kvm/ppc/mpic: add KVM_CAP_IRQ_MPIC

Enabling this capability connects the vcpu to the designated in-kernel
MPIC.  Using explicit connections between vcpus and irqchips allows
for flexibility, but the main benefit at the moment is that it
simplifies the code -- KVM doesn't need vm-global state to remember
which MPIC object is associated with this vm, and it doesn't need to
care about ordering between irqchip creation and vcpu creation.

Signed-off-by: Scott Wood <scottwood@freescale.com>
[agraf: add stub functions for kvmppc_mpic_{dis,}connect_vcpu]
Signed-off-by: Alexander Graf <agraf@suse.de>

5 files changed, 132 insertions, 8 deletions

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 153c8c2b0f88..c3f8ceffa412 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -377,6 +377,11 @@ struct kvmppc_booke_debug_reg {
         u64 dac[KVMPPC_BOOKE_MAX_DAC];
 };
 
+#define KVMPPC_IRQ_DEFAULT      0
+#define KVMPPC_IRQ_MPIC         1
+
+struct openpic;
+
 struct kvm_vcpu_arch {
         ulong host_stack;
         u32 host_pid;
@@ -558,6 +563,10 @@ struct kvm_vcpu_arch {
         unsigned long magic_page_pa; /* phys addr to map the magic page to */
         unsigned long magic_page_ea; /* effect. addr to map the magic page to */
 
+        int irq_type;           /* one of KVM_IRQ_* */
+        int irq_cpu_id;
+        struct openpic *mpic;   /* KVM_IRQ_MPIC */
+
 #ifdef CONFIG_KVM_BOOK3S_64_HV
         struct kvm_vcpu_arch_shared shregs;
 
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 3810f9c7616c..df9c80b37905 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -248,7 +248,6 @@ int kvmppc_set_one_reg(struct kvm_vcpu *vcpu, u64 id, union kvmppc_one_reg *);
 void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 pid);
 
 struct openpic;
-void kvmppc_mpic_put(struct openpic *opp);
 
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 static inline void kvmppc_set_xics_phys(int cpu, unsigned long addr)
@@ -278,6 +277,9 @@ static inline void kvmppc_set_epr(struct kvm_vcpu *vcpu, u32 epr)
 #ifdef CONFIG_KVM_MPIC
 
 void kvmppc_mpic_set_epr(struct kvm_vcpu *vcpu);
+int kvmppc_mpic_connect_vcpu(struct kvm_device *dev, struct kvm_vcpu *vcpu,
+                             u32 cpu);
+void kvmppc_mpic_disconnect_vcpu(struct openpic *opp, struct kvm_vcpu *vcpu);
 
 #else
 
@@ -285,6 +287,17 @@ static inline void kvmppc_mpic_set_epr(struct kvm_vcpu *vcpu)
 {
 }
 
+static inline int kvmppc_mpic_connect_vcpu(struct kvm_device *dev,
+                struct kvm_vcpu *vcpu, u32 cpu)
+{
+        return -EINVAL;
+}
+
+static inline void kvmppc_mpic_disconnect_vcpu(struct openpic *opp,
+                struct kvm_vcpu *vcpu)
+{
+}
+
 #endif /* CONFIG_KVM_MPIC */
 
 int kvm_vcpu_ioctl_config_tlb(struct kvm_vcpu *vcpu,
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 4da11ed48c59..1020119226db 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -430,6 +430,10 @@ static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
                 if (update_epr == true) {
                         if (vcpu->arch.epr_flags & KVMPPC_EPR_USER)
                                 kvm_make_request(KVM_REQ_EPR_EXIT, vcpu);
+                        else if (vcpu->arch.epr_flags & KVMPPC_EPR_KERNEL) {
+                                BUG_ON(vcpu->arch.irq_type != KVMPPC_IRQ_MPIC);
+                                kvmppc_mpic_set_epr(vcpu);
+                        }
                 }
 
                 new_msr &= msr_mask;
diff --git a/arch/powerpc/kvm/mpic.c b/arch/powerpc/kvm/mpic.c
index cb451b91e342..10bc08a246fd 100644
--- a/arch/powerpc/kvm/mpic.c
+++ b/arch/powerpc/kvm/mpic.c
@@ -115,7 +115,7 @@ static int get_current_cpu(void)
 {
 #if defined(CONFIG_KVM) && defined(CONFIG_BOOKE)
         struct kvm_vcpu *vcpu = current->thread.kvm_vcpu;
-        return vcpu ? vcpu->vcpu_id : -1;
+        return vcpu ? vcpu->arch.irq_cpu_id : -1;
 #else
         /* XXX */
         return -1;
@@ -249,7 +249,7 @@ static void mpic_irq_raise(struct openpic *opp, struct irq_dest *dst,
                 return;
         }
 
-        pr_debug("%s: cpu %d output %d\n", __func__, dst->vcpu->vcpu_id,
+        pr_debug("%s: cpu %d output %d\n", __func__, dst->vcpu->arch.irq_cpu_id,
                 output);
 
         if (output != ILR_INTTGT_INT)   /* TODO */
@@ -267,7 +267,7 @@ static void mpic_irq_lower(struct openpic *opp, struct irq_dest *dst,
                 return;
         }
 
-        pr_debug("%s: cpu %d output %d\n", __func__, dst->vcpu->vcpu_id,
+        pr_debug("%s: cpu %d output %d\n", __func__, dst->vcpu->arch.irq_cpu_id,
                 output);
 
         if (output != ILR_INTTGT_INT)   /* TODO */
@@ -1165,6 +1165,20 @@ static uint32_t openpic_iack(struct openpic *opp, struct irq_dest *dst,
         return retval;
 }
 
+void kvmppc_mpic_set_epr(struct kvm_vcpu *vcpu)
+{
+        struct openpic *opp = vcpu->arch.mpic;
+        int cpu = vcpu->arch.irq_cpu_id;
+        unsigned long flags;
+
+        spin_lock_irqsave(&opp->lock, flags);
+
+        if ((opp->gcr & opp->mpic_mode_mask) == GCR_MODE_PROXY)
+                kvmppc_set_epr(vcpu, openpic_iack(opp, &opp->dst[cpu], cpu));
+
+        spin_unlock_irqrestore(&opp->lock, flags);
+}
+
 static int openpic_cpu_read_internal(void *opaque, gpa_t addr,
                                      u32 *ptr, int idx)
 {
@@ -1431,10 +1445,10 @@ static void map_mmio(struct openpic *opp)
 
 static void unmap_mmio(struct openpic *opp)
 {
-        BUG_ON(opp->mmio_mapped);
-        opp->mmio_mapped = false;
-
-        kvm_io_bus_unregister_dev(opp->kvm, KVM_MMIO_BUS, &opp->mmio);
+        if (opp->mmio_mapped) {
+                opp->mmio_mapped = false;
+                kvm_io_bus_unregister_dev(opp->kvm, KVM_MMIO_BUS, &opp->mmio);
+        }
 }
 
 static int set_base_addr(struct openpic *opp, struct kvm_device_attr *attr)
@@ -1693,3 +1707,57 @@ struct kvm_device_ops kvm_mpic_ops = {
         .get_attr = mpic_get_attr,
         .has_attr = mpic_has_attr,
 };
+
+int kvmppc_mpic_connect_vcpu(struct kvm_device *dev, struct kvm_vcpu *vcpu,
+                             u32 cpu)
+{
+        struct openpic *opp = dev->private;
+        int ret = 0;
+
+        if (dev->ops != &kvm_mpic_ops)
+                return -EPERM;
+        if (opp->kvm != vcpu->kvm)
+                return -EPERM;
+        if (cpu < 0 || cpu >= MAX_CPU)
+                return -EPERM;
+
+        spin_lock_irq(&opp->lock);
+
+        if (opp->dst[cpu].vcpu) {
+                ret = -EEXIST;
+                goto out;
+        }
+        if (vcpu->arch.irq_type) {
+                ret = -EBUSY;
+                goto out;
+        }
+
+        opp->dst[cpu].vcpu = vcpu;
+        opp->nb_cpus = max(opp->nb_cpus, cpu + 1);
+
+        vcpu->arch.mpic = opp;
+        vcpu->arch.irq_cpu_id = cpu;
+        vcpu->arch.irq_type = KVMPPC_IRQ_MPIC;
+
+        /* This might need to be changed if GCR gets extended */
+        if (opp->mpic_mode_mask == GCR_MODE_PROXY)
+                vcpu->arch.epr_flags |= KVMPPC_EPR_KERNEL;
+
+        kvm_device_get(dev);
+out:
+        spin_unlock_irq(&opp->lock);
+        return ret;
+}
+
+/*
+ * This should only happen immediately before the mpic is destroyed,
+ * so we shouldn't need to worry about anything still trying to
+ * access the vcpu pointer.
+ */
+void kvmppc_mpic_disconnect_vcpu(struct openpic *opp, struct kvm_vcpu *vcpu)
+{
+        BUG_ON(!opp->dst[vcpu->arch.irq_cpu_id].vcpu);
+
+        opp->dst[vcpu->arch.irq_cpu_id].vcpu = NULL;
+        kvm_device_put(opp->dev);
+}
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 88d69cf1f953..5d046bbdf11f 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -25,6 +25,7 @@
 #include <linux/hrtimer.h>
 #include <linux/fs.h>
 #include <linux/slab.h>
+#include <linux/file.h>
 #include <asm/cputable.h>
 #include <asm/uaccess.h>
 #include <asm/kvm_ppc.h>
@@ -327,6 +328,9 @@ int kvm_dev_ioctl_check_extension(long ext)
 #if defined(CONFIG_KVM_E500V2) || defined(CONFIG_KVM_E500MC)
         case KVM_CAP_SW_TLB:
 #endif
+#ifdef CONFIG_KVM_MPIC
+        case KVM_CAP_IRQ_MPIC:
+#endif
                 r = 1;
                 break;
         case KVM_CAP_COALESCED_MMIO:
@@ -460,6 +464,13 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
         tasklet_kill(&vcpu->arch.tasklet);
 
         kvmppc_remove_vcpu_debugfs(vcpu);
+
+        switch (vcpu->arch.irq_type) {
+        case KVMPPC_IRQ_MPIC:
+                kvmppc_mpic_disconnect_vcpu(vcpu->arch.mpic, vcpu);
+                break;
+        }
+
         kvmppc_core_vcpu_free(vcpu);
 }
 
@@ -787,6 +798,25 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
                 break;
         }
 #endif
+#ifdef CONFIG_KVM_MPIC
+        case KVM_CAP_IRQ_MPIC: {
+                struct file *filp;
+                struct kvm_device *dev;
+
+                r = -EBADF;
+                filp = fget(cap->args[0]);
+                if (!filp)
+                        break;
+
+                r = -EPERM;
+                dev = kvm_device_from_filp(filp);
+                if (dev)
+                        r = kvmppc_mpic_connect_vcpu(dev, vcpu, cap->args[1]);
+
+                fput(filp);
+                break;
+        }
+#endif
         default:
                 r = -EINVAL;
                 break;