kvm/ppc/mpic: in-kernel MPIC emulation

Hook the MPIC code up to the KVM interfaces, add locking, etc.
Signed-off-by: Scott Wood <scottwood@freescale.com>
[agraf: add stub function for kvmppc_mpic_set_epr, non-booke, 64bit]
Signed-off-by: Alexander Graf <agraf@suse.de>

Documentation/virtual/kvm/devices/mpic.txt

+MPIC interrupt controller
+=========================
+
+Device types supported:
+  KVM_DEV_TYPE_FSL_MPIC_20     Freescale MPIC v2.0
+  KVM_DEV_TYPE_FSL_MPIC_42     Freescale MPIC v4.2
+
+Only one MPIC instance, of any type, may be instantiated.  The created
+MPIC will act as the system interrupt controller, connecting to each
+vcpu's interrupt inputs.
+
+Groups:
+  KVM_DEV_MPIC_GRP_MISC
+  Attributes:
+    KVM_DEV_MPIC_BASE_ADDR (rw, 64-bit)
+      Base address of the 256 KiB MPIC register space.  Must be
+      naturally aligned.  A value of zero disables the mapping.
+      Reset value is zero.
+
+  KVM_DEV_MPIC_GRP_REGISTER (rw, 32-bit)
+    Access an MPIC register, as if the access were made from the guest.
+    "attr" is the byte offset into the MPIC register space.  Accesses
+    must be 4-byte aligned.
+
+    MSIs may be signaled by using this attribute group to write
+    to the relevant MSIIR.
+
+  KVM_DEV_MPIC_GRP_IRQ_ACTIVE (rw, 32-bit)
+    IRQ input line for each standard openpic source.  0 is inactive and 1
+    is active, regardless of interrupt sense.
+
+    For edge-triggered interrupts:  Writing 1 is considered an activating
+    edge, and writing 0 is ignored.  Reading returns 1 if a previously
+    signaled edge has not been acknowledged, and 0 otherwise.
+
+    "attr" is the IRQ number.  IRQ numbers for standard sources are the
+    byte offset of the relevant IVPR from EIVPR0, divided by 32.

arch/powerpc/include/asm/kvm_host.h

@@ -361,6 +361,11 @@ struct kvmppc_slb {
 #define KVMPPC_BOOKE_MAX_IAC	4
 #define KVMPPC_BOOKE_MAX_DAC	2
 
+/* KVMPPC_EPR_USER takes precedence over KVMPPC_EPR_KERNEL */
+#define KVMPPC_EPR_NONE		0 /* EPR not supported */
+#define KVMPPC_EPR_USER		1 /* exit to userspace to fill EPR */
+#define KVMPPC_EPR_KERNEL	2 /* in-kernel irqchip */
+
 struct kvmppc_booke_debug_reg {
 	u32 dbcr0;
 	u32 dbcr1;
@@ -526,7 +531,7 @@ struct kvm_vcpu_arch {
 	u8 sane;
 	u8 cpu_type;
 	u8 hcall_needed;
-	u8 epr_enabled;
+	u8 epr_flags; /* KVMPPC_EPR_xxx */
 	u8 epr_needed;
 
 	u32 cpr0_cfgaddr; /* holds the last set cpr0_cfgaddr */
@@ -593,5 +598,6 @@ struct kvm_vcpu_arch {
 #define KVM_MMIO_REG_FQPR	0x0060
 
 #define __KVM_HAVE_ARCH_WQP
+#define __KVM_HAVE_CREATE_DEVICE
 
 #endif /* __POWERPC_KVM_HOST_H__ */

arch/powerpc/include/asm/kvm_ppc.h

@@ -164,6 +164,8 @@ extern int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu);
 
 extern int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *);
 
+int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq);
+
 /*
  * Cuts out inst bits with ordering according to spec.
  * That means the leftmost bit is zero. All given bits are included.
@@ -245,6 +247,9 @@ 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)
 {
@@ -270,6 +275,18 @@ static inline void kvmppc_set_epr(struct kvm_vcpu *vcpu, u32 epr)
 #endif
 }
 
+#ifdef CONFIG_KVM_MPIC
+
+void kvmppc_mpic_set_epr(struct kvm_vcpu *vcpu);
+
+#else
+
+static inline void kvmppc_mpic_set_epr(struct kvm_vcpu *vcpu)
+{
+}
+
+#endif /* CONFIG_KVM_MPIC */
+
 int kvm_vcpu_ioctl_config_tlb(struct kvm_vcpu *vcpu,
 			      struct kvm_config_tlb *cfg);
 int kvm_vcpu_ioctl_dirty_tlb(struct kvm_vcpu *vcpu,

arch/powerpc/include/uapi/asm/kvm.h

@@ -382,6 +382,14 @@ struct kvm_get_htab_header {
 	__u16	n_invalid;
 };
 
+/* Device control API: PPC-specific devices */
+#define KVM_DEV_MPIC_GRP_MISC		1
+#define   KVM_DEV_MPIC_BASE_ADDR	0	/* 64-bit */
+
+#define KVM_DEV_MPIC_GRP_REGISTER	2	/* 32-bit */
+#define KVM_DEV_MPIC_GRP_IRQ_ACTIVE	3	/* 32-bit */
+
+/* One-Reg API: PPC-specific registers */
 #define KVM_REG_PPC_HIOR	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x1)
 #define KVM_REG_PPC_IAC1	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x2)
 #define KVM_REG_PPC_IAC2	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x3)

arch/powerpc/kvm/Kconfig

@@ -151,6 +151,15 @@ config KVM_E500MC
 
 	  If unsure, say N.
 
+config KVM_MPIC
+	bool "KVM in-kernel MPIC emulation"
+	depends on KVM
+	help
+	  Enable support for emulating MPIC devices inside the
+          host kernel, rather than relying on userspace to emulate.
+          Currently, support is limited to certain versions of
+          Freescale's MPIC implementation.
+
 source drivers/vhost/Kconfig
 
 endif # VIRTUALIZATION

arch/powerpc/kvm/Makefile

@@ -103,6 +103,8 @@ kvm-book3s_32-objs := \
 	book3s_32_mmu.o
 kvm-objs-$(CONFIG_KVM_BOOK3S_32) := $(kvm-book3s_32-objs)
 
+kvm-objs-$(CONFIG_KVM_MPIC) += mpic.o
+
 kvm-objs := $(kvm-objs-m) $(kvm-objs-y)
 
 obj-$(CONFIG_KVM_440) += kvm.o

arch/powerpc/kvm/booke.c

@@ -346,7 +346,7 @@ static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
 		keep_irq = true;
 	}
 
-	if ((priority == BOOKE_IRQPRIO_EXTERNAL) && vcpu->arch.epr_enabled)
+	if ((priority == BOOKE_IRQPRIO_EXTERNAL) && vcpu->arch.epr_flags)
 		update_epr = true;
 
 	switch (priority) {
@@ -427,8 +427,10 @@ static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
 			set_guest_esr(vcpu, vcpu->arch.queued_esr);
 		if (update_dear == true)
 			set_guest_dear(vcpu, vcpu->arch.queued_dear);
-		if (update_epr == true)
-			kvm_make_request(KVM_REQ_EPR_EXIT, vcpu);
+		if (update_epr == true) {
+			if (vcpu->arch.epr_flags & KVMPPC_EPR_USER)
+				kvm_make_request(KVM_REQ_EPR_EXIT, vcpu);
+		}
 
 		new_msr &= msr_mask;
 #if defined(CONFIG_64BIT)

arch/powerpc/kvm/powerpc.c

@@ -317,6 +317,7 @@ int kvm_dev_ioctl_check_extension(long ext)
 	case KVM_CAP_ENABLE_CAP:
 	case KVM_CAP_ONE_REG:
 	case KVM_CAP_IOEVENTFD:
+	case KVM_CAP_DEVICE_CTRL:
 		r = 1;
 		break;
 #ifndef CONFIG_KVM_BOOK3S_64_HV
@@ -762,7 +763,10 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
 		break;
 	case KVM_CAP_PPC_EPR:
 		r = 0;
-		vcpu->arch.epr_enabled = cap->args[0];
+		if (cap->args[0])
+			vcpu->arch.epr_flags |= KVMPPC_EPR_USER;
+		else
+			vcpu->arch.epr_flags &= ~KVMPPC_EPR_USER;
 		break;
 #ifdef CONFIG_BOOKE
 	case KVM_CAP_PPC_BOOKE_WATCHDOG:
@@ -908,6 +912,7 @@ static int kvm_vm_ioctl_get_pvinfo(struct kvm_ppc_pvinfo *pvinfo)
 long kvm_arch_vm_ioctl(struct file *filp,
                        unsigned int ioctl, unsigned long arg)
 {
+	struct kvm *kvm __maybe_unused = filp->private_data;
 	void __user *argp = (void __user *)arg;
 	long r;
 
@@ -926,7 +931,6 @@ long kvm_arch_vm_ioctl(struct file *filp,
 #ifdef CONFIG_PPC_BOOK3S_64
 	case KVM_CREATE_SPAPR_TCE: {
 		struct kvm_create_spapr_tce create_tce;
-		struct kvm *kvm = filp->private_data;
 
 		r = -EFAULT;
 		if (copy_from_user(&create_tce, argp, sizeof(create_tce)))
@@ -938,7 +942,6 @@ long kvm_arch_vm_ioctl(struct file *filp,
 
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 	case KVM_ALLOCATE_RMA: {
-		struct kvm *kvm = filp->private_data;
 		struct kvm_allocate_rma rma;
 
 		r = kvm_vm_ioctl_allocate_rma(kvm, &rma);
@@ -948,7 +951,6 @@ long kvm_arch_vm_ioctl(struct file *filp,
 	}
 
 	case KVM_PPC_ALLOCATE_HTAB: {
-		struct kvm *kvm = filp->private_data;
 		u32 htab_order;
 
 		r = -EFAULT;
@@ -965,7 +967,6 @@ long kvm_arch_vm_ioctl(struct file *filp,
 	}
 
 	case KVM_PPC_GET_HTAB_FD: {
-		struct kvm *kvm = filp->private_data;
 		struct kvm_get_htab_fd ghf;
 
 		r = -EFAULT;
@@ -978,7 +979,6 @@ long kvm_arch_vm_ioctl(struct file *filp,
 
 #ifdef CONFIG_PPC_BOOK3S_64
 	case KVM_PPC_GET_SMMU_INFO: {
-		struct kvm *kvm = filp->private_data;
 		struct kvm_ppc_smmu_info info;
 
 		memset(&info, 0, sizeof(info));

include/linux/kvm_host.h

@@ -1099,6 +1099,8 @@ void kvm_device_get(struct kvm_device *dev);
 void kvm_device_put(struct kvm_device *dev);
 struct kvm_device *kvm_device_from_filp(struct file *filp);
 
+extern struct kvm_device_ops kvm_mpic_ops;
+
 #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
 
 static inline void kvm_vcpu_set_in_spin_loop(struct kvm_vcpu *vcpu, bool val)

include/uapi/linux/kvm.h

@@ -837,6 +837,9 @@ struct kvm_device_attr {
 	__u64	addr;		/* userspace address of attr data */
 };
 
+#define KVM_DEV_TYPE_FSL_MPIC_20	1
+#define KVM_DEV_TYPE_FSL_MPIC_42	2
+
 /*
  * ioctls for VM fds
  */

virt/kvm/kvm_main.c

@@ -2238,6 +2238,12 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
 	int ret;
 
 	switch (cd->type) {
+#ifdef CONFIG_KVM_MPIC
+	case KVM_DEV_TYPE_FSL_MPIC_20:
+	case KVM_DEV_TYPE_FSL_MPIC_42:
+		ops = &kvm_mpic_ops;
+		break;
+#endif
 	default:
 		return -ENODEV;
 	}