On 07.12.2012, at 13:30, Cornelia Huck wrote:
> Add support for handling I/O interrupts (standard, subchannel-related
> ones and rudimentary adapter interrupts).
>
> The subchannel-identifying parameters are encoded into the interrupt
> type.
>
> I/O interrupts are floating, so they can't be injected on a specific
> vcpu.
>
> Reviewed-by: Marcelo Tosatti <[email protected]>
> Signed-off-by: Cornelia Huck <[email protected]>
> ---
> Documentation/virtual/kvm/api.txt | 4 ++
> arch/s390/include/asm/kvm_host.h | 2 +
> arch/s390/kvm/interrupt.c | 115 ++++++++++++++++++++++++++++++++++++--
> include/uapi/linux/kvm.h | 6 ++
> 4 files changed, 122 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/virtual/kvm/api.txt
> b/Documentation/virtual/kvm/api.txt
> index 6671fdc..e298a72 100644
> --- a/Documentation/virtual/kvm/api.txt
> +++ b/Documentation/virtual/kvm/api.txt
> @@ -2068,6 +2068,10 @@ KVM_S390_INT_VIRTIO (vm) - virtio external interrupt;
> external interrupt
> KVM_S390_INT_SERVICE (vm) - sclp external interrupt; sclp parameter in parm
> KVM_S390_INT_EMERGENCY (vcpu) - sigp emergency; source cpu in parm
> KVM_S390_INT_EXTERNAL_CALL (vcpu) - sigp external call; source cpu in parm
> +KVM_S390_INT_IO(ai,cssid,ssid,schid) (vm) - compound value to indicate an
> + I/O interrupt (ai - adapter interrupt; cssid,ssid,schid - subchannel);
> + I/O interruption parameters in parm (subchannel) and parm64 (intparm,
> + interruption subclass)
>
> Note that the vcpu ioctl is asynchronous to vcpu execution.
>
> diff --git a/arch/s390/include/asm/kvm_host.h
> b/arch/s390/include/asm/kvm_host.h
> index b784154..e47f697 100644
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -76,6 +76,7 @@ struct kvm_s390_sie_block {
> __u64 epoch; /* 0x0038 */
> __u8 reserved40[4]; /* 0x0040 */
> #define LCTL_CR0 0x8000
> +#define LCTL_CR6 0x0200
> __u16 lctl; /* 0x0044 */
> __s16 icpua; /* 0x0046 */
> __u32 ictl; /* 0x0048 */
> @@ -127,6 +128,7 @@ struct kvm_vcpu_stat {
> u32 deliver_prefix_signal;
> u32 deliver_restart_signal;
> u32 deliver_program_int;
> + u32 deliver_io_int;
> u32 exit_wait_state;
> u32 instruction_stidp;
> u32 instruction_spx;
> diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
> index c30615e..070ba22 100644
> --- a/arch/s390/kvm/interrupt.c
> +++ b/arch/s390/kvm/interrupt.c
> @@ -21,11 +21,26 @@
> #include "gaccess.h"
> #include "trace-s390.h"
>
> +#define IOINT_SCHID_MASK 0x0000ffff
> +#define IOINT_SSID_MASK 0x00030000
> +#define IOINT_CSSID_MASK 0x03fc0000
> +#define IOINT_AI_MASK 0x04000000
> +
> +static int is_ioint(u64 type)
> +{
> + return ((type & 0xfffe0000u) != 0xfffe0000u);
> +}
> +
> static int psw_extint_disabled(struct kvm_vcpu *vcpu)
> {
> return !(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_EXT);
> }
>
> +static int psw_ioint_disabled(struct kvm_vcpu *vcpu)
> +{
> + return !(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_IO);
> +}
> +
> static int psw_interrupts_disabled(struct kvm_vcpu *vcpu)
> {
> if ((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PER) ||
> @@ -68,7 +83,18 @@ static int __interrupt_is_deliverable(struct kvm_vcpu
> *vcpu,
> case KVM_S390_RESTART:
> return 1;
> default:
> - BUG();
> + if (is_ioint(inti->type)) {
Though I usually like if (...) { positive) } else { abort(); } coding style in
general, it makes code quite hard to read when you are limited to 80 characters
per line :)
I think it'd really help readability if you instead would write
if (!is_ioint(...)) {
BUG();
}
and then continue without indent. That problem gets even more obvious further
down the file.
> + if (psw_ioint_disabled(vcpu))
> + return 0;
> + if (vcpu->arch.sie_block->gcr[6] &
> + inti->io.io_int_word)
> + return 1;
> + return 0;
> + } else {
> + printk(KERN_WARNING "illegal interrupt type %llx\n",
> + inti->type);
> + BUG();
> + }
> }
> return 0;
> }
> @@ -117,6 +143,13 @@ static void __set_intercept_indicator(struct kvm_vcpu
> *vcpu,
> __set_cpuflag(vcpu, CPUSTAT_STOP_INT);
> break;
> default:
> + if (is_ioint(inti->type)) {
> + if (psw_ioint_disabled(vcpu))
> + __set_cpuflag(vcpu, CPUSTAT_IO_INT);
> + else
> + vcpu->arch.sie_block->lctl |= LCTL_CR6;
> + break;
> + }
> BUG();
Please reverse the logic here, just like you did above :).
> }
> }
> @@ -298,7 +331,49 @@ static void __do_deliver_interrupt(struct kvm_vcpu *vcpu,
> break;
>
> default:
> - BUG();
> + if (is_ioint(inti->type)) {
> + __u32 param0 = ((__u32)inti->io.subchannel_id << 16) |
> + inti->io.subchannel_nr;
> + __u64 param1 = ((__u64)inti->io.io_int_parm << 32) |
> + inti->io.io_int_word;
> + VCPU_EVENT(vcpu, 4,
> + "interrupt: I/O %llx", inti->type);
> + vcpu->stat.deliver_io_int++;
> + trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id,
> inti->type,
> + param0, param1);
> + rc = put_guest_u16(vcpu, __LC_SUBCHANNEL_ID,
> + inti->io.subchannel_id);
> + if (rc == -EFAULT)
> + exception = 1;
> +
> + rc = put_guest_u16(vcpu, __LC_SUBCHANNEL_NR,
> + inti->io.subchannel_nr);
> + if (rc == -EFAULT)
> + exception = 1;
> +
> + rc = put_guest_u32(vcpu, __LC_IO_INT_PARM,
> + inti->io.io_int_parm);
> + if (rc == -EFAULT)
> + exception = 1;
> +
> + rc = put_guest_u32(vcpu, __LC_IO_INT_WORD,
> + inti->io.io_int_word);
> + if (rc == -EFAULT)
> + exception = 1;
> +
> + rc = copy_to_guest(vcpu, __LC_IO_OLD_PSW,
> + &vcpu->arch.sie_block->gpsw,
> + sizeof(psw_t));
> + if (rc == -EFAULT)
> + exception = 1;
> +
> + rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
> + __LC_IO_NEW_PSW, sizeof(psw_t));
> + if (rc == -EFAULT)
> + exception = 1;
> + break;
> + } else
> + BUG();
> }
> if (exception) {
> printk("kvm: The guest lowcore is not mapped during interrupt "
> @@ -545,7 +620,7 @@ int kvm_s390_inject_vm(struct kvm *kvm,
> {
> struct kvm_s390_local_interrupt *li;
> struct kvm_s390_float_interrupt *fi;
> - struct kvm_s390_interrupt_info *inti;
> + struct kvm_s390_interrupt_info *inti, *iter;
> int sigcpu;
>
> inti = kzalloc(sizeof(*inti), GFP_KERNEL);
> @@ -569,9 +644,26 @@ int kvm_s390_inject_vm(struct kvm *kvm,
> case KVM_S390_SIGP_STOP:
> case KVM_S390_INT_EXTERNAL_CALL:
> case KVM_S390_INT_EMERGENCY:
> - default:
> kfree(inti);
> return -EINVAL;
> + default:
> + if (!is_ioint(s390int->type)) {
> + kfree(inti);
> + return -EINVAL;
> + }
> + if (s390int->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;
> + inti->io.io_int_word = s390int->parm64 & 0x00000000ffffffffull;
> + break;
> }
> trace_kvm_s390_inject_vm(s390int->type, s390int->parm, s390int->parm64,
> 2);
> @@ -579,7 +671,19 @@ int kvm_s390_inject_vm(struct kvm *kvm,
> mutex_lock(&kvm->lock);
> fi = &kvm->arch.float_int;
> spin_lock(&fi->lock);
> - list_add_tail(&inti->list, &fi->list);
> + if (!is_ioint(inti->type))
> + list_add_tail(&inti->list, &fi->list);
> + else {
> + /* Keep I/O interrupts sorted in isc order. */
> + list_for_each_entry(iter, &fi->list, list) {
> + if (!is_ioint(iter->type))
> + continue;
> + if (iter->io.io_int_word <= inti->io.io_int_word)
> + 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) {
> @@ -654,6 +758,7 @@ int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,
> case KVM_S390_INT_VIRTIO:
> case KVM_S390_INT_SERVICE:
> default:
> + /* also includes IOINT */
> kfree(inti);
> return -EINVAL;
> }
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index 494a84c..e676940 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -401,6 +401,12 @@ struct kvm_s390_psw {
> #define KVM_S390_INT_SERVICE 0xffff2401u
> #define KVM_S390_INT_EMERGENCY 0xffff1201u
> #define KVM_S390_INT_EXTERNAL_CALL 0xffff1202u
> +#define KVM_S390_INT_IO(ai,cssid,ssid,schid) \
This one wants a comment saying that the namespace for everything not starting
with 0xfffe/0xffff is taken by INT_IO.
Alex
> + (((schid)) | \
> + ((ssid) << 16) | \
> + ((cssid) << 18) | \
> + ((ai) << 26))
> +
>
> struct kvm_s390_interrupt {
> __u32 type;
> --
> 1.7.12.4
>
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