linux/arch/riscv/kvm/vcpu_sbi_base.c
Anup Patel 96b3d4bd93 RISC-V: KVM: Add ONE_REG interface to enable/disable SBI extensions
We add ONE_REG interface to enable/disable SBI extensions (just
like the ONE_REG interface for ISA extensions). This allows KVM
user-space to decide the set of SBI extension enabled for a Guest
and by default all SBI extensions are enabled.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-04-21 17:38:44 +05:30

99 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2021 Western Digital Corporation or its affiliates.
*
* Authors:
* Atish Patra <atish.patra@wdc.com>
*/
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/kvm_host.h>
#include <linux/version.h>
#include <asm/sbi.h>
#include <asm/kvm_vcpu_sbi.h>
static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
struct kvm_vcpu_sbi_return *retdata)
{
struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
const struct kvm_vcpu_sbi_extension *sbi_ext;
unsigned long *out_val = &retdata->out_val;
switch (cp->a6) {
case SBI_EXT_BASE_GET_SPEC_VERSION:
*out_val = (KVM_SBI_VERSION_MAJOR <<
SBI_SPEC_VERSION_MAJOR_SHIFT) |
KVM_SBI_VERSION_MINOR;
break;
case SBI_EXT_BASE_GET_IMP_ID:
*out_val = KVM_SBI_IMPID;
break;
case SBI_EXT_BASE_GET_IMP_VERSION:
*out_val = LINUX_VERSION_CODE;
break;
case SBI_EXT_BASE_PROBE_EXT:
if ((cp->a0 >= SBI_EXT_EXPERIMENTAL_START &&
cp->a0 <= SBI_EXT_EXPERIMENTAL_END) ||
(cp->a0 >= SBI_EXT_VENDOR_START &&
cp->a0 <= SBI_EXT_VENDOR_END)) {
/*
* For experimental/vendor extensions
* forward it to the userspace
*/
kvm_riscv_vcpu_sbi_forward(vcpu, run);
retdata->uexit = true;
} else {
sbi_ext = kvm_vcpu_sbi_find_ext(vcpu, cp->a0);
*out_val = sbi_ext && sbi_ext->probe ?
sbi_ext->probe(vcpu) : !!sbi_ext;
}
break;
case SBI_EXT_BASE_GET_MVENDORID:
*out_val = vcpu->arch.mvendorid;
break;
case SBI_EXT_BASE_GET_MARCHID:
*out_val = vcpu->arch.marchid;
break;
case SBI_EXT_BASE_GET_MIMPID:
*out_val = vcpu->arch.mimpid;
break;
default:
retdata->err_val = SBI_ERR_NOT_SUPPORTED;
break;
}
return 0;
}
const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_base = {
.extid_start = SBI_EXT_BASE,
.extid_end = SBI_EXT_BASE,
.handler = kvm_sbi_ext_base_handler,
};
static int kvm_sbi_ext_forward_handler(struct kvm_vcpu *vcpu,
struct kvm_run *run,
struct kvm_vcpu_sbi_return *retdata)
{
/*
* Both SBI experimental and vendor extensions are
* unconditionally forwarded to userspace.
*/
kvm_riscv_vcpu_sbi_forward(vcpu, run);
retdata->uexit = true;
return 0;
}
const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_experimental = {
.extid_start = SBI_EXT_EXPERIMENTAL_START,
.extid_end = SBI_EXT_EXPERIMENTAL_END,
.handler = kvm_sbi_ext_forward_handler,
};
const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_vendor = {
.extid_start = SBI_EXT_VENDOR_START,
.extid_end = SBI_EXT_VENDOR_END,
.handler = kvm_sbi_ext_forward_handler,
};