KVM: x86: move kvm_set_irq_inatomic to legacy device assignment

The function is not used outside device assignment, and
kvm_arch_set_irq_inatomic has a different prototype.  Move it here and
make it static to avoid confusion.

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/arch/x86/kvm/assigned-dev.c b/arch/x86/kvm/assigned-dev.c
index 1c17ee807ef7..9dc091acd5fb 100644
--- a/arch/x86/kvm/assigned-dev.c
+++ b/arch/x86/kvm/assigned-dev.c
@@ -21,6 +21,7 @@
 #include <linux/fs.h>
 #include "irq.h"
 #include "assigned-dev.h"
+#include "trace/events/kvm.h"
 
 struct kvm_assigned_dev_kernel {
 	struct kvm_irq_ack_notifier ack_notifier;
@@ -131,6 +132,42 @@ static irqreturn_t kvm_assigned_dev_thread_intx(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+/*
+ * Deliver an IRQ in an atomic context if we can, or return a failure,
+ * user can retry in a process context.
+ * Return value:
+ *  -EWOULDBLOCK - Can't deliver in atomic context: retry in a process context.
+ *  Other values - No need to retry.
+ */
+static int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq,
+				int level)
+{
+	struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS];
+	struct kvm_kernel_irq_routing_entry *e;
+	int ret = -EINVAL;
+	int idx;
+
+	trace_kvm_set_irq(irq, level, irq_source_id);
+
+	/*
+	 * Injection into either PIC or IOAPIC might need to scan all CPUs,
+	 * which would need to be retried from thread context;  when same GSI
+	 * is connected to both PIC and IOAPIC, we'd have to report a
+	 * partial failure here.
+	 * Since there's no easy way to do this, we only support injecting MSI
+	 * which is limited to 1:1 GSI mapping.
+	 */
+	idx = srcu_read_lock(&kvm->irq_srcu);
+	if (kvm_irq_map_gsi(kvm, entries, irq) > 0) {
+		e = &entries[0];
+		ret = kvm_arch_set_irq_inatomic(e, kvm, irq_source_id,
+						irq, level);
+	}
+	srcu_read_unlock(&kvm->irq_srcu, idx);
+	return ret;
+}
+
+
 static irqreturn_t kvm_assigned_dev_msi(int irq, void *dev_id)
 {
 	struct kvm_assigned_dev_kernel *assigned_dev = dev_id;