diff options
Diffstat (limited to 'arch/x86/kvm/assigned-dev.c')
| -rw-r--r-- | arch/x86/kvm/assigned-dev.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/arch/x86/kvm/assigned-dev.c b/arch/x86/kvm/assigned-dev.c index 1c17ee80..9dc091a 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; |