[Qemu-devel] [PATCH] kvm: x86: Fix kvm_arch_fixup_msi_route for remap-less case

[Jan Kiszka]

The AMD IOMMU does not (yet) support interrupt remapping. But
kvm_arch_fixup_msi_route assumes that all implementations do and crashes
when the AMD IOMMU is used in KVM mode.

Fixes: 8b5ed7dffa1f ("intel_iommu: add support for split irqchip")
Reported-by: Christopher Goldsworthy <christopher.goldswor...@outlook.com>
Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
---
 target/i386/kvm.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index 9313602d3d..1fe3a73a10 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -3677,6 +3677,10 @@ int kvm_arch_fixup_msi_route(struct 
kvm_irq_routing_entry *route,
         MSIMessage src, dst;
         X86IOMMUClass *class = X86_IOMMU_GET_CLASS(iommu);
 
+        if (!class->int_remap) {
+            return 0;
+        }
+
         src.address = route->u.msi.address_hi;
         src.address <<= VTD_MSI_ADDR_HI_SHIFT;
         src.address |= route->u.msi.address_lo;
-- 
2.16.4