From: Jens Freimann <jfrei@xxxxxxxxxxxxxxxxxx>
This patch adds support to migrate vcpu interrupts. Two new vcpu ioctls
are added which get/set the complete status of pending interrupts in one
go. The ioctls are marked as available with the new capability
KVM_CAP_S390_IRQ_STATE.
We can not use a ONEREG, as the number of pending local interrupts is not
constant and depends on the number of CPUs.
To retrieve the interrupt state we add an ioctl KVM_S390_GET_IRQ_STATE.
Its input parameter is a pointer to a struct kvm_s390_irq_state which
has a buffer and length. For all currently pending interrupts, we copy
a struct kvm_s390_irq into the buffer and pass it to userspace.
To store interrupt state into a buffer provided by userspace, we add an
ioctl KVM_S390_SET_IRQ_STATE. It passes a struct kvm_s390_irq_state into
the kernel and injects all interrupts contained in the buffer.
Signed-off-by: Jens Freimann <jfrei@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Acked-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
---
Documentation/virtual/kvm/api.txt | 61 +++++++++++++++++
arch/s390/kvm/interrupt.c | 140 ++++++++++++++++++++++++++++++++++++++
arch/s390/kvm/kvm-s390.c | 36 ++++++++++
arch/s390/kvm/kvm-s390.h | 4 ++
include/uapi/linux/kvm.h | 11 +++
5 files changed, 252 insertions(+)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index a7c651d..18fb763 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2875,6 +2875,67 @@ KVM_S390_MCHK - machine check interrupt; parameters in .mchk
Note that the vcpu ioctl is asynchronous to vcpu execution.
+4.94 KVM_S390_GET_IRQ_STATE
+
+Capability: KVM_CAP_S390_IRQ_STATE
+Architectures: s390
+Type: vcpu ioctl
+Parameters: struct kvm_s390_irq_state (out)
+Returns: >= number of bytes copied into buffer,
+ -EINVAL if buffer size is 0,
+ -ENOBUFS if buffer size is too small to fit all pending interrupts,
+ -EFAULT if the buffer address was invalid
+
+This ioctl allows userspace to retrieve the complete state of all currently
+pending interrupts in a single buffer. Use cases include migration
+and introspection. The parameter structure contains the address of a
+userspace buffer and its length:
+
+struct kvm_s390_irq_state {
+ __u64 buf;
+ __u32 flags;
+ __u32 len;
+ __u32 reserved[4];
+};
+
+Userspace passes in the above struct and for each pending interrupt a
+struct kvm_s390_irq is copied to the provided buffer.
+
+If -ENOBUFS is returned the buffer provided was too small and userspace
+may retry with a bigger buffer.
+
+4.95 KVM_S390_SET_IRQ_STATE
+
+Capability: KVM_CAP_S390_IRQ_STATE
+Architectures: s390
+Type: vcpu ioctl
+Parameters: struct kvm_s390_irq_state (in)
+Returns: 0 on success,
+ -EFAULT if the buffer address was invalid,
+ -EINVAL for an invalid buffer length (see below),
+ -EBUSY if there were already interrupts pending,
+ errors occurring when actually injecting the
+ interrupt. See KVM_S390_IRQ.
+
+This ioctl allows userspace to set the complete state of all cpu-local
+interrupts currently pending for the vcpu. It is intended for restoring
+interrupt state after a migration. The input parameter is a userspace buffer
+containing a struct kvm_s390_irq_state:
+
+struct kvm_s390_irq_state {
+ __u64 buf;
+ __u32 len;
+ __u32 pad;
+};
+
+The userspace memory referenced by buf contains a struct kvm_s390_irq
+for each interrupt to be injected into the guest.
+If one of the interrupts could not be injected for some reason the
+ioctl aborts.
+
+len must be a multiple of sizeof(struct kvm_s390_irq). It must be > 0
+and it must not exceed (max_vcpus + 32) * sizeof(struct kvm_s390_irq),
+which is the maximum number of possibly pending cpu-local interrupts.
5. The kvm_run structure
------------------------
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 2f78f1a..ee2dfdc 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -2125,3 +2125,143 @@ int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e, struct kvm *kvm,
{
return -EINVAL;
}
+
+int kvm_s390_set_irq_state(struct kvm_vcpu *vcpu, void __user *irqstate, int len)
+{
+ struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
+ struct kvm_s390_irq *buf;
+ int r = 0;
+ int n;
+
+ buf = vmalloc(len);
+ if (!buf)
+ return -ENOMEM;
+
+ if (copy_from_user((void *) buf, irqstate, len)) {
+ r = -EFAULT;
+ goto out_free;
+ }
+
+ /*
+ * Don't allow setting the interrupt state
+ * when there are already interrupts pending
+ */
+ spin_lock(&li->lock);
+ if (li->pending_irqs) {
+ r = -EBUSY;
+ goto out_unlock;
+ }
+
+ for (n = 0; n < len / sizeof(*buf); n++) {
+ r = do_inject_vcpu(vcpu, &buf[n]);
+ if (r)
+ break;
+ }
+
+out_unlock:
+ spin_unlock(&li->lock);
+out_free:
+ vfree(buf);
+
+ return r;
+}
+
+static void store_local_irq(struct kvm_s390_local_interrupt *li,
+ struct kvm_s390_irq *irq,
+ unsigned long irq_type)
+{
+ switch (irq_type) {
+ case IRQ_PEND_MCHK_EX:
+ case IRQ_PEND_MCHK_REP:
+ irq->type = KVM_S390_MCHK;
+ irq->u.mchk = li->irq.mchk;
+ break;
+ case IRQ_PEND_PROG:
+ irq->type = KVM_S390_PROGRAM_INT;
+ irq->u.pgm = li->irq.pgm;
+ break;
+ case IRQ_PEND_PFAULT_INIT:
+ irq->type = KVM_S390_INT_PFAULT_INIT;
+ irq->u.ext = li->irq.ext;
+ break;
+ case IRQ_PEND_EXT_EXTERNAL:
+ irq->type = KVM_S390_INT_EXTERNAL_CALL;
+ irq->u.extcall = li->irq.extcall;
+ break;
+ case IRQ_PEND_EXT_CLOCK_COMP:
+ irq->type = KVM_S390_INT_CLOCK_COMP;
+ break;
+ case IRQ_PEND_EXT_CPU_TIMER:
+ irq->type = KVM_S390_INT_CPU_TIMER;
+ break;
+ case IRQ_PEND_SIGP_STOP:
+ irq->type = KVM_S390_SIGP_STOP;
+ irq->u.stop = li->irq.stop;
+ break;
+ case IRQ_PEND_RESTART:
+ irq->type = KVM_S390_RESTART;
+ break;
+ case IRQ_PEND_SET_PREFIX:
+ irq->type = KVM_S390_SIGP_SET_PREFIX;
+ irq->u.prefix = li->irq.prefix;
+ break;
+ }
+}
+
+int kvm_s390_get_irq_state(struct kvm_vcpu *vcpu, __u8 __user *buf, int len)
+{
+ uint8_t sigp_ctrl = vcpu->kvm->arch.sca->cpu[vcpu->vcpu_id].sigp_ctrl;
+ unsigned long sigp_emerg_pending[BITS_TO_LONGS(KVM_MAX_VCPUS)];
+ struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
+ unsigned long pending_irqs;
+ struct kvm_s390_irq irq;
+ unsigned long irq_type;
+ int cpuaddr;
+ int n = 0;
+
+ spin_lock(&li->lock);
+ pending_irqs = li->pending_irqs;
+ memcpy(&sigp_emerg_pending, &li->sigp_emerg_pending,
+ sizeof(sigp_emerg_pending));
+ spin_unlock(&li->lock);
+
+ for_each_set_bit(irq_type, &pending_irqs, IRQ_PEND_COUNT) {
+ memset(&irq, 0, sizeof(irq));
+ if (irq_type == IRQ_PEND_EXT_EMERGENCY)
+ continue;
+ if (n + sizeof(irq) > len)
+ return -ENOBUFS;
+ store_local_irq(&vcpu->arch.local_int, &irq, irq_type);
+ if (copy_to_user(&buf[n], &irq, sizeof(irq)))
+ return -EFAULT;
+ n += sizeof(irq);
+ }
+
+ if (test_bit(IRQ_PEND_EXT_EMERGENCY, &pending_irqs)) {
+ for_each_set_bit(cpuaddr, sigp_emerg_pending, KVM_MAX_VCPUS) {
+ memset(&irq, 0, sizeof(irq));
+ if (n + sizeof(irq) > len)
+ return -ENOBUFS;
+ irq.type = KVM_S390_INT_EMERGENCY;
+ irq.u.emerg.code = cpuaddr;
+ if (copy_to_user(&buf[n], &irq, sizeof(irq)))
+ return -EFAULT;
+ n += sizeof(irq);
+ }
+ }
+
+ if ((sigp_ctrl & SIGP_CTRL_C) &&
+ (atomic_read(&vcpu->arch.sie_block->cpuflags) &
+ CPUSTAT_ECALL_PEND)) {
+ if (n + sizeof(irq) > len)
+ return -ENOBUFS;
+ memset(&irq, 0, sizeof(irq));
+ irq.type = KVM_S390_INT_EXTERNAL_CALL;
+ irq.u.extcall.code = sigp_ctrl & SIGP_CTRL_SCN_MASK;
+ if (copy_to_user(&buf[n], &irq, sizeof(irq)))
+ return -EFAULT;
+ n += sizeof(irq);
+ }
+
+ return n;
+}
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 8bc25d4..3040b14 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -41,6 +41,9 @@
#include "trace-s390.h"
#define MEM_OP_MAX_SIZE 65536 /* Maximum transfer size for KVM_S390_MEM_OP */
+#define LOCAL_IRQS 32
+#define VCPU_IRQS_MAX_BUF (sizeof(struct kvm_s390_irq) * \
+ (KVM_MAX_VCPUS + LOCAL_IRQS))
#define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU
@@ -181,6 +184,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_S390_USER_SIGP:
case KVM_CAP_S390_USER_STSI:
case KVM_CAP_S390_SKEYS:
+ case KVM_CAP_S390_IRQ_STATE:
r = 1;
break;
case KVM_CAP_S390_MEM_OP:
@@ -2500,6 +2504,38 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
r = -EFAULT;
break;
}
+ case KVM_S390_SET_IRQ_STATE: {
+ struct kvm_s390_irq_state irq_state;
+
+ r = -EFAULT;
+ if (copy_from_user(&irq_state, argp, sizeof(irq_state)))
+ break;
+ if (irq_state.len > VCPU_IRQS_MAX_BUF ||
+ irq_state.len == 0 ||
+ irq_state.len % sizeof(struct kvm_s390_irq) > 0) {
+ r = -EINVAL;
+ break;
+ }
+ r = kvm_s390_set_irq_state(vcpu,
+ (void __user *) irq_state.buf,
+ irq_state.len);
+ break;
+ }
+ case KVM_S390_GET_IRQ_STATE: {
+ struct kvm_s390_irq_state irq_state;
+
+ r = -EFAULT;
+ if (copy_from_user(&irq_state, argp, sizeof(irq_state)))
+ break;
+ if (irq_state.len == 0) {
+ r = -EINVAL;
+ break;
+ }
+ r = kvm_s390_get_irq_state(vcpu,
+ (__u8 __user *) irq_state.buf,
+ irq_state.len);
+ break;
+ }
default:
r = -ENOTTY;
}
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index 343644a..ca108b9 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -272,6 +272,10 @@ int kvm_s390_ext_call_pending(struct kvm_vcpu *vcpu);
extern struct kvm_device_ops kvm_flic_ops;
int kvm_s390_is_stop_irq_pending(struct kvm_vcpu *vcpu);
void kvm_s390_clear_stop_irq(struct kvm_vcpu *vcpu);
+int kvm_s390_set_irq_state(struct kvm_vcpu *vcpu,
+ void __user *buf, int len);
+int kvm_s390_get_irq_state(struct kvm_vcpu *vcpu,
+ __u8 __user *buf, int len);
/* implemented in guestdbg.c */
void kvm_s390_backup_guest_per_regs(struct kvm_vcpu *vcpu);
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index e61f49a..7437ce9 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -558,6 +558,13 @@ struct kvm_s390_irq {
} u;
};
+struct kvm_s390_irq_state {
+ __u64 buf;
+ __u32 flags;
+ __u32 len;
+ __u32 reserved[4];
+};
+
/* for KVM_SET_GUEST_DEBUG */
#define KVM_GUESTDBG_ENABLE 0x00000001
@@ -803,6 +810,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_S390_USER_STSI 109
#define KVM_CAP_S390_SKEYS 110
#define KVM_CAP_S390_INJECT_IRQ 111
+#define KVM_CAP_S390_IRQ_STATE 112
#ifdef KVM_CAP_IRQ_ROUTING
@@ -1185,6 +1193,9 @@ struct kvm_s390_ucas_mapping {
#define KVM_S390_SET_SKEYS _IOW(KVMIO, 0xb3, struct kvm_s390_skeys)
/* Available with KVM_CAP_S390_INJECT_IRQ */
#define KVM_S390_IRQ _IOW(KVMIO, 0xb4, struct kvm_s390_irq)
+/* Available with KVM_CAP_S390_IRQ_STATE */
+#define KVM_S390_SET_IRQ_STATE _IOW(KVMIO, 0xb5, struct kvm_s390_irq_state)
+#define KVM_S390_GET_IRQ_STATE _IOW(KVMIO, 0xb6, struct kvm_s390_irq_state)
#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)
#define KVM_DEV_ASSIGN_PCI_2_3 (1 << 1)
--
2.3.0
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