diff options
| -rw-r--r-- | xen/arch/x86/hvm/hvm.c | 32 | ||||
| -rw-r--r-- | xen/common/domain.c | 1 | ||||
| -rw-r--r-- | xen/include/xen/sched.h | 6 |
3 files changed, 37 insertions, 2 deletions
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 6f4a92445e..a43ca392b2 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -1661,14 +1661,38 @@ static int hvmop_set_pci_link_route( static int hvmop_flush_tlb_all(void) { + struct domain *d = current->domain; struct vcpu *v; + /* Avoid deadlock if more than one vcpu tries this at the same time. */ + if ( !spin_trylock(&d->hypercall_deadlock_mutex) ) + return -EAGAIN; + + /* Pause all other vcpus. */ + for_each_vcpu ( d, v ) + if ( v != current ) + vcpu_pause_nosync(v); + + /* Now that all VCPUs are signalled to deschedule, we wait... */ + for_each_vcpu ( d, v ) + if ( v != current ) + while ( !vcpu_runnable(v) && v->is_running ) + cpu_relax(); + + /* All other vcpus are paused, safe to unlock now. */ + spin_unlock(&d->hypercall_deadlock_mutex); + /* Flush paging-mode soft state (e.g., va->gfn cache; PAE PDPE cache). */ - for_each_vcpu ( current->domain, v ) + for_each_vcpu ( d, v ) paging_update_cr3(v); /* Flush all dirty TLBs. */ - flush_tlb_mask(current->domain->domain_dirty_cpumask); + flush_tlb_mask(d->domain_dirty_cpumask); + + /* Done. */ + for_each_vcpu ( d, v ) + if ( v != current ) + vcpu_unpause(v); return 0; } @@ -1780,6 +1804,10 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE(void) arg) } } + if ( rc == -EAGAIN ) + rc = hypercall_create_continuation( + __HYPERVISOR_hvm_op, "lh", op, arg); + return rc; } diff --git a/xen/common/domain.c b/xen/common/domain.c index e3b583d021..55152a3953 100644 --- a/xen/common/domain.c +++ b/xen/common/domain.c @@ -68,6 +68,7 @@ struct domain *alloc_domain(domid_t domid) spin_lock_init(&d->big_lock); spin_lock_init(&d->page_alloc_lock); spin_lock_init(&d->shutdown_lock); + spin_lock_init(&d->hypercall_deadlock_mutex); INIT_LIST_HEAD(&d->page_list); INIT_LIST_HEAD(&d->xenpage_list); diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h index cf5342ccf1..67a203b969 100644 --- a/xen/include/xen/sched.h +++ b/xen/include/xen/sched.h @@ -227,6 +227,12 @@ struct domain int32_t time_offset_seconds; struct rcu_head rcu; + + /* + * Hypercall deadlock avoidance lock. Used if a hypercall might + * cause a deadlock. Acquirers don't spin waiting; they preempt. + */ + spinlock_t hypercall_deadlock_mutex; }; struct domain_setup_info |