* [PATCH v4 1/2] xen/arm: vgic: Keep track of vIRQ used by a domain
2015-02-19 18:12 [PATCH v4 0/2] xen/arm: Automatically find a PPI for the DOM0 event IRQ Julien Grall
@ 2015-02-19 18:12 ` Julien Grall
2015-02-25 14:38 ` Ian Campbell
2015-02-19 18:12 ` [PATCH v4 2/2] xen/arm: Automatically find a PPI for the DOM0 event channel interrupt Julien Grall
1 sibling, 1 reply; 4+ messages in thread
From: Julien Grall @ 2015-02-19 18:12 UTC (permalink / raw)
To: xen-devel
Cc: ian.campbell, Julien Grall, tim, stefano.stabellini, parth.dixit,
christoffer.dall
While it's easy to know which hardware IRQ is assigned to a domain, there
is no way to know which vIRQ is allocated by Xen for a specific domain.
Introduce a bitmap to keep track of every vIRQ used by a domain. This
will be used later to find free vIRQ for interrupt device assignment and
emulated interrupt.
Signed-off-by: Julien Grall <julien.grall@linaro.org>
---
Changes in v4:
- Move to a do {} while
Changes in v3:
- Typoes in commit message
- Remove pointless reserved in vgic_reserve_virq
- Move the retry after looking for first/end. I keep the goto
rather than a loop because it's more clear that we retry because
we were unable to set the bit
- Introduce vgic_allocate_{spi,ppi} helpers
- Use NR_GIC_SGI
Changes in v2:
- Remove lock
- Update the prototype of vgic_free_irq to actually show we are
taking in parameter a vIRQ and and IRQ
- vgic_free_virq was completely buggy. Rewrite it
- The usage of find_next_zero_bit was buggy. I don't know how it
was working before.
- Make find_next_zero_bit common for SPIs and PPIs
- Use if (...) BUG() rather than BUG_ON()
- Fix comments and some printk message
- Update the commit message
- Add missing vgic_reserve_irq for the event channel PPI
---
xen/arch/arm/domain.c | 3 ++
xen/arch/arm/domain_build.c | 6 ++++
xen/arch/arm/platforms/xgene-storm.c | 4 +++
xen/arch/arm/vgic.c | 55 ++++++++++++++++++++++++++++++++++++
xen/arch/arm/vtimer.c | 25 ++++++++++++++++
xen/include/asm-arm/domain.h | 1 +
xen/include/asm-arm/vgic.h | 23 +++++++++++++++
7 files changed, 117 insertions(+)
diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index 3e3fe92..7a690b2 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -547,6 +547,9 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags)
else
d->arch.evtchn_irq = platform_dom0_evtchn_ppi();
+ if ( !vgic_reserve_virq(d, d->arch.evtchn_irq) )
+ BUG();
+
/*
* Virtual UART is only used by linux early printk and decompress code.
* Only use it for the hardware domain because the linux kernel may not
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index c2dcb49..c1df1fc 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -970,6 +970,12 @@ static int map_device(struct domain *d, struct dt_device_node *dev)
irq = res;
DPRINT("irq %u = %u\n", i, irq);
+ /*
+ * Checking the return of vgic_reserve_virq is not
+ * necessary. It should not fail except when we try to map
+ * the IRQ twice. This can legitimately happen if the IRQ is shared
+ */
+ vgic_reserve_virq(d, irq);
res = route_irq_to_guest(d, irq, dt_node_name(dev));
if ( res )
{
diff --git a/xen/arch/arm/platforms/xgene-storm.c b/xen/arch/arm/platforms/xgene-storm.c
index 0b3492d..ef3ba63 100644
--- a/xen/arch/arm/platforms/xgene-storm.c
+++ b/xen/arch/arm/platforms/xgene-storm.c
@@ -71,6 +71,10 @@ static int map_one_spi(struct domain *d, const char *what,
printk("Additional IRQ %u (%s)\n", irq, what);
+ if ( !vgic_reserve_virq(d, irq) )
+ printk("Failed to reserve vIRQ %u on dom%d\n",
+ irq, d->domain_id);
+
ret = route_irq_to_guest(d, irq, what);
if ( ret )
printk("Failed to route %s to dom%d\n", what, d->domain_id);
diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index b272d86..c14d79d 100644
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -110,6 +110,15 @@ int domain_vgic_init(struct domain *d)
d->arch.vgic.handler->domain_init(d);
+ d->arch.vgic.allocated_irqs =
+ xzalloc_array(unsigned long, BITS_TO_LONGS(vgic_num_irqs(d)));
+ if ( !d->arch.vgic.allocated_irqs )
+ return -ENOMEM;
+
+ /* vIRQ0-15 (SGIs) are reserved */
+ for ( i = 0; i < NR_GIC_SGI; i++ )
+ set_bit(i, d->arch.vgic.allocated_irqs);
+
return 0;
}
@@ -122,6 +131,7 @@ void domain_vgic_free(struct domain *d)
{
xfree(d->arch.vgic.shared_irqs);
xfree(d->arch.vgic.pending_irqs);
+ xfree(d->arch.vgic.allocated_irqs);
}
int vcpu_vgic_init(struct vcpu *v)
@@ -452,6 +462,51 @@ int vgic_emulate(struct cpu_user_regs *regs, union hsr hsr)
return v->domain->arch.vgic.handler->emulate_sysreg(regs, hsr);
}
+bool_t vgic_reserve_virq(struct domain *d, unsigned int virq)
+{
+ if ( virq >= vgic_num_irqs(d) )
+ return 0;
+
+ return !test_and_set_bit(virq, d->arch.vgic.allocated_irqs);
+}
+
+int vgic_allocate_virq(struct domain *d, bool_t spi)
+{
+ int first, end;
+ unsigned int virq;
+
+ if ( !spi )
+ {
+ /* We only allocate PPIs. SGIs are all reserved */
+ first = 16;
+ end = 32;
+ }
+ else
+ {
+ first = 32;
+ end = vgic_num_irqs(d);
+ }
+
+ /*
+ * There is no spinlock to protect allocated_irqs, therefore
+ * test_and_set_bit may fail. If so retry it.
+ */
+ do
+ {
+ virq = find_next_zero_bit(d->arch.vgic.allocated_irqs, end, first);
+ if ( virq >= end )
+ return -1;
+ }
+ while ( test_and_set_bit(virq, d->arch.vgic.allocated_irqs) );
+
+ return virq;
+}
+
+void vgic_free_virq(struct domain *d, unsigned int virq)
+{
+ clear_bit(virq, d->arch.vgic.allocated_irqs);
+}
+
/*
* Local variables:
* mode: C
diff --git a/xen/arch/arm/vtimer.c b/xen/arch/arm/vtimer.c
index 848e2c6..4427ae5 100644
--- a/xen/arch/arm/vtimer.c
+++ b/xen/arch/arm/vtimer.c
@@ -56,6 +56,31 @@ int domain_vtimer_init(struct domain *d)
{
d->arch.phys_timer_base.offset = NOW();
d->arch.virt_timer_base.offset = READ_SYSREG64(CNTPCT_EL0);
+
+ /* At this stage vgic_reserve_virq can't fail */
+ if ( is_hardware_domain(d) )
+ {
+ if ( !vgic_reserve_virq(d, timer_get_irq(TIMER_PHYS_SECURE_PPI)) )
+ BUG();
+
+ if ( !vgic_reserve_virq(d, timer_get_irq(TIMER_PHYS_NONSECURE_PPI)) )
+ BUG();
+
+ if ( !vgic_reserve_virq(d, timer_get_irq(TIMER_VIRT_PPI)) )
+ BUG();
+ }
+ else
+ {
+ if ( !vgic_reserve_virq(d, GUEST_TIMER_PHYS_S_PPI) )
+ BUG();
+
+ if ( !vgic_reserve_virq(d, GUEST_TIMER_PHYS_NS_PPI) )
+ BUG();
+
+ if ( !vgic_reserve_virq(d, GUEST_TIMER_VIRT_PPI) )
+ BUG();
+ }
+
return 0;
}
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index 81e3185..9e0419e 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -90,6 +90,7 @@ struct arch_domain
spinlock_t lock;
int ctlr;
int nr_spis; /* Number of SPIs */
+ unsigned long *allocated_irqs; /* bitmap of IRQs allocated */
struct vgic_irq_rank *shared_irqs;
/*
* SPIs are domain global, SGIs and PPIs are per-VCPU and stored in
diff --git a/xen/include/asm-arm/vgic.h b/xen/include/asm-arm/vgic.h
index 0c7da7f..dd93872 100644
--- a/xen/include/asm-arm/vgic.h
+++ b/xen/include/asm-arm/vgic.h
@@ -199,6 +199,29 @@ extern int vgic_to_sgi(struct vcpu *v, register_t sgir,
enum gic_sgi_mode irqmode, int virq,
unsigned long vcpu_mask);
extern void vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int irq);
+
+/* Reserve a specific guest vIRQ */
+extern bool_t vgic_reserve_virq(struct domain *d, unsigned int virq);
+
+/*
+ * Allocate a guest VIRQ
+ * - spi == 0 => allocate a PPI. It will be the same on every vCPU
+ * - spi == 1 => allocate an SPI
+ */
+extern int vgic_allocate_virq(struct domain *d, bool_t spi);
+
+static inline int vgic_allocate_ppi(struct domain *d)
+{
+ return vgic_allocate_virq(d, 0 /* ppi */);
+}
+
+static inline int vgic_allocate_spi(struct domain *d)
+{
+ return vgic_allocate_virq(d, 1 /* spi */);
+}
+
+extern void vgic_free_virq(struct domain *d, unsigned int virq);
+
#endif /* __ASM_ARM_VGIC_H__ */
/*
--
2.1.4
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v4 2/2] xen/arm: Automatically find a PPI for the DOM0 event channel interrupt
2015-02-19 18:12 [PATCH v4 0/2] xen/arm: Automatically find a PPI for the DOM0 event IRQ Julien Grall
2015-02-19 18:12 ` [PATCH v4 1/2] xen/arm: vgic: Keep track of vIRQ used by a domain Julien Grall
@ 2015-02-19 18:12 ` Julien Grall
1 sibling, 0 replies; 4+ messages in thread
From: Julien Grall @ 2015-02-19 18:12 UTC (permalink / raw)
To: xen-devel
Cc: ian.campbell, Julien Grall, tim, stefano.stabellini, parth.dixit,
christoffer.dall
Use the new vgic interface to know which virtual PPI is free and use it
for the event channel code.
At the DOM0 creation time, Xen doesn't know which vIRQ will be free.
All the vIRQ will be reserved when we parse the device tree. So we can
allocate the vIRQ just after the device tree has been parsed.
It's safe to defer the allocation because no vIRQ can be injected as
long as the vCPU is not online.
As the device tree node "hypervisor" containing the description of the
event channel interrupt is created earlier, add a placeholder which will
be fix up once Xen has allocated the PPI.
Also correct the check in arch_domain_create to use is_hardware_domain.
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---
Changes in v4:
- Add Ian's ack
Changes in v3:
- Create placeholder in make_hypervisor_node
- Introduce a new function evtchn_fixup to allocate the
interrupt and fixup the device tree
- Use the newly function vgic_reserve_ppi
- Typoes
Changes in v2:
- Correct the BUG_ON in arch_domain_create
- Use if (...) BUG() rather than BUG_ON()
---
xen/arch/arm/domain.c | 17 +++++++-----
xen/arch/arm/domain_build.c | 51 +++++++++++++++++++++++++++++-------
xen/arch/arm/platform.c | 7 -----
xen/arch/arm/platforms/xgene-storm.c | 1 -
xen/include/asm-arm/platform.h | 4 ---
5 files changed, 53 insertions(+), 27 deletions(-)
diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index 7a690b2..fdba081 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -542,13 +542,18 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags)
if ( (rc = domain_vtimer_init(d)) != 0 )
goto fail;
- if ( d->domain_id )
+ /*
+ * The hardware domain will get a PPI later in
+ * arch/arm/domain_build.c depending on the
+ * interrupt map of the hardware.
+ */
+ if ( !is_hardware_domain(d) )
+ {
d->arch.evtchn_irq = GUEST_EVTCHN_PPI;
- else
- d->arch.evtchn_irq = platform_dom0_evtchn_ppi();
-
- if ( !vgic_reserve_virq(d, d->arch.evtchn_irq) )
- BUG();
+ /* At this stage vgic_reserve_virq should never fail */
+ if ( !vgic_reserve_virq(d, GUEST_EVTCHN_PPI) )
+ BUG();
+ }
/*
* Virtual UART is only used by linux early printk and decompress code.
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index c1df1fc..550193e 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -627,16 +627,10 @@ static int make_hypervisor_node(struct domain *d,
return res;
/*
- * interrupts is evtchn upcall:
- * - Active-low level-sensitive
- * - All cpus
- *
- * TODO: Handle correctly the cpumask
+ * Placeholder for the event channel interrupt. The values will be
+ * replaced later.
*/
- DPRINT(" Event channel interrupt to %u\n", d->arch.evtchn_irq);
- set_interrupt_ppi(intr, d->arch.evtchn_irq, 0xf,
- DT_IRQ_TYPE_LEVEL_LOW);
-
+ set_interrupt_ppi(intr, ~0, 0xf, DT_IRQ_TYPE_INVALID);
res = fdt_property_interrupts(fdt, &intr, 1);
if ( res )
return res;
@@ -1277,6 +1271,43 @@ static void initrd_load(struct kernel_info *kinfo)
}
}
+static void evtchn_fixup(struct domain *d, struct kernel_info *kinfo)
+{
+ int res, node;
+ gic_interrupt_t intr;
+
+ /*
+ * The allocation of the event channel IRQ has been deferred until
+ * now. At this time, all PPIs used by DOM0 have been registered.
+ */
+ res = vgic_allocate_ppi(d);
+ if ( res < 0 )
+ panic("Unable to allocate a PPI for the event channel interrupt\n");
+
+ d->arch.evtchn_irq = res;
+
+ printk("Allocating PPI %u for event channel interrupt\n",
+ d->arch.evtchn_irq);
+
+ /* Fix up "interrupts" in /hypervisor node */
+ node = fdt_path_offset(kinfo->fdt, "/hypervisor");
+ if ( node < 0 )
+ panic("Cannot find the /hypervisor node");
+
+ /* Interrupt event channel upcall:
+ * - Active-low level-sensitive
+ * - All CPUs
+ *
+ * TODO: Handle properly the cpumask
+ */
+ set_interrupt_ppi(intr, d->arch.evtchn_irq, 0xf,
+ DT_IRQ_TYPE_LEVEL_LOW);
+ res = fdt_setprop_inplace(kinfo->fdt, node, "interrupts",
+ &intr, sizeof(intr));
+ if ( res )
+ panic("Cannot fix up \"interrupts\" property of the hypervisor node");
+}
+
int construct_dom0(struct domain *d)
{
struct kernel_info kinfo = {};
@@ -1338,6 +1369,8 @@ int construct_dom0(struct domain *d)
kernel_load(&kinfo);
/* initrd_load will fix up the fdt, so call it before dtb_load */
initrd_load(&kinfo);
+ /* Allocate the event channel IRQ and fix up the device tree */
+ evtchn_fixup(d, &kinfo);
dtb_load(&kinfo);
/* Now that we are done restore the original p2m and current. */
diff --git a/xen/arch/arm/platform.c b/xen/arch/arm/platform.c
index cb4cda8..d016797 100644
--- a/xen/arch/arm/platform.c
+++ b/xen/arch/arm/platform.c
@@ -160,13 +160,6 @@ bool_t platform_device_is_blacklisted(const struct dt_device_node *node)
return dt_match_node(blacklist, node);
}
-unsigned int platform_dom0_evtchn_ppi(void)
-{
- if ( platform && platform->dom0_evtchn_ppi )
- return platform->dom0_evtchn_ppi;
- return GUEST_EVTCHN_PPI;
-}
-
void platform_dom0_gnttab(paddr_t *start, paddr_t *size)
{
if ( platform && platform->dom0_gnttab_size )
diff --git a/xen/arch/arm/platforms/xgene-storm.c b/xen/arch/arm/platforms/xgene-storm.c
index ef3ba63..eee650e 100644
--- a/xen/arch/arm/platforms/xgene-storm.c
+++ b/xen/arch/arm/platforms/xgene-storm.c
@@ -232,7 +232,6 @@ PLATFORM_START(xgene_storm, "APM X-GENE STORM")
.quirks = xgene_storm_quirks,
.specific_mapping = xgene_storm_specific_mapping,
- .dom0_evtchn_ppi = 24,
.dom0_gnttab_start = 0x1f800000,
.dom0_gnttab_size = 0x20000,
PLATFORM_END
diff --git a/xen/include/asm-arm/platform.h b/xen/include/asm-arm/platform.h
index eefaca6..4eba37b 100644
--- a/xen/include/asm-arm/platform.h
+++ b/xen/include/asm-arm/platform.h
@@ -38,10 +38,6 @@ struct platform_desc {
*/
const struct dt_device_match *blacklist_dev;
/*
- * The IRQ (PPI) to use to inject event channels to dom0.
- */
- unsigned int dom0_evtchn_ppi;
- /*
* The location of a region of physical address space which dom0
* can use for grant table mappings. If size is zero defaults to
* 0xb0000000-0xb0020000.
--
2.1.4
^ permalink raw reply related [flat|nested] 4+ messages in thread