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authorJames Hogan <james.hogan@imgtec.com>2014-12-02 15:48:24 +0000
committerJames Hogan <james.hogan@imgtec.com>2015-03-27 21:25:21 +0000
commitab86bd600400357ffa0dfdb1797f587476d01352 (patch)
tree265d24436dc03ac0e1ff2fa3a1652feb3346b6ff /arch/mips/kvm
parentc2537ed9fb8e17d713e5e67fcede047699d25814 (diff)
MIPS: KVM: Expose MSA registers
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@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Cc: linux-api@vger.kernel.org Cc: linux-doc@vger.kernel.org
Diffstat (limited to 'arch/mips/kvm')
-rw-r--r--arch/mips/kvm/mips.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index e02c7e5a12ff..35d3146895f1 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);