diff options
author | Anup Patel <anup.patel@wdc.com> | 2021-09-27 14:40:04 +0300 |
---|---|---|
committer | Anup Patel <anup@brainfault.org> | 2021-10-04 13:16:22 +0300 |
commit | 92ad82002c39ede73b397d17ba7ab9842517dbe5 (patch) | |
tree | bfb635437292d7f47bad2e4be6d5b129c4f8b795 /arch/riscv/kvm | |
parent | cce69aff689ee53c64b19d052d88f5bbbfd322f6 (diff) | |
download | linux-92ad82002c39ede73b397d17ba7ab9842517dbe5.tar.xz |
RISC-V: KVM: Implement KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls
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.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'arch/riscv/kvm')
-rw-r--r-- | arch/riscv/kvm/vcpu.c | 241 |
1 files changed, 238 insertions, 3 deletions
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index 3342c7305265..a15d97f3e5f6 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> const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = { @@ -136,6 +135,220 @@ 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) & 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_val &= VSIP_VALID_MASK; + 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) { @@ -160,8 +373,30 @@ 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, |