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-rw-r--r--Documentation/virtual/kvm/api.txt12
-rw-r--r--arch/mips/kvm/mips.c18
-rw-r--r--include/uapi/linux/kvm.h1
3 files changed, 31 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 62809871814b..1490eb0ef798 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -3335,6 +3335,18 @@ done the KVM_REG_MIPS_FPR_* and KVM_REG_MIPS_FCR_* registers can be accessed
Config5.FRE bits are accessible via the KVM API and also from the guest,
depending on them being supported by the FPU.
+6.10 KVM_CAP_MIPS_MSA
+
+Architectures: mips
+Target: vcpu
+Parameters: args[0] is reserved for future use (should be 0).
+
+This capability allows the use of the MIPS SIMD Architecture (MSA) by the guest.
+It allows the Config3.MSAP bit to be set to enable the use of MSA by the guest.
+Once this is done the KVM_REG_MIPS_VEC_* and KVM_REG_MIPS_MSA_* registers can be
+accessed, and the Config5.MSAEn bit is accessible via the KVM API and also from
+the guest.
+
7. Capabilities that can be enabled on VMs
------------------------------------------
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 35d3146895f1..bb68e8d520e8 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -880,6 +880,9 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
case KVM_CAP_MIPS_FPU:
vcpu->arch.fpu_enabled = true;
break;
+ case KVM_CAP_MIPS_MSA:
+ vcpu->arch.msa_enabled = true;
+ break;
default:
r = -EINVAL;
break;
@@ -1071,6 +1074,21 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_MIPS_FPU:
r = !!cpu_has_fpu;
break;
+ case KVM_CAP_MIPS_MSA:
+ /*
+ * We don't support MSA vector partitioning yet:
+ * 1) It would require explicit support which can't be tested
+ * yet due to lack of support in current hardware.
+ * 2) It extends the state that would need to be saved/restored
+ * by e.g. QEMU for migration.
+ *
+ * When vector partitioning hardware becomes available, support
+ * could be added by requiring a flag when enabling
+ * KVM_CAP_MIPS_MSA capability to indicate that userland knows
+ * to save/restore the appropriate extra state.
+ */
+ r = cpu_has_msa && !(boot_cpu_data.msa_id & MSA_IR_WRPF);
+ break;
default:
r = 0;
break;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index ce49688976d2..05a2083f7a28 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -803,6 +803,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_S390_USER_STSI 109
#define KVM_CAP_S390_SKEYS 110
#define KVM_CAP_MIPS_FPU 111
+#define KVM_CAP_MIPS_MSA 112
#ifdef KVM_CAP_IRQ_ROUTING