KVM: PPC: Book3S: Add support for ibm,int-on/off RTAS calls

This adds support for the ibm,int-on and ibm,int-off RTAS calls to the
in-kernel XICS emulation and corrects the handling of the saved
priority by the ibm,set-xive RTAS call.  With this, ibm,int-off sets
the specified interrupt's priority in its saved_priority field and
sets the priority to 0xff (the least favoured value).  ibm,int-on
restores the saved_priority to the priority field, and ibm,set-xive
sets both the priority and the saved_priority to the specified
priority value.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

4 files changed, 113 insertions, 15 deletions

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 1589fd8bf063..cfaa47995c0e 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -174,6 +174,8 @@ extern int kvmppc_xics_set_xive(struct kvm *kvm, u32 irq, u32 server,
                                 u32 priority);
 extern int kvmppc_xics_get_xive(struct kvm *kvm, u32 irq, u32 *server,
                                 u32 *priority);
+extern int kvmppc_xics_int_on(struct kvm *kvm, u32 irq);
+extern int kvmppc_xics_int_off(struct kvm *kvm, u32 irq);
 
 /*
  * Cuts out inst bits with ordering according to spec.
diff --git a/arch/powerpc/kvm/book3s_rtas.c b/arch/powerpc/kvm/book3s_rtas.c
index 77f9aa5f4ba5..3219ba895246 100644
--- a/arch/powerpc/kvm/book3s_rtas.c
+++ b/arch/powerpc/kvm/book3s_rtas.c
@@ -63,6 +63,44 @@ static void kvm_rtas_get_xive(struct kvm_vcpu *vcpu, struct rtas_args *args)
 out:
         args->rets[0] = rc;
 }
+
+static void kvm_rtas_int_off(struct kvm_vcpu *vcpu, struct rtas_args *args)
+{
+        u32 irq;
+        int rc;
+
+        if (args->nargs != 1 || args->nret != 1) {
+                rc = -3;
+                goto out;
+        }
+
+        irq = args->args[0];
+
+        rc = kvmppc_xics_int_off(vcpu->kvm, irq);
+        if (rc)
+                rc = -3;
+out:
+        args->rets[0] = rc;
+}
+
+static void kvm_rtas_int_on(struct kvm_vcpu *vcpu, struct rtas_args *args)
+{
+        u32 irq;
+        int rc;
+
+        if (args->nargs != 1 || args->nret != 1) {
+                rc = -3;
+                goto out;
+        }
+
+        irq = args->args[0];
+
+        rc = kvmppc_xics_int_on(vcpu->kvm, irq);
+        if (rc)
+                rc = -3;
+out:
+        args->rets[0] = rc;
+}
 #endif /* CONFIG_KVM_XICS */
 
 struct rtas_handler {
@@ -74,6 +112,8 @@ static struct rtas_handler rtas_handlers[] = {
 #ifdef CONFIG_KVM_XICS
         { .name = "ibm,set-xive", .handler = kvm_rtas_set_xive },
         { .name = "ibm,get-xive", .handler = kvm_rtas_get_xive },
+        { .name = "ibm,int-off",  .handler = kvm_rtas_int_off },
+        { .name = "ibm,int-on",   .handler = kvm_rtas_int_on },
 #endif
 };
 
diff --git a/arch/powerpc/kvm/book3s_xics.c b/arch/powerpc/kvm/book3s_xics.c
index 7fd247cbd0d1..9fb2d3909c46 100644
--- a/arch/powerpc/kvm/book3s_xics.c
+++ b/arch/powerpc/kvm/book3s_xics.c
@@ -123,6 +123,28 @@ static void ics_check_resend(struct kvmppc_xics *xics, struct kvmppc_ics *ics,
         mutex_unlock(&ics->lock);
 }
 
+static bool write_xive(struct kvmppc_xics *xics, struct kvmppc_ics *ics,
+                       struct ics_irq_state *state,
+                       u32 server, u32 priority, u32 saved_priority)
+{
+        bool deliver;
+
+        mutex_lock(&ics->lock);
+
+        state->server = server;
+        state->priority = priority;
+        state->saved_priority = saved_priority;
+        deliver = false;
+        if ((state->masked_pending || state->resend) && priority != MASKED) {
+                state->masked_pending = 0;
+                deliver = true;
+        }
+
+        mutex_unlock(&ics->lock);
+
+        return deliver;
+}
+
 int kvmppc_xics_set_xive(struct kvm *kvm, u32 irq, u32 server, u32 priority)
 {
         struct kvmppc_xics *xics = kvm->arch.xics;
@@ -130,7 +152,6 @@ int kvmppc_xics_set_xive(struct kvm *kvm, u32 irq, u32 server, u32 priority)
         struct kvmppc_ics *ics;
         struct ics_irq_state *state;
         u16 src;
-        bool deliver;
 
         if (!xics)
                 return -ENODEV;
@@ -144,23 +165,11 @@ int kvmppc_xics_set_xive(struct kvm *kvm, u32 irq, u32 server, u32 priority)
         if (!icp)
                 return -EINVAL;
 
-        mutex_lock(&ics->lock);
-
         XICS_DBG("set_xive %#x server %#x prio %#x MP:%d RS:%d\n",
                  irq, server, priority,
                  state->masked_pending, state->resend);
 
-        state->server = server;
-        state->priority = priority;
-        deliver = false;
-        if ((state->masked_pending || state->resend) && priority != MASKED) {
-                state->masked_pending = 0;
-                deliver = true;
-        }
-
-        mutex_unlock(&ics->lock);
-
-        if (deliver)
+        if (write_xive(xics, ics, state, server, priority, priority))
                 icp_deliver_irq(xics, icp, irq);
 
         return 0;
@@ -189,6 +198,53 @@ int kvmppc_xics_get_xive(struct kvm *kvm, u32 irq, u32 *server, u32 *priority)
         return 0;
 }
 
+int kvmppc_xics_int_on(struct kvm *kvm, u32 irq)
+{
+        struct kvmppc_xics *xics = kvm->arch.xics;
+        struct kvmppc_icp *icp;
+        struct kvmppc_ics *ics;
+        struct ics_irq_state *state;
+        u16 src;
+
+        if (!xics)
+                return -ENODEV;
+
+        ics = kvmppc_xics_find_ics(xics, irq, &src);
+        if (!ics)
+                return -EINVAL;
+        state = &ics->irq_state[src];
+
+        icp = kvmppc_xics_find_server(kvm, state->server);
+        if (!icp)
+                return -EINVAL;
+
+        if (write_xive(xics, ics, state, state->server, state->saved_priority,
+                       state->saved_priority))
+                icp_deliver_irq(xics, icp, irq);
+
+        return 0;
+}
+
+int kvmppc_xics_int_off(struct kvm *kvm, u32 irq)
+{
+        struct kvmppc_xics *xics = kvm->arch.xics;
+        struct kvmppc_ics *ics;
+        struct ics_irq_state *state;
+        u16 src;
+
+        if (!xics)
+                return -ENODEV;
+
+        ics = kvmppc_xics_find_ics(xics, irq, &src);
+        if (!ics)
+                return -EINVAL;
+        state = &ics->irq_state[src];
+
+        write_xive(xics, ics, state, state->server, MASKED, state->priority);
+
+        return 0;
+}
+
 /* -- ICP routines, including hcalls -- */
 
 static inline bool icp_try_update(struct kvmppc_icp *icp,
diff --git a/arch/powerpc/kvm/book3s_xics.h b/arch/powerpc/kvm/book3s_xics.h
index c816c5a49c90..e4fdec3dde77 100644
--- a/arch/powerpc/kvm/book3s_xics.h
+++ b/arch/powerpc/kvm/book3s_xics.h
@@ -36,7 +36,7 @@ struct ics_irq_state {
         u32 number;
         u32 server;
         u8  priority;
-        u8  saved_priority; /* currently unused */
+        u8  saved_priority;
         u8  resend;
         u8  masked_pending;
         u8  asserted; /* Only for LSI */