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Re: [Qemu-devel] [PATCH v2 2/2] KVM: s390: add floating irq controller
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From: |
Christian Borntraeger |
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Subject: |
Re: [Qemu-devel] [PATCH v2 2/2] KVM: s390: add floating irq controller |
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Date: |
Fri, 06 Sep 2013 15:22:55 +0200 |
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User-agent: |
Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130803 Thunderbird/17.0.8 |
On 06/09/13 14:19, Jens Freimann wrote:
> This patch adds a floating irq controller as a kvm_device.
> It will be necessary for migration of floating interrupts as well
> as for hardening the reset code by allowing user space to explicitly
> remove all pending floating interrupts.
>
> Signed-off-by: Jens Freimann <address@hidden>
> Reviewed-by: Cornelia Huck <address@hidden>
Acked-by: Christian Borntraeger <address@hidden>
> ---
> Documentation/virtual/kvm/devices/s390_flic.txt | 36 +++
> arch/s390/include/asm/kvm_host.h | 1 +
> arch/s390/include/uapi/asm/kvm.h | 5 +
> arch/s390/kvm/interrupt.c | 304
> ++++++++++++++++++++----
> arch/s390/kvm/kvm-s390.c | 1 +
> include/linux/kvm_host.h | 1 +
> include/uapi/linux/kvm.h | 2 +
> virt/kvm/kvm_main.c | 5 +
> 8 files changed, 304 insertions(+), 51 deletions(-)
>
> diff --git a/Documentation/virtual/kvm/devices/s390_flic.txt
> b/Documentation/virtual/kvm/devices/s390_flic.txt
> new file mode 100644
> index 0000000..06aef31
> --- /dev/null
> +++ b/Documentation/virtual/kvm/devices/s390_flic.txt
> @@ -0,0 +1,36 @@
> +FLIC (floating interrupt controller)
> +====================================
> +
> +FLIC handles floating (non per-cpu) interrupts, i.e. I/O, service and some
> +machine check interruptions. All interrupts are stored in a per-vm list of
> +pending interrupts. FLIC performs operations on this list.
> +
> +Only one FLIC instance may be instantiated.
> +
> +FLIC provides support to
> +- add/delete interrupts (KVM_DEV_FLIC_ENQUEUE and _DEQUEUE)
> +- purge all pending floating interrupts (KVM_DEV_FLIC_CLEAR_IRQS)
> +
> +Groups:
> + KVM_DEV_FLIC_ENQUEUE
> + Adds one interrupt to the list of pending floating interrupts. Interrupts
> + are taken from this list for injection into the guest. attr contains
> + a struct kvm_s390_irq which contains all data relevant for
> + interrupt injection.
> + The format of the data structure kvm_s390_irq as it is copied from
> userspace
> + is defined in usr/include/linux/kvm.h.
> + For historic reasons list members are stored in a different data
> structure, i.e.
> + we need to copy the relevant data into a struct kvm_s390_interrupt_info
> + which can then be added to the list.
> +
> + KVM_DEV_FLIC_DEQUEUE
> + Takes one element off the pending interrupts list and copies it into
> userspace.
> + Dequeued interrupts are not injected into the guest.
> + attr->addr contains the userspace address of a struct kvm_s390_irq.
> + List elements are stored in the format of struct kvm_s390_interrupt_info
> + (arch/s390/include/asm/kvm_host.h) and are copied into a struct
> kvm_s390_irq
> + (usr/include/linux/kvm.h)
> +
> + KVM_DEV_FLIC_CLEAR_IRQS
> + Simply deletes all elements from the list of currently pending floating
> interrupts.
> + No interrupts are injected into the guest.
> diff --git a/arch/s390/include/asm/kvm_host.h
> b/arch/s390/include/asm/kvm_host.h
> index adb05c5..e1cc166 100644
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -238,6 +238,7 @@ struct kvm_arch{
> struct sca_block *sca;
> debug_info_t *dbf;
> struct kvm_s390_float_interrupt float_int;
> + struct kvm_device *flic;
> struct gmap *gmap;
> int css_support;
> };
> diff --git a/arch/s390/include/uapi/asm/kvm.h
> b/arch/s390/include/uapi/asm/kvm.h
> index d25da59..33d52b8 100644
> --- a/arch/s390/include/uapi/asm/kvm.h
> +++ b/arch/s390/include/uapi/asm/kvm.h
> @@ -16,6 +16,11 @@
>
> #define __KVM_S390
>
> +/* Device control API: s390-specific devices */
> +#define KVM_DEV_FLIC_DEQUEUE 1
> +#define KVM_DEV_FLIC_ENQUEUE 2
> +#define KVM_DEV_FLIC_CLEAR_IRQS 3
> +
> /* for KVM_GET_REGS and KVM_SET_REGS */
> struct kvm_regs {
> /* general purpose regs for s390 */
> diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
> index 7f35cb3..d6d5e36 100644
> --- a/arch/s390/kvm/interrupt.c
> +++ b/arch/s390/kvm/interrupt.c
> @@ -656,53 +656,86 @@ struct kvm_s390_interrupt_info
> *kvm_s390_get_io_int(struct kvm *kvm,
> return inti;
> }
>
> -int kvm_s390_inject_vm(struct kvm *kvm,
> - struct kvm_s390_interrupt *s390int)
> +static void __inject_vm(struct kvm *kvm, struct kvm_s390_interrupt_info
> *inti)
> {
> struct kvm_s390_local_interrupt *li;
> struct kvm_s390_float_interrupt *fi;
> - struct kvm_s390_interrupt_info *inti, *iter;
> + struct kvm_s390_interrupt_info *iter;
> int sigcpu;
>
> + mutex_lock(&kvm->lock);
> + fi = &kvm->arch.float_int;
> + spin_lock(&fi->lock);
> + if (!is_ioint(inti->type)) {
> + list_add_tail(&inti->list, &fi->list);
> + } else {
> + u64 isc_bits = int_word_to_isc_bits(inti->io.io_int_word);
> +
> + /* Keep I/O interrupts sorted in isc order. */
> + list_for_each_entry(iter, &fi->list, list) {
> + if (!is_ioint(iter->type))
> + continue;
> + if (int_word_to_isc_bits(iter->io.io_int_word)
> + <= isc_bits)
> + continue;
> + break;
> + }
> + list_add_tail(&inti->list, &iter->list);
> + }
> + atomic_set(&fi->active, 1);
> + sigcpu = find_first_bit(fi->idle_mask, KVM_MAX_VCPUS);
> + if (sigcpu == KVM_MAX_VCPUS) {
> + do {
> + sigcpu = fi->next_rr_cpu++;
> + if (sigcpu == KVM_MAX_VCPUS)
> + sigcpu = fi->next_rr_cpu = 0;
> + } while (fi->local_int[sigcpu] == NULL);
> + }
> + li = fi->local_int[sigcpu];
> + spin_lock_bh(&li->lock);
> + atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);
> + if (waitqueue_active(li->wq))
> + wake_up_interruptible(li->wq);
> + spin_unlock_bh(&li->lock);
> + spin_unlock(&fi->lock);
> + mutex_unlock(&kvm->lock);
> +}
> +
> +int kvm_s390_inject_vm(struct kvm *kvm,
> + struct kvm_s390_interrupt *s390int)
> +{
> + struct kvm_s390_interrupt_info *inti;
> +
> inti = kzalloc(sizeof(*inti), GFP_KERNEL);
> if (!inti)
> return -ENOMEM;
>
> - switch (s390int->type) {
> + inti->type = s390int->type;
> + switch (inti->type) {
> case KVM_S390_INT_VIRTIO:
> VM_EVENT(kvm, 5, "inject: virtio parm:%x,parm64:%llx",
> s390int->parm, s390int->parm64);
> - inti->type = s390int->type;
> inti->ext.ext_params = s390int->parm;
> inti->ext.ext_params2 = s390int->parm64;
> break;
> case KVM_S390_INT_SERVICE:
> VM_EVENT(kvm, 5, "inject: sclp parm:%x", s390int->parm);
> - inti->type = s390int->type;
> inti->ext.ext_params = s390int->parm;
> break;
> - case KVM_S390_PROGRAM_INT:
> - case KVM_S390_SIGP_STOP:
> - case KVM_S390_INT_EXTERNAL_CALL:
> - case KVM_S390_INT_EMERGENCY:
> - kfree(inti);
> - return -EINVAL;
> case KVM_S390_MCHK:
> VM_EVENT(kvm, 5, "inject: machine check parm64:%llx",
> s390int->parm64);
> - inti->type = s390int->type;
> inti->mchk.cr14 = s390int->parm; /* upper bits are not used */
> inti->mchk.mcic = s390int->parm64;
> break;
> case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
> - if (s390int->type & IOINT_AI_MASK)
> + if (inti->type & IOINT_AI_MASK)
> VM_EVENT(kvm, 5, "%s", "inject: I/O (AI)");
> else
> VM_EVENT(kvm, 5, "inject: I/O css %x ss %x schid %04x",
> s390int->type & IOINT_CSSID_MASK,
> s390int->type & IOINT_SSID_MASK,
> s390int->type & IOINT_SCHID_MASK);
> - inti->type = s390int->type;
> inti->io.subchannel_id = s390int->parm >> 16;
> inti->io.subchannel_nr = s390int->parm & 0x0000ffffu;
> inti->io.io_int_parm = s390int->parm64 >> 32;
> @@ -715,42 +748,7 @@ int kvm_s390_inject_vm(struct kvm *kvm,
> trace_kvm_s390_inject_vm(s390int->type, s390int->parm, s390int->parm64,
> 2);
>
> - mutex_lock(&kvm->lock);
> - fi = &kvm->arch.float_int;
> - spin_lock(&fi->lock);
> - if (!is_ioint(inti->type))
> - list_add_tail(&inti->list, &fi->list);
> - else {
> - u64 isc_bits = int_word_to_isc_bits(inti->io.io_int_word);
> -
> - /* Keep I/O interrupts sorted in isc order. */
> - list_for_each_entry(iter, &fi->list, list) {
> - if (!is_ioint(iter->type))
> - continue;
> - if (int_word_to_isc_bits(iter->io.io_int_word)
> - <= isc_bits)
> - continue;
> - break;
> - }
> - list_add_tail(&inti->list, &iter->list);
> - }
> - atomic_set(&fi->active, 1);
> - sigcpu = find_first_bit(fi->idle_mask, KVM_MAX_VCPUS);
> - if (sigcpu == KVM_MAX_VCPUS) {
> - do {
> - sigcpu = fi->next_rr_cpu++;
> - if (sigcpu == KVM_MAX_VCPUS)
> - sigcpu = fi->next_rr_cpu = 0;
> - } while (fi->local_int[sigcpu] == NULL);
> - }
> - li = fi->local_int[sigcpu];
> - spin_lock_bh(&li->lock);
> - atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);
> - if (waitqueue_active(li->wq))
> - wake_up_interruptible(li->wq);
> - spin_unlock_bh(&li->lock);
> - spin_unlock(&fi->lock);
> - mutex_unlock(&kvm->lock);
> + __inject_vm(kvm, inti);
> return 0;
> }
>
> @@ -838,3 +836,207 @@ int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,
> mutex_unlock(&vcpu->kvm->lock);
> return 0;
> }
> +
> +static void clear_floating_interrupts(struct kvm *kvm)
> +{
> + struct kvm_s390_float_interrupt *fi;
> + struct kvm_s390_interrupt_info *n, *inti = NULL;
> +
> + mutex_lock(&kvm->lock);
> + fi = &kvm->arch.float_int;
> + spin_lock(&fi->lock);
> + list_for_each_entry_safe(inti, n, &fi->list, list) {
> + list_del(&inti->list);
> + kfree(inti);
> + }
> + atomic_set(&fi->active, 0);
> + spin_unlock(&fi->lock);
> + mutex_unlock(&kvm->lock);
> +}
> +
> +static inline int copy_irq_to_user(struct kvm_s390_interrupt_info *inti,
> + u64 addr)
> +{
> + struct kvm_s390_irq __user *uptr = (struct kvm_s390_irq __user *) addr;
> + void __user *target;
> + void *source;
> + u64 size;
> + int r = 0;
> +
> + switch (inti->type) {
> + case KVM_S390_INT_VIRTIO:
> + case KVM_S390_INT_SERVICE:
> + source = &inti->ext;
> + target = &uptr->ext;
> + size = sizeof(inti->ext);
> + break;
> + case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
> + source = &inti->io;
> + target = &uptr->io;
> + size = sizeof(inti->io);
> + break;
> + case KVM_S390_MCHK:
> + source = &inti->mchk;
> + target = &uptr->mchk;
> + size = sizeof(inti->mchk);
> + break;
> + case KVM_S390_INT_MAX:
> + goto out;
> + default:
> + return -EINVAL;
> + }
> +
> + r = put_user(inti->type, (u64 __user *) &uptr->type);
> + if (copy_to_user(target, source, size))
> + r = -EFAULT;
> +
> +out:
> + return r;
> +}
> +
> +static int dequeue_floating_irq(struct kvm *kvm, __u64 addr)
> +{
> + struct kvm_s390_interrupt_info *inti;
> + struct kvm_s390_float_interrupt *fi;
> + int r = 0;
> +
> +
> + mutex_lock(&kvm->lock);
> + fi = &kvm->arch.float_int;
> + spin_lock(&fi->lock);
> + if (list_empty(&fi->list)) {
> + mutex_unlock(&kvm->lock);
> + spin_unlock(&fi->lock);
> + return -ENODATA;
> + }
> + inti = list_first_entry(&fi->list,
> + struct kvm_s390_interrupt_info, list);
> + list_del(&inti->list);
> + spin_unlock(&fi->lock);
> + mutex_unlock(&kvm->lock);
> +
> + r = copy_irq_to_user(inti, addr);
> +
> + kfree(inti);
> + return r;
> +}
> +
> +static int flic_get_attr(struct kvm_device *dev, struct kvm_device_attr
> *attr)
> +{
> + int r;
> +
> + switch (attr->group) {
> + case KVM_DEV_FLIC_DEQUEUE:
> + r = dequeue_floating_irq(dev->kvm, attr->addr);
> + break;
> + default:
> + r = -EINVAL;
> + }
> +
> + return r;
> +}
> +
> +static inline int copy_irq_from_user(struct kvm_s390_interrupt_info *inti,
> + u64 addr)
> +{
> + struct kvm_s390_irq __user *uptr = (struct kvm_s390_irq __user *) addr;
> + void *target = NULL;
> + void *source;
> + u64 size;
> + int r = 0;
> +
> + if (get_user(inti->type, (u64 __user *)addr))
> + return -EFAULT;
> + switch (inti->type) {
> + case KVM_S390_INT_VIRTIO:
> + case KVM_S390_INT_SERVICE:
> + target = (void *) &inti->ext;
> + source = &uptr->ext;
> + size = sizeof(inti->ext);
> + break;
> + case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
> + target = (void *) &inti->io;
> + source = &uptr->io;
> + size = sizeof(inti->io);
> + break;
> + case KVM_S390_MCHK:
> + target = (void *) &inti->mchk;
> + source = &uptr->mchk;
> + size = sizeof(inti->mchk);
> + break;
> + case KVM_S390_INT_MAX:
> + goto out;
> + default:
> + r = -EINVAL;
> + return r;
> + }
> +
> + if (copy_from_user(target, source, size))
> + r = -EFAULT;
> +
> +out:
> + return r;
> +}
> +
> +static int enqueue_floating_irq(struct kvm_device *dev,
> + struct kvm_device_attr *attr)
> +{
> + struct kvm_s390_interrupt_info *inti = NULL;
> + int r = 0;
> +
> + inti = kzalloc(sizeof(*inti), GFP_KERNEL);
> + if (!inti)
> + return -ENOMEM;
> +
> + r = copy_irq_from_user(inti, attr->addr);
> + if (r) {
> + kfree(inti);
> + return r;
> + }
> + __inject_vm(dev->kvm, inti);
> +
> + return r;
> +}
> +
> +static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr
> *attr)
> +{
> + int r = 0;
> +
> + switch (attr->group) {
> + case KVM_DEV_FLIC_ENQUEUE:
> + r = enqueue_floating_irq(dev, attr);
> + break;
> + case KVM_DEV_FLIC_CLEAR_IRQS:
> + r = 0;
> + clear_floating_interrupts(dev->kvm);
> + break;
> + default:
> + r = -EINVAL;
> + }
> +
> + return r;
> +}
> +
> +static int flic_create(struct kvm_device *dev, u32 type)
> +{
> + if (!dev)
> + return -EINVAL;
> + if (dev->kvm->arch.flic)
> + return -EINVAL;
> + dev->kvm->arch.flic = dev;
> + return 0;
> +}
> +
> +static void flic_destroy(struct kvm_device *dev)
> +{
> + dev->kvm->arch.flic = NULL;
> +}
> +
> +/* s390 floating irq controller (flic) */
> +struct kvm_device_ops kvm_flic_ops = {
> + .name = "kvm-flic",
> + .get_attr = flic_get_attr,
> + .set_attr = flic_set_attr,
> + .create = flic_create,
> + .destroy = flic_destroy,
> +};
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 776dafe..760febf 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -157,6 +157,7 @@ int kvm_dev_ioctl_check_extension(long ext)
> case KVM_CAP_ENABLE_CAP:
> case KVM_CAP_S390_CSS_SUPPORT:
> case KVM_CAP_IOEVENTFD:
> + case KVM_CAP_DEVICE_CTRL:
> r = 1;
> break;
> case KVM_CAP_NR_VCPUS:
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index ca645a0..e89304d 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -1065,6 +1065,7 @@ struct kvm_device *kvm_device_from_filp(struct file
> *filp);
>
> extern struct kvm_device_ops kvm_mpic_ops;
> extern struct kvm_device_ops kvm_xics_ops;
> +extern struct kvm_device_ops kvm_flic_ops;
>
> #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
>
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index eeb08a1..9c8b457 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -426,6 +426,7 @@ struct kvm_s390_psw {
> ((ai) << 26))
> #define KVM_S390_INT_IO_MIN 0x00000000u
> #define KVM_S390_INT_IO_MAX 0xfffdffffu
> +#define KVM_S390_INT_MAX 0xffffffffu
>
>
> struct kvm_s390_interrupt {
> @@ -906,6 +907,7 @@ struct kvm_device_attr {
> #define KVM_DEV_TYPE_FSL_MPIC_20 1
> #define KVM_DEV_TYPE_FSL_MPIC_42 2
> #define KVM_DEV_TYPE_XICS 3
> +#define KVM_DEV_TYPE_FLIC 4
>
> /*
> * ioctls for VM fds
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index bf040c4..79a2ecc 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -2265,6 +2265,11 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
> ops = &kvm_xics_ops;
> break;
> #endif
> +#ifdef CONFIG_S390
> + case KVM_DEV_TYPE_FLIC:
> + ops = &kvm_flic_ops;
> + break;
> +#endif
> default:
> return -ENODEV;
> }
>