[PATCH 04/14] KVM: PPC: Book3S HV: Introduce kvmppc_passthru_irqmap

[Suresh Warrier]

This patch introduces an IRQ mapping structure, the
kvmppc_passthru_irqmap structure that is to be used
to map the real hardware IRQ in the host with the virtual
hardware IRQ (gsi) that is injected into a guest by KVM for
passthrough adapters.

Currently, we assume a separate IRQ mapping structure for
each guest. Each kvmppc_passthru_irqmap has two mapping arrays,
the mapped array contains all defined real<->virtual IRQs, the
cached array can be used to limit the real<->virtual IRQs to
a smaller subset, like a cache of the most frequently used
mappings.

Signed-off-by: Suresh Warrier <warrier at linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/kvm_host.h | 21 +++++++++++++++++++++
 arch/powerpc/include/asm/kvm_ppc.h  | 15 +++++++++++++++
 arch/powerpc/kvm/book3s_hv.c        | 19 +++++++++++++++++++
 3 files changed, 55 insertions(+)

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index ffdbc2d..fc10248 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -191,6 +191,8 @@ struct kvmppc_spapr_tce_table {
 struct kvmppc_xics;
 struct kvmppc_icp;
 
+struct kvmppc_passthru_irqmap;
+
 /*
  * The reverse mapping array has one entry for each HPTE,
  * which stores the guest's view of the second word of the HPTE
@@ -261,6 +263,7 @@ struct kvm_arch {
 #endif
 #ifdef CONFIG_KVM_XICS
 	struct kvmppc_xics *xics;
+	struct kvmppc_passthru_irqmap *pimap;
 #endif
 	struct kvmppc_ops *kvm_ops;
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
@@ -391,6 +394,24 @@ struct kvmhv_tb_accumulator {
 	u64	tb_max;		/* max time */
 };
 
+#ifdef CONFIG_PPC_BOOK3S_64
+struct kvmppc_irq_map {
+	u32	r_hwirq;
+	u32	v_hwirq;
+	struct irq_desc *desc;
+};
+
+#define	KVMPPC_PIRQ_CACHED	16
+#define	KVMPPC_PIRQ_MAPPED	1024
+struct kvmppc_passthru_irqmap {
+	int n_cached;
+	int n_mapped;
+	struct irq_chip *irq_chip;
+	struct kvmppc_irq_map cached[KVMPPC_PIRQ_CACHED];
+	struct kvmppc_irq_map mapped[KVMPPC_PIRQ_MAPPED];
+};
+#endif
+
 # ifdef CONFIG_PPC_FSL_BOOK3E
 #define KVMPPC_BOOKE_IAC_NUM	2
 #define KVMPPC_BOOKE_DAC_NUM	2
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 780a017..75d4c64 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -457,8 +457,19 @@ static inline int kvmppc_xics_enabled(struct kvm_vcpu *vcpu)
 {
 	return vcpu->arch.irq_type == KVMPPC_IRQ_XICS;
 }
+
+static inline struct kvmppc_passthru_irqmap *kvmppc_get_passthru_irqmap(
+				struct kvm_vcpu *vcpu)
+{
+	if (vcpu)
+		return vcpu->kvm->arch.pimap;
+	else
+		return NULL;
+}
+
 extern void kvmppc_alloc_host_rm_ops(void);
 extern void kvmppc_free_host_rm_ops(void);
+extern void kvmppc_free_pimap(struct kvm *kvm);
 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);
@@ -470,8 +481,12 @@ extern int kvmppc_xics_connect_vcpu(struct kvm_device *dev,
 extern void kvmppc_xics_ipi_action(void);
 extern int h_ipi_redirect;
 #else
+static inline struct kvmppc_passthru_irqmap *kvmppc_get_passthru_irqmap(
+				struct kvm_vcpu *vcpu)
+	{ return NULL; }
 static inline void kvmppc_alloc_host_rm_ops(void) {};
 static inline void kvmppc_free_host_rm_ops(void) {};
+static inline void kvmppc_free_pimap(struct kvm *kvm) {};
 static inline int kvmppc_xics_enabled(struct kvm_vcpu *vcpu)
 	{ return 0; }
 static inline void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu) { }
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index f47fffe..22d3054 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3275,6 +3275,25 @@ static int kvmppc_core_check_processor_compat_hv(void)
 	return 0;
 }
 
+#ifdef CONFIG_KVM_XICS
+
+void kvmppc_free_pimap(struct kvm *kvm)
+{
+	kfree(kvm->arch.pimap);
+}
+
+struct kvmppc_passthru_irqmap *kvmppc_alloc_pimap(struct irq_desc *desc)
+{
+	struct kvmppc_passthru_irqmap *pimap;
+
+	pimap = kzalloc(sizeof(struct kvmppc_passthru_irqmap), GFP_KERNEL);
+	if (pimap != NULL)
+		pimap->irq_chip = irq_data_get_irq_chip(&desc->irq_data);
+
+	return pimap;
+}
+#endif
+
 static long kvm_arch_vm_ioctl_hv(struct file *filp,
 				 unsigned int ioctl, unsigned long arg)
 {
-- 
1.8.3.4