Add KVM register numbers for the MIPS SIMD Architecture (MSA) registers,
and implement access to them with the KVM_GET_ONE_REG / KVM_SET_ONE_REG
ioctls when the MSA capability is enabled (exposed in a later patch) and
present in the guest according to its Config3.MSAP bit.
The MSA vector registers use the same register numbers as the FPU
registers except with a different size (128bits). Since MSA depends on
Status.FR=1, these registers are inaccessible when Status.FR=0. These
registers are returned as a single native endian 128bit value, rather
than least significant half first with each 64-bit half native endian as
the kernel uses internally.
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Gleb Natapov <gleb@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-api@xxxxxxxxxxxxxxx
Cc: linux-doc@xxxxxxxxxxxxxxx
---
Documentation/virtual/kvm/api.txt | 3 ++
arch/mips/include/uapi/asm/kvm.h | 12 ++++++--
arch/mips/kvm/mips.c | 65 +++++++++++++++++++++++++++++++++++++++
3 files changed, 78 insertions(+), 2 deletions(-)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 44623688d566..47ddf0475211 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1981,8 +1981,11 @@ registers, find a list below:
MIPS | KVM_REG_MIPS_COUNT_HZ | 64
MIPS | KVM_REG_MIPS_FPR_32(0..31) | 32
MIPS | KVM_REG_MIPS_FPR_64(0..31) | 64
+ MIPS | KVM_REG_MIPS_VEC_128(0..31) | 128
MIPS | KVM_REG_MIPS_FCR_IR | 32
MIPS | KVM_REG_MIPS_FCR_CSR | 32
+ MIPS | KVM_REG_MIPS_MSA_IR | 32
+ MIPS | KVM_REG_MIPS_MSA_CSR | 32
ARM registers are mapped using the lower 32 bits. The upper 16 of that
is the register group type, or coprocessor number:
diff --git a/arch/mips/include/uapi/asm/kvm.h b/arch/mips/include/uapi/asm/kvm.h
index 401e6a6f8bb8..6985eb59b085 100644
--- a/arch/mips/include/uapi/asm/kvm.h
+++ b/arch/mips/include/uapi/asm/kvm.h
@@ -58,7 +58,7 @@ struct kvm_fpu {
*
* Register set = 2: KVM specific registers (see definitions below).
*
- * Register set = 3: FPU registers (see definitions below).
+ * Register set = 3: FPU / MSA registers (see definitions below).
*
* Other sets registers may be added in the future. Each set would
* have its own identifier in bits[31..16].
@@ -148,7 +148,7 @@ struct kvm_fpu {
/*
- * KVM_REG_MIPS_FPU - Floating Point registers.
+ * KVM_REG_MIPS_FPU - Floating Point and MIPS SIMD Architecture (MSA) registers.
*
* bits[15..8] - Register subset (see definitions below).
* bits[7..5] - Must be zero.
@@ -157,12 +157,14 @@ struct kvm_fpu {
#define KVM_REG_MIPS_FPR (KVM_REG_MIPS_FPU | 0x0000000000000000ULL)
#define KVM_REG_MIPS_FCR (KVM_REG_MIPS_FPU | 0x0000000000000100ULL)
+#define KVM_REG_MIPS_MSACR (KVM_REG_MIPS_FPU | 0x0000000000000200ULL)
/*
* KVM_REG_MIPS_FPR - Floating point / Vector registers.
*/
#define KVM_REG_MIPS_FPR_32(n) (KVM_REG_MIPS_FPR | KVM_REG_SIZE_U32 | (n))
#define KVM_REG_MIPS_FPR_64(n) (KVM_REG_MIPS_FPR | KVM_REG_SIZE_U64 | (n))
+#define KVM_REG_MIPS_VEC_128(n) (KVM_REG_MIPS_FPR | KVM_REG_SIZE_U128 | (n))
/*
* KVM_REG_MIPS_FCR - Floating point control registers.
@@ -170,6 +172,12 @@ struct kvm_fpu {
#define KVM_REG_MIPS_FCR_IR (KVM_REG_MIPS_FCR | KVM_REG_SIZE_U32 | 0)
#define KVM_REG_MIPS_FCR_CSR (KVM_REG_MIPS_FCR | KVM_REG_SIZE_U32 | 31)
+/*
+ * KVM_REG_MIPS_MSACR - MIPS SIMD Architecture (MSA) control registers.
+ */
+#define KVM_REG_MIPS_MSA_IR (KVM_REG_MIPS_MSACR | KVM_REG_SIZE_U32 | 0)
+#define KVM_REG_MIPS_MSA_CSR (KVM_REG_MIPS_MSACR | KVM_REG_SIZE_U32 | 1)
+
/*
* KVM MIPS specific structures and definitions
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index a44a37475156..9319c4360285 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -531,6 +531,7 @@ static int kvm_mips_get_reg(struct kvm_vcpu *vcpu,
struct mips_fpu_struct *fpu = &vcpu->arch.fpu;
int ret;
s64 v;
+ s64 vs[2];
unsigned int idx;
switch (reg->id) {
@@ -579,6 +580,35 @@ static int kvm_mips_get_reg(struct kvm_vcpu *vcpu,
v = fpu->fcr31;
break;
+ /* MIPS SIMD Architecture (MSA) registers */
+ case KVM_REG_MIPS_VEC_128(0) ... KVM_REG_MIPS_VEC_128(31):
+ if (!kvm_mips_guest_has_msa(&vcpu->arch))
+ return -EINVAL;
+ /* Can't access MSA registers in FR=0 mode */
+ if (!(kvm_read_c0_guest_status(cop0) & ST0_FR))
+ return -EINVAL;
+ idx = reg->id - KVM_REG_MIPS_VEC_128(0);
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+ /* least significant byte first */
+ vs[0] = get_fpr64(&fpu->fpr[idx], 0);
+ vs[1] = get_fpr64(&fpu->fpr[idx], 1);
+#else
+ /* most significant byte first */
+ vs[0] = get_fpr64(&fpu->fpr[idx], 1);
+ vs[1] = get_fpr64(&fpu->fpr[idx], 0);
+#endif
+ break;
+ case KVM_REG_MIPS_MSA_IR:
+ if (!kvm_mips_guest_has_msa(&vcpu->arch))
+ return -EINVAL;
+ v = boot_cpu_data.msa_id;
+ break;
+ case KVM_REG_MIPS_MSA_CSR:
+ if (!kvm_mips_guest_has_msa(&vcpu->arch))
+ return -EINVAL;
+ v = fpu->msacsr;
+ break;
+
/* Co-processor 0 registers */
case KVM_REG_MIPS_CP0_INDEX:
v = (long)kvm_read_c0_guest_index(cop0);
@@ -664,6 +694,10 @@ static int kvm_mips_get_reg(struct kvm_vcpu *vcpu,
u32 v32 = (u32)v;
return put_user(v32, uaddr32);
+ } else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U128) {
+ void __user *uaddr = (void __user *)(long)reg->addr;
+
+ return copy_to_user(uaddr, vs, 16);
} else {
return -EINVAL;
}
@@ -675,6 +709,7 @@ static int kvm_mips_set_reg(struct kvm_vcpu *vcpu,
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct mips_fpu_struct *fpu = &vcpu->arch.fpu;
s64 v;
+ s64 vs[2];
unsigned int idx;
if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U64) {
@@ -689,6 +724,10 @@ static int kvm_mips_set_reg(struct kvm_vcpu *vcpu,
if (get_user(v32, uaddr32) != 0)
return -EFAULT;
v = (s64)v32;
+ } else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U128) {
+ void __user *uaddr = (void __user *)(long)reg->addr;
+
+ return copy_from_user(vs, uaddr, 16);
} else {
return -EINVAL;
}
@@ -742,6 +781,32 @@ static int kvm_mips_set_reg(struct kvm_vcpu *vcpu,
fpu->fcr31 = v;
break;
+ /* MIPS SIMD Architecture (MSA) registers */
+ case KVM_REG_MIPS_VEC_128(0) ... KVM_REG_MIPS_VEC_128(31):
+ if (!kvm_mips_guest_has_msa(&vcpu->arch))
+ return -EINVAL;
+ idx = reg->id - KVM_REG_MIPS_VEC_128(0);
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+ /* least significant byte first */
+ set_fpr64(&fpu->fpr[idx], 0, vs[0]);
+ set_fpr64(&fpu->fpr[idx], 1, vs[1]);
+#else
+ /* most significant byte first */
+ set_fpr64(&fpu->fpr[idx], 1, vs[0]);
+ set_fpr64(&fpu->fpr[idx], 0, vs[1]);
+#endif
+ break;
+ case KVM_REG_MIPS_MSA_IR:
+ if (!kvm_mips_guest_has_msa(&vcpu->arch))
+ return -EINVAL;
+ /* Read-only */
+ break;
+ case KVM_REG_MIPS_MSA_CSR:
+ if (!kvm_mips_guest_has_msa(&vcpu->arch))
+ return -EINVAL;
+ fpu->msacsr = v;
+ break;
+
/* Co-processor 0 registers */
case KVM_REG_MIPS_CP0_INDEX:
kvm_write_c0_guest_index(cop0, v);
--
2.0.5
