From: Feng Wu <feng...@intel.com>
When cpu is offline, we need to move all the vcpus in its blocking
list to another online cpu, this patch handles it.
Signed-off-by: Feng Wu <feng...@intel.com>
Signed-off-by: Chao Gao <chao....@intel.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com>
Acked-by: Kevin Tian <kevin.t...@intel.com>
---
xen/arch/x86/hvm/vmx/vmcs.c | 1 +
xen/arch/x86/hvm/vmx/vmx.c | 70 +++++++++++++++++++++++++++++++++++++++
xen/include/asm-x86/hvm/vmx/vmx.h | 1 +
3 files changed, 72 insertions(+)
diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index 934674c..99c77b9 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -591,6 +591,7 @@ void vmx_cpu_dead(unsigned int cpu)
vmx_free_vmcs(per_cpu(vmxon_region, cpu));
per_cpu(vmxon_region, cpu) = 0;
nvmx_cpu_dead(cpu);
+ vmx_pi_desc_fixup(cpu);
}
int vmx_cpu_up(void)
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index d201956..25f9ec9 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -199,6 +199,76 @@ static void vmx_pi_do_resume(struct vcpu *v)
vmx_pi_unblock_vcpu(v);
}
+void vmx_pi_desc_fixup(unsigned int cpu)
+{
+ unsigned int new_cpu, dest;
+ unsigned long flags;
+ struct arch_vmx_struct *vmx, *tmp;
+ spinlock_t *new_lock, *old_lock = &per_cpu(vmx_pi_blocking, cpu).lock;
+ struct list_head *blocked_vcpus = &per_cpu(vmx_pi_blocking, cpu).list;
+
+ if ( !iommu_intpost )
+ return;
+
+ /*
+ * We are in the context of CPU_DEAD or CPU_UP_CANCELED notification,
+ * and it is impossible for a second CPU go down in parallel. So we
+ * can safely acquire the old cpu's lock and then acquire the new_cpu's
+ * lock after that.
+ */
+ spin_lock_irqsave(old_lock, flags);
+
+ list_for_each_entry_safe(vmx, tmp, blocked_vcpus, pi_blocking.list)
+ {
+ /*
+ * Suppress notification or we may miss an interrupt when the
+ * target cpu is dying.
+ */
+ pi_set_sn(&vmx->pi_desc);
+
+ /*
+ * Check whether a notification is pending before doing the
+ * movement, if that is the case we need to wake up it directly
+ * other than moving it to the new cpu's list.
+ */
+ if ( pi_test_on(&vmx->pi_desc) )
+ {
+ list_del(&vmx->pi_blocking.list);
+ vmx->pi_blocking.lock = NULL;
+ vcpu_unblock(container_of(vmx, struct vcpu, arch.hvm_vmx));
+ }
+ else
+ {
+ /*
+ * We need to find an online cpu as the NDST of the PI descriptor,
it
+ * doesn't matter whether it is within the cpupool of the domain or
+ * not. As long as it is online, the vCPU will be woken up once the
+ * notification event arrives.
+ */
+ new_cpu = cpumask_any(&cpu_online_map);
+ new_lock = &per_cpu(vmx_pi_blocking, new_cpu).lock;
+
+ spin_lock(new_lock);
+
+ ASSERT(vmx->pi_blocking.lock == old_lock);
+
+ dest = cpu_physical_id(new_cpu);
+ write_atomic(&vmx->pi_desc.ndst,
+ x2apic_enabled ? dest : MASK_INSR(dest,
PI_xAPIC_NDST_MASK));
+
+ list_move(&vmx->pi_blocking.list,
+ &per_cpu(vmx_pi_blocking, new_cpu).list);
+ vmx->pi_blocking.lock = new_lock;
+
+ spin_unlock(new_lock);
+ }
+
+ pi_clear_sn(&vmx->pi_desc);
+ }
+
+ spin_unlock_irqrestore(old_lock, flags);
+}
+
/*
* To handle posted interrupts correctly, we need to set the following
* state:
diff --git a/xen/include/asm-x86/hvm/vmx/vmx.h
b/xen/include/asm-x86/hvm/vmx/vmx.h
index 2b781ab..5ead57c 100644
--- a/xen/include/asm-x86/hvm/vmx/vmx.h
+++ b/xen/include/asm-x86/hvm/vmx/vmx.h
@@ -597,6 +597,7 @@ void free_p2m_hap_data(struct p2m_domain *p2m);
void p2m_init_hap_data(struct p2m_domain *p2m);
void vmx_pi_per_cpu_init(unsigned int cpu);
+void vmx_pi_desc_fixup(unsigned int cpu);
void vmx_pi_hooks_assign(struct domain *d);
void vmx_pi_hooks_deassign(struct domain *d);
--
1.8.3.1
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