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authorMichael S. Tsirkin <mst@redhat.com>2012-10-17 12:06:06 -0400
committerGleb Natapov <gleb@redhat.com>2012-12-05 08:10:53 -0500
commit78c634402a1825f1f5bef13077f0985f3b8a3212 (patch)
tree1dac3b54821c39c1b893f0a2db4806dacc917bdc /virt
parent01f218803757c9ec1152ac2fd39d03c27c452634 (diff)
kvm: deliver msi interrupts from irq handler
We can deliver certain interrupts, notably MSI, from atomic context. Use kvm_set_irq_inatomic, to implement an irq handler for msi. This reduces the pressure on scheduler in case where host and guest irq share a host cpu. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/assigned-dev.c36
1 files changed, 26 insertions, 10 deletions
diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index 23a41a9f8db9..3642239252b0 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -105,6 +105,15 @@ static irqreturn_t kvm_assigned_dev_thread_intx(int irq, void *dev_id)
105} 105}
106 106
107#ifdef __KVM_HAVE_MSI 107#ifdef __KVM_HAVE_MSI
108static irqreturn_t kvm_assigned_dev_msi(int irq, void *dev_id)
109{
110 struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
111 int ret = kvm_set_irq_inatomic(assigned_dev->kvm,
112 assigned_dev->irq_source_id,
113 assigned_dev->guest_irq, 1);
114 return unlikely(ret == -EWOULDBLOCK) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
115}
116
108static irqreturn_t kvm_assigned_dev_thread_msi(int irq, void *dev_id) 117static irqreturn_t kvm_assigned_dev_thread_msi(int irq, void *dev_id)
109{ 118{
110 struct kvm_assigned_dev_kernel *assigned_dev = dev_id; 119 struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
@@ -117,6 +126,23 @@ static irqreturn_t kvm_assigned_dev_thread_msi(int irq, void *dev_id)
117#endif 126#endif
118 127
119#ifdef __KVM_HAVE_MSIX 128#ifdef __KVM_HAVE_MSIX
129static irqreturn_t kvm_assigned_dev_msix(int irq, void *dev_id)
130{
131 struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
132 int index = find_index_from_host_irq(assigned_dev, irq);
133 u32 vector;
134 int ret = 0;
135
136 if (index >= 0) {
137 vector = assigned_dev->guest_msix_entries[index].vector;
138 ret = kvm_set_irq_inatomic(assigned_dev->kvm,
139 assigned_dev->irq_source_id,
140 vector, 1);
141 }
142
143 return unlikely(ret == -EWOULDBLOCK) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
144}
145
120static irqreturn_t kvm_assigned_dev_thread_msix(int irq, void *dev_id) 146static irqreturn_t kvm_assigned_dev_thread_msix(int irq, void *dev_id)
121{ 147{
122 struct kvm_assigned_dev_kernel *assigned_dev = dev_id; 148 struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
@@ -334,11 +360,6 @@ static int assigned_device_enable_host_intx(struct kvm *kvm,
334} 360}
335 361
336#ifdef __KVM_HAVE_MSI 362#ifdef __KVM_HAVE_MSI
337static irqreturn_t kvm_assigned_dev_msi(int irq, void *dev_id)
338{
339 return IRQ_WAKE_THREAD;
340}
341
342static int assigned_device_enable_host_msi(struct kvm *kvm, 363static int assigned_device_enable_host_msi(struct kvm *kvm,
343 struct kvm_assigned_dev_kernel *dev) 364 struct kvm_assigned_dev_kernel *dev)
344{ 365{
@@ -363,11 +384,6 @@ static int assigned_device_enable_host_msi(struct kvm *kvm,
363#endif 384#endif
364 385
365#ifdef __KVM_HAVE_MSIX 386#ifdef __KVM_HAVE_MSIX
366static irqreturn_t kvm_assigned_dev_msix(int irq, void *dev_id)
367{
368 return IRQ_WAKE_THREAD;
369}
370
371static int assigned_device_enable_host_msix(struct kvm *kvm, 387static int assigned_device_enable_host_msix(struct kvm *kvm,
372 struct kvm_assigned_dev_kernel *dev) 388 struct kvm_assigned_dev_kernel *dev)
373{ 389{