KVM: PPC: Book3S: Add kernel emulation for the XICS interrupt controller

This adds in-kernel emulation of the XICS (eXternal Interrupt
Controller Specification) interrupt controller specified by PAPR, for
both HV and PR KVM guests.

The XICS emulation supports up to 1048560 interrupt sources.
Interrupt source numbers below 16 are reserved; 0 is used to mean no
interrupt and 2 is used for IPIs.  Internally these are represented in
blocks of 1024, called ICS (interrupt controller source) entities, but
that is not visible to userspace.

Each vcpu gets one ICP (interrupt controller presentation) entity,
used to store the per-vcpu state such as vcpu priority, pending
interrupt state, IPI request, etc.

This does not include any API or any way to connect vcpus to their
ICP state; that will be added in later patches.

This is based on an initial implementation by Michael Ellerman
<michael@ellerman.id.au> reworked by Benjamin Herrenschmidt and
Paul Mackerras.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
[agraf: fix typo, add dependency on !KVM_MPIC]
Signed-off-by: Alexander Graf <agraf@suse.de>

3 files changed, 42 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index c55f7e6affaa..349ed85c7d61 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -142,6 +142,8 @@ extern int kvmppc_mmu_hv_init(void);
 extern int kvmppc_ld(struct kvm_vcpu *vcpu, ulong *eaddr, int size, void *ptr, bool data);
 extern int kvmppc_st(struct kvm_vcpu *vcpu, ulong *eaddr, int size, void *ptr, bool data);
 extern void kvmppc_book3s_queue_irqprio(struct kvm_vcpu *vcpu, unsigned int vec);
+extern void kvmppc_book3s_dequeue_irqprio(struct kvm_vcpu *vcpu,
+                                          unsigned int vec);
 extern void kvmppc_inject_interrupt(struct kvm_vcpu *vcpu, int vec, u64 flags);
 extern void kvmppc_set_bat(struct kvm_vcpu *vcpu, struct kvmppc_bat *bat,
                            bool upper, u32 val);
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 311f7e6f09e9..af326cde7cb6 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -192,6 +192,10 @@ struct kvmppc_linear_info {
         int              type;
 };
 
+/* XICS components, defined in book3s_xics.c */
+struct kvmppc_xics;
+struct kvmppc_icp;
+
 /*
  * The reverse mapping array has one entry for each HPTE,
  * which stores the guest's view of the second word of the HPTE
@@ -264,6 +268,9 @@ struct kvm_arch {
 #ifdef CONFIG_KVM_MPIC
         struct openpic *mpic;
 #endif
+#ifdef CONFIG_KVM_XICS
+        struct kvmppc_xics *xics;
+#endif
 };
 
 /*
@@ -387,6 +394,7 @@ struct kvmppc_booke_debug_reg {
 
 #define KVMPPC_IRQ_DEFAULT      0
 #define KVMPPC_IRQ_MPIC         1
+#define KVMPPC_IRQ_XICS         2
 
 struct openpic;
 
@@ -574,6 +582,9 @@ struct kvm_vcpu_arch {
         int irq_type;           /* one of KVM_IRQ_* */
         int irq_cpu_id;
         struct openpic *mpic;   /* KVM_IRQ_MPIC */
+#ifdef CONFIG_KVM_XICS
+        struct kvmppc_icp *icp; /* XICS presentation controller */
+#endif
 
 #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 8a30eb7f2bec..6582eed321ba 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -130,6 +130,7 @@ extern long kvmppc_prepare_vrma(struct kvm *kvm,
 extern void kvmppc_map_vrma(struct kvm_vcpu *vcpu,
                         struct kvm_memory_slot *memslot, unsigned long porder);
 extern int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu);
+
 extern long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
                                 struct kvm_create_spapr_tce *args);
 extern long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
@@ -169,6 +170,10 @@ int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq);
 extern int kvm_vm_ioctl_rtas_define_token(struct kvm *kvm, void __user *argp);
 extern int kvmppc_rtas_hcall(struct kvm_vcpu *vcpu);
 extern void kvmppc_rtas_tokens_free(struct kvm *kvm);
+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);
 
 /*
  * Cuts out inst bits with ordering according to spec.
@@ -267,6 +272,30 @@ static inline void kvmppc_set_xics_phys(int cpu, unsigned long addr)
 
 static inline void kvm_linear_init(void)
 {}
+
+#endif
+
+#ifdef CONFIG_KVM_XICS
+static inline int kvmppc_xics_enabled(struct kvm_vcpu *vcpu)
+{
+        return vcpu->arch.irq_type == KVMPPC_IRQ_XICS;
+}
+extern void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu);
+extern int kvmppc_xics_create_icp(struct kvm_vcpu *vcpu, unsigned long server);
+extern int kvm_vm_ioctl_xics_irq(struct kvm *kvm, struct kvm_irq_level *args);
+extern int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd);
+#else
+static inline int kvmppc_xics_enabled(struct kvm_vcpu *vcpu)
+        { return 0; }
+static inline void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu) { }
+static inline int kvmppc_xics_create_icp(struct kvm_vcpu *vcpu,
+                                         unsigned long server)
+        { return -EINVAL; }
+static inline int kvm_vm_ioctl_xics_irq(struct kvm *kvm,
+                                        struct kvm_irq_level *args)
+        { return -ENOTTY; }
+static inline int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd)
+        { return 0; }
 #endif
 
 static inline void kvmppc_set_epr(struct kvm_vcpu *vcpu, u32 epr)