From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre Morel Subject: Re: [PATCH v5 14/15] KVM: s390: add and wire function gib_alert_irq_handler() Date: Thu, 3 Jan 2019 16:16:19 +0100 Message-ID: <7dfe72db-97d2-9f33-68f7-acf8ec5ddc5e@linux.ibm.com> References: <20181219191756.57973-1-mimu@linux.ibm.com> <20181219191756.57973-15-mimu@linux.ibm.com> Reply-To: pmorel@linux.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20181219191756.57973-15-mimu@linux.ibm.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Michael Mueller , KVM Mailing List Cc: Linux-S390 Mailing List , linux-kernel@vger.kernel.org, kvm390-list@tuxmaker.boeblingen.de.ibm.com, Martin Schwidefsky , Heiko Carstens , Christian Borntraeger , Janosch Frank , David Hildenbrand , Cornelia Huck , Halil Pasic List-ID: On 19/12/2018 20:17, Michael Mueller wrote: > The patch implements a handler for GIB alert interruptions > on the host. Its task is to alert guests that interrupts are > pending for them. > > A GIB alert interrupt statistic counter is added as well: > > $ cat /proc/interrupts > CPU0 CPU1 > ... > GAL: 23 37 [I/O] GIB Alert > ... > > Signed-off-by: Michael Mueller > --- > arch/s390/include/asm/irq.h | 1 + > arch/s390/include/asm/isc.h | 1 + > arch/s390/kernel/irq.c | 1 + > arch/s390/kvm/interrupt.c | 36 ++++++++++++++++++++++++++++++++++-- > 4 files changed, 37 insertions(+), 2 deletions(-) > > diff --git a/arch/s390/include/asm/irq.h b/arch/s390/include/asm/irq.h > index 2f7f27e5493f..afaf5e3c57fd 100644 > --- a/arch/s390/include/asm/irq.h > +++ b/arch/s390/include/asm/irq.h > @@ -62,6 +62,7 @@ enum interruption_class { > IRQIO_MSI, > IRQIO_VIR, > IRQIO_VAI, > + IRQIO_GAL, > NMI_NMI, > CPU_RST, > NR_ARCH_IRQS > diff --git a/arch/s390/include/asm/isc.h b/arch/s390/include/asm/isc.h > index 6cb9e2ed05b6..b2cc1ec78d06 100644 > --- a/arch/s390/include/asm/isc.h > +++ b/arch/s390/include/asm/isc.h > @@ -21,6 +21,7 @@ > /* Adapter interrupts. */ > #define QDIO_AIRQ_ISC IO_SCH_ISC /* I/O subchannel in qdio mode */ > #define PCI_ISC 2 /* PCI I/O subchannels */ > +#define GAL_ISC 5 /* GIB alert */ > #define AP_ISC 6 /* adjunct processor (crypto) devices */ > > /* Functions for registration of I/O interruption subclasses */ > diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c > index 0e8d68bac82c..0cd5a5f96729 100644 > --- a/arch/s390/kernel/irq.c > +++ b/arch/s390/kernel/irq.c > @@ -88,6 +88,7 @@ static const struct irq_class irqclass_sub_desc[] = { > {.irq = IRQIO_MSI, .name = "MSI", .desc = "[I/O] MSI Interrupt" }, > {.irq = IRQIO_VIR, .name = "VIR", .desc = "[I/O] Virtual I/O Devices"}, > {.irq = IRQIO_VAI, .name = "VAI", .desc = "[I/O] Virtual I/O Devices AI"}, > + {.irq = IRQIO_GAL, .name = "GAL", .desc = "[I/O] GIB Alert"}, > {.irq = NMI_NMI, .name = "NMI", .desc = "[NMI] Machine Check"}, > {.irq = CPU_RST, .name = "RST", .desc = "[CPU] CPU Restart"}, > }; > diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c > index 03e7ba4f215a..79b9c262479b 100644 > --- a/arch/s390/kvm/interrupt.c > +++ b/arch/s390/kvm/interrupt.c > @@ -26,6 +26,7 @@ > #include > #include > #include > +#include > #include "kvm-s390.h" > #include "gaccess.h" > #include "trace-s390.h" > @@ -3043,7 +3044,7 @@ static void __floating_airqs_kick(struct kvm *kvm) > #define NONE_GISA_ADDR 0x00000001UL > #define GISA_ADDR_MASK 0xfffff000UL > > -static void __maybe_unused process_gib_alert_list(void) > +static void process_gib_alert_list(void) > { > u32 final, next_alert, origin = 0UL; > struct kvm_s390_gisa *gisa; > @@ -3091,7 +3092,10 @@ void kvm_s390_gisa_clear(struct kvm *kvm) > { > if (!kvm->arch.gisa) > return; > + if (set_iam(kvm->arch.gisa, 0) == -EBUSY) > + process_gib_alert_list(); We call process_gib_alert_list() from different contexts shouldn't we protect the calls? > nullify_gisa(kvm->arch.gisa); > + set_iam(kvm->arch.gisa, kvm->arch.iam); > VM_EVENT(kvm, 3, "gisa 0x%pK cleared", kvm->arch.gisa); > } > > @@ -3111,6 +3115,8 @@ void kvm_s390_gisa_destroy(struct kvm *kvm) > { > if (!kvm->arch.gisa) > return; > + if (set_iam(kvm->arch.gisa, 0) == -EBUSY) > + process_gib_alert_list(); idem. > kvm->arch.gisa = NULL; > } > > @@ -3159,11 +3165,23 @@ int kvm_s390_gisc_unregister(struct kvm *kvm, u32 gisc) > } > EXPORT_SYMBOL_GPL(kvm_s390_gisc_unregister); > > +static void gib_alert_irq_handler(struct airq_struct *airq) > +{ > + inc_irq_stat(IRQIO_GAL); > + process_gib_alert_list(); idem. > +} > + > +static struct airq_struct gib_alert_irq = { > + .handler = gib_alert_irq_handler, > + .lsi_ptr = &gib_alert_irq.lsi_mask, > +}; > + > void kvm_s390_gib_destroy(void) > { > if (!gib) > return; > chsc_sgib(0); > + unregister_adapter_interrupt(&gib_alert_irq); > free_page((unsigned long)gib); > gib = NULL; > } > @@ -3183,16 +3201,30 @@ int kvm_s390_gib_init(u8 nisc) > goto out; > } > > + gib_alert_irq.isc = nisc; > + if (register_adapter_interrupt(&gib_alert_irq)) { > + pr_err("Registering the GIB alert interruption handler failed\n"); > + rc = -EIO; > + goto out_free; > + } > + > gib->nisc = nisc; > if (chsc_sgib((u32)(u64)gib)) { > pr_err("Associating the GIB with the AIV facility failed\n"); > free_page((unsigned long)gib); > gib = NULL; > rc = -EIO; > - goto out; > + goto out_unreg; > } > > KVM_EVENT(3, "gib 0x%pK (nisc=%d) initialized", gib, gib->nisc); > + goto out; > + > +out_unreg: > + unregister_adapter_interrupt(&gib_alert_irq); > +out_free: > + free_page((unsigned long)gib); > + gib = NULL; > out: > return rc; > } > -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany