For KVM RISC-V, we use KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls to access
VCPU config and registers from user-space.
We have three types of VCPU registers:
1. CONFIG - these are VCPU config and capabilities
2. CORE - these are VCPU general purpose registers
3. CSR - these are VCPU control and status registers
The CONFIG registers available to user-space are ISA and TIMEBASE. Out
of these, TIMEBASE is a read-only register which inform user-space about
VCPU timer base frequency. The ISA register is a read and write register
where user-space can only write the desired VCPU ISA capabilities before
running the VCPU.
The CORE registers available to user-space are PC, RA, SP, GP, TP, A0-A7,
T0-T6, S0-S11 and MODE. Most of these are RISC-V general registers except
PC and MODE. The PC register represents program counter whereas the MODE
register represent VCPU privilege mode (i.e. S/U-mode).
The CSRs available to user-space are SSTATUS, SIE, STVEC, SSCRATCH, SEPC,
SCAUSE, STVAL, SIP, and SATP. All of these are read/write registers.
In future, more VCPU register types will be added (such as FP) for the
KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls.
Signed-off-by: Anup Patel <anup.pa...@wdc.com>
Acked-by: Paolo Bonzini <pbonz...@redhat.com>
Reviewed-by: Paolo Bonzini <pbonz...@redhat.com>
---
arch/riscv/include/uapi/asm/kvm.h | 46 +++++-
arch/riscv/kvm/vcpu.c | 235 +++++++++++++++++++++++++++++-
2 files changed, 278 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/include/uapi/asm/kvm.h
b/arch/riscv/include/uapi/asm/kvm.h
index 6dbc056d58ba..08c4515ad71b 100644
--- a/arch/riscv/include/uapi/asm/kvm.h
+++ b/arch/riscv/include/uapi/asm/kvm.h
@@ -23,8 +23,15 @@
/* for KVM_GET_REGS and KVM_SET_REGS */
struct kvm_regs {
+ /* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
+ struct user_regs_struct regs;
+ unsigned long mode;
};
+/* Possible privilege modes for kvm_regs */
+#define KVM_RISCV_MODE_S 1
+#define KVM_RISCV_MODE_U 0
+
/* for KVM_GET_FPU and KVM_SET_FPU */
struct kvm_fpu {
};
@@ -41,10 +48,47 @@ struct kvm_guest_debug_arch {
struct kvm_sync_regs {
};
-/* dummy definition */
+/* for KVM_GET_SREGS and KVM_SET_SREGS */
struct kvm_sregs {
+ unsigned long sstatus;
+ unsigned long sie;
+ unsigned long stvec;
+ unsigned long sscratch;
+ unsigned long sepc;
+ unsigned long scause;
+ unsigned long stval;
+ unsigned long sip;
+ unsigned long satp;
+};
+
+/* for KVM_GET_ONE_REG and KVM_SET_ONE_REG */
+struct kvm_riscv_config {
+ unsigned long isa;
+ unsigned long tbfreq;
};
+#define KVM_REG_SIZE(id) \
+ (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT))
+
+/* If you need to interpret the index values, here is the key: */
+#define KVM_REG_RISCV_TYPE_MASK 0x00000000FF000000
+#define KVM_REG_RISCV_TYPE_SHIFT 24
+
+/* Config registers are mapped as type 1 */
+#define KVM_REG_RISCV_CONFIG (0x01 << KVM_REG_RISCV_TYPE_SHIFT)
+#define KVM_REG_RISCV_CONFIG_REG(name) \
+ (offsetof(struct kvm_riscv_config, name) / sizeof(unsigned long))
+
+/* Core registers are mapped as type 2 */
+#define KVM_REG_RISCV_CORE (0x02 << KVM_REG_RISCV_TYPE_SHIFT)
+#define KVM_REG_RISCV_CORE_REG(name) \
+ (offsetof(struct kvm_regs, name) / sizeof(unsigned long))
+
+/* Control and status registers are mapped as type 3 */
+#define KVM_REG_RISCV_CSR (0x03 << KVM_REG_RISCV_TYPE_SHIFT)
+#define KVM_REG_RISCV_CSR_REG(name) \
+ (offsetof(struct kvm_sregs, name) / sizeof(unsigned long))
+
#endif
#endif /* __LINUX_KVM_RISCV_H */
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index 3223f723f79e..b95dfc959009 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -165,6 +165,215 @@ vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu,
struct vm_fault *vmf)
return VM_FAULT_SIGBUS;
}
+static int kvm_riscv_vcpu_get_reg_config(struct kvm_vcpu *vcpu,
+ const struct kvm_one_reg *reg)
+{
+ unsigned long __user *uaddr =
+ (unsigned long __user *)(unsigned long)reg->addr;
+ unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
+ KVM_REG_SIZE_MASK |
+ KVM_REG_RISCV_CONFIG);
+ unsigned long reg_val;
+
+ if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
+ return -EINVAL;
+
+ switch (reg_num) {
+ case KVM_REG_RISCV_CONFIG_REG(isa):
+ reg_val = vcpu->arch.isa;
+ break;
+ case KVM_REG_RISCV_CONFIG_REG(tbfreq):
+ reg_val = riscv_timebase;
+ break;
+ default:
+ return -EINVAL;
+ };
+
+ if (copy_to_user(uaddr, ®_val, KVM_REG_SIZE(reg->id)))
+ return -EFAULT;
+
+ return 0;
+}
+
+static int kvm_riscv_vcpu_set_reg_config(struct kvm_vcpu *vcpu,
+ const struct kvm_one_reg *reg)
+{
+ unsigned long __user *uaddr =
+ (unsigned long __user *)(unsigned long)reg->addr;
+ unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
+ KVM_REG_SIZE_MASK |
+ KVM_REG_RISCV_CONFIG);
+ unsigned long reg_val;
+
+ if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
+ return -EINVAL;
+
+ if (copy_from_user(®_val, uaddr, KVM_REG_SIZE(reg->id)))
+ return -EFAULT;
+
+ switch (reg_num) {
+ case KVM_REG_RISCV_CONFIG_REG(isa):
+ if (!vcpu->arch.ran_atleast_once) {
+ vcpu->arch.isa = reg_val;
+ vcpu->arch.isa &= riscv_isa_extension_base(NULL);
+ vcpu->arch.isa &= KVM_RISCV_ISA_ALLOWED;
+ } else {
+ return -ENOTSUPP;
+ }
+ break;
+ case KVM_REG_RISCV_CONFIG_REG(tbfreq):
+ return -ENOTSUPP;
+ default:
+ return -EINVAL;
+ };
+
+ return 0;
+}
+
+static int kvm_riscv_vcpu_get_reg_core(struct kvm_vcpu *vcpu,
+ const struct kvm_one_reg *reg)
+{
+ struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
+ unsigned long __user *uaddr =
+ (unsigned long __user *)(unsigned long)reg->addr;
+ unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
+ KVM_REG_SIZE_MASK |
+ KVM_REG_RISCV_CORE);
+ unsigned long reg_val;
+
+ if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
+ return -EINVAL;
+
+ if (reg_num == KVM_REG_RISCV_CORE_REG(regs.pc))
+ reg_val = cntx->sepc;
+ else if (KVM_REG_RISCV_CORE_REG(regs.pc) < reg_num &&
+ reg_num <= KVM_REG_RISCV_CORE_REG(regs.t6))
+ reg_val = ((unsigned long *)cntx)[reg_num];
+ else if (reg_num == KVM_REG_RISCV_CORE_REG(mode))
+ reg_val = (cntx->sstatus & SR_SPP) ?
+ KVM_RISCV_MODE_S : KVM_RISCV_MODE_U;
+ else
+ return -EINVAL;
+
+ if (copy_to_user(uaddr, ®_val, KVM_REG_SIZE(reg->id)))
+ return -EFAULT;
+
+ return 0;
+}
+
+static int kvm_riscv_vcpu_set_reg_core(struct kvm_vcpu *vcpu,
+ const struct kvm_one_reg *reg)
+{
+ struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
+ unsigned long __user *uaddr =
+ (unsigned long __user *)(unsigned long)reg->addr;
+ unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
+ KVM_REG_SIZE_MASK |
+ KVM_REG_RISCV_CORE);
+ unsigned long reg_val;
+
+ if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
+ return -EINVAL;
+
+ if (copy_from_user(®_val, uaddr, KVM_REG_SIZE(reg->id)))
+ return -EFAULT;
+
+ if (reg_num == KVM_REG_RISCV_CORE_REG(regs.pc))
+ cntx->sepc = reg_val;
+ else if (KVM_REG_RISCV_CORE_REG(regs.pc) < reg_num &&
+ reg_num <= KVM_REG_RISCV_CORE_REG(regs.t6))
+ ((unsigned long *)cntx)[reg_num] = reg_val;
+ else if (reg_num == KVM_REG_RISCV_CORE_REG(mode)) {
+ if (reg_val == KVM_RISCV_MODE_S)
+ cntx->sstatus |= SR_SPP;
+ else
+ cntx->sstatus &= ~SR_SPP;
+ } else
+ return -EINVAL;
+
+ return 0;
+}
+
+static int kvm_riscv_vcpu_get_reg_csr(struct kvm_vcpu *vcpu,
+ const struct kvm_one_reg *reg)
+{
+ struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
+ unsigned long __user *uaddr =
+ (unsigned long __user *)(unsigned long)reg->addr;
+ unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
+ KVM_REG_SIZE_MASK |
+ KVM_REG_RISCV_CSR);
+ unsigned long reg_val;
+
+ if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
+ return -EINVAL;
+ if (reg_num >= sizeof(struct kvm_sregs) / sizeof(unsigned long))
+ return -EINVAL;
+
+ if (reg_num == KVM_REG_RISCV_CSR_REG(sip))
+ kvm_riscv_vcpu_flush_interrupts(vcpu);
+
+ reg_val = ((unsigned long *)csr)[reg_num];
+
+ if (copy_to_user(uaddr, ®_val, KVM_REG_SIZE(reg->id)))
+ return -EFAULT;
+
+ return 0;
+}
+
+static int kvm_riscv_vcpu_set_reg_csr(struct kvm_vcpu *vcpu,
+ const struct kvm_one_reg *reg)
+{
+ struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
+ unsigned long __user *uaddr =
+ (unsigned long __user *)(unsigned long)reg->addr;
+ unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
+ KVM_REG_SIZE_MASK |
+ KVM_REG_RISCV_CSR);
+ unsigned long reg_val;
+
+ if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
+ return -EINVAL;
+ if (reg_num >= sizeof(struct kvm_sregs) / sizeof(unsigned long))
+ return -EINVAL;
+
+ if (copy_from_user(®_val, uaddr, KVM_REG_SIZE(reg->id)))
+ return -EFAULT;
+
+ ((unsigned long *)csr)[reg_num] = reg_val;
+
+ if (reg_num == KVM_REG_RISCV_CSR_REG(sip))
+ WRITE_ONCE(vcpu->arch.irqs_pending_mask, 0);
+
+ return 0;
+}
+
+static int kvm_riscv_vcpu_set_reg(struct kvm_vcpu *vcpu,
+ const struct kvm_one_reg *reg)
+{
+ if ((reg->id & KVM_REG_RISCV_TYPE_MASK) == KVM_REG_RISCV_CONFIG)
+ return kvm_riscv_vcpu_set_reg_config(vcpu, reg);
+ else if ((reg->id & KVM_REG_RISCV_TYPE_MASK) == KVM_REG_RISCV_CORE)
+ return kvm_riscv_vcpu_set_reg_core(vcpu, reg);
+ else if ((reg->id & KVM_REG_RISCV_TYPE_MASK) == KVM_REG_RISCV_CSR)
+ return kvm_riscv_vcpu_set_reg_csr(vcpu, reg);
+
+ return -EINVAL;
+}
+
+static int kvm_riscv_vcpu_get_reg(struct kvm_vcpu *vcpu,
+ const struct kvm_one_reg *reg)
+{
+ if ((reg->id & KVM_REG_RISCV_TYPE_MASK) == KVM_REG_RISCV_CONFIG)
+ return kvm_riscv_vcpu_get_reg_config(vcpu, reg);
+ else if ((reg->id & KVM_REG_RISCV_TYPE_MASK) == KVM_REG_RISCV_CORE)
+ return kvm_riscv_vcpu_get_reg_core(vcpu, reg);
+ else if ((reg->id & KVM_REG_RISCV_TYPE_MASK) == KVM_REG_RISCV_CSR)
+ return kvm_riscv_vcpu_get_reg_csr(vcpu, reg);
+
+ return -EINVAL;
+}
+
long kvm_arch_vcpu_async_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
@@ -189,8 +398,30 @@ long kvm_arch_vcpu_async_ioctl(struct file *filp,
long kvm_arch_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
- /* TODO: */
- return -EINVAL;
+ struct kvm_vcpu *vcpu = filp->private_data;
+ void __user *argp = (void __user *)arg;
+ long r = -EINVAL;
+
+ switch (ioctl) {
+ case KVM_SET_ONE_REG:
+ case KVM_GET_ONE_REG: {
+ struct kvm_one_reg reg;
+
+ r = -EFAULT;
+ if (copy_from_user(®, argp, sizeof(reg)))
+ break;
+
+ if (ioctl == KVM_SET_ONE_REG)
+ r = kvm_riscv_vcpu_set_reg(vcpu, ®);
+ else
+ r = kvm_riscv_vcpu_get_reg(vcpu, ®);
+ break;
+ }
+ default:
+ break;
+ }
+
+ return r;
}
int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
--
2.17.1
