From: James Hogan Date: Mon, 8 Dec 2014 23:07:56 +0000 (+0000) Subject: MIPS: KVM: Wire up FPU capability X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=5fafd8748b366105e08c198892e9fe02ef15c021;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git MIPS: KVM: Wire up FPU capability Now that the code is in place for KVM to support FPU in MIPS KVM guests, wire up the new KVM_CAP_MIPS_FPU capability. For backwards compatibility, the capability must be explicitly enabled in order to detect or make use of the FPU from the guest. Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: Ralf Baechle Cc: Gleb Natapov Cc: Jonathan Corbet Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Cc: linux-api@vger.kernel.org Cc: linux-doc@vger.kernel.org --- diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index f3c198360785..a1e9bfa5fe9e 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -3312,6 +3312,19 @@ Parameters: none This capability enables the in-kernel irqchip for s390. Please refer to "4.24 KVM_CREATE_IRQCHIP" for details. +6.9 KVM_CAP_MIPS_FPU + +Architectures: mips +Target: vcpu +Parameters: args[0] is reserved for future use (should be 0). + +This capability allows the use of the host Floating Point Unit by the guest. It +allows the Config1.FP bit to be set to enable the FPU in the guest. Once this is +done the KVM_REG_MIPS_FPR_* and KVM_REG_MIPS_FCR_* registers can be accessed +(depending on the current guest FPU register mode), and the Status.FR, +Config5.FRE bits are accessible via the KVM API and also from the guest, +depending on them being supported by the FPU. + 7. Capabilities that can be enabled on VMs ------------------------------------------ diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index 5e41afe15ae8..7f86cb73d05d 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -797,6 +797,30 @@ static int kvm_mips_set_reg(struct kvm_vcpu *vcpu, return 0; } +static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu, + struct kvm_enable_cap *cap) +{ + int r = 0; + + if (!kvm_vm_ioctl_check_extension(vcpu->kvm, cap->cap)) + return -EINVAL; + if (cap->flags) + return -EINVAL; + if (cap->args[0]) + return -EINVAL; + + switch (cap->cap) { + case KVM_CAP_MIPS_FPU: + vcpu->arch.fpu_enabled = true; + break; + default: + r = -EINVAL; + break; + } + + return r; +} + long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { @@ -854,6 +878,15 @@ long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl, r = kvm_vcpu_ioctl_interrupt(vcpu, &irq); break; } + case KVM_ENABLE_CAP: { + struct kvm_enable_cap cap; + + r = -EFAULT; + if (copy_from_user(&cap, argp, sizeof(cap))) + goto out; + r = kvm_vcpu_ioctl_enable_cap(vcpu, &cap); + break; + } default: r = -ENOIOCTLCMD; } @@ -962,11 +995,15 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) switch (ext) { case KVM_CAP_ONE_REG: + case KVM_CAP_ENABLE_CAP: r = 1; break; case KVM_CAP_COALESCED_MMIO: r = KVM_COALESCED_MMIO_PAGE_OFFSET; break; + case KVM_CAP_MIPS_FPU: + r = !!cpu_has_fpu; + break; default: r = 0; break; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 1162ef7a3fa1..ce49688976d2 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -802,6 +802,7 @@ struct kvm_ppc_smmu_info { #define KVM_CAP_S390_MEM_OP 108 #define KVM_CAP_S390_USER_STSI 109 #define KVM_CAP_S390_SKEYS 110 +#define KVM_CAP_MIPS_FPU 111 #ifdef KVM_CAP_IRQ_ROUTING