diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv_builtin.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_builtin.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c index 5f0380db3eab..0c84d6bc8356 100644 --- a/arch/powerpc/kvm/book3s_hv_builtin.c +++ b/arch/powerpc/kvm/book3s_hv_builtin.c @@ -25,6 +25,7 @@ #include <asm/xics.h> #include <asm/dbell.h> #include <asm/cputhreads.h> +#include <asm/io.h> #define KVM_CMA_CHUNK_ORDER 18 @@ -286,3 +287,158 @@ void kvmhv_commence_exit(int trap) struct kvmppc_host_rm_ops *kvmppc_host_rm_ops_hv; EXPORT_SYMBOL_GPL(kvmppc_host_rm_ops_hv); + +#ifdef CONFIG_KVM_XICS +static struct kvmppc_irq_map *get_irqmap(struct kvmppc_passthru_irqmap *pimap, + u32 xisr) +{ + int i; + + /* + * We access the mapped array here without a lock. That + * is safe because we never reduce the number of entries + * in the array and we never change the v_hwirq field of + * an entry once it is set. + * + * We have also carefully ordered the stores in the writer + * and the loads here in the reader, so that if we find a matching + * hwirq here, the associated GSI and irq_desc fields are valid. + */ + for (i = 0; i < pimap->n_mapped; i++) { + if (xisr == pimap->mapped[i].r_hwirq) { + /* + * Order subsequent reads in the caller to serialize + * with the writer. + */ + smp_rmb(); + return &pimap->mapped[i]; + } + } + return NULL; +} + +/* + * If we have an interrupt that's not an IPI, check if we have a + * passthrough adapter and if so, check if this external interrupt + * is for the adapter. + * We will attempt to deliver the IRQ directly to the target VCPU's + * ICP, the virtual ICP (based on affinity - the xive value in ICS). + * + * If the delivery fails or if this is not for a passthrough adapter, + * return to the host to handle this interrupt. We earlier + * saved a copy of the XIRR in the PACA, it will be picked up by + * the host ICP driver. + */ +static int kvmppc_check_passthru(u32 xisr, __be32 xirr) +{ + struct kvmppc_passthru_irqmap *pimap; + struct kvmppc_irq_map *irq_map; + struct kvm_vcpu *vcpu; + + vcpu = local_paca->kvm_hstate.kvm_vcpu; + if (!vcpu) + return 1; + pimap = kvmppc_get_passthru_irqmap(vcpu->kvm); + if (!pimap) + return 1; + irq_map = get_irqmap(pimap, xisr); + if (!irq_map) + return 1; + + /* We're handling this interrupt, generic code doesn't need to */ + local_paca->kvm_hstate.saved_xirr = 0; + + return kvmppc_deliver_irq_passthru(vcpu, xirr, irq_map, pimap); +} + +#else +static inline int kvmppc_check_passthru(u32 xisr, __be32 xirr) +{ + return 1; +} +#endif + +/* + * Determine what sort of external interrupt is pending (if any). + * Returns: + * 0 if no interrupt is pending + * 1 if an interrupt is pending that needs to be handled by the host + * 2 Passthrough that needs completion in the host + * -1 if there was a guest wakeup IPI (which has now been cleared) + * -2 if there is PCI passthrough external interrupt that was handled + */ + +long kvmppc_read_intr(void) +{ + unsigned long xics_phys; + u32 h_xirr; + __be32 xirr; + u32 xisr; + u8 host_ipi; + + /* see if a host IPI is pending */ + host_ipi = local_paca->kvm_hstate.host_ipi; + if (host_ipi) + return 1; + + /* Now read the interrupt from the ICP */ + xics_phys = local_paca->kvm_hstate.xics_phys; + if (unlikely(!xics_phys)) + return 1; + + /* + * Save XIRR for later. Since we get control in reverse endian + * on LE systems, save it byte reversed and fetch it back in + * host endian. Note that xirr is the value read from the + * XIRR register, while h_xirr is the host endian version. + */ + xirr = _lwzcix(xics_phys + XICS_XIRR); + h_xirr = be32_to_cpu(xirr); + local_paca->kvm_hstate.saved_xirr = h_xirr; + xisr = h_xirr & 0xffffff; + /* + * Ensure that the store/load complete to guarantee all side + * effects of loading from XIRR has completed + */ + smp_mb(); + + /* if nothing pending in the ICP */ + if (!xisr) + return 0; + + /* We found something in the ICP... + * + * If it is an IPI, clear the MFRR and EOI it. + */ + if (xisr == XICS_IPI) { + _stbcix(xics_phys + XICS_MFRR, 0xff); + _stwcix(xics_phys + XICS_XIRR, xirr); + /* + * Need to ensure side effects of above stores + * complete before proceeding. + */ + smp_mb(); + + /* + * We need to re-check host IPI now in case it got set in the + * meantime. If it's clear, we bounce the interrupt to the + * guest + */ + host_ipi = local_paca->kvm_hstate.host_ipi; + if (unlikely(host_ipi != 0)) { + /* We raced with the host, + * we need to resend that IPI, bummer + */ + _stbcix(xics_phys + XICS_MFRR, IPI_PRIORITY); + /* Let side effects complete */ + smp_mb(); + return 1; + } + + /* OK, it's an IPI for us */ + local_paca->kvm_hstate.saved_xirr = 0; + return -1; + } + + return kvmppc_check_passthru(xisr, xirr); +} |