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e3c13e56a4
Currently, KVM switches back to the host to handle any external interrupt (when the interrupt is received while running in the guest). This patch updates real-mode KVM to check if an interrupt is generated by a passthrough adapter that is owned by this guest. If so, the real mode KVM will directly inject the corresponding virtual interrupt to the guest VCPU's ICS and also EOI the interrupt in hardware. In short, the interrupt is handled entirely in real mode in the guest context without switching back to the host. In some rare cases, the interrupt cannot be completely handled in real mode, for instance, a VCPU that is sleeping needs to be woken up. In this case, KVM simply switches back to the host with trap reason set to 0x500. This works, but it is clearly not very efficient. A following patch will distinguish this case and handle it correctly in the host. Note that we can use the existing check_too_hard() routine even though we are not in a hypercall to determine if there is unfinished business that needs to be completed in host virtual mode. The patch assumes that the mapping between hardware interrupt IRQ and virtual IRQ to be injected to the guest already exists for the PCI passthrough interrupts that need to be handled in real mode. If the mapping does not exist, KVM falls back to the default existing behavior. The KVM real mode code reads mappings from the mapped array in the passthrough IRQ map without taking any lock. We carefully order the loads and stores of the fields in the kvmppc_irq_map data structure using memory barriers to avoid an inconsistent mapping being seen by the reader. Thus, although it is possible to miss a map entry, it is not possible to read a stale value. [paulus@ozlabs.org - get irq_chip from irq_map rather than pimap, pulled out powernv eoi change into a separate patch, made kvmppc_read_intr get the vcpu from the paca rather than being passed in, rewrote the logic at the end of kvmppc_read_intr to avoid deep indentation, simplified logic in book3s_hv_rmhandlers.S since we were always restoring SRR0/1 anyway, get rid of the cached array (just use the mapped array), removed the kick_all_cpus_sync() call, clear saved_xirr PACA field when we handle the interrupt in real mode, fix compilation with CONFIG_KVM_XICS=n.] Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> |
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| .. | ||
| book3s_32_mmu_host.c | ||
| book3s_32_mmu.c | ||
| book3s_32_sr.S | ||
| book3s_64_mmu_host.c | ||
| book3s_64_mmu_hv.c | ||
| book3s_64_mmu.c | ||
| book3s_64_slb.S | ||
| book3s_64_vio_hv.c | ||
| book3s_64_vio.c | ||
| book3s_emulate.c | ||
| book3s_exports.c | ||
| book3s_hv_builtin.c | ||
| book3s_hv_hmi.c | ||
| book3s_hv_interrupts.S | ||
| book3s_hv_ras.c | ||
| book3s_hv_rm_mmu.c | ||
| book3s_hv_rm_xics.c | ||
| book3s_hv_rmhandlers.S | ||
| book3s_hv.c | ||
| book3s_interrupts.S | ||
| book3s_mmu_hpte.c | ||
| book3s_paired_singles.c | ||
| book3s_pr_papr.c | ||
| book3s_pr.c | ||
| book3s_rmhandlers.S | ||
| book3s_rtas.c | ||
| book3s_segment.S | ||
| book3s_xics.c | ||
| book3s_xics.h | ||
| book3s.c | ||
| book3s.h | ||
| booke_emulate.c | ||
| booke_interrupts.S | ||
| booke.c | ||
| booke.h | ||
| bookehv_interrupts.S | ||
| e500_emulate.c | ||
| e500_mmu_host.c | ||
| e500_mmu_host.h | ||
| e500_mmu.c | ||
| e500.c | ||
| e500.h | ||
| e500mc.c | ||
| emulate_loadstore.c | ||
| emulate.c | ||
| fpu.S | ||
| irq.h | ||
| Kconfig | ||
| Makefile | ||
| mpic.c | ||
| powerpc.c | ||
| timing.c | ||
| timing.h | ||
| trace_book3s.h | ||
| trace_booke.h | ||
| trace_hv.h | ||
| trace_pr.h | ||
| trace.h | ||