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linux/arch/riscv/kvm/vcpu_sbi_hsm.c
Yong-Xuan Wang 9752fed8f6 RISCV: KVM: Introduce vcpu->reset_cntx_lock
Originally, the use of kvm->lock in SBI_EXT_HSM_HART_START also avoids
the simultaneous updates to the reset context of target VCPU. Since this
lock has been replace with vcpu->mp_state_lock, and this new lock also
protects the vcpu->mp_state. We have to add a separate lock for
vcpu->reset_cntx.

Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20240417074528.16506-3-yongxuan.wang@sifive.com
Signed-off-by: Anup Patel <anup@brainfault.org>
2024-04-22 10:39:03 +05:30

137 lines
3.1 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 <asm/sbi.h>
#include <asm/kvm_vcpu_sbi.h>
static int kvm_sbi_hsm_vcpu_start(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *reset_cntx;
struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
struct kvm_vcpu *target_vcpu;
unsigned long target_vcpuid = cp->a0;
int ret = 0;
target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid);
if (!target_vcpu)
return SBI_ERR_INVALID_PARAM;
spin_lock(&target_vcpu->arch.mp_state_lock);
if (!kvm_riscv_vcpu_stopped(target_vcpu)) {
ret = SBI_ERR_ALREADY_AVAILABLE;
goto out;
}
spin_lock(&target_vcpu->arch.reset_cntx_lock);
reset_cntx = &target_vcpu->arch.guest_reset_context;
/* start address */
reset_cntx->sepc = cp->a1;
/* target vcpu id to start */
reset_cntx->a0 = target_vcpuid;
/* private data passed from kernel */
reset_cntx->a1 = cp->a2;
spin_unlock(&target_vcpu->arch.reset_cntx_lock);
kvm_make_request(KVM_REQ_VCPU_RESET, target_vcpu);
__kvm_riscv_vcpu_power_on(target_vcpu);
out:
spin_unlock(&target_vcpu->arch.mp_state_lock);
return ret;
}
static int kvm_sbi_hsm_vcpu_stop(struct kvm_vcpu *vcpu)
{
int ret = 0;
spin_lock(&vcpu->arch.mp_state_lock);
if (kvm_riscv_vcpu_stopped(vcpu)) {
ret = SBI_ERR_FAILURE;
goto out;
}
__kvm_riscv_vcpu_power_off(vcpu);
out:
spin_unlock(&vcpu->arch.mp_state_lock);
return ret;
}
static int kvm_sbi_hsm_vcpu_get_status(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
unsigned long target_vcpuid = cp->a0;
struct kvm_vcpu *target_vcpu;
target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid);
if (!target_vcpu)
return SBI_ERR_INVALID_PARAM;
if (!kvm_riscv_vcpu_stopped(target_vcpu))
return SBI_HSM_STATE_STARTED;
else if (vcpu->stat.generic.blocking)
return SBI_HSM_STATE_SUSPENDED;
else
return SBI_HSM_STATE_STOPPED;
}
static int kvm_sbi_ext_hsm_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
struct kvm_vcpu_sbi_return *retdata)
{
int ret = 0;
struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
unsigned long funcid = cp->a6;
switch (funcid) {
case SBI_EXT_HSM_HART_START:
ret = kvm_sbi_hsm_vcpu_start(vcpu);
break;
case SBI_EXT_HSM_HART_STOP:
ret = kvm_sbi_hsm_vcpu_stop(vcpu);
break;
case SBI_EXT_HSM_HART_STATUS:
ret = kvm_sbi_hsm_vcpu_get_status(vcpu);
if (ret >= 0) {
retdata->out_val = ret;
retdata->err_val = 0;
}
return 0;
case SBI_EXT_HSM_HART_SUSPEND:
switch (cp->a0) {
case SBI_HSM_SUSPEND_RET_DEFAULT:
kvm_riscv_vcpu_wfi(vcpu);
break;
case SBI_HSM_SUSPEND_NON_RET_DEFAULT:
ret = SBI_ERR_NOT_SUPPORTED;
break;
default:
ret = SBI_ERR_INVALID_PARAM;
}
break;
default:
ret = SBI_ERR_NOT_SUPPORTED;
}
retdata->err_val = ret;
return 0;
}
const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm = {
.extid_start = SBI_EXT_HSM,
.extid_end = SBI_EXT_HSM,
.handler = kvm_sbi_ext_hsm_handler,
};