[Qemu-devel] [PATCH 2/3] KVM: add kvm_arch_irqchip_add_msi_route

[Alexey Kardashevskiy <aik@ozlabs.ru>]

At the moment kvm_irqchip_add_msi_route() adds routing entries for every
MSI IRQ we want to use with IRQFD.

However on PPC64-pSeries no routing is required as QEMU is already doing
MSIMessage to IRQ converson. When the guest needs to allocate some
MSI vectors, it asks a hypervisor (QEMU) which returns IRQs and does all
the MSIMessage allocation/initialization in QEMU.

The patch adds callbacks to let a specific platform define how exactly
the routing is configured.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 include/sysemu/kvm.h |    1 +
 kvm-all.c            |    5 +++++
 target-arm/kvm.c     |    6 ++++++
 target-i386/kvm.c    |    6 ++++++
 target-ppc/kvm.c     |   10 ++++++++++
 target-s390x/kvm.c   |    6 ++++++
 6 files changed, 34 insertions(+)

diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index 8b19322..9d5459d 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -215,6 +215,7 @@ int kvm_arch_on_sigbus_vcpu(CPUState *cpu, int code, void *addr);
 int kvm_arch_on_sigbus(int code, void *addr);
 
 void kvm_arch_init_irq_routing(KVMState *s);
+int kvm_arch_irqchip_add_msi_route(KVMState *s, MSIMessage msg);
 
 int kvm_set_irq(KVMState *s, int irq, int level);
 int kvm_irqchip_send_msi(KVMState *s, MSIMessage msg);
diff --git a/kvm-all.c b/kvm-all.c
index 91aa7ff..a92cc04 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1187,6 +1187,11 @@ int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
     struct kvm_irq_routing_entry kroute;
     int virq;
 
+    virq = kvm_arch_irqchip_add_msi_route(s, msg);
+    if (virq >= 0) {
+        return virq;
+    }
+
     if (!kvm_gsi_routing_enabled()) {
         return -ENOSYS;
     }
diff --git a/target-arm/kvm.c b/target-arm/kvm.c
index 7a90d38..1a9bec1 100644
--- a/target-arm/kvm.c
+++ b/target-arm/kvm.c
@@ -22,6 +22,7 @@
 #include "kvm_arm.h"
 #include "cpu.h"
 #include "hw/arm/arm.h"
+#include "hw/pci/msi.h"
 
 const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
     KVM_CAP_LAST_INFO
@@ -497,3 +498,8 @@ void kvm_arch_remove_all_hw_breakpoints(void)
 void kvm_arch_init_irq_routing(KVMState *s)
 {
 }
+
+int kvm_arch_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
+{
+    return -1;
+}
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 7ba98cd..96bb85c 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -33,6 +33,7 @@
 #include "exec/ioport.h"
 #include "hyperv.h"
 #include "hw/pci/pci.h"
+#include "hw/pci/msi.h"
 
 //#define DEBUG_KVM
 
@@ -2207,6 +2208,11 @@ void kvm_arch_init_irq_routing(KVMState *s)
     kvm_gsi_routing_allowed = true;
 }
 
+int kvm_arch_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
+{
+    return -1;
+}
+
 /* Classic KVM device assignment interface. Will remain x86 only. */
 int kvm_device_pci_assign(KVMState *s, PCIHostDeviceAddress *dev_addr,
                           uint32_t flags, uint32_t *dev_id)
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index b60b684..d6da146 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -35,6 +35,7 @@
 #include "hw/sysbus.h"
 #include "hw/ppc/spapr.h"
 #include "hw/ppc/spapr_vio.h"
+#include "hw/pci/msi.h"
 #include "sysemu/watchdog.h"
 
 //#define DEBUG_KVM
@@ -1973,3 +1974,12 @@ int kvm_arch_on_sigbus(int code, void *addr)
 void kvm_arch_init_irq_routing(KVMState *s)
 {
 }
+
+int kvm_arch_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
+{
+    if (!kvm_msi_via_irqfd_allowed)
+        return -1;
+
+    msg.address -= spapr->msi_win_addr;
+    return (msg.address >> 2) + msg.data;
+}
diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
index 4d9ac4a..4fa7a3d 100644
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -36,6 +36,7 @@
 #include "sysemu/device_tree.h"
 #include "qapi/qmp/qjson.h"
 #include "monitor/monitor.h"
+#include "hw/pci/msi.h"
 
 /* #define DEBUG_KVM */
 
@@ -932,3 +933,8 @@ void kvm_s390_enable_css_support(S390CPU *cpu)
 void kvm_arch_init_irq_routing(KVMState *s)
 {
 }
+
+int kvm_arch_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
+{
+    return -1;
+}
-- 
1.7.10.4