LoongArch: KVM: Implement basic vcpu ioctl interfaces

Implement basic vcpu ioctl interfaces, including:

1, vcpu KVM_ENABLE_CAP ioctl interface.

2, vcpu get registers and set registers operations, it is called when
user space use the ioctl interface to get or set regs.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Tested-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index 349cecca1e6210fa264e401f4476c061cc31f500..4870655659096442a2021d81382de9635a5498e4 100644 (file)
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -141,6 +141,267 @@ static int kvm_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
        return RESUME_GUEST;
 }
 
+static int _kvm_getcsr(struct kvm_vcpu *vcpu, unsigned int id, u64 *val)
+{
+       unsigned long gintc;
+       struct loongarch_csrs *csr = vcpu->arch.csr;
+
+       if (get_gcsr_flag(id) & INVALID_GCSR)
+               return -EINVAL;
+
+       if (id == LOONGARCH_CSR_ESTAT) {
+               /* ESTAT IP0~IP7 get from GINTC */
+               gintc = kvm_read_sw_gcsr(csr, LOONGARCH_CSR_GINTC) & 0xff;
+               *val = kvm_read_sw_gcsr(csr, LOONGARCH_CSR_ESTAT) | (gintc << 2);
+               return 0;
+       }
+
+       /*
+        * Get software CSR state since software state is consistent
+        * with hardware for synchronous ioctl
+        */
+       *val = kvm_read_sw_gcsr(csr, id);
+
+       return 0;
+}
+
+static int _kvm_setcsr(struct kvm_vcpu *vcpu, unsigned int id, u64 val)
+{
+       int ret = 0, gintc;
+       struct loongarch_csrs *csr = vcpu->arch.csr;
+
+       if (get_gcsr_flag(id) & INVALID_GCSR)
+               return -EINVAL;
+
+       if (id == LOONGARCH_CSR_ESTAT) {
+               /* ESTAT IP0~IP7 inject through GINTC */
+               gintc = (val >> 2) & 0xff;
+               kvm_set_sw_gcsr(csr, LOONGARCH_CSR_GINTC, gintc);
+
+               gintc = val & ~(0xffUL << 2);
+               kvm_set_sw_gcsr(csr, LOONGARCH_CSR_ESTAT, gintc);
+
+               return ret;
+       }
+
+       kvm_write_sw_gcsr(csr, id, val);
+
+       return ret;
+}
+
+static int kvm_get_one_reg(struct kvm_vcpu *vcpu,
+               const struct kvm_one_reg *reg, u64 *v)
+{
+       int id, ret = 0;
+       u64 type = reg->id & KVM_REG_LOONGARCH_MASK;
+
+       switch (type) {
+       case KVM_REG_LOONGARCH_CSR:
+               id = KVM_GET_IOC_CSR_IDX(reg->id);
+               ret = _kvm_getcsr(vcpu, id, v);
+               break;
+       case KVM_REG_LOONGARCH_CPUCFG:
+               id = KVM_GET_IOC_CPUCFG_IDX(reg->id);
+               if (id >= 0 && id < KVM_MAX_CPUCFG_REGS)
+                       *v = vcpu->arch.cpucfg[id];
+               else
+                       ret = -EINVAL;
+               break;
+       case KVM_REG_LOONGARCH_KVM:
+               switch (reg->id) {
+               case KVM_REG_LOONGARCH_COUNTER:
+                       *v = drdtime() + vcpu->kvm->arch.time_offset;
+                       break;
+               default:
+                       ret = -EINVAL;
+                       break;
+               }
+               break;
+       default:
+               ret = -EINVAL;
+               break;
+       }
+
+       return ret;
+}
+
+static int kvm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
+       int ret = 0;
+       u64 v, size = reg->id & KVM_REG_SIZE_MASK;
+
+       switch (size) {
+       case KVM_REG_SIZE_U64:
+               ret = kvm_get_one_reg(vcpu, reg, &v);
+               if (ret)
+                       return ret;
+               ret = put_user(v, (u64 __user *)(long)reg->addr);
+               break;
+       default:
+               ret = -EINVAL;
+               break;
+       }
+
+       return ret;
+}
+
+static int kvm_set_one_reg(struct kvm_vcpu *vcpu,
+                       const struct kvm_one_reg *reg, u64 v)
+{
+       int id, ret = 0;
+       u64 type = reg->id & KVM_REG_LOONGARCH_MASK;
+
+       switch (type) {
+       case KVM_REG_LOONGARCH_CSR:
+               id = KVM_GET_IOC_CSR_IDX(reg->id);
+               ret = _kvm_setcsr(vcpu, id, v);
+               break;
+       case KVM_REG_LOONGARCH_CPUCFG:
+               id = KVM_GET_IOC_CPUCFG_IDX(reg->id);
+               if (id >= 0 && id < KVM_MAX_CPUCFG_REGS)
+                       vcpu->arch.cpucfg[id] = (u32)v;
+               else
+                       ret = -EINVAL;
+               break;
+       case KVM_REG_LOONGARCH_KVM:
+               switch (reg->id) {
+               case KVM_REG_LOONGARCH_COUNTER:
+                       /*
+                        * gftoffset is relative with board, not vcpu
+                        * only set for the first time for smp system
+                        */
+                       if (vcpu->vcpu_id == 0)
+                               vcpu->kvm->arch.time_offset = (signed long)(v - drdtime());
+                       break;
+               case KVM_REG_LOONGARCH_VCPU_RESET:
+                       kvm_reset_timer(vcpu);
+                       memset(&vcpu->arch.irq_pending, 0, sizeof(vcpu->arch.irq_pending));
+                       memset(&vcpu->arch.irq_clear, 0, sizeof(vcpu->arch.irq_clear));
+                       break;
+               default:
+                       ret = -EINVAL;
+                       break;
+               }
+               break;
+       default:
+               ret = -EINVAL;
+               break;
+       }
+
+       return ret;
+}
+
+static int kvm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
+       int ret = 0;
+       u64 v, size = reg->id & KVM_REG_SIZE_MASK;
+
+       switch (size) {
+       case KVM_REG_SIZE_U64:
+               ret = get_user(v, (u64 __user *)(long)reg->addr);
+               if (ret)
+                       return ret;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return kvm_set_one_reg(vcpu, reg, v);
+}
+
+int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
+{
+       return -ENOIOCTLCMD;
+}
+
+int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
+{
+       return -ENOIOCTLCMD;
+}
+
+int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(vcpu->arch.gprs); i++)
+               regs->gpr[i] = vcpu->arch.gprs[i];
+
+       regs->pc = vcpu->arch.pc;
+
+       return 0;
+}
+
+int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+       int i;
+
+       for (i = 1; i < ARRAY_SIZE(vcpu->arch.gprs); i++)
+               vcpu->arch.gprs[i] = regs->gpr[i];
+
+       vcpu->arch.gprs[0] = 0; /* zero is special, and cannot be set. */
+       vcpu->arch.pc = regs->pc;
+
+       return 0;
+}
+
+static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
+                                    struct kvm_enable_cap *cap)
+{
+       /* FPU is enabled by default, will support LSX/LASX later. */
+       return -EINVAL;
+}
+
+long kvm_arch_vcpu_ioctl(struct file *filp,
+                        unsigned int ioctl, unsigned long arg)
+{
+       long r;
+       void __user *argp = (void __user *)arg;
+       struct kvm_vcpu *vcpu = filp->private_data;
+
+       /*
+        * Only software CSR should be modified
+        *
+        * If any hardware CSR register is modified, vcpu_load/vcpu_put pair
+        * should be used. Since CSR registers owns by this vcpu, if switch
+        * to other vcpus, other vcpus need reload CSR registers.
+        *
+        * If software CSR is modified, bit KVM_LARCH_HWCSR_USABLE should
+        * be clear in vcpu->arch.aux_inuse, and vcpu_load will check
+        * aux_inuse flag and reload CSR registers form software.
+        */
+
+       switch (ioctl) {
+       case KVM_SET_ONE_REG:
+       case KVM_GET_ONE_REG: {
+               struct kvm_one_reg reg;
+
+               r = -EFAULT;
+               if (copy_from_user(&reg, argp, sizeof(reg)))
+                       break;
+               if (ioctl == KVM_SET_ONE_REG) {
+                       r = kvm_set_reg(vcpu, &reg);
+                       vcpu->arch.aux_inuse &= ~KVM_LARCH_HWCSR_USABLE;
+               } else
+                       r = kvm_get_reg(vcpu, &reg);
+               break;
+       }
+       case KVM_ENABLE_CAP: {
+               struct kvm_enable_cap cap;
+
+               r = -EFAULT;
+               if (copy_from_user(&cap, argp, sizeof(cap)))
+                       break;
+               r = kvm_vcpu_ioctl_enable_cap(vcpu, &cap);
+               break;
+       }
+       default:
+               r = -ENOIOCTLCMD;
+               break;
+       }
+
+       return r;
+}
+
 int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
 {
        return 0;