linux/arch/riscv/kvm/vcpu_vector.c
Andrew Jones 630b4cee9c RISC-V: KVM: Improve vector save/restore functions
Make two nonfunctional changes to the vector get/set vector reg
functions and their supporting function for simplification and
readability. The first is to not pass KVM_REG_RISCV_VECTOR, but
rather integrate it directly into the masking. The second is to
rename reg_val to reg_addr where and address is used instead of
a value.

Also opportunistically touch up some of the code formatting for
a third nonfunctional change.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-08-08 17:26:05 +05:30

185 lines
4.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2022 SiFive
*
* Authors:
* Vincent Chen <vincent.chen@sifive.com>
* Greentime Hu <greentime.hu@sifive.com>
*/
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/kvm_host.h>
#include <linux/uaccess.h>
#include <asm/hwcap.h>
#include <asm/kvm_vcpu_vector.h>
#include <asm/vector.h>
#ifdef CONFIG_RISCV_ISA_V
void kvm_riscv_vcpu_vector_reset(struct kvm_vcpu *vcpu)
{
unsigned long *isa = vcpu->arch.isa;
struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
cntx->sstatus &= ~SR_VS;
if (riscv_isa_extension_available(isa, v)) {
cntx->sstatus |= SR_VS_INITIAL;
WARN_ON(!cntx->vector.datap);
memset(cntx->vector.datap, 0, riscv_v_vsize);
} else {
cntx->sstatus |= SR_VS_OFF;
}
}
static void kvm_riscv_vcpu_vector_clean(struct kvm_cpu_context *cntx)
{
cntx->sstatus &= ~SR_VS;
cntx->sstatus |= SR_VS_CLEAN;
}
void kvm_riscv_vcpu_guest_vector_save(struct kvm_cpu_context *cntx,
unsigned long *isa)
{
if ((cntx->sstatus & SR_VS) == SR_VS_DIRTY) {
if (riscv_isa_extension_available(isa, v))
__kvm_riscv_vector_save(cntx);
kvm_riscv_vcpu_vector_clean(cntx);
}
}
void kvm_riscv_vcpu_guest_vector_restore(struct kvm_cpu_context *cntx,
unsigned long *isa)
{
if ((cntx->sstatus & SR_VS) != SR_VS_OFF) {
if (riscv_isa_extension_available(isa, v))
__kvm_riscv_vector_restore(cntx);
kvm_riscv_vcpu_vector_clean(cntx);
}
}
void kvm_riscv_vcpu_host_vector_save(struct kvm_cpu_context *cntx)
{
/* No need to check host sstatus as it can be modified outside */
if (riscv_isa_extension_available(NULL, v))
__kvm_riscv_vector_save(cntx);
}
void kvm_riscv_vcpu_host_vector_restore(struct kvm_cpu_context *cntx)
{
if (riscv_isa_extension_available(NULL, v))
__kvm_riscv_vector_restore(cntx);
}
int kvm_riscv_vcpu_alloc_vector_context(struct kvm_vcpu *vcpu,
struct kvm_cpu_context *cntx)
{
cntx->vector.datap = kmalloc(riscv_v_vsize, GFP_KERNEL);
if (!cntx->vector.datap)
return -ENOMEM;
vcpu->arch.host_context.vector.datap = kzalloc(riscv_v_vsize, GFP_KERNEL);
if (!vcpu->arch.host_context.vector.datap)
return -ENOMEM;
return 0;
}
void kvm_riscv_vcpu_free_vector_context(struct kvm_vcpu *vcpu)
{
kfree(vcpu->arch.guest_reset_context.vector.datap);
kfree(vcpu->arch.host_context.vector.datap);
}
#endif
static int kvm_riscv_vcpu_vreg_addr(struct kvm_vcpu *vcpu,
unsigned long reg_num,
size_t reg_size,
void **reg_addr)
{
struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
size_t vlenb = riscv_v_vsize / 32;
if (reg_num < KVM_REG_RISCV_VECTOR_REG(0)) {
if (reg_size != sizeof(unsigned long))
return -EINVAL;
switch (reg_num) {
case KVM_REG_RISCV_VECTOR_CSR_REG(vstart):
*reg_addr = &cntx->vector.vstart;
break;
case KVM_REG_RISCV_VECTOR_CSR_REG(vl):
*reg_addr = &cntx->vector.vl;
break;
case KVM_REG_RISCV_VECTOR_CSR_REG(vtype):
*reg_addr = &cntx->vector.vtype;
break;
case KVM_REG_RISCV_VECTOR_CSR_REG(vcsr):
*reg_addr = &cntx->vector.vcsr;
break;
case KVM_REG_RISCV_VECTOR_CSR_REG(datap):
default:
return -ENOENT;
}
} else if (reg_num <= KVM_REG_RISCV_VECTOR_REG(31)) {
if (reg_size != vlenb)
return -EINVAL;
*reg_addr = cntx->vector.datap +
(reg_num - KVM_REG_RISCV_VECTOR_REG(0)) * vlenb;
} else {
return -ENOENT;
}
return 0;
}
int kvm_riscv_vcpu_get_reg_vector(struct kvm_vcpu *vcpu,
const struct kvm_one_reg *reg)
{
unsigned long *isa = vcpu->arch.isa;
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_VECTOR);
size_t reg_size = KVM_REG_SIZE(reg->id);
void *reg_addr;
int rc;
if (!riscv_isa_extension_available(isa, v))
return -ENOENT;
rc = kvm_riscv_vcpu_vreg_addr(vcpu, reg_num, reg_size, &reg_addr);
if (rc)
return rc;
if (copy_to_user(uaddr, reg_addr, reg_size))
return -EFAULT;
return 0;
}
int kvm_riscv_vcpu_set_reg_vector(struct kvm_vcpu *vcpu,
const struct kvm_one_reg *reg)
{
unsigned long *isa = vcpu->arch.isa;
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_VECTOR);
size_t reg_size = KVM_REG_SIZE(reg->id);
void *reg_addr;
int rc;
if (!riscv_isa_extension_available(isa, v))
return -ENOENT;
rc = kvm_riscv_vcpu_vreg_addr(vcpu, reg_num, reg_size, &reg_addr);
if (rc)
return rc;
if (copy_from_user(reg_addr, uaddr, reg_size))
return -EFAULT;
return 0;
}