KVM: PPC: Book3S: Get/set guest SPRs using the GET/SET_ONE_REG interface

This enables userspace to get and set various SPRs (special-purpose
registers) using the KVM_[GS]ET_ONE_REG ioctls. With this, userspace
can get and set all the SPRs that are part of the guest state, either
through the KVM_[GS]ET_REGS ioctls, the KVM_[GS]ET_SREGS ioctls, or
the KVM_[GS]ET_ONE_REG ioctls.

The SPRs that are added here are:

- DABR: Data address breakpoint register
- DSCR: Data stream control register
- PURR: Processor utilization of resources register
- SPURR: Scaled PURR
- DAR: Data address register
- DSISR: Data storage interrupt status register
- AMR: Authority mask register
- UAMOR: User authority mask override register
- MMCR0, MMCR1, MMCRA: Performance monitor unit control registers
- PMC1..PMC8: Performance monitor unit counter registers

In order to reduce code duplication between PR and HV KVM code, this
moves the kvm_vcpu_ioctl_[gs]et_one_reg functions into book3s.c and
centralizes the copying between user and kernel space there. The
registers that are handled differently between PR and HV, and those
that exist only in one flavor, are handled in kvmppc_[gs]et_one_reg()
functions that are specific to each flavor.

Signed-off-by: Paul Mackerras <[e-mail]>
[agraf: minimal style fixes]
Signed-off-by: Alexander Graf <[e-mail]>

Documentation/virtual/kvm/api.txt

···
   PPC   | KVM_REG_PPC_IAC4      | 64
   PPC   | KVM_REG_PPC_DAC1      | 64
   PPC   | KVM_REG_PPC_DAC2      | 64
+  PPC   | KVM_REG_PPC_DABR      | 64
+  PPC   | KVM_REG_PPC_DSCR      | 64
+  PPC   | KVM_REG_PPC_PURR      | 64
+  PPC   | KVM_REG_PPC_SPURR     | 64
+  PPC   | KVM_REG_PPC_DAR       | 64
+  PPC   | KVM_REG_PPC_DSISR     | 32
+  PPC   | KVM_REG_PPC_AMR       | 64
+  PPC   | KVM_REG_PPC_UAMOR     | 64
+  PPC   | KVM_REG_PPC_MMCR0     | 64
+  PPC   | KVM_REG_PPC_MMCR1     | 64
+  PPC   | KVM_REG_PPC_MMCRA     | 64
+  PPC   | KVM_REG_PPC_PMC1      | 32
+  PPC   | KVM_REG_PPC_PMC2      | 32
+  PPC   | KVM_REG_PPC_PMC3      | 32
+  PPC   | KVM_REG_PPC_PMC4      | 32
+  PPC   | KVM_REG_PPC_PMC5      | 32
+  PPC   | KVM_REG_PPC_PMC6      | 32
+  PPC   | KVM_REG_PPC_PMC7      | 32
+  PPC   | KVM_REG_PPC_PMC8      | 32
 
 4.69 KVM_GET_ONE_REG
 

arch/powerpc/include/asm/kvm.h

···
 #define KVM_REG_PPC_IAC4	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x5)
 #define KVM_REG_PPC_DAC1	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x6)
 #define KVM_REG_PPC_DAC2	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x7)
+#define KVM_REG_PPC_DABR	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x8)
+#define KVM_REG_PPC_DSCR	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x9)
+#define KVM_REG_PPC_PURR	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xa)
+#define KVM_REG_PPC_SPURR	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xb)
+#define KVM_REG_PPC_DAR		(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc)
+#define KVM_REG_PPC_DSISR	(KVM_REG_PPC | KVM_REG_SIZE_U32 | 0xd)
+#define KVM_REG_PPC_AMR		(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xe)
+#define KVM_REG_PPC_UAMOR	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xf)
+
+#define KVM_REG_PPC_MMCR0	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x10)
+#define KVM_REG_PPC_MMCR1	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x11)
+#define KVM_REG_PPC_MMCRA	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x12)
+
+#define KVM_REG_PPC_PMC1	(KVM_REG_PPC | KVM_REG_SIZE_U32 | 0x18)
+#define KVM_REG_PPC_PMC2	(KVM_REG_PPC | KVM_REG_SIZE_U32 | 0x19)
+#define KVM_REG_PPC_PMC3	(KVM_REG_PPC | KVM_REG_SIZE_U32 | 0x1a)
+#define KVM_REG_PPC_PMC4	(KVM_REG_PPC | KVM_REG_SIZE_U32 | 0x1b)
+#define KVM_REG_PPC_PMC5	(KVM_REG_PPC | KVM_REG_SIZE_U32 | 0x1c)
+#define KVM_REG_PPC_PMC6	(KVM_REG_PPC | KVM_REG_SIZE_U32 | 0x1d)
+#define KVM_REG_PPC_PMC7	(KVM_REG_PPC | KVM_REG_SIZE_U32 | 0x1e)
+#define KVM_REG_PPC_PMC8	(KVM_REG_PPC | KVM_REG_SIZE_U32 | 0x1f)
 
 #endif /* __LINUX_KVM_POWERPC_H */

arch/powerpc/include/asm/kvm_ppc.h

···
 #include <linux/types.h>
 #include <linux/kvm_types.h>
 #include <linux/kvm_host.h>
+#include <linux/bug.h>
 #ifdef CONFIG_PPC_BOOK3S
 #include <asm/kvm_book3s.h>
 #else
···
 	return r;
 }
 
+union kvmppc_one_reg {
+	u32	wval;
+	u64	dval;
+};
+
+#define one_reg_size(id)	\
+	(1ul << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT))
+
+#define get_reg_val(id, reg)	({		\
+	union kvmppc_one_reg __u;		\
+	switch (one_reg_size(id)) {		\
+	case 4: __u.wval = (reg); break;	\
+	case 8: __u.dval = (reg); break;	\
+	default: BUG();				\
+	}					\
+	__u;					\
+})
+
+
+#define set_reg_val(id, val)	({		\
+	u64 __v;				\
+	switch (one_reg_size(id)) {		\
+	case 4: __v = (val).wval; break;	\
+	case 8: __v = (val).dval; break;	\
+	default: BUG();				\
+	}					\
+	__v;					\
+})
+
 void kvmppc_core_get_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs);
 int kvmppc_core_set_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs);
 
···
 
 int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg);
 int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg);
+int kvmppc_get_one_reg(struct kvm_vcpu *vcpu, u64 id, union kvmppc_one_reg *);
+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);
 

arch/powerpc/kvm/book3s.c

···
 	return -ENOTSUPP;
 }
 
+int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
+{
+	int r;
+	union kvmppc_one_reg val;
+	int size;
+
+	size = one_reg_size(reg->id);
+	if (size > sizeof(val))
+		return -EINVAL;
+
+	r = kvmppc_get_one_reg(vcpu, reg->id, &val);
+
+	if (r == -EINVAL) {
+		r = 0;
+		switch (reg->id) {
+		case KVM_REG_PPC_DAR:
+			val = get_reg_val(reg->id, vcpu->arch.shared->dar);
+			break;
+		case KVM_REG_PPC_DSISR:
+			val = get_reg_val(reg->id, vcpu->arch.shared->dsisr);
+			break;
+		default:
+			r = -EINVAL;
+			break;
+		}
+	}
+	if (r)
+		return r;
+
+	if (copy_to_user((char __user *)(unsigned long)reg->addr, &val, size))
+		r = -EFAULT;
+
+	return r;
+}
+
+int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
+{
+	int r;
+	union kvmppc_one_reg val;
+	int size;
+
+	size = one_reg_size(reg->id);
+	if (size > sizeof(val))
+		return -EINVAL;
+
+	if (copy_from_user(&val, (char __user *)(unsigned long)reg->addr, size))
+		return -EFAULT;
+
+	r = kvmppc_set_one_reg(vcpu, reg->id, &val);
+
+	if (r == -EINVAL) {
+		r = 0;
+		switch (reg->id) {
+		case KVM_REG_PPC_DAR:
+			vcpu->arch.shared->dar = set_reg_val(reg->id, val);
+			break;
+		case KVM_REG_PPC_DSISR:
+			vcpu->arch.shared->dsisr = set_reg_val(reg->id, val);
+			break;
+		default:
+			r = -EINVAL;
+			break;
+		}
+	}
+
+	return r;
+}
+
 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
                                   struct kvm_translation *tr)
 {

arch/powerpc/kvm/book3s_hv.c

···
 	return 0;
 }
 
-int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
+int kvmppc_get_one_reg(struct kvm_vcpu *vcpu, u64 id, union kvmppc_one_reg *val)
 {
-	int r = -EINVAL;
+	int r = 0;
+	long int i;
 
-	switch (reg->id) {
+	switch (id) {
 	case KVM_REG_PPC_HIOR:
-		r = put_user(0, (u64 __user *)reg->addr);
+		*val = get_reg_val(id, 0);
+		break;
+	case KVM_REG_PPC_DABR:
+		*val = get_reg_val(id, vcpu->arch.dabr);
+		break;
+	case KVM_REG_PPC_DSCR:
+		*val = get_reg_val(id, vcpu->arch.dscr);
+		break;
+	case KVM_REG_PPC_PURR:
+		*val = get_reg_val(id, vcpu->arch.purr);
+		break;
+	case KVM_REG_PPC_SPURR:
+		*val = get_reg_val(id, vcpu->arch.spurr);
+		break;
+	case KVM_REG_PPC_AMR:
+		*val = get_reg_val(id, vcpu->arch.amr);
+		break;
+	case KVM_REG_PPC_UAMOR:
+		*val = get_reg_val(id, vcpu->arch.uamor);
+		break;
+	case KVM_REG_PPC_MMCR0 ... KVM_REG_PPC_MMCRA:
+		i = id - KVM_REG_PPC_MMCR0;
+		*val = get_reg_val(id, vcpu->arch.mmcr[i]);
+		break;
+	case KVM_REG_PPC_PMC1 ... KVM_REG_PPC_PMC8:
+		i = id - KVM_REG_PPC_PMC1;
+		*val = get_reg_val(id, vcpu->arch.pmc[i]);
 		break;
 	default:
+		r = -EINVAL;
 		break;
 	}
 
 	return r;
 }
 
-int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
+int kvmppc_set_one_reg(struct kvm_vcpu *vcpu, u64 id, union kvmppc_one_reg *val)
 {
-	int r = -EINVAL;
+	int r = 0;
+	long int i;
 
-	switch (reg->id) {
+	switch (id) {
 	case KVM_REG_PPC_HIOR:
-	{
-		u64 hior;
 		/* Only allow this to be set to zero */
-		r = get_user(hior, (u64 __user *)reg->addr);
-		if (!r && (hior != 0))
+		if (set_reg_val(id, *val))
 			r = -EINVAL;
 		break;
-	}
+	case KVM_REG_PPC_DABR:
+		vcpu->arch.dabr = set_reg_val(id, *val);
+		break;
+	case KVM_REG_PPC_DSCR:
+		vcpu->arch.dscr = set_reg_val(id, *val);
+		break;
+	case KVM_REG_PPC_PURR:
+		vcpu->arch.purr = set_reg_val(id, *val);
+		break;
+	case KVM_REG_PPC_SPURR:
+		vcpu->arch.spurr = set_reg_val(id, *val);
+		break;
+	case KVM_REG_PPC_AMR:
+		vcpu->arch.amr = set_reg_val(id, *val);
+		break;
+	case KVM_REG_PPC_UAMOR:
+		vcpu->arch.uamor = set_reg_val(id, *val);
+		break;
+	case KVM_REG_PPC_MMCR0 ... KVM_REG_PPC_MMCRA:
+		i = id - KVM_REG_PPC_MMCR0;
+		vcpu->arch.mmcr[i] = set_reg_val(id, *val);
+		break;
+	case KVM_REG_PPC_PMC1 ... KVM_REG_PPC_PMC8:
+		i = id - KVM_REG_PPC_PMC1;
+		vcpu->arch.pmc[i] = set_reg_val(id, *val);
+		break;
 	default:
+		r = -EINVAL;
 		break;
 	}
 

arch/powerpc/kvm/book3s_pr.c

···
 	return 0;
 }
 
-int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
+int kvmppc_get_one_reg(struct kvm_vcpu *vcpu, u64 id, union kvmppc_one_reg *val)
 {
-	int r = -EINVAL;
+	int r = 0;
 
-	switch (reg->id) {
+	switch (id) {
 	case KVM_REG_PPC_HIOR:
-		r = copy_to_user((u64 __user *)(long)reg->addr,
-				&to_book3s(vcpu)->hior, sizeof(u64));
+		*val = get_reg_val(id, to_book3s(vcpu)->hior);
 		break;
 	default:
+		r = -EINVAL;
 		break;
 	}
 
 	return r;
 }
 
-int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
+int kvmppc_set_one_reg(struct kvm_vcpu *vcpu, u64 id, union kvmppc_one_reg *val)
 {
-	int r = -EINVAL;
+	int r = 0;
 
-	switch (reg->id) {
+	switch (id) {
 	case KVM_REG_PPC_HIOR:
-		r = copy_from_user(&to_book3s(vcpu)->hior,
-				   (u64 __user *)(long)reg->addr, sizeof(u64));
-		if (!r)
-			to_book3s(vcpu)->hior_explicit = true;
+		to_book3s(vcpu)->hior = set_reg_val(id, *val);
+		to_book3s(vcpu)->hior_explicit = true;
 		break;
 	default:
+		r = -EINVAL;
 		break;
 	}