From: Anup Patel anup.patel@wdc.com
euleros inclusion category: feature bugzilla: NA CVE: NA
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 register available to user-space is ISA. 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.
Link: https://gitee.com/openeuler/kernel/issues/I26X9V Signed-off-by: Anup Patel anup.patel@wdc.com Acked-by: Paolo Bonzini pbonzini@redhat.com Reviewed-by: Paolo Bonzini pbonzini@redhat.com --- arch/riscv/include/uapi/asm/kvm.h | 53 ++++++- arch/riscv/kvm/vcpu.c | 246 +++++++++++++++++++++++++++++- 2 files changed, 295 insertions(+), 4 deletions(-)
diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h index 3d3d70371..f7e9dc388 100644 --- a/arch/riscv/include/uapi/asm/kvm.h +++ b/arch/riscv/include/uapi/asm/kvm.h @@ -41,10 +41,61 @@ struct kvm_guest_debug_arch { struct kvm_sync_regs { };
-/* dummy definition */ +/* for KVM_GET_SREGS and KVM_SET_SREGS */ struct kvm_sregs { };
+/* CONFIG registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */ +struct kvm_riscv_config { + unsigned long isa; +}; + +/* CORE registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */ +struct kvm_riscv_core { + struct user_regs_struct regs; + unsigned long mode; +}; + +/* Possible privilege modes for kvm_riscv_core */ +#define KVM_RISCV_MODE_S 1 +#define KVM_RISCV_MODE_U 0 + +/* CSR registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */ +struct kvm_riscv_csr { + 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; + unsigned long scounteren; +}; + +#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_riscv_core, 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_riscv_csr, 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 7acb2e622..e38eedc78 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -18,7 +18,6 @@ #include <linux/fs.h> #include <linux/kvm_host.h> #include <asm/csr.h> -#include <asm/delay.h> #include <asm/hwcap.h>
struct kvm_stats_debugfs_item debugfs_entries[] = { @@ -148,6 +147,225 @@ 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; + 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 -EOPNOTSUPP; + } + break; + 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 >= sizeof(struct kvm_riscv_core) / 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 (reg_num >= sizeof(struct kvm_riscv_core) / 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_riscv_csr) / sizeof(unsigned long)) + return -EINVAL; + + if (reg_num == KVM_REG_RISCV_CSR_REG(sip)) { + kvm_riscv_vcpu_flush_interrupts(vcpu); + reg_val = csr->hvip >> VSIP_TO_HVIP_SHIFT; + reg_val = reg_val & VSIP_VALID_MASK; + } else if (reg_num == KVM_REG_RISCV_CSR_REG(sie)) { + reg_val = csr->hie >> VSIP_TO_HVIP_SHIFT; + reg_val = reg_val & VSIP_VALID_MASK; + } else + 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_riscv_csr) / sizeof(unsigned long)) + return -EINVAL; + + if (copy_from_user(®_val, uaddr, KVM_REG_SIZE(reg->id))) + return -EFAULT; + + if (reg_num == KVM_REG_RISCV_CSR_REG(sip) || + reg_num == KVM_REG_RISCV_CSR_REG(sie)) { + reg_val = reg_val & VSIP_VALID_MASK; + reg_val = reg_val << VSIP_TO_HVIP_SHIFT; + } + + ((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) { @@ -172,8 +390,30 @@ 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,