From patchwork Fri Sep 21 10:01:32 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Mackerras X-Patchwork-Id: 10609587 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 094A4112B for ; Fri, 21 Sep 2018 10:02:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EE9162D876 for ; Fri, 21 Sep 2018 10:02:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E2D7C2D879; Fri, 21 Sep 2018 10:02:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 17F332D885 for ; Fri, 21 Sep 2018 10:02:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389603AbeIUPua (ORCPT ); Fri, 21 Sep 2018 11:50:30 -0400 Received: from ozlabs.org ([203.11.71.1]:43697 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727697AbeIUPua (ORCPT ); Fri, 21 Sep 2018 11:50:30 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPSA id 42Gpzt3ptZz9sBq; Fri, 21 Sep 2018 20:02:18 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ozlabs.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ozlabs.org; s=201707; t=1537524138; bh=s0PLv8bGTu9J+nvM4yDMDNSIuD76JtGvmVPoyqyu08M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QzZK2Ih8Dxue7cHbDayKh0AgCP4H9YavkI6MFbCn3k9zUNXFM94YSQJtBrAMH8l1b BSsIHFyuuPU8ja5OntEEcq+bAg2duWhfgM2HQpxphJzCdBl3h3xSHusKO6b59BBiw8 GdnFVnL0fGtxJLQjHrr2sEujfpikvad0sMkXoMAD/kjKo4IujHuQFJRxbVLdrExFgE WHR0yoK6eOM2YRea4BuyWeXvS+ujkRVnCx/aO4zGJyjd/jD+u9nfABD8zDzKT4E1n4 Z+l4ktFlD/K3Te55nJN29UqgMKSUN+pIUTntBTCWAXke8edRILAb2kVwZFWTUN9/eO hv/CnRJHABqeA== From: Paul Mackerras To: kvm-ppc@vger.kernel.org, kvm@vger.kernel.org Cc: David Gibson Subject: [RFC PATCH 01/32] KVM: PPC: Book3S: Simplify external interrupt handling Date: Fri, 21 Sep 2018 20:01:32 +1000 Message-Id: <1537524123-9578-2-git-send-email-paulus@ozlabs.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1537524123-9578-1-git-send-email-paulus@ozlabs.org> References: <1537524123-9578-1-git-send-email-paulus@ozlabs.org> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently we use two bits in the vcpu pending_exceptions bitmap to indicate that an external interrupt is pending for the guest, one for "one-shot" interrupts that are cleared when delivered, and one for interrupts that persist until cleared by an explicit action of the OS (e.g. an acknowledge to an interrupt controller). The BOOK3S_IRQPRIO_EXTERNAL bit is used for one-shot interrupt requests and BOOK3S_IRQPRIO_EXTERNAL_LEVEL is used for persisting interrupts. In practice BOOK3S_IRQPRIO_EXTERNAL never gets used, because our Book3S platforms generally, and pseries in particular, expect external interrupt requests to persist until they are acknowledged at the interrupt controller. That combined with the confusion introduced by having two bits for what is essentially the same thing makes it attractive to simplify things by only using one bit. This patch does that. With this patch there is only BOOK3S_IRQPRIO_EXTERNAL, and by default it has the semantics of a persisting interrupt. In order to avoid breaking the ABI, we introduce a new "external_oneshot" flag which preserves the behaviour of the KVM_INTERRUPT ioctl with the KVM_INTERRUPT_SET argument. Signed-off-by: Paul Mackerras Reviewed-by: David Gibson --- arch/powerpc/include/asm/kvm_asm.h | 4 +-- arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/kvm/book3s.c | 43 ++++++++++++++++++++------ arch/powerpc/kvm/book3s_hv_rm_xics.c | 5 ++- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 4 +-- arch/powerpc/kvm/book3s_pr.c | 1 - arch/powerpc/kvm/book3s_xics.c | 11 +++---- arch/powerpc/kvm/book3s_xive_template.c | 2 +- arch/powerpc/kvm/trace_book3s.h | 1 - tools/perf/arch/powerpc/util/book3s_hv_exits.h | 1 - 10 files changed, 44 insertions(+), 29 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_asm.h b/arch/powerpc/include/asm/kvm_asm.h index a790d5c..1f32191 100644 --- a/arch/powerpc/include/asm/kvm_asm.h +++ b/arch/powerpc/include/asm/kvm_asm.h @@ -84,7 +84,6 @@ #define BOOK3S_INTERRUPT_INST_STORAGE 0x400 #define BOOK3S_INTERRUPT_INST_SEGMENT 0x480 #define BOOK3S_INTERRUPT_EXTERNAL 0x500 -#define BOOK3S_INTERRUPT_EXTERNAL_LEVEL 0x501 #define BOOK3S_INTERRUPT_EXTERNAL_HV 0x502 #define BOOK3S_INTERRUPT_ALIGNMENT 0x600 #define BOOK3S_INTERRUPT_PROGRAM 0x700 @@ -134,8 +133,7 @@ #define BOOK3S_IRQPRIO_EXTERNAL 14 #define BOOK3S_IRQPRIO_DECREMENTER 15 #define BOOK3S_IRQPRIO_PERFORMANCE_MONITOR 16 -#define BOOK3S_IRQPRIO_EXTERNAL_LEVEL 17 -#define BOOK3S_IRQPRIO_MAX 18 +#define BOOK3S_IRQPRIO_MAX 17 #define BOOK3S_HFLAG_DCBZ32 0x1 #define BOOK3S_HFLAG_SLB 0x2 diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 906bcbdf..3cd0b9f 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -707,6 +707,7 @@ struct kvm_vcpu_arch { u8 hcall_needed; u8 epr_flags; /* KVMPPC_EPR_xxx */ u8 epr_needed; + u8 external_oneshot; /* clear external irq after delivery */ u32 cpr0_cfgaddr; /* holds the last set cpr0_cfgaddr */ diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index 87348e4..66a5521 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -150,7 +150,6 @@ static int kvmppc_book3s_vec2irqprio(unsigned int vec) case 0x400: prio = BOOK3S_IRQPRIO_INST_STORAGE; break; case 0x480: prio = BOOK3S_IRQPRIO_INST_SEGMENT; break; case 0x500: prio = BOOK3S_IRQPRIO_EXTERNAL; break; - case 0x501: prio = BOOK3S_IRQPRIO_EXTERNAL_LEVEL; break; case 0x600: prio = BOOK3S_IRQPRIO_ALIGNMENT; break; case 0x700: prio = BOOK3S_IRQPRIO_PROGRAM; break; case 0x800: prio = BOOK3S_IRQPRIO_FP_UNAVAIL; break; @@ -236,18 +235,35 @@ EXPORT_SYMBOL_GPL(kvmppc_core_dequeue_dec); void kvmppc_core_queue_external(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq) { - unsigned int vec = BOOK3S_INTERRUPT_EXTERNAL; - - if (irq->irq == KVM_INTERRUPT_SET_LEVEL) - vec = BOOK3S_INTERRUPT_EXTERNAL_LEVEL; + /* + * This case (KVM_INTERRUPT_SET) should never actually arise for + * a pseries guest (because pseries guests expect their interrupt + * controllers to continue asserting an external interrupt request + * until it is acknowledged at the interrupt controller), but is + * included to avoid ABI breakage and potentially for other + * sorts of guest. + * + * There is a subtlety here: HV KVM does not test the + * external_oneshot flag in the code that synthesizes + * external interrupts for the guest just before entering + * the guest. That is OK even if userspace did do a + * KVM_INTERRUPT_SET on a pseries guest vcpu, because the + * caller (kvm_vcpu_ioctl_interrupt) does a kvm_vcpu_kick() + * which ends up doing a smp_send_reschedule(), which will + * pull the guest all the way out to the host, meaning that + * we will call kvmppc_core_prepare_to_enter() before entering + * the guest again, and that will handle the external_oneshot + * flag correctly. + */ + if (irq->irq == KVM_INTERRUPT_SET) + vcpu->arch.external_oneshot = 1; - kvmppc_book3s_queue_irqprio(vcpu, vec); + kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_EXTERNAL); } void kvmppc_core_dequeue_external(struct kvm_vcpu *vcpu) { kvmppc_book3s_dequeue_irqprio(vcpu, BOOK3S_INTERRUPT_EXTERNAL); - kvmppc_book3s_dequeue_irqprio(vcpu, BOOK3S_INTERRUPT_EXTERNAL_LEVEL); } void kvmppc_core_queue_data_storage(struct kvm_vcpu *vcpu, ulong dar, @@ -278,7 +294,6 @@ static int kvmppc_book3s_irqprio_deliver(struct kvm_vcpu *vcpu, vec = BOOK3S_INTERRUPT_DECREMENTER; break; case BOOK3S_IRQPRIO_EXTERNAL: - case BOOK3S_IRQPRIO_EXTERNAL_LEVEL: deliver = (kvmppc_get_msr(vcpu) & MSR_EE) && !crit; vec = BOOK3S_INTERRUPT_EXTERNAL; break; @@ -352,8 +367,16 @@ static bool clear_irqprio(struct kvm_vcpu *vcpu, unsigned int priority) case BOOK3S_IRQPRIO_DECREMENTER: /* DEC interrupts get cleared by mtdec */ return false; - case BOOK3S_IRQPRIO_EXTERNAL_LEVEL: - /* External interrupts get cleared by userspace */ + case BOOK3S_IRQPRIO_EXTERNAL: + /* + * External interrupts get cleared by userspace + * except when set by the KVM_INTERRUPT ioctl with + * KVM_INTERRUPT_SET (not KVM_INTERRUPT_SET_LEVEL). + */ + if (vcpu->arch.external_oneshot) { + vcpu->arch.external_oneshot = 0; + return true; + } return false; } diff --git a/arch/powerpc/kvm/book3s_hv_rm_xics.c b/arch/powerpc/kvm/book3s_hv_rm_xics.c index 758d1d2..8b9f356 100644 --- a/arch/powerpc/kvm/book3s_hv_rm_xics.c +++ b/arch/powerpc/kvm/book3s_hv_rm_xics.c @@ -136,7 +136,7 @@ static void icp_rm_set_vcpu_irq(struct kvm_vcpu *vcpu, /* Mark the target VCPU as having an interrupt pending */ vcpu->stat.queue_intr++; - set_bit(BOOK3S_IRQPRIO_EXTERNAL_LEVEL, &vcpu->arch.pending_exceptions); + set_bit(BOOK3S_IRQPRIO_EXTERNAL, &vcpu->arch.pending_exceptions); /* Kick self ? Just set MER and return */ if (vcpu == this_vcpu) { @@ -170,8 +170,7 @@ static void icp_rm_set_vcpu_irq(struct kvm_vcpu *vcpu, static void icp_rm_clr_vcpu_irq(struct kvm_vcpu *vcpu) { /* Note: Only called on self ! */ - clear_bit(BOOK3S_IRQPRIO_EXTERNAL_LEVEL, - &vcpu->arch.pending_exceptions); + clear_bit(BOOK3S_IRQPRIO_EXTERNAL, &vcpu->arch.pending_exceptions); mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~LPCR_MER); } diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 1d14046..77960e6 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -1122,11 +1122,11 @@ kvmppc_cede_reentry: /* r4 = vcpu, r13 = paca */ /* Check if we can deliver an external or decrementer interrupt now */ ld r0, VCPU_PENDING_EXC(r4) - rldicl r0, r0, 64 - BOOK3S_IRQPRIO_EXTERNAL_LEVEL, 63 + rldicl r0, r0, 64 - BOOK3S_IRQPRIO_EXTERNAL, 63 cmpdi cr1, r0, 0 andi. r8, r11, MSR_EE mfspr r8, SPRN_LPCR - /* Insert EXTERNAL_LEVEL bit into LPCR at the MER bit position */ + /* Insert EXTERNAL bit into LPCR at the MER bit position */ rldimi r8, r0, LPCR_MER_SH, 63 - LPCR_MER_SH mtspr SPRN_LPCR, r8 isync diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index 614ebb4..059683e4 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -1246,7 +1246,6 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu, r = RESUME_GUEST; break; case BOOK3S_INTERRUPT_EXTERNAL: - case BOOK3S_INTERRUPT_EXTERNAL_LEVEL: case BOOK3S_INTERRUPT_EXTERNAL_HV: case BOOK3S_INTERRUPT_H_VIRT: vcpu->stat.ext_intr_exits++; diff --git a/arch/powerpc/kvm/book3s_xics.c b/arch/powerpc/kvm/book3s_xics.c index b8356cd..d9ba1b0 100644 --- a/arch/powerpc/kvm/book3s_xics.c +++ b/arch/powerpc/kvm/book3s_xics.c @@ -310,7 +310,7 @@ static inline bool icp_try_update(struct kvmppc_icp *icp, */ if (new.out_ee) { kvmppc_book3s_queue_irqprio(icp->vcpu, - BOOK3S_INTERRUPT_EXTERNAL_LEVEL); + BOOK3S_INTERRUPT_EXTERNAL); if (!change_self) kvmppc_fast_vcpu_kick(icp->vcpu); } @@ -593,8 +593,7 @@ static noinline unsigned long kvmppc_h_xirr(struct kvm_vcpu *vcpu) u32 xirr; /* First, remove EE from the processor */ - kvmppc_book3s_dequeue_irqprio(icp->vcpu, - BOOK3S_INTERRUPT_EXTERNAL_LEVEL); + kvmppc_book3s_dequeue_irqprio(icp->vcpu, BOOK3S_INTERRUPT_EXTERNAL); /* * ICP State: Accept_Interrupt @@ -754,8 +753,7 @@ static noinline void kvmppc_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr) * 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); + kvmppc_book3s_dequeue_irqprio(icp->vcpu, BOOK3S_INTERRUPT_EXTERNAL); do { old_state = new_state = READ_ONCE(icp->state); @@ -1167,8 +1165,7 @@ int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval) * Deassert the CPU interrupt request. * icp_try_update will reassert it if necessary. */ - kvmppc_book3s_dequeue_irqprio(icp->vcpu, - BOOK3S_INTERRUPT_EXTERNAL_LEVEL); + kvmppc_book3s_dequeue_irqprio(icp->vcpu, BOOK3S_INTERRUPT_EXTERNAL); /* * Note that if we displace an interrupt from old_state.xisr, diff --git a/arch/powerpc/kvm/book3s_xive_template.c b/arch/powerpc/kvm/book3s_xive_template.c index 4171ede..203ea65 100644 --- a/arch/powerpc/kvm/book3s_xive_template.c +++ b/arch/powerpc/kvm/book3s_xive_template.c @@ -285,7 +285,7 @@ X_STATIC unsigned long GLUE(X_PFX,h_xirr)(struct kvm_vcpu *vcpu) * set by pull or an escalation interrupts). */ if (test_bit(BOOK3S_IRQPRIO_EXTERNAL, &vcpu->arch.pending_exceptions)) - clear_bit(BOOK3S_IRQPRIO_EXTERNAL_LEVEL, + clear_bit(BOOK3S_IRQPRIO_EXTERNAL, &vcpu->arch.pending_exceptions); pr_devel(" new pending=0x%02x hw_cppr=%d cppr=%d\n", diff --git a/arch/powerpc/kvm/trace_book3s.h b/arch/powerpc/kvm/trace_book3s.h index f3b2375..372a82f 100644 --- a/arch/powerpc/kvm/trace_book3s.h +++ b/arch/powerpc/kvm/trace_book3s.h @@ -14,7 +14,6 @@ {0x400, "INST_STORAGE"}, \ {0x480, "INST_SEGMENT"}, \ {0x500, "EXTERNAL"}, \ - {0x501, "EXTERNAL_LEVEL"}, \ {0x502, "EXTERNAL_HV"}, \ {0x600, "ALIGNMENT"}, \ {0x700, "PROGRAM"}, \ diff --git a/tools/perf/arch/powerpc/util/book3s_hv_exits.h b/tools/perf/arch/powerpc/util/book3s_hv_exits.h index 853b95d1..2011376 100644 --- a/tools/perf/arch/powerpc/util/book3s_hv_exits.h +++ b/tools/perf/arch/powerpc/util/book3s_hv_exits.h @@ -15,7 +15,6 @@ {0x400, "INST_STORAGE"}, \ {0x480, "INST_SEGMENT"}, \ {0x500, "EXTERNAL"}, \ - {0x501, "EXTERNAL_LEVEL"}, \ {0x502, "EXTERNAL_HV"}, \ {0x600, "ALIGNMENT"}, \ {0x700, "PROGRAM"}, \