kvm irqfd: support direct msimessage to irq translation

On PPC64 systems MSI Messages are translated to system IRQ in a PCI
host bridge. This is already supported for emulated MSI/MSIX but
not for irqfd where the current QEMU allocates IRQ numbers from
irqchip and maps MSIMessages to IRQ in the host kernel.

This adds a new direct mapping flag which tells
the kvm_irqchip_add_msi_route() function that a new VIRQ
should not be allocated, instead the value from MSIMessage::data
should be used. It is up to the platform code to make sure that
this contains a valid IRQ number as sPAPR does in spapr_pci.c.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Alexey Kardashevskiy 2013-09-03 18:08:25 +10:00 committed by Paolo Bonzini
parent 0e5035776d
commit 76fe21deda
3 changed files with 23 additions and 0 deletions

View file

@ -111,6 +111,7 @@ bool kvm_halt_in_kernel_allowed;
bool kvm_irqfds_allowed;
bool kvm_msi_via_irqfd_allowed;
bool kvm_gsi_routing_allowed;
bool kvm_gsi_direct_mapping;
bool kvm_allowed;
bool kvm_readonly_mem_allowed;
@ -1069,6 +1070,10 @@ void kvm_irqchip_release_virq(KVMState *s, int virq)
struct kvm_irq_routing_entry *e;
int i;
if (kvm_gsi_direct_mapping()) {
return;
}
for (i = 0; i < s->irq_routes->nr; i++) {
e = &s->irq_routes->entries[i];
if (e->gsi == virq) {
@ -1190,6 +1195,10 @@ int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
struct kvm_irq_routing_entry kroute = {};
int virq;
if (kvm_gsi_direct_mapping()) {
return msg.data & 0xffff;
}
if (!kvm_gsi_routing_enabled()) {
return -ENOSYS;
}
@ -1216,6 +1225,10 @@ int kvm_irqchip_update_msi_route(KVMState *s, int virq, MSIMessage msg)
{
struct kvm_irq_routing_entry kroute = {};
if (kvm_gsi_direct_mapping()) {
return 0;
}
if (!kvm_irqchip_in_kernel()) {
return -ENOSYS;
}