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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v3 12/12] xen/domain: Allocate d->vcpu[] in domain_create()
For ARM, the call to arch_domain_create() needs to have completed before
domain_max_vcpus() will return the correct upper bound.
For each arch's dom0's, drop the temporary max_vcpus parameter, and allocation
of dom0->vcpu.
With d->max_vcpus now correctly configured before evtchn_init(), the poll mask
can be constructed suitably for the domain, rather than for the worst-case
setting.
Due to the evtchn_init() fixes, it no longer calls domain_max_vcpus(), and
ARM's two implementations of vgic_max_vcpus() no longer need work around the
out-of-order call.
From this point on, d->max_vcpus and d->vcpus[] are valid for any domain which
can be looked up by domid.
The XEN_DOMCTL_max_vcpus hypercall is modified to reject any call attempt with
max != d->max_vcpus, which does match the older semantics (not that it is
obvious from the code). The logic to allocate d->vcpu[] is dropped, but at
this point the hypercall still needs making to allocate each vcpu.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
CC: Julien Grall <julien.grall@xxxxxxx>
CC: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
CC: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
CC: Tim Deegan <tim@xxxxxxx>
CC: Wei Liu <wei.liu2@xxxxxxxxxx>
v2:
* Allocate in domain_create() rather than arch_domain_create().
* Retain domain_max_vcpus().
v3:
* Only drop the GIC_INVALID case in vgic_max_vcpus().
* Leave a note concerning the new behaviour of XEN_DOMCTL_max_vcpus in the
interim before it gets deleted.
---
xen/arch/arm/domain_build.c | 8 +-------
xen/arch/arm/setup.c | 2 +-
xen/arch/arm/vgic.c | 11 +----------
xen/arch/arm/vgic/vgic.c | 9 ---------
xen/arch/x86/dom0_build.c | 8 +-------
xen/arch/x86/setup.c | 2 +-
xen/common/domain.c | 18 ++++++++++++++++++
xen/common/domctl.c | 46 ++++++++-------------------------------------
xen/common/event_channel.c | 3 +--
xen/include/xen/domain.h | 2 +-
10 files changed, 33 insertions(+), 76 deletions(-)
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 6900a93..9ceb33d 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -72,14 +72,8 @@ unsigned int __init dom0_max_vcpus(void)
return opt_dom0_max_vcpus;
}
-struct vcpu *__init alloc_dom0_vcpu0(struct domain *dom0,
- unsigned int max_vcpus)
+struct vcpu *__init alloc_dom0_vcpu0(struct domain *dom0)
{
- dom0->vcpu = xzalloc_array(struct vcpu *, max_vcpus);
- if ( !dom0->vcpu )
- return NULL;
- dom0->max_vcpus = max_vcpus;
-
return alloc_vcpu(dom0, 0, 0);
}
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 048d5f3..01aaaab 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -854,7 +854,7 @@ void __init start_xen(unsigned long boot_phys_offset,
dom0_cfg.max_vcpus = dom0_max_vcpus();
dom0 = domain_create(0, &dom0_cfg, true);
- if ( IS_ERR(dom0) || (alloc_dom0_vcpu0(dom0, dom0_cfg.max_vcpus) == NULL) )
+ if ( IS_ERR(dom0) || (alloc_dom0_vcpu0(dom0) == NULL) )
panic("Error creating domain 0");
if ( construct_dom0(dom0) != 0)
diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index 7a2c455..5a4f082 100644
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -669,16 +669,7 @@ void vgic_free_virq(struct domain *d, unsigned int virq)
unsigned int vgic_max_vcpus(const struct domain *d)
{
- /*
- * Since evtchn_init would call domain_max_vcpus for poll_mask
- * allocation when the vgic_ops haven't been initialised yet,
- * we return MAX_VIRT_CPUS if d->arch.vgic.handler is null.
- */
- if ( !d->arch.vgic.handler )
- return MAX_VIRT_CPUS;
- else
- return min_t(unsigned int, MAX_VIRT_CPUS,
- d->arch.vgic.handler->max_vcpus);
+ return min_t(unsigned int, MAX_VIRT_CPUS, d->arch.vgic.handler->max_vcpus);
}
/*
diff --git a/xen/arch/arm/vgic/vgic.c b/xen/arch/arm/vgic/vgic.c
index 832632a..3272952 100644
--- a/xen/arch/arm/vgic/vgic.c
+++ b/xen/arch/arm/vgic/vgic.c
@@ -955,15 +955,6 @@ unsigned int vgic_max_vcpus(const struct domain *d)
switch ( d->arch.vgic.version )
{
- case GIC_INVALID:
- /*
- * Since evtchn_init would call domain_max_vcpus for poll_mask
- * allocation before the VGIC has been initialised, we need to
- * return some safe value in this case. As this is for allocation
- * purposes, go with the maximum value.
- */
- vgic_vcpu_limit = MAX_VIRT_CPUS;
- break;
case GIC_V2:
vgic_vcpu_limit = VGIC_V2_MAX_CPUS;
break;
diff --git a/xen/arch/x86/dom0_build.c b/xen/arch/x86/dom0_build.c
index b42eac3..423fdec 100644
--- a/xen/arch/x86/dom0_build.c
+++ b/xen/arch/x86/dom0_build.c
@@ -199,17 +199,11 @@ unsigned int __init dom0_max_vcpus(void)
return max_vcpus;
}
-struct vcpu *__init alloc_dom0_vcpu0(struct domain *dom0,
- unsigned int max_vcpus)
+struct vcpu *__init alloc_dom0_vcpu0(struct domain *dom0)
{
dom0->node_affinity = dom0_nodes;
dom0->auto_node_affinity = !dom0_nr_pxms;
- dom0->vcpu = xzalloc_array(struct vcpu *, max_vcpus);
- if ( !dom0->vcpu )
- return NULL;
- dom0->max_vcpus = max_vcpus;
-
return dom0_setup_vcpu(dom0, 0,
cpumask_last(&dom0_cpus) /* so it wraps around to
first pcpu */);
}
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 3ffcb7a..c9e66ea 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -1701,7 +1701,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
/* Create initial domain 0. */
dom0 = domain_create(get_initial_domain_id(), &dom0_cfg, !pv_shim);
- if ( IS_ERR(dom0) || (alloc_dom0_vcpu0(dom0, dom0_cfg.max_vcpus) == NULL) )
+ if ( IS_ERR(dom0) || (alloc_dom0_vcpu0(dom0) == NULL) )
panic("Error creating domain 0");
/* Grab the DOM0 command line. */
diff --git a/xen/common/domain.c b/xen/common/domain.c
index 8143532..f64ad5f 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -338,6 +338,19 @@ struct domain *domain_create(domid_t domid,
if ( !is_idle_domain(d) )
{
+ /* Check d->max_vcpus and allocate d->vcpu[]. */
+ err = -EINVAL;
+ if ( config->max_vcpus < 1 ||
+ config->max_vcpus > domain_max_vcpus(d) )
+ goto fail;
+
+ err = -ENOMEM;
+ d->vcpu = xzalloc_array(struct vcpu *, config->max_vcpus);
+ if ( !d->vcpu )
+ goto fail;
+
+ d->max_vcpus = config->max_vcpus;
+
watchdog_domain_init(d);
init_status |= INIT_watchdog;
@@ -422,6 +435,11 @@ struct domain *domain_create(domid_t domid,
sched_destroy_domain(d);
+ if ( d->max_vcpus )
+ {
+ d->max_vcpus = 0;
+ XFREE(d->vcpu);
+ }
if ( init_status & INIT_arch )
arch_domain_destroy(d);
if ( init_status & INIT_gnttab )
diff --git a/xen/common/domctl.c b/xen/common/domctl.c
index 58e51b2..8a803b3 100644
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -547,6 +547,13 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t)
u_domctl)
break;
}
+ /*
+ * Note: The parameter passed to XEN_DOMCTL_max_vcpus must match the value
+ * passed to XEN_DOMCTL_createdomain. This hypercall is in the process of
+ * being removed (once the failure paths in domain_create() have been
+ * improved), but is still required in the short term to allocate the
+ * vcpus themselves.
+ */
case XEN_DOMCTL_max_vcpus:
{
unsigned int i, max = op->u.max_vcpus.max, cpu;
@@ -554,16 +561,9 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t)
u_domctl)
ret = -EINVAL;
if ( (d == current->domain) || /* no domain_pause() */
- (max > domain_max_vcpus(d)) )
+ (max != d->max_vcpus) ) /* max_vcpus set up in createdomain */
break;
- /* Until Xenoprof can dynamically grow its vcpu-s array... */
- if ( d->xenoprof )
- {
- ret = -EAGAIN;
- break;
- }
-
/* Needed, for example, to ensure writable p.t. state is synced. */
domain_pause(d);
@@ -581,38 +581,8 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t)
u_domctl)
}
}
- /* We cannot reduce maximum VCPUs. */
- ret = -EINVAL;
- if ( (max < d->max_vcpus) && (d->vcpu[max] != NULL) )
- goto maxvcpu_out;
-
- /*
- * For now don't allow increasing the vcpu count from a non-zero
- * value: This code and all readers of d->vcpu would otherwise need
- * to be converted to use RCU, but at present there's no tools side
- * code path that would issue such a request.
- */
- ret = -EBUSY;
- if ( (d->max_vcpus > 0) && (max > d->max_vcpus) )
- goto maxvcpu_out;
-
ret = -ENOMEM;
online = cpupool_domain_cpumask(d);
- if ( max > d->max_vcpus )
- {
- struct vcpu **vcpus;
-
- BUG_ON(d->vcpu != NULL);
- BUG_ON(d->max_vcpus != 0);
-
- if ( (vcpus = xzalloc_array(struct vcpu *, max)) == NULL )
- goto maxvcpu_out;
-
- /* Install vcpu array /then/ update max_vcpus. */
- d->vcpu = vcpus;
- smp_wmb();
- d->max_vcpus = max;
- }
for ( i = 0; i < max; i++ )
{
diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
index 41cbbae..381f30e 100644
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -1303,8 +1303,7 @@ int evtchn_init(struct domain *d, unsigned int max_port)
evtchn_from_port(d, 0)->state = ECS_RESERVED;
#if MAX_VIRT_CPUS > BITS_PER_LONG
- d->poll_mask = xzalloc_array(unsigned long,
- BITS_TO_LONGS(domain_max_vcpus(d)));
+ d->poll_mask = xzalloc_array(unsigned long, BITS_TO_LONGS(d->max_vcpus));
if ( !d->poll_mask )
{
free_evtchn_bucket(d, d->evtchn);
diff --git a/xen/include/xen/domain.h b/xen/include/xen/domain.h
index 651205d..ce31999 100644
--- a/xen/include/xen/domain.h
+++ b/xen/include/xen/domain.h
@@ -17,7 +17,7 @@ struct vcpu *alloc_vcpu(
struct domain *d, unsigned int vcpu_id, unsigned int cpu_id);
unsigned int dom0_max_vcpus(void);
-struct vcpu *alloc_dom0_vcpu0(struct domain *dom0, unsigned int max_vcpus);
+struct vcpu *alloc_dom0_vcpu0(struct domain *dom0);
int vcpu_reset(struct vcpu *);
int vcpu_up(struct vcpu *v);
--
2.1.4
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