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89911501f3
There are three cases which we need to care about, PV guest, PV domain 0 and HVM guest. The PV guest case is simple since it has no access to ACPI or real APICs and therefore has no GSIs therefore we simply dynamically allocate all IRQs. The potentially interesting case here is PIRQ type event channels associated with passed through PCI devices. However even in this case the guest has no direct interaction with the physical GSI since that happens in the PCI backend. The PV domain 0 and HVM guest cases are actually the same. In domain 0 case the kernel sees the host ACPI and GSIs (although it only sees the APIC indirectly via the hypervisor) and in the HVM guest case it sees the virtualised ACPI and emulated APICs. In these cases we start allocating dynamic IRQs at nr_irqs_gsi so that they cannot clash with any GSI. Currently xen_allocate_irq_dynamic starts at nr_irqs and works backwards looking for a free IRQ in order to (try and) avoid clashing with GSIs used in domain 0 and in HVM guests. This change avoids that although we retain the behaviour of allowing dynamic IRQs to encroach on the GSI range if no suitable IRQs are available since a future IRQ clash is deemed preferable to failure right now. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> |
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| .. | ||
| xenbus | ||
| xenfs | ||
| balloon.c | ||
| biomerge.c | ||
| cpu_hotplug.c | ||
| events.c | ||
| evtchn.c | ||
| features.c | ||
| gntdev.c | ||
| grant-table.c | ||
| Kconfig | ||
| Makefile | ||
| manage.c | ||
| pci.c | ||
| platform-pci.c | ||
| swiotlb-xen.c | ||
| sys-hypervisor.c | ||
| xencomm.c | ||