linux/virt/kvm/arm/pvtime.c

132 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2019 Arm Ltd.
#include <linux/arm-smccc.h>
#include <linux/kvm_host.h>
#include <asm/kvm_mmu.h>
#include <asm/pvclock-abi.h>
#include <kvm/arm_hypercalls.h>
void kvm_update_stolen_time(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = vcpu->kvm;
u64 steal;
__le64 steal_le;
u64 offset;
int idx;
u64 base = vcpu->arch.steal.base;
if (base == GPA_INVALID)
return;
/* Let's do the local bookkeeping */
steal = vcpu->arch.steal.steal;
steal += current->sched_info.run_delay - vcpu->arch.steal.last_steal;
vcpu->arch.steal.last_steal = current->sched_info.run_delay;
vcpu->arch.steal.steal = steal;
steal_le = cpu_to_le64(steal);
idx = srcu_read_lock(&kvm->srcu);
offset = offsetof(struct pvclock_vcpu_stolen_time, stolen_time);
kvm_put_guest(kvm, base + offset, steal_le, u64);
srcu_read_unlock(&kvm->srcu, idx);
}
long kvm_hypercall_pv_features(struct kvm_vcpu *vcpu)
{
u32 feature = smccc_get_arg1(vcpu);
long val = SMCCC_RET_NOT_SUPPORTED;
switch (feature) {
case ARM_SMCCC_HV_PV_TIME_FEATURES:
case ARM_SMCCC_HV_PV_TIME_ST:
val = SMCCC_RET_SUCCESS;
break;
}
return val;
}
gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu)
{
struct pvclock_vcpu_stolen_time init_values = {};
struct kvm *kvm = vcpu->kvm;
u64 base = vcpu->arch.steal.base;
int idx;
if (base == GPA_INVALID)
return base;
/*
* Start counting stolen time from the time the guest requests
* the feature enabled.
*/
vcpu->arch.steal.steal = 0;
vcpu->arch.steal.last_steal = current->sched_info.run_delay;
idx = srcu_read_lock(&kvm->srcu);
kvm_write_guest(kvm, base, &init_values, sizeof(init_values));
srcu_read_unlock(&kvm->srcu, idx);
return base;
}
int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
u64 __user *user = (u64 __user *)attr->addr;
struct kvm *kvm = vcpu->kvm;
u64 ipa;
int ret = 0;
int idx;
if (attr->attr != KVM_ARM_VCPU_PVTIME_IPA)
return -ENXIO;
if (get_user(ipa, user))
return -EFAULT;
if (!IS_ALIGNED(ipa, 64))
return -EINVAL;
if (vcpu->arch.steal.base != GPA_INVALID)
return -EEXIST;
/* Check the address is in a valid memslot */
idx = srcu_read_lock(&kvm->srcu);
if (kvm_is_error_hva(gfn_to_hva(kvm, ipa >> PAGE_SHIFT)))
ret = -EINVAL;
srcu_read_unlock(&kvm->srcu, idx);
if (!ret)
vcpu->arch.steal.base = ipa;
return ret;
}
int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
u64 __user *user = (u64 __user *)attr->addr;
u64 ipa;
if (attr->attr != KVM_ARM_VCPU_PVTIME_IPA)
return -ENXIO;
ipa = vcpu->arch.steal.base;
if (put_user(ipa, user))
return -EFAULT;
return 0;
}
int kvm_arm_pvtime_has_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
switch (attr->attr) {
case KVM_ARM_VCPU_PVTIME_IPA:
return 0;
}
return -ENXIO;
}