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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 09/11] xen: Add DOMCTL to limit the number of event channels a domain may use
On 02/10/13 18:06, David Vrabel wrote:
> On 02/10/13 17:35, David Vrabel wrote:
>>
>> --- a/xen/xsm/flask/hooks.c
>> +++ b/xen/xsm/flask/hooks.c
>> @@ -727,6 +727,9 @@ static int flask_domctl(struct domain *d, int cmd)
>> case XEN_DOMCTL_audit_p2m:
>> return current_has_perm(d, SECCLASS_HVM, HVM__AUDIT_P2M);
>>
>> + case XEN_DOMCTL_set_max_evtchn:
>> + return current_has_perm(d, SECCLASS_DOMAIN,
>> DOMAIN__SET_MAX_EVTCHN);#
>
> Sorry, I forgot to try a build with XSM and FLASK enabled. This should
> have been SECCLASS_DOMAIN2 and DOMAIN2__SET_MAX_EVTCHN.
And here's a fixed version of the patch.
Daniel, can you review the XSM parts of this, please?
8<-----------------------------------
xen: Add DOMCTL to limit the number of event channels a domain may use
Add XEN_DOMCTL_set_max_evtchn which may be used during domain creation to
set the maximum event channel port a domain may use. This may be used to
limit the amount of Xen resources (global mapping space and xenheap) that
a domain may use for event channels.
A domain that does not have a limit set may use all the event channels
supported by the event channel ABI in use.
Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>
---
tools/flask/policy/policy/mls | 2 +-
tools/flask/policy/policy/modules/xen/xen.if | 2 +-
tools/flask/policy/policy/modules/xen/xen.te | 2 +-
xen/common/domctl.c | 8 ++++++++
xen/common/event_channel.c | 7 ++++++-
xen/include/public/domctl.h | 13 +++++++++++++
xen/include/xen/sched.h | 1 +
xen/xsm/flask/hooks.c | 3 +++
xen/xsm/flask/policy/access_vectors | 2 ++
9 files changed, 36 insertions(+), 4 deletions(-)
diff --git a/tools/flask/policy/policy/mls b/tools/flask/policy/policy/mls
index 9290a76..fb603cd 100644
--- a/tools/flask/policy/policy/mls
+++ b/tools/flask/policy/policy/mls
@@ -74,7 +74,7 @@ mlsconstrain domain { getaffinity getdomaininfo getvcpuinfo
getvcpucontext getad
((l1 dom l2) or (t1 == mls_priv));
# all the domain "write" ops
-mlsconstrain domain { setvcpucontext pause unpause resume create max_vcpus
destroy setaffinity scheduler setdomainmaxmem setdomainhandle setdebugging
hypercall settime set_target shutdown setaddrsize trigger setextvcpucontext }
+mlsconstrain domain { setvcpucontext pause unpause resume create max_vcpus
destroy setaffinity scheduler setdomainmaxmem setdomainhandle setdebugging
hypercall settime set_target shutdown setaddrsize trigger setextvcpucontext
set_max_evtchn }
((l1 eq l2) or (t1 == mls_priv));
# This is incomplete - similar constraints must be written for all classes
diff --git a/tools/flask/policy/policy/modules/xen/xen.if
b/tools/flask/policy/policy/modules/xen/xen.if
index 97af0a8..63e40f0 100644
--- a/tools/flask/policy/policy/modules/xen/xen.if
+++ b/tools/flask/policy/policy/modules/xen/xen.if
@@ -48,7 +48,7 @@ define(`create_domain_common', `
allow $1 $2:domain { create max_vcpus setdomainmaxmem setaddrsize
getdomaininfo hypercall setvcpucontext setextvcpucontext
getscheduler getvcpuinfo getvcpuextstate getaddrsize
- getaffinity setaffinity };
+ getaffinity setaffinity set_max_evtchn };
allow $1 $2:domain2 { set_cpuid settsc setscheduler setclaim };
allow $1 $2:security check_context;
allow $1 $2:shadow enable;
diff --git a/tools/flask/policy/policy/modules/xen/xen.te
b/tools/flask/policy/policy/modules/xen/xen.te
index c89ce28..5f9de5c 100644
--- a/tools/flask/policy/policy/modules/xen/xen.te
+++ b/tools/flask/policy/policy/modules/xen/xen.te
@@ -73,7 +73,7 @@ allow dom0_t dom0_t:domain {
getdomaininfo getvcpuinfo getvcpucontext setdomainmaxmem setdomainhandle
setdebugging hypercall settime setaddrsize getaddrsize trigger
getextvcpucontext setextvcpucontext getvcpuextstate setvcpuextstate
- getpodtarget setpodtarget set_misc_info set_virq_handler
+ getpodtarget setpodtarget set_misc_info set_virq_handler set_max_evtchn
};
allow dom0_t dom0_t:domain2 {
set_cpuid gettsc settsc setscheduler
diff --git a/xen/common/domctl.c b/xen/common/domctl.c
index 9760d50..870eef1 100644
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -863,6 +863,14 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t)
u_domctl)
}
break;
+ case XEN_DOMCTL_set_max_evtchn:
+ {
+ d->max_evtchn_port = min_t(unsigned int,
+ op->u.set_max_evtchn.max_port,
+ INT_MAX);
+ }
+ break;
+
default:
ret = arch_do_domctl(op, d, u_domctl);
break;
diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
index 0c0bbe4..34efd24 100644
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -168,10 +168,14 @@ static int get_free_port(struct domain *d)
return -EINVAL;
for ( port = 0; port_is_valid(d, port); port++ )
+ {
+ if ( port > d->max_evtchn_port )
+ return -ENOSPC;
if ( evtchn_from_port(d, port)->state == ECS_FREE )
return port;
+ }
- if ( port == d->max_evtchns )
+ if ( port == d->max_evtchns || port > d->max_evtchn_port )
return -ENOSPC;
if ( !group_from_port(d, port) )
@@ -1230,6 +1234,7 @@ void evtchn_check_pollers(struct domain *d, unsigned int
port)
int evtchn_init(struct domain *d)
{
evtchn_2l_init(d);
+ d->max_evtchn_port = INT_MAX;
d->evtchn = alloc_evtchn_bucket(d, 0);
if ( !d->evtchn )
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 4c5b2bb..d4e479f 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -852,6 +852,17 @@ struct xen_domctl_set_broken_page_p2m {
typedef struct xen_domctl_set_broken_page_p2m xen_domctl_set_broken_page_p2m_t;
DEFINE_XEN_GUEST_HANDLE(xen_domctl_set_broken_page_p2m_t);
+/*
+ * XEN_DOMCTL_set_max_evtchn: sets the maximum event channel port
+ * number the guest may use. Use this limit the amount of resources
+ * (global mapping space, xenheap) a guest may use for event channels.
+ */
+struct xen_domctl_set_max_evtchn {
+ uint32_t max_port;
+};
+typedef struct xen_domctl_set_max_evtchn xen_domctl_set_max_evtchn_t;
+DEFINE_XEN_GUEST_HANDLE(xen_domctl_set_max_evtchn_t);
+
struct xen_domctl {
uint32_t cmd;
#define XEN_DOMCTL_createdomain 1
@@ -920,6 +931,7 @@ struct xen_domctl {
#define XEN_DOMCTL_set_broken_page_p2m 67
#define XEN_DOMCTL_setnodeaffinity 68
#define XEN_DOMCTL_getnodeaffinity 69
+#define XEN_DOMCTL_set_max_evtchn 70
#define XEN_DOMCTL_gdbsx_guestmemio 1000
#define XEN_DOMCTL_gdbsx_pausevcpu 1001
#define XEN_DOMCTL_gdbsx_unpausevcpu 1002
@@ -975,6 +987,7 @@ struct xen_domctl {
struct xen_domctl_set_access_required access_required;
struct xen_domctl_audit_p2m audit_p2m;
struct xen_domctl_set_virq_handler set_virq_handler;
+ struct xen_domctl_set_max_evtchn set_max_evtchn;
struct xen_domctl_gdbsx_memio gdbsx_guest_memio;
struct xen_domctl_set_broken_page_p2m set_broken_page_p2m;
struct xen_domctl_gdbsx_pauseunp_vcpu gdbsx_pauseunp_vcpu;
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index ab7be82..0da0096 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -291,6 +291,7 @@ struct domain
struct evtchn *evtchn; /* first bucket only */
struct evtchn **evtchn_group[NR_EVTCHN_GROUPS]; /* all other buckets */
unsigned int max_evtchns;
+ unsigned int max_evtchn_port;
spinlock_t event_lock;
const struct evtchn_port_ops *evtchn_port_ops;
struct evtchn_fifo_domain *evtchn_fifo;
diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c
index fa0589a..b1e2593 100644
--- a/xen/xsm/flask/hooks.c
+++ b/xen/xsm/flask/hooks.c
@@ -727,6 +727,9 @@ static int flask_domctl(struct domain *d, int cmd)
case XEN_DOMCTL_audit_p2m:
return current_has_perm(d, SECCLASS_HVM, HVM__AUDIT_P2M);
+ case XEN_DOMCTL_set_max_evtchn:
+ return current_has_perm(d, SECCLASS_DOMAIN2, DOMAIN2__SET_MAX_EVTCHN);
+
default:
printk("flask_domctl: Unknown op %d\n", cmd);
return -EPERM;
diff --git a/xen/xsm/flask/policy/access_vectors
b/xen/xsm/flask/policy/access_vectors
index 5dfe13b..1fbe241 100644
--- a/xen/xsm/flask/policy/access_vectors
+++ b/xen/xsm/flask/policy/access_vectors
@@ -194,6 +194,8 @@ class domain2
setscheduler
# XENMEM_claim_pages
setclaim
+# XEN_DOMCTL_set_max_evtchn
+ set_max_evtchn
}
# Similar to class domain, but primarily contains domctls related to HVM
domains
--
1.7.2.5
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