release_irq(desc->irq, info);
+ xfree(info);
+ return retval;
+ }
+
+ return 0;
+}
+
int release_guest_irq(struct domain *d, unsigned int virq)
{
struct irq_desc *desc;
diff --git a/xen/include/asm-arm/gic.h b/xen/include/asm-arm/gic.h
index fe9af3e..1e611fa 100644
--- a/xen/include/asm-arm/gic.h
+++ b/xen/include/asm-arm/gic.h
@@ -224,6 +224,8 @@ extern void gic_route_irq_to_xen(struct irq_desc *desc,
const cpumask_t *cpu_mas
extern int gic_route_irq_to_guest(struct domain *, unsigned int virq,
struct irq_desc *desc,
unsigned int priority);
+int gic_route_irq_to_current_guest(struct irq_desc *desc,
+ unsigned int priority);
/* Remove an IRQ passthrough to a guest */
int gic_remove_irq_from_guest(struct domain *d, unsigned int virq,
diff --git a/xen/include/asm-arm/irq.h b/xen/include/asm-arm/irq.h
index d354e3b..b302e3e 100644
--- a/xen/include/asm-arm/irq.h
+++ b/xen/include/asm-arm/irq.h
@@ -43,7 +43,7 @@ void init_secondary_IRQ(void);
int route_irq_to_guest(struct domain *d, unsigned int virq,
unsigned int irq, const char *devname);
-int route_irq_to_current_vcpu(unsigned int irq, const char *devname);
+int route_hwppi_to_current_vcpu(unsigned int irq, const char *devname);
int release_guest_irq(struct domain *d, unsigned int irq);
void arch_move_irqs(struct vcpu *v);
--
2.1.4
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |