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>
---
xen/arch/x86/hvm/vmx/vmcs.c | 1 +
xen/arch/x86/hvm/vmx/vmx.c | 54 +++++++++++++++++++++++++++++++++++++++
xen/include/asm-x86/hvm/vmx/vmx.h | 1 +
3 files changed, 56 insertions(+)
diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index 1bd875a..f554d4c 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -578,6 +578,7 @@ 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 071c063..5f428b7 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -211,6 +211,60 @@ static void vmx_pi_blocking_cleanup(struct vcpu *v)
vmx_pi_remove_vcpu_from_blocking_list(v);
}
+void vmx_pi_desc_fixup(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;
+
+ spin_lock_irqsave(old_lock, flags);
+
+ list_for_each_entry_safe(vmx, tmp, blocked_vcpus, pi_blocking.list)
+ {
+ /*
+ * 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.
+ */
+restart:
+ new_cpu = cpumask_any(&cpu_online_map);
+ new_lock = &per_cpu(vmx_pi_blocking, new_cpu).lock;
+
+ spin_lock(new_lock);
+
+ /*
+ * If the new_cpu is not online, that means it became offline between
+ * we got 'new_cpu' and acquiring its lock above, we need to find
+ * another online cpu instead. Such as, this fucntion is being called
+ * on 'new_cpu' at the same time. Can this happen??
+ */
+ if ( !cpu_online(new_cpu) )
+ {
+ spin_unlock(new_lock);
+ goto restart;
+ }
+
+ 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);
+ }
+
+ spin_unlock_irqrestore(old_lock, flags);
+}
+
/* This function is called when pcidevs_lock is held */
void vmx_pi_hooks_assign(struct domain *d)
{
diff --git a/xen/include/asm-x86/hvm/vmx/vmx.h
b/xen/include/asm-x86/hvm/vmx/vmx.h
index 4cdd9b1..9783c70 100644
--- a/xen/include/asm-x86/hvm/vmx/vmx.h
+++ b/xen/include/asm-x86/hvm/vmx/vmx.h
@@ -569,6 +569,7 @@ 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(int cpu);
void vmx_pi_hooks_assign(struct domain *d);
void vmx_pi_hooks_deassign(struct domain *d);
--
2.1.0
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