At the moment QEMU creates a route for every MSI IRQ.
Now we are about to add IRQFD support on PPC64-pseries platform.
pSeries already has in-kernel emulated interrupt controller with
8192 IRQs. Also, pSeries PHB already supports MSIMessage to IRQ
mapping as a part of PAPR requirements for MSI/MSIX guests.
Specifically, the pSeries guest does not touch MSIMessage's at
all, instead it uses rtas_ibm_change_msi and rtas_ibm_query_interrupt_source
rtas calls to do the mapping.
Therefore we do not really need more routing than we got already.
The patch introduces the infrastructure to enable direct IRQ mapping.
Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
The patch is raw and ugly indeed, I made it only to demonstrate
the idea and see if it has right to live or not.
For some reason which I do not really understand (limited GSI numbers?)
the existing code always adds routing and I do not see why we would need it.
Thanks!
---
hw/misc/vfio.c | 11 +++++++++--
hw/pci/pci.c | 13 +++++++++++++
hw/ppc/spapr_pci.c | 13 +++++++++++++
hw/virtio/virtio-pci.c | 26 ++++++++++++++++++++------
include/hw/pci/pci.h | 4 ++++
include/hw/pci/pci_bus.h | 1 +
6 files changed, 60 insertions(+), 8 deletions(-)
diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
index 14aac04..2d9eef7 100644
--- a/hw/misc/vfio.c
+++ b/hw/misc/vfio.c
@@ -639,7 +639,11 @@ static int vfio_msix_vector_do_use(PCIDevice *pdev,
unsigned int nr,
* Attempt to enable route through KVM irqchip,
* default to userspace handling if unavailable.
*/
- vector->virq = msg ? kvm_irqchip_add_msi_route(kvm_state, *msg) : -1;
+
+ vector->virq = msg ? pci_bus_map_msi(vdev->pdev.bus, *msg) : -1;
+ if (vector->virq < 0) {
+ vector->virq = msg ? kvm_irqchip_add_msi_route(kvm_state, *msg) : -1;
+ }
if (vector->virq < 0 ||
kvm_irqchip_add_irqfd_notifier(kvm_state, &vector->interrupt,
vector->virq) < 0) {
@@ -807,7 +811,10 @@ retry:
* Attempt to enable route through KVM irqchip,
* default to userspace handling if unavailable.
*/
- vector->virq = kvm_irqchip_add_msi_route(kvm_state, msg);
+ vector->virq = pci_bus_map_msi(vdev->pdev.bus, msg);
+ if (vector->virq < 0) {
+ vector->virq = kvm_irqchip_add_msi_route(kvm_state, msg);
+ }
if (vector->virq < 0 ||
kvm_irqchip_add_irqfd_notifier(kvm_state, &vector->interrupt,
vector->virq) < 0) {
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index a976e46..a9875e9 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1254,6 +1254,19 @@ void pci_device_set_intx_routing_notifier(PCIDevice *dev,
dev->intx_routing_notifier = notifier;
}
+void pci_bus_set_map_msi_fn(PCIBus *bus, pci_map_msi_fn map_msi_fn)
+{
+ bus->map_msi = map_msi_fn;
+}
+
+int pci_bus_map_msi(PCIBus *bus, MSIMessage msg)
+{
+ if (bus->map_msi) {
+ return bus->map_msi(bus, msg);
+ }
+ return -1;
+}
+
/*
* PCI-to-PCI bridge specification
* 9.1: Interrupt routing. Table 9-1
diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index 80408c9..9ef9a29 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -500,6 +500,18 @@ static void spapr_msi_write(void *opaque, hwaddr addr,
qemu_irq_pulse(xics_get_qirq(spapr->icp, irq));
}
+static int spapr_msi_get_irq(PCIBus *bus, MSIMessage msg)
+{
+ DeviceState *par = bus->qbus.parent;
+ sPAPRPHBState *sphb = (sPAPRPHBState *) par;
+ unsigned long addr = msg.address - sphb->msi_win_addr;
+ int ndev = addr >> 16;
+ int vec = ((addr & 0xFFFF) >> 2) | msg.data;
+ uint32_t irq = sphb->msi_table[ndev].irq + vec;
+
+ return (int)irq;
+}
+
static const MemoryRegionOps spapr_msi_ops = {
/* There is no .read as the read result is undefined by PCI spec */
.read = NULL,
@@ -664,6 +676,7 @@ static int _spapr_phb_init(SysBusDevice *s)
sphb->lsi_table[i].irq = irq;
}
+ pci_bus_set_map_msi_fn(bus, spapr_msi_get_irq);
return 0;
}
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index d309416..587f53e 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -472,6 +472,8 @@ static unsigned virtio_pci_get_features(DeviceState *d)
return proxy->host_features;
}
+extern int spapr_msi_get_irq(PCIBus *bus, MSIMessage *msg);
+
static int kvm_virtio_pci_vq_vector_use(VirtIOPCIProxy *proxy,
unsigned int queue_no,
unsigned int vector,
@@ -481,7 +483,10 @@ static int kvm_virtio_pci_vq_vector_use(VirtIOPCIProxy
*proxy,
int ret;
if (irqfd->users == 0) {
- ret = kvm_irqchip_add_msi_route(kvm_state, msg);
+ ret = pci_bus_map_msi(proxy->pci_dev.bus, msg);
+ if (ret < 0) {
+ ret = kvm_irqchip_add_msi_route(kvm_state, msg);
+ }
if (ret < 0) {
return ret;
}
@@ -609,14 +614,23 @@ static int virtio_pci_vq_vector_unmask(VirtIOPCIProxy
*proxy,
VirtQueue *vq = virtio_get_queue(proxy->vdev, queue_no);
EventNotifier *n = virtio_queue_get_guest_notifier(vq);
VirtIOIRQFD *irqfd;
- int ret = 0;
+ int ret = 0, tmp;
if (proxy->vector_irqfd) {
irqfd = &proxy->vector_irqfd[vector];
- if (irqfd->msg.data != msg.data || irqfd->msg.address != msg.address) {
- ret = kvm_irqchip_update_msi_route(kvm_state, irqfd->virq, msg);
- if (ret < 0) {
- return ret;
+
+ tmp = pci_bus_map_msi(proxy->pci_dev.bus, msg);
+ if (tmp >= 0) {
+ if (irqfd->virq != tmp) {
+ fprintf(stderr, "FIXME: MSI(-X) vector has changed from %X to
%x\n",
+ irqfd->virq, tmp);
+ }
+ } else {
+ if (irqfd->msg.data != msg.data || irqfd->msg.address !=
msg.address) {
+ ret = kvm_irqchip_update_msi_route(kvm_state, irqfd->virq,
msg);
+ if (ret < 0) {
+ return ret;
+ }
}
}
}
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 8797802..632739a 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -332,6 +332,7 @@ MemoryRegion *pci_address_space_io(PCIDevice *dev);
typedef void (*pci_set_irq_fn)(void *opaque, int irq_num, int level);
typedef int (*pci_map_irq_fn)(PCIDevice *pci_dev, int irq_num);
typedef PCIINTxRoute (*pci_route_irq_fn)(void *opaque, int pin);
+typedef int (*pci_map_msi_fn)(PCIBus *bus, MSIMessage msg);
typedef enum {
PCI_HOTPLUG_DISABLED,
@@ -375,6 +376,9 @@ bool pci_intx_route_changed(PCIINTxRoute *old, PCIINTxRoute
*new);
void pci_bus_fire_intx_routing_notifier(PCIBus *bus);
void pci_device_set_intx_routing_notifier(PCIDevice *dev,
PCIINTxRoutingNotifier notifier);
+void pci_bus_set_map_msi_fn(PCIBus *bus, pci_map_msi_fn map_msi_fn);
+int pci_bus_map_msi(PCIBus *bus, MSIMessage msg);
+
void pci_device_reset(PCIDevice *dev);
void pci_bus_reset(PCIBus *bus);
diff --git a/include/hw/pci/pci_bus.h b/include/hw/pci/pci_bus.h
index 66762f6..81efd2b 100644
--- a/include/hw/pci/pci_bus.h
+++ b/include/hw/pci/pci_bus.h
@@ -16,6 +16,7 @@ struct PCIBus {
pci_set_irq_fn set_irq;
pci_map_irq_fn map_irq;
pci_route_irq_fn route_intx_to_irq;
+ pci_map_msi_fn map_msi;
pci_hotplug_fn hotplug;
DeviceState *hotplug_qdev;
void *irq_opaque;
--
1.7.10.4
