This adds the API for userspace to instantiate an XICS device in a VM
and connect VCPUs to it. The API consists of a new device type for
the KVM_CREATE_DEVICE ioctl, a new capability KVM_CAP_IRQ_XICS, which
functions similarly to KVM_CAP_IRQ_MPIC, and the KVM_IRQ_LINE ioctl,
which is used to assert and deassert interrupt inputs of the XICS.
The XICS device has one attribute group, KVM_DEV_XICS_GRP_SOURCES.
Each attribute within this group corresponds to the state of one
interrupt source. The attribute number is the same as the interrupt
source number.
Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx>
---
Documentation/virtual/kvm/api.txt | 8 ++
Documentation/virtual/kvm/devices/xics.txt | 66 +++++++++
arch/powerpc/kvm/book3s_xics.c | 206 +++++++++++++++++++++++++++-
arch/powerpc/kvm/powerpc.c | 31 +++++
include/linux/kvm_host.h | 1 +
include/uapi/linux/kvm.h | 14 ++
virt/kvm/kvm_main.c | 14 ++
7 files changed, 335 insertions(+), 5 deletions(-)
create mode 100644 Documentation/virtual/kvm/devices/xics.txt
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 54bb6ad..db230f8 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2756,3 +2756,11 @@ Parameters: args[0] is the MPIC device fd
args[1] is the MPIC CPU number for this vcpu
This capability connects the vcpu to an in-kernel MPIC device.
+
+6.7 KVM_CAP_IRQ_XICS
+
+Architectures: ppc
+Parameters: args[0] is the XICS device fd
+ args[1] is the XICS CPU number (server ID) for this vcpu
+
+This capability connects the vcpu to an in-kernel XICS device.
diff --git a/Documentation/virtual/kvm/devices/xics.txt b/Documentation/virtual/kvm/devices/xics.txt
new file mode 100644
index 0000000..4286493
--- /dev/null
+++ b/Documentation/virtual/kvm/devices/xics.txt
@@ -0,0 +1,66 @@
+XICS interrupt controller
+
+Device type supported: KVM_DEV_TYPE_XICS
+
+Groups:
+ KVM_DEV_XICS_SOURCES
+ Attributes: One per interrupt source, indexed by the source number.
+
+This device emulates the XICS (eXternal Interrupt Controller
+Specification) defined in PAPR. The XICS has a set of interrupt
+sources, each identified by a 20-bit source number, and a set of
+Interrupt Control Presentation (ICP) entities, also called "servers",
+each associated with a virtual CPU.
+
+The ICP entities are created by enabling the KVM_CAP_IRQ_ARCH
+capability for each vcpu, specifying KVM_CAP_IRQ_XICS in args[0] and
+the interrupt server number (i.e. the vcpu number from the XICS's
+point of view) in args[1] of the kvm_enable_cap struct. Each ICP has
+64 bits of state which can be read and written using the
+KVM_GET_ONE_REG and KVM_SET_ONE_REG ioctls on the vcpu. The 64 bit
+state word has the following bitfields, starting at the
+least-significant end of the word:
+
+* Unused, 16 bits
+
+* Pending interrupt priority, 8 bits
+ Zero is the highest priority, 255 means no interrupt is pending.
+
+* Pending IPI (inter-processor interrupt) priority, 8 bits
+ Zero is the highest priority, 255 means no IPI is pending.
+
+* Pending interrupt source number, 24 bits
+ Zero means no interrupt pending, 2 means an IPI is pending
+
+* Current processor priority, 8 bits
+ Zero is the highest priority, meaning no interrupts can be
+ delivered, and 255 is the lowest priority.
+
+Each source has 64 bits of state that can be read and written using
+the KVM_GET_DEVICE_ATTR and KVM_SET_DEVICE_ATTR ioctls, specifying the
+KVM_DEV_XICS_SOURCES attribute group, with the attribute number being
+the interrupt source number. The 64 bit state word has the following
+bitfields, starting from the least-significant end of the word:
+
+* Destination (server number), 32 bits
+ This specifies where the interrupt should be sent, and is the
+ interrupt server number specified for the destination vcpu.
+
+* Priority, 8 bits
+ This is the priority specified for this interrupt source, where 0 is
+ the highest priority and 255 is the lowest. An interrupt with a
+ priority of 255 will never be delivered.
+
+* Level sensitive flag, 1 bit
+ This bit is 1 for a level-sensitive interrupt source, or 0 for
+ edge-sensitive (or MSI).
+
+* Masked flag, 1 bit
+ This bit is set to 1 if the interrupt is masked (cannot be delivered
+ regardless of its priority), for example by the ibm,int-off RTAS
+ call, or 0 if it is not masked.
+
+* Pending flag, 1 bit
+ This bit is 1 if the source has a pending interrupt, otherwise 0.
+
+Only one XICS instance may be created per VM.
diff --git a/arch/powerpc/kvm/book3s_xics.c b/arch/powerpc/kvm/book3s_xics.c
index 4eb4f4b..eb58abf 100644
--- a/arch/powerpc/kvm/book3s_xics.c
+++ b/arch/powerpc/kvm/book3s_xics.c
@@ -11,6 +11,7 @@
#include <linux/kvm_host.h>
#include <linux/err.h>
#include <linux/gfp.h>
+#include <linux/anon_inodes.h>
#include <asm/uaccess.h>
#include <asm/kvm_book3s.h>
@@ -890,8 +891,8 @@ static void xics_debugfs_init(struct kvmppc_xics *xics)
kfree(name);
}
-struct kvmppc_ics *kvmppc_xics_create_ics(struct kvmppc_xics *xics,
- int irq)
+static struct kvmppc_ics *kvmppc_xics_create_ics(struct kvmppc_xics *xics,
+ int irq)
{
struct kvmppc_ics *ics;
int i, icsid;
@@ -1043,6 +1044,94 @@ int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval)
return 0;
}
+static int xics_get_source(struct kvm *kvm, long irq, u64 addr)
+{
+ int ret;
+ struct kvmppc_xics *xics = kvm->arch.xics;
+ struct kvmppc_ics *ics;
+ struct ics_irq_state *irqp;
+ u64 __user *ubufp = (u64 __user *) addr;
+ u16 idx;
+ u64 val, prio;
+
+ ics = kvmppc_xics_find_ics(xics, irq, &idx);
+ if (!ics)
+ return -ENOENT;
+
+ irqp = &ics->irq_state[idx];
+ mutex_lock(&ics->lock);
+ ret = -ENOENT;
+ if (irqp->exists) {
+ val = irqp->server;
+ prio = irqp->priority;
+ if (prio == MASKED) {
+ val |= KVM_XICS_MASKED;
+ prio = irqp->saved_priority;
+ }
+ val |= prio << KVM_XICS_PRIORITY_SHIFT;
+ if (irqp->asserted)
+ val |= KVM_XICS_LEVEL_SENSITIVE | KVM_XICS_PENDING;
+ else if (irqp->masked_pending || irqp->resend)
+ val |= KVM_XICS_PENDING;
+ ret = 0;
+ }
+ mutex_unlock(&ics->lock);
+
+ if (!ret && put_user(val, ubufp))
+ ret = -EFAULT;
+
+ return ret;
+}
+
+static int xics_set_source(struct kvm *kvm, long irq, u64 addr)
+{
+ struct kvmppc_xics *xics = kvm->arch.xics;
+ struct kvmppc_ics *ics;
+ struct ics_irq_state *irqp;
+ u64 __user *ubufp = (u64 __user *) addr;
+ u16 idx;
+ u64 val;
+ u8 prio;
+ u32 server;
+
+ if (irq < KVMPPC_XICS_FIRST_IRQ || irq >= KVMPPC_XICS_NR_IRQS)
+ return -ENOENT;
+
+ ics = kvmppc_xics_find_ics(xics, irq, &idx);
+ if (!ics) {
+ ics = kvmppc_xics_create_ics(xics, irq);
+ if (!ics)
+ return -ENOMEM;
+ }
+ irqp = &ics->irq_state[idx];
+ if (get_user(val, ubufp))
+ return -EFAULT;
+
+ server = val & KVM_XICS_DESTINATION_MASK;
+ prio = val >> KVM_XICS_PRIORITY_SHIFT;
+ if (prio != MASKED && kvmppc_xics_find_server(kvm, server) == NULL)
+ return -EINVAL;
+
+ mutex_lock(&ics->lock);
+ irqp->server = server;
+ irqp->saved_priority = prio;
+ if (val & KVM_XICS_MASKED)
+ prio = MASKED;
+ irqp->priority = prio;
+ irqp->resend = 0;
+ irqp->masked_pending = 0;
+ irqp->asserted = 0;
+ if ((val & KVM_XICS_PENDING) && (val & KVM_XICS_LEVEL_SENSITIVE))
+ irqp->asserted = 1;
+ irqp->exists = 1;
+ mutex_unlock(&ics->lock);
+
+ if (val & KVM_XICS_PENDING)
+ icp_deliver_irq(xics, NULL, irqp->number);
+
+ return 0;
+}
+
/* -- ioctls -- */
int kvm_vm_ioctl_xics_irq(struct kvm *kvm, struct kvm_irq_level *args)
@@ -1069,14 +1158,70 @@ int kvm_vm_ioctl_xics_irq(struct kvm *kvm, struct kvm_irq_level *args)
return r;
}
-void kvmppc_xics_free(struct kvmppc_xics *xics)
+static int xics_set_attr(struct kvmppc_xics *xics, struct kvm_device_attr *attr)
+{
+ switch (attr->group) {
+ case KVM_DEV_XICS_GRP_SOURCES:
+ return xics_set_source(xics->kvm, attr->attr, attr->addr);
+ }
+ return -ENXIO;
+}
+
+static int xics_get_attr(struct kvmppc_xics *xics, struct kvm_device_attr *attr)
+{
+ switch (attr->group) {
+ case KVM_DEV_XICS_GRP_SOURCES:
+ return xics_get_source(xics->kvm, attr->attr, attr->addr);
+ }
+ return -ENXIO;
+}
+
+static int xics_has_attr(struct kvmppc_xics *xics, struct kvm_device_attr *attr)
+{
+ switch (attr->group) {
+ case KVM_DEV_XICS_GRP_SOURCES:
+ if (attr->attr >= KVMPPC_XICS_FIRST_IRQ &&
+ attr->attr < KVMPPC_XICS_NR_IRQS)
+ return 0;
+ break;
+ }
+ return -ENXIO;
+}
+
+static long kvm_xics_ioctl(struct file *filp, unsigned int ioctl,
+ unsigned long arg)
+{
+ struct kvmppc_xics *xics = filp->private_data;
+ struct kvm_device_attr attr;
+ int (*accessor)(struct kvmppc_xics *xics, struct kvm_device_attr *attr);
+
+ switch (ioctl) {
+ case KVM_SET_DEVICE_ATTR:
+ accessor = xics_set_attr;
+ break;
+ case KVM_GET_DEVICE_ATTR:
+ accessor = xics_get_attr;
+ break;
+ case KVM_HAS_DEVICE_ATTR:
+ accessor = xics_has_attr;
+ break;
+ default:
+ return -ENOTTY;
+ }
+
+ if (copy_from_user(&attr, (void __user *)arg, sizeof(attr)))
+ return -EFAULT;
+
+ return accessor(xics, &attr);
+}
+
+static void kvmppc_xics_free(struct kvmppc_xics *xics)
{
int i;
debugfs_remove(xics->dentry);
if (xics->kvm) {
- kvm_put_kvm(xics->kvm);
xics->kvm->arch.xics = NULL;
xics->kvm = NULL;
}
@@ -1088,9 +1233,30 @@ void kvmppc_xics_free(struct kvmppc_xics *xics)
kfree(xics);
}
+static void kvmppc_xics_put(struct kvmppc_xics *xics)
+{
+ if (xics && atomic_dec_and_test(&xics->usecount))
+ kvmppc_xics_free(xics);
+}
+
+static int kvm_xics_release(struct inode *inode, struct file *filp)
+{
+ struct kvmppc_xics *xics = filp->private_data;
+
+ kvmppc_xics_put(xics);
+ kvm_put_kvm(xics->kvm);
+ return 0;
+}
+
+static const struct file_operations kvm_xics_fops = {
+ .unlocked_ioctl = kvm_xics_ioctl,
+ .release = kvm_xics_release,
+};
+
int kvm_create_xics(struct kvm *kvm, u32 type)
{
struct kvmppc_xics *xics;
+ int fd;
/* Already there ? */
if (kvm->arch.xics)
@@ -1100,6 +1266,12 @@ int kvm_create_xics(struct kvm *kvm, u32 type)
if (!xics)
return -ENOMEM;
+ fd = anon_inode_getfd("kvm-xics", &kvm_xics_fops, xics, O_RDWR);
+ if (fd < 0) {
+ kfree(xics);
+ return fd;
+ }
+
xics->kvm = kvm;
kvm->arch.xics = xics;
xics_debugfs_init(xics);
@@ -1112,8 +1284,31 @@ int kvm_create_xics(struct kvm *kvm, u32 type)
}
#endif /* CONFIG_KVM_BOOK3S_64_HV */
+ atomic_set(&xics->usecount, 1);
kvm_get_kvm(kvm);
- return 0;
+ return fd;
+}
+
+int kvmppc_xics_connect_vcpu(struct file *xics_filp, struct kvm_vcpu *vcpu,
+ u32 xcpu)
+{
+ struct kvmppc_xics *xics = xics_filp->private_data;
+ int r = -EBUSY;
+
+ if (xics_filp->f_op != &kvm_xics_fops)
+ return -EPERM;
+ if (xics->kvm != vcpu->kvm)
+ return -EPERM;
+ if (vcpu->arch.irq_type)
+ return -EBUSY;
+
+ r = kvmppc_xics_create_icp(vcpu, xcpu);
+ if (!r) {
+ atomic_inc(&xics->usecount);
+ vcpu->arch.irq_type = KVMPPC_IRQ_XICS;
+ }
+
+ return r;
}
void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu)
@@ -1123,4 +1318,5 @@ void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu)
kfree(vcpu->arch.icp);
vcpu->arch.icp = NULL;
vcpu->arch.irq_type = KVMPPC_IRQ_DEFAULT;
+ kvmppc_xics_put(vcpu->kvm->arch.xics);
}
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index bc6d7cf..b6dd4aa 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -341,6 +341,9 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_SPAPR_TCE:
case KVM_CAP_PPC_ALLOC_HTAB:
case KVM_CAP_PPC_RTAS:
+#ifdef CONFIG_KVM_XICS
+ case KVM_CAP_IRQ_XICS:
+#endif
r = 1;
break;
#endif /* CONFIG_PPC_BOOK3S_64 */
@@ -830,6 +833,21 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
break;
}
#endif
+#ifdef CONFIG_KVM_XICS
+ case KVM_CAP_IRQ_XICS: {
+ struct file *filp;
+
+ r = -EBADF;
+ filp = fget(cap->args[0]);
+ if (!filp)
+ break;
+
+ r = kvmppc_xics_connect_vcpu(filp, vcpu, cap->args[1]);
+
+ fput(filp);
+ break;
+ }
+#endif /* CONFIG_KVM_XICS */
default:
r = -EINVAL;
break;
@@ -1038,6 +1056,19 @@ long kvm_arch_vm_ioctl(struct file *filp,
break;
}
#endif /* CONFIG_PPC_BOOK3S_64 */
+
+ case KVM_IRQ_LINE: {
+ struct kvm *kvm = filp->private_data;
+ struct kvm_irq_level args;
+
+ r = -EFAULT;
+ if (copy_from_user(&args, argp, sizeof(args)))
+ break;
+
+ /* Call all the interrupt controllers */
+ r = kvm_vm_ioctl_xics_irq(kvm, &args);
+ break;
+ }
default:
r = -ENOTTY;
}
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 852a3a1..41963e0 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1085,6 +1085,7 @@ static inline bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu)
}
int kvm_create_mpic(struct kvm *kvm, u32 type);
+extern int kvm_create_xics(struct kvm *kvm, u32 type);
#endif /* CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT */
#else
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 373f4aa..28b269e 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -671,6 +671,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_DEVICE_CTRL 89
#define KVM_CAP_IRQ_MPIC 90
#define KVM_CAP_PPC_RTAS 91
+#define KVM_CAP_IRQ_XICS 92
#ifdef KVM_CAP_IRQ_ROUTING
@@ -940,6 +941,19 @@ struct kvm_device_attr {
#define KVM_DEV_MPIC_GRP_REGISTER 2 /* 32-bit */
#define KVM_DEV_MPIC_GRP_IRQ_ACTIVE 3 /* 32-bit */
+/* PPC64 eXternal Interrupt Controller Specification */
+#define KVM_DEV_TYPE_XICS 3
+#define KVM_DEV_XICS_GRP_SOURCES 1 /* 64-bit source attributes */
+
+/* Layout of 64-bit source attribute values */
+#define KVM_XICS_DESTINATION_SHIFT 0
+#define KVM_XICS_DESTINATION_MASK 0xffffffffULL
+#define KVM_XICS_PRIORITY_SHIFT 32
+#define KVM_XICS_PRIORITY_MASK 0xff
+#define KVM_XICS_LEVEL_SENSITIVE (1ULL << 40)
+#define KVM_XICS_MASKED (1ULL << 41)
+#define KVM_XICS_PENDING (1ULL << 42)
+
/* ioctl for vm fd */
#define KVM_CREATE_DEVICE _IOWR(KVMIO, 0xe0, struct kvm_create_device)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index ca3adf9..b97d3e9 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2171,6 +2171,20 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
return kvm_create_mpic(kvm, cd->type);
}
#endif
+#ifdef CONFIG_KVM_XICS
+ case KVM_DEV_TYPE_XICS: {
+ int fd;
+
+ if (cd->flags & KVM_CREATE_DEVICE_TEST)
+ return 0;
+
+ fd = kvm_create_xics(kvm, cd->type);
+ if (fd < 0)
+ return fd;
+ cd->fd = fd;
+ return 0;
+ }
+#endif
default:
return -ENODEV;
}
--
1.7.10.4
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