On Mon, Dec 11, 2023 at 12:52:40AM +0800, Jiqian Chen wrote: > In PVH dom0, it uses the linux local interrupt mechanism, > when it allocs irq for a gsi, it is dynamic, and follow > the principle of applying first, distributing first. And > the irq number is alloced from small to large, but the > applying gsi number is not, may gsi 38 comes before gsi > 28, that causes the irq number is not equal with the gsi > number. And when passthrough a device, qemu wants to use > gsi to map pirq, xen_pt_realize->xc_physdev_map_pirq, but > the gsi number is got from file > /sys/bus/pci/devices/<sbdf>/irq in current code, so it > will fail when mapping. > > Use real gsi number read from gsi sysfs. > > Co-developed-by: Huang Rui <ray.hu...@amd.com> > Signed-off-by: Jiqian Chen <jiqian.c...@amd.com> > --- > hw/xen/xen-host-pci-device.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/xen/xen-host-pci-device.c b/hw/xen/xen-host-pci-device.c > index 8c6e9a1716..e270ac2631 100644 > --- a/hw/xen/xen-host-pci-device.c > +++ b/hw/xen/xen-host-pci-device.c > @@ -364,7 +364,7 @@ void xen_host_pci_device_get(XenHostPCIDevice *d, > uint16_t domain, > } > d->device_id = v; > > - xen_host_pci_get_dec_value(d, "irq", &v, errp); > + xen_host_pci_get_dec_value(d, "gsi", &v, errp);
Don't you need to fallthrough to use the irq number on failure? Otherwise passthrough won't work on older Linux versions that don't expose the gsi node. Thanks, Roger.
