diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_xics.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_xics.c | 1270 |
1 files changed, 1270 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_xics.c b/arch/powerpc/kvm/book3s_xics.c new file mode 100644 index 00000000000..f7a10375661 --- /dev/null +++ b/arch/powerpc/kvm/book3s_xics.c @@ -0,0 +1,1270 @@ +/* + * Copyright 2012 Michael Ellerman, IBM Corporation. + * Copyright 2012 Benjamin Herrenschmidt, IBM Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/kvm_host.h> +#include <linux/err.h> +#include <linux/gfp.h> +#include <linux/anon_inodes.h> + +#include <asm/uaccess.h> +#include <asm/kvm_book3s.h> +#include <asm/kvm_ppc.h> +#include <asm/hvcall.h> +#include <asm/xics.h> +#include <asm/debug.h> + +#include <linux/debugfs.h> +#include <linux/seq_file.h> + +#include "book3s_xics.h" + +#if 1 +#define XICS_DBG(fmt...) do { } while (0) +#else +#define XICS_DBG(fmt...) trace_printk(fmt) +#endif + +#define ENABLE_REALMODE true +#define DEBUG_REALMODE false + +/* + * LOCKING + * ======= + * + * Each ICS has a mutex protecting the information about the IRQ + * sources and avoiding simultaneous deliveries if the same interrupt. + * + * ICP operations are done via a single compare & swap transaction + * (most ICP state fits in the union kvmppc_icp_state) + */ + +/* + * TODO + * ==== + * + * - To speed up resends, keep a bitmap of "resend" set bits in the + * ICS + * + * - Speed up server# -> ICP lookup (array ? hash table ?) + * + * - Make ICS lockless as well, or at least a per-interrupt lock or hashed + * locks array to improve scalability + */ + +/* -- ICS routines -- */ + +static void icp_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp, + u32 new_irq); + +static int ics_deliver_irq(struct kvmppc_xics *xics, u32 irq, u32 level, + bool report_status) +{ + struct ics_irq_state *state; + struct kvmppc_ics *ics; + u16 src; + + XICS_DBG("ics deliver %#x (level: %d)\n", irq, level); + + ics = kvmppc_xics_find_ics(xics, irq, &src); + if (!ics) { + XICS_DBG("ics_deliver_irq: IRQ 0x%06x not found !\n", irq); + return -EINVAL; + } + state = &ics->irq_state[src]; + if (!state->exists) + return -EINVAL; + + if (report_status) + return state->asserted; + + /* + * We set state->asserted locklessly. This should be fine as + * we are the only setter, thus concurrent access is undefined + * to begin with. + */ + if (level == KVM_INTERRUPT_SET_LEVEL) + state->asserted = 1; + else if (level == KVM_INTERRUPT_UNSET) { + state->asserted = 0; + return 0; + } + + /* Attempt delivery */ + icp_deliver_irq(xics, NULL, irq); + + return state->asserted; +} + +static void ics_check_resend(struct kvmppc_xics *xics, struct kvmppc_ics *ics, + struct kvmppc_icp *icp) +{ + int i; + + mutex_lock(&ics->lock); + + for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) { + struct ics_irq_state *state = &ics->irq_state[i]; + + if (!state->resend) + continue; + + XICS_DBG("resend %#x prio %#x\n", state->number, + state->priority); + + mutex_unlock(&ics->lock); + icp_deliver_irq(xics, icp, state->number); + mutex_lock(&ics->lock); + } + + mutex_unlock(&ics->lock); +} + +static bool write_xive(struct kvmppc_xics *xics, struct kvmppc_ics *ics, + struct ics_irq_state *state, + u32 server, u32 priority, u32 saved_priority) +{ + bool deliver; + + mutex_lock(&ics->lock); + + state->server = server; + state->priority = priority; + state->saved_priority = saved_priority; + deliver = false; + if ((state->masked_pending || state->resend) && priority != MASKED) { + state->masked_pending = 0; + deliver = true; + } + + mutex_unlock(&ics->lock); + + return deliver; +} + +int kvmppc_xics_set_xive(struct kvm *kvm, u32 irq, u32 server, u32 priority) +{ + struct kvmppc_xics *xics = kvm->arch.xics; + struct kvmppc_icp *icp; + struct kvmppc_ics *ics; + struct ics_irq_state *state; + u16 src; + + if (!xics) + return -ENODEV; + + ics = kvmppc_xics_find_ics(xics, irq, &src); + if (!ics) + return -EINVAL; + state = &ics->irq_state[src]; + + icp = kvmppc_xics_find_server(kvm, server); + if (!icp) + return -EINVAL; + + XICS_DBG("set_xive %#x server %#x prio %#x MP:%d RS:%d\n", + irq, server, priority, + state->masked_pending, state->resend); + + if (write_xive(xics, ics, state, server, priority, priority)) + icp_deliver_irq(xics, icp, irq); + + return 0; +} + +int kvmppc_xics_get_xive(struct kvm *kvm, u32 irq, u32 *server, u32 *priority) +{ + struct kvmppc_xics *xics = kvm->arch.xics; + struct kvmppc_ics *ics; + struct ics_irq_state *state; + u16 src; + + if (!xics) + return -ENODEV; + + ics = kvmppc_xics_find_ics(xics, irq, &src); + if (!ics) + return -EINVAL; + state = &ics->irq_state[src]; + + mutex_lock(&ics->lock); + *server = state->server; + *priority = state->priority; + mutex_unlock(&ics->lock); + + return 0; +} + +int kvmppc_xics_int_on(struct kvm *kvm, u32 irq) +{ + struct kvmppc_xics *xics = kvm->arch.xics; + struct kvmppc_icp *icp; + struct kvmppc_ics *ics; + struct ics_irq_state *state; + u16 src; + + if (!xics) + return -ENODEV; + + ics = kvmppc_xics_find_ics(xics, irq, &src); + if (!ics) + return -EINVAL; + state = &ics->irq_state[src]; + + icp = kvmppc_xics_find_server(kvm, state->server); + if (!icp) + return -EINVAL; + + if (write_xive(xics, ics, state, state->server, state->saved_priority, + state->saved_priority)) + icp_deliver_irq(xics, icp, irq); + + return 0; +} + +int kvmppc_xics_int_off(struct kvm *kvm, u32 irq) +{ + struct kvmppc_xics *xics = kvm->arch.xics; + struct kvmppc_ics *ics; + struct ics_irq_state *state; + u16 src; + + if (!xics) + return -ENODEV; + + ics = kvmppc_xics_find_ics(xics, irq, &src); + if (!ics) + return -EINVAL; + state = &ics->irq_state[src]; + + write_xive(xics, ics, state, state->server, MASKED, state->priority); + + return 0; +} + +/* -- ICP routines, including hcalls -- */ + +static inline bool icp_try_update(struct kvmppc_icp *icp, + union kvmppc_icp_state old, + union kvmppc_icp_state new, + bool change_self) +{ + bool success; + + /* Calculate new output value */ + new.out_ee = (new.xisr && (new.pending_pri < new.cppr)); + + /* Attempt atomic update */ + success = cmpxchg64(&icp->state.raw, old.raw, new.raw) == old.raw; + if (!success) + goto bail; + + XICS_DBG("UPD [%04x] - C:%02x M:%02x PP: %02x PI:%06x R:%d O:%d\n", + icp->server_num, + old.cppr, old.mfrr, old.pending_pri, old.xisr, + old.need_resend, old.out_ee); + XICS_DBG("UPD - C:%02x M:%02x PP: %02x PI:%06x R:%d O:%d\n", + new.cppr, new.mfrr, new.pending_pri, new.xisr, + new.need_resend, new.out_ee); + /* + * Check for output state update + * + * Note that this is racy since another processor could be updating + * the state already. This is why we never clear the interrupt output + * here, we only ever set it. The clear only happens prior to doing + * an update and only by the processor itself. Currently we do it + * in Accept (H_XIRR) and Up_Cppr (H_XPPR). + * + * We also do not try to figure out whether the EE state has changed, + * we unconditionally set it if the new state calls for it. The reason + * for that is that we opportunistically remove the pending interrupt + * flag when raising CPPR, so we need to set it back here if an + * interrupt is still pending. + */ + if (new.out_ee) { + kvmppc_book3s_queue_irqprio(icp->vcpu, + BOOK3S_INTERRUPT_EXTERNAL_LEVEL); + if (!change_self) + kvmppc_fast_vcpu_kick(icp->vcpu); + } + bail: + return success; +} + +static void icp_check_resend(struct kvmppc_xics *xics, + struct kvmppc_icp *icp) +{ + u32 icsid; + + /* Order this load with the test for need_resend in the caller */ + smp_rmb(); + for_each_set_bit(icsid, icp->resend_map, xics->max_icsid + 1) { + struct kvmppc_ics *ics = xics->ics[icsid]; + + if (!test_and_clear_bit(icsid, icp->resend_map)) + continue; + if (!ics) + continue; + ics_check_resend(xics, ics, icp); + } +} + +static bool icp_try_to_deliver(struct kvmppc_icp *icp, u32 irq, u8 priority, + u32 *reject) +{ + union kvmppc_icp_state old_state, new_state; + bool success; + + XICS_DBG("try deliver %#x(P:%#x) to server %#x\n", irq, priority, + icp->server_num); + + do { + old_state = new_state = ACCESS_ONCE(icp->state); + + *reject = 0; + + /* See if we can deliver */ + success = new_state.cppr > priority && + new_state.mfrr > priority && + new_state.pending_pri > priority; + + /* + * If we can, check for a rejection and perform the + * delivery + */ + if (success) { + *reject = new_state.xisr; + new_state.xisr = irq; + new_state.pending_pri = priority; + } else { + /* + * If we failed to deliver we set need_resend + * so a subsequent CPPR state change causes us + * to try a new delivery. + */ + new_state.need_resend = true; + } + + } while (!icp_try_update(icp, old_state, new_state, false)); + + return success; +} + +static void icp_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp, + u32 new_irq) +{ + struct ics_irq_state *state; + struct kvmppc_ics *ics; + u32 reject; + u16 src; + + /* + * This is used both for initial delivery of an interrupt and + * for subsequent rejection. + * + * Rejection can be racy vs. resends. We have evaluated the + * rejection in an atomic ICP transaction which is now complete, + * so potentially the ICP can already accept the interrupt again. + * + * So we need to retry the delivery. Essentially the reject path + * boils down to a failed delivery. Always. + * + * Now the interrupt could also have moved to a different target, + * thus we may need to re-do the ICP lookup as well + */ + + again: + /* Get the ICS state and lock it */ + ics = kvmppc_xics_find_ics(xics, new_irq, &src); + if (!ics) { + XICS_DBG("icp_deliver_irq: IRQ 0x%06x not found !\n", new_irq); + return; + } + state = &ics->irq_state[src]; + + /* Get a lock on the ICS */ + mutex_lock(&ics->lock); + + /* Get our server */ + if (!icp || state->server != icp->server_num) { + icp = kvmppc_xics_find_server(xics->kvm, state->server); + if (!icp) { + pr_warn("icp_deliver_irq: IRQ 0x%06x server 0x%x not found !\n", + new_irq, state->server); + goto out; + } + } + + /* Clear the resend bit of that interrupt */ + state->resend = 0; + + /* + * If masked, bail out + * + * Note: PAPR doesn't mention anything about masked pending + * when doing a resend, only when doing a delivery. + * + * However that would have the effect of losing a masked + * interrupt that was rejected and isn't consistent with + * the whole masked_pending business which is about not + * losing interrupts that occur while masked. + * + * I don't differenciate normal deliveries and resends, this + * implementation will differ from PAPR and not lose such + * interrupts. + */ + if (state->priority == MASKED) { + XICS_DBG("irq %#x masked pending\n", new_irq); + state->masked_pending = 1; + goto out; + } + + /* + * Try the delivery, this will set the need_resend flag + * in the ICP as part of the atomic transaction if the + * delivery is not possible. + * + * Note that if successful, the new delivery might have itself + * rejected an interrupt that was "delivered" before we took the + * icp mutex. + * + * In this case we do the whole sequence all over again for the + * new guy. We cannot assume that the rejected interrupt is less + * favored than the new one, and thus doesn't need to be delivered, + * because by the time we exit icp_try_to_deliver() the target + * processor may well have alrady consumed & completed it, and thus + * the rejected interrupt might actually be already acceptable. + */ + if (icp_try_to_deliver(icp, new_irq, state->priority, &reject)) { + /* + * Delivery was successful, did we reject somebody else ? + */ + if (reject && reject != XICS_IPI) { + mutex_unlock(&ics->lock); + new_irq = reject; + goto again; + } + } else { + /* + * We failed to deliver the interrupt we need to set the + * resend map bit and mark the ICS state as needing a resend + */ + set_bit(ics->icsid, icp->resend_map); + state->resend = 1; + + /* + * If the need_resend flag got cleared in the ICP some time + * between icp_try_to_deliver() atomic update and now, then + * we know it might have missed the resend_map bit. So we + * retry + */ + smp_mb(); + if (!icp->state.need_resend) { + mutex_unlock(&ics->lock); + goto again; + } + } + out: + mutex_unlock(&ics->lock); +} + +static void icp_down_cppr(struct kvmppc_xics *xics, struct kvmppc_icp *icp, + u8 new_cppr) +{ + union kvmppc_icp_state old_state, new_state; + bool resend; + + /* + * This handles several related states in one operation: + * + * ICP State: Down_CPPR + * + * Load CPPR with new value and if the XISR is 0 + * then check for resends: + * + * ICP State: Resend + * + * If MFRR is more favored than CPPR, check for IPIs + * and notify ICS of a potential resend. This is done + * asynchronously (when used in real mode, we will have + * to exit here). + * + * We do not handle the complete Check_IPI as documented + * here. In the PAPR, this state will be used for both + * Set_MFRR and Down_CPPR. However, we know that we aren't + * changing the MFRR state here so we don't need to handle + * the case of an MFRR causing a reject of a pending irq, + * this will have been handled when the MFRR was set in the + * first place. + * + * Thus we don't have to handle rejects, only resends. + * + * When implementing real mode for HV KVM, resend will lead to + * a H_TOO_HARD return and the whole transaction will be handled + * in virtual mode. + */ + do { + old_state = new_state = ACCESS_ONCE(icp->state); + + /* Down_CPPR */ + new_state.cppr = new_cppr; + + /* + * Cut down Resend / Check_IPI / IPI + * + * The logic is that we cannot have a pending interrupt + * trumped by an IPI at this point (see above), so we + * know that either the pending interrupt is already an + * IPI (in which case we don't care to override it) or + * it's either more favored than us or non existent + */ + if (new_state.mfrr < new_cppr && + new_state.mfrr <= new_state.pending_pri) { + WARN_ON(new_state.xisr != XICS_IPI && + new_state.xisr != 0); + new_state.pending_pri = new_state.mfrr; + new_state.xisr = XICS_IPI; + } + + /* Latch/clear resend bit */ + resend = new_state.need_resend; + new_state.need_resend = 0; + + } while (!icp_try_update(icp, old_state, new_state, true)); + + /* + * Now handle resend checks. Those are asynchronous to the ICP + * state update in HW (ie bus transactions) so we can handle them + * separately here too + */ + if (resend) + icp_check_resend(xics, icp); +} + +static noinline unsigned long kvmppc_h_xirr(struct kvm_vcpu *vcpu) +{ + union kvmppc_icp_state old_state, new_state; + struct kvmppc_icp *icp = vcpu->arch.icp; + u32 xirr; + + /* First, remove EE from the processor */ + kvmppc_book3s_dequeue_irqprio(icp->vcpu, + BOOK3S_INTERRUPT_EXTERNAL_LEVEL); + + /* + * ICP State: Accept_Interrupt + * + * Return the pending interrupt (if any) along with the + * current CPPR, then clear the XISR & set CPPR to the + * pending priority + */ + do { + old_state = new_state = ACCESS_ONCE(icp->state); + + xirr = old_state.xisr | (((u32)old_state.cppr) << 24); + if (!old_state.xisr) + break; + new_state.cppr = new_state.pending_pri; + new_state.pending_pri = 0xff; + new_state.xisr = 0; + + } while (!icp_try_update(icp, old_state, new_state, true)); + + XICS_DBG("h_xirr vcpu %d xirr %#x\n", vcpu->vcpu_id, xirr); + + return xirr; +} + +static noinline int kvmppc_h_ipi(struct kvm_vcpu *vcpu, unsigned long server, + unsigned long mfrr) +{ + union kvmppc_icp_state old_state, new_state; + struct kvmppc_xics *xics = vcpu->kvm->arch.xics; + struct kvmppc_icp *icp; + u32 reject; + bool resend; + bool local; + + XICS_DBG("h_ipi vcpu %d to server %lu mfrr %#lx\n", + vcpu->vcpu_id, server, mfrr); + + icp = vcpu->arch.icp; + local = icp->server_num == server; + if (!local) { + icp = kvmppc_xics_find_server(vcpu->kvm, server); + if (!icp) + return H_PARAMETER; + } + + /* + * ICP state: Set_MFRR + * + * If the CPPR is more favored than the new MFRR, then + * nothing needs to be rejected as there can be no XISR to + * reject. If the MFRR is being made less favored then + * there might be a previously-rejected interrupt needing + * to be resent. + * + * If the CPPR is less favored, then we might be replacing + * an interrupt, and thus need to possibly reject it as in + * + * ICP state: Check_IPI + */ + do { + old_state = new_state = ACCESS_ONCE(icp->state); + + /* Set_MFRR */ + new_state.mfrr = mfrr; + + /* Check_IPI */ + reject = 0; + resend = false; + if (mfrr < new_state.cppr) { + /* Reject a pending interrupt if not an IPI */ + if (mfrr <= new_state.pending_pri) + reject = new_state.xisr; + new_state.pending_pri = mfrr; + new_state.xisr = XICS_IPI; + } + + if (mfrr > old_state.mfrr && mfrr > new_state.cppr) { + resend = new_state.need_resend; + new_state.need_resend = 0; + } + } while (!icp_try_update(icp, old_state, new_state, local)); + + /* Handle reject */ + if (reject && reject != XICS_IPI) + icp_deliver_irq(xics, icp, reject); + + /* Handle resend */ + if (resend) + icp_check_resend(xics, icp); + + return H_SUCCESS; +} + +static noinline void kvmppc_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr) +{ + union kvmppc_icp_state old_state, new_state; + struct kvmppc_xics *xics = vcpu->kvm->arch.xics; + struct kvmppc_icp *icp = vcpu->arch.icp; + u32 reject; + + XICS_DBG("h_cppr vcpu %d cppr %#lx\n", vcpu->vcpu_id, cppr); + + /* + * ICP State: Set_CPPR + * + * We can safely compare the new value with the current + * value outside of the transaction as the CPPR is only + * ever changed by the processor on itself + */ + if (cppr > icp->state.cppr) + icp_down_cppr(xics, icp, cppr); + else if (cppr == icp->state.cppr) + return; + + /* + * ICP State: Up_CPPR + * + * The processor is raising its priority, this can result + * in a rejection of a pending interrupt: + * + * ICP State: Reject_Current + * + * We can remove EE from the current processor, the update + * transaction will set it again if needed + */ + kvmppc_book3s_dequeue_irqprio(icp->vcpu, + BOOK3S_INTERRUPT_EXTERNAL_LEVEL); + + do { + old_state = new_state = ACCESS_ONCE(icp->state); + + reject = 0; + new_state.cppr = cppr; + + if (cppr <= new_state.pending_pri) { + reject = new_state.xisr; + new_state.xisr = 0; + new_state.pending_pri = 0xff; + } + + } while (!icp_try_update(icp, old_state, new_state, true)); + + /* + * Check for rejects. They are handled by doing a new delivery + * attempt (see comments in icp_deliver_irq). + */ + if (reject && reject != XICS_IPI) + icp_deliver_irq(xics, icp, reject); +} + +static noinline int kvmppc_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr) +{ + struct kvmppc_xics *xics = vcpu->kvm->arch.xics; + struct kvmppc_icp *icp = vcpu->arch.icp; + struct kvmppc_ics *ics; + struct ics_irq_state *state; + u32 irq = xirr & 0x00ffffff; + u16 src; + + XICS_DBG("h_eoi vcpu %d eoi %#lx\n", vcpu->vcpu_id, xirr); + + /* + * ICP State: EOI + * + * Note: If EOI is incorrectly used by SW to lower the CPPR + * value (ie more favored), we do not check for rejection of + * a pending interrupt, this is a SW error and PAPR sepcifies + * that we don't have to deal with it. + * + * The sending of an EOI to the ICS is handled after the + * CPPR update + * + * ICP State: Down_CPPR which we handle + * in a separate function as it's shared with H_CPPR. + */ + icp_down_cppr(xics, icp, xirr >> 24); + + /* IPIs have no EOI */ + if (irq == XICS_IPI) + return H_SUCCESS; + /* + * EOI handling: If the interrupt is still asserted, we need to + * resend it. We can take a lockless "peek" at the ICS state here. + * + * "Message" interrupts will never have "asserted" set + */ + ics = kvmppc_xics_find_ics(xics, irq, &src); + if (!ics) { + XICS_DBG("h_eoi: IRQ 0x%06x not found !\n", irq); + return H_PARAMETER; + } + state = &ics->irq_state[src]; + + /* Still asserted, resend it */ + if (state->asserted) + icp_deliver_irq(xics, icp, irq); + + return H_SUCCESS; +} + +static noinline int kvmppc_xics_rm_complete(struct kvm_vcpu *vcpu, u32 hcall) +{ + struct kvmppc_xics *xics = vcpu->kvm->arch.xics; + struct kvmppc_icp *icp = vcpu->arch.icp; + + XICS_DBG("XICS_RM: H_%x completing, act: %x state: %lx tgt: %p\n", + hcall, icp->rm_action, icp->rm_dbgstate.raw, icp->rm_dbgtgt); + + if (icp->rm_action & XICS_RM_KICK_VCPU) + kvmppc_fast_vcpu_kick(icp->rm_kick_target); + if (icp->rm_action & XICS_RM_CHECK_RESEND) + icp_check_resend(xics, icp); + if (icp->rm_action & XICS_RM_REJECT) + icp_deliver_irq(xics, icp, icp->rm_reject); + + icp->rm_action = 0; + + return H_SUCCESS; +} + +int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 req) +{ + struct kvmppc_xics *xics = vcpu->kvm->arch.xics; + unsigned long res; + int rc = H_SUCCESS; + + /* Check if we have an ICP */ + if (!xics || !vcpu->arch.icp) + return H_HARDWARE; + + /* Check for real mode returning too hard */ + if (xics->real_mode) + return kvmppc_xics_rm_complete(vcpu, req); + + switch (req) { + case H_XIRR: + res = kvmppc_h_xirr(vcpu); + kvmppc_set_gpr(vcpu, 4, res); + break; + case H_CPPR: + kvmppc_h_cppr(vcpu, kvmppc_get_gpr(vcpu, 4)); + break; + case H_EOI: + rc = kvmppc_h_eoi(vcpu, kvmppc_get_gpr(vcpu, 4)); + break; + case H_IPI: + rc = kvmppc_h_ipi(vcpu, kvmppc_get_gpr(vcpu, 4), + kvmppc_get_gpr(vcpu, 5)); + break; + } + + return rc; +} + + +/* -- Initialisation code etc. -- */ + +static int xics_debug_show(struct seq_file *m, void *private) +{ + struct kvmppc_xics *xics = m->private; + struct kvm *kvm = xics->kvm; + struct kvm_vcpu *vcpu; + int icsid, i; + + if (!kvm) + return 0; + + seq_printf(m, "=========\nICP state\n=========\n"); + + kvm_for_each_vcpu(i, vcpu, kvm) { + struct kvmppc_icp *icp = vcpu->arch.icp; + union kvmppc_icp_state state; + + if (!icp) + continue; + + state.raw = ACCESS_ONCE(icp->state.raw); + seq_printf(m, "cpu server %#lx XIRR:%#x PPRI:%#x CPPR:%#x MFRR:%#x OUT:%d NR:%d\n", + icp->server_num, state.xisr, + state.pending_pri, state.cppr, state.mfrr, + state.out_ee, state.need_resend); + } + + for (icsid = 0; icsid <= KVMPPC_XICS_MAX_ICS_ID; icsid++) { + struct kvmppc_ics *ics = xics->ics[icsid]; + + if (!ics) + continue; + + seq_printf(m, "=========\nICS state for ICS 0x%x\n=========\n", + icsid); + + mutex_lock(&ics->lock); + + for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) { + struct ics_irq_state *irq = &ics->irq_state[i]; + + seq_printf(m, "irq 0x%06x: server %#x prio %#x save prio %#x asserted %d resend %d masked pending %d\n", + irq->number, irq->server, irq->priority, + irq->saved_priority, irq->asserted, + irq->resend, irq->masked_pending); + + } + mutex_unlock(&ics->lock); + } + return 0; +} + +static int xics_debug_open(struct inode *inode, struct file *file) +{ + return single_open(file, xics_debug_show, inode->i_private); +} + +static const struct file_operations xics_debug_fops = { + .open = xics_debug_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static void xics_debugfs_init(struct kvmppc_xics *xics) +{ + char *name; + + name = kasprintf(GFP_KERNEL, "kvm-xics-%p", xics); + if (!name) { + pr_err("%s: no memory for name\n", __func__); + return; + } + + xics->dentry = debugfs_create_file(name, S_IRUGO, powerpc_debugfs_root, + xics, &xics_debug_fops); + + pr_debug("%s: created %s\n", __func__, name); + kfree(name); +} + +static struct kvmppc_ics *kvmppc_xics_create_ics(struct kvm *kvm, + struct kvmppc_xics *xics, int irq) +{ + struct kvmppc_ics *ics; + int i, icsid; + + icsid = irq >> KVMPPC_XICS_ICS_SHIFT; + + mutex_lock(&kvm->lock); + + /* ICS already exists - somebody else got here first */ + if (xics->ics[icsid]) + goto out; + + /* Create the ICS */ + ics = kzalloc(sizeof(struct kvmppc_ics), GFP_KERNEL); + if (!ics) + goto out; + + mutex_init(&ics->lock); + ics->icsid = icsid; + + for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) { + ics->irq_state[i].number = (icsid << KVMPPC_XICS_ICS_SHIFT) | i; + ics->irq_state[i].priority = MASKED; + ics->irq_state[i].saved_priority = MASKED; + } + smp_wmb(); + xics->ics[icsid] = ics; + + if (icsid > xics->max_icsid) + xics->max_icsid = icsid; + + out: + mutex_unlock(&kvm->lock); + return xics->ics[icsid]; +} + +int kvmppc_xics_create_icp(struct kvm_vcpu *vcpu, unsigned long server_num) +{ + struct kvmppc_icp *icp; + + if (!vcpu->kvm->arch.xics) + return -ENODEV; + + if (kvmppc_xics_find_server(vcpu->kvm, server_num)) + return -EEXIST; + + icp = kzalloc(sizeof(struct kvmppc_icp), GFP_KERNEL); + if (!icp) + return -ENOMEM; + + icp->vcpu = vcpu; + icp->server_num = server_num; + icp->state.mfrr = MASKED; + icp->state.pending_pri = MASKED; + vcpu->arch.icp = icp; + + XICS_DBG("created server for vcpu %d\n", vcpu->vcpu_id); + + return 0; +} + +u64 kvmppc_xics_get_icp(struct kvm_vcpu *vcpu) +{ + struct kvmppc_icp *icp = vcpu->arch.icp; + union kvmppc_icp_state state; + + if (!icp) + return 0; + state = icp->state; + return ((u64)state.cppr << KVM_REG_PPC_ICP_CPPR_SHIFT) | + ((u64)state.xisr << KVM_REG_PPC_ICP_XISR_SHIFT) | + ((u64)state.mfrr << KVM_REG_PPC_ICP_MFRR_SHIFT) | + ((u64)state.pending_pri << KVM_REG_PPC_ICP_PPRI_SHIFT); +} + +int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval) +{ + struct kvmppc_icp *icp = vcpu->arch.icp; + struct kvmppc_xics *xics = vcpu->kvm->arch.xics; + union kvmppc_icp_state old_state, new_state; + struct kvmppc_ics *ics; + u8 cppr, mfrr, pending_pri; + u32 xisr; + u16 src; + bool resend; + + if (!icp || !xics) + return -ENOENT; + + cppr = icpval >> KVM_REG_PPC_ICP_CPPR_SHIFT; + xisr = (icpval >> KVM_REG_PPC_ICP_XISR_SHIFT) & + KVM_REG_PPC_ICP_XISR_MASK; + mfrr = icpval >> KVM_REG_PPC_ICP_MFRR_SHIFT; + pending_pri = icpval >> KVM_REG_PPC_ICP_PPRI_SHIFT; + + /* Require the new state to be internally consistent */ + if (xisr == 0) { + if (pending_pri != 0xff) + return -EINVAL; + } else if (xisr == XICS_IPI) { + if (pending_pri != mfrr || pending_pri >= cppr) + return -EINVAL; + } else { + if (pending_pri >= mfrr || pending_pri >= cppr) + return -EINVAL; + ics = kvmppc_xics_find_ics(xics, xisr, &src); + if (!ics) + return -EINVAL; + } + + new_state.raw = 0; + new_state.cppr = cppr; + new_state.xisr = xisr; + new_state.mfrr = mfrr; + new_state.pending_pri = pending_pri; + + /* + * Deassert the CPU interrupt request. + * icp_try_update will reassert it if necessary. + */ + kvmppc_book3s_dequeue_irqprio(icp->vcpu, + BOOK3S_INTERRUPT_EXTERNAL_LEVEL); + + /* + * Note that if we displace an interrupt from old_state.xisr, + * we don't mark it as rejected. We expect userspace to set + * the state of the interrupt sources to be consistent with + * the ICP states (either before or afterwards, which doesn't + * matter). We do handle resends due to CPPR becoming less + * favoured because that is necessary to end up with a + * consistent state in the situation where userspace restores + * the ICS states before the ICP states. + */ + do { + old_state = ACCESS_ONCE(icp->state); + + if (new_state.mfrr <= old_state.mfrr) { + resend = false; + new_state.need_resend = old_state.need_resend; + } else { + resend = old_state.need_resend; + new_state.need_resend = 0; + } + } while (!icp_try_update(icp, old_state, new_state, false)); + + if (resend) + icp_check_resend(xics, icp); + + return 0; +} + +static int xics_get_source(struct kvmppc_xics *xics, long irq, u64 addr) +{ + int ret; + struct kvmppc_ics *ics; + struct ics_irq_state *irqp; + u64 __user *ubufp = (u64 __user *) addr; + u16 idx; + u64 val, prio; + + ics = kvmppc_xics_find_ics(xics, irq, &idx); + if (!ics) + return -ENOENT; + + irqp = &ics->irq_state[idx]; + mutex_lock(&ics->lock); + ret = -ENOENT; + if (irqp->exists) { + val = irqp->server; + prio = irqp->priority; + if (prio == MASKED) { + val |= KVM_XICS_MASKED; + prio = irqp->saved_priority; + } + val |= prio << KVM_XICS_PRIORITY_SHIFT; + if (irqp->asserted) + val |= KVM_XICS_LEVEL_SENSITIVE | KVM_XICS_PENDING; + else if (irqp->masked_pending || irqp->resend) + val |= KVM_XICS_PENDING; + ret = 0; + } + mutex_unlock(&ics->lock); + + if (!ret && put_user(val, ubufp)) + ret = -EFAULT; + + return ret; +} + +static int xics_set_source(struct kvmppc_xics *xics, long irq, u64 addr) +{ + struct kvmppc_ics *ics; + struct ics_irq_state *irqp; + u64 __user *ubufp = (u64 __user *) addr; + u16 idx; + u64 val; + u8 prio; + u32 server; + + if (irq < KVMPPC_XICS_FIRST_IRQ || irq >= KVMPPC_XICS_NR_IRQS) + return -ENOENT; + + ics = kvmppc_xics_find_ics(xics, irq, &idx); + if (!ics) { + ics = kvmppc_xics_create_ics(xics->kvm, xics, irq); + if (!ics) + return -ENOMEM; + } + irqp = &ics->irq_state[idx]; + if (get_user(val, ubufp)) + return -EFAULT; + + server = val & KVM_XICS_DESTINATION_MASK; + prio = val >> KVM_XICS_PRIORITY_SHIFT; + if (prio != MASKED && + kvmppc_xics_find_server(xics->kvm, server) == NULL) + return -EINVAL; + + mutex_lock(&ics->lock); + irqp->server = server; + irqp->saved_priority = prio; + if (val & KVM_XICS_MASKED) + prio = MASKED; + irqp->priority = prio; + irqp->resend = 0; + irqp->masked_pending = 0; + irqp->asserted = 0; + if ((val & KVM_XICS_PENDING) && (val & KVM_XICS_LEVEL_SENSITIVE)) + irqp->asserted = 1; + irqp->exists = 1; + mutex_unlock(&ics->lock); + + if (val & KVM_XICS_PENDING) + icp_deliver_irq(xics, NULL, irqp->number); + + return 0; +} + +int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level, + bool line_status) +{ + struct kvmppc_xics *xics = kvm->arch.xics; + + return ics_deliver_irq(xics, irq, level, line_status); +} + +static int xics_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr) +{ + struct kvmppc_xics *xics = dev->private; + + switch (attr->group) { + case KVM_DEV_XICS_GRP_SOURCES: + return xics_set_source(xics, attr->attr, attr->addr); + } + return -ENXIO; +} + +static int xics_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr) +{ + struct kvmppc_xics *xics = dev->private; + + switch (attr->group) { + case KVM_DEV_XICS_GRP_SOURCES: + return xics_get_source(xics, attr->attr, attr->addr); + } + return -ENXIO; +} + +static int xics_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr) +{ + switch (attr->group) { + case KVM_DEV_XICS_GRP_SOURCES: + if (attr->attr >= KVMPPC_XICS_FIRST_IRQ && + attr->attr < KVMPPC_XICS_NR_IRQS) + return 0; + break; + } + return -ENXIO; +} + +static void kvmppc_xics_free(struct kvm_device *dev) +{ + struct kvmppc_xics *xics = dev->private; + int i; + struct kvm *kvm = xics->kvm; + + debugfs_remove(xics->dentry); + + if (kvm) + kvm->arch.xics = NULL; + + for (i = 0; i <= xics->max_icsid; i++) + kfree(xics->ics[i]); + kfree(xics); + kfree(dev); +} + +static int kvmppc_xics_create(struct kvm_device *dev, u32 type) +{ + struct kvmppc_xics *xics; + struct kvm *kvm = dev->kvm; + int ret = 0; + + xics = kzalloc(sizeof(*xics), GFP_KERNEL); + if (!xics) + return -ENOMEM; + + dev->private = xics; + xics->dev = dev; + xics->kvm = kvm; + + /* Already there ? */ + mutex_lock(&kvm->lock); + if (kvm->arch.xics) + ret = -EEXIST; + else + kvm->arch.xics = xics; + mutex_unlock(&kvm->lock); + + if (ret) + return ret; + + xics_debugfs_init(xics); + +#ifdef CONFIG_KVM_BOOK3S_64_HV + if (cpu_has_feature(CPU_FTR_ARCH_206)) { + /* Enable real mode support */ + xics->real_mode = ENABLE_REALMODE; + xics->real_mode_dbg = DEBUG_REALMODE; + } +#endif /* CONFIG_KVM_BOOK3S_64_HV */ + + return 0; +} + +struct kvm_device_ops kvm_xics_ops = { + .name = "kvm-xics", + .create = kvmppc_xics_create, + .destroy = kvmppc_xics_free, + .set_attr = xics_set_attr, + .get_attr = xics_get_attr, + .has_attr = xics_has_attr, +}; + +int kvmppc_xics_connect_vcpu(struct kvm_device *dev, struct kvm_vcpu *vcpu, + u32 xcpu) +{ + struct kvmppc_xics *xics = dev->private; + int r = -EBUSY; + + if (dev->ops != &kvm_xics_ops) + return -EPERM; + if (xics->kvm != vcpu->kvm) + return -EPERM; + if (vcpu->arch.irq_type) + return -EBUSY; + + r = kvmppc_xics_create_icp(vcpu, xcpu); + if (!r) + vcpu->arch.irq_type = KVMPPC_IRQ_XICS; + + return r; +} + +void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu) +{ + if (!vcpu->arch.icp) + return; + kfree(vcpu->arch.icp); + vcpu->arch.icp = NULL; + vcpu->arch.irq_type = KVMPPC_IRQ_DEFAULT; +} |