linux/arch/arm64/kvm/pvtime.c
Keqian Zhu 652d0b701d KVM: arm64: Use kvm_write_guest_lock when init stolen time
There is a lock version kvm_write_guest. Use it to simplify code.

Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20200817110728.12196-3-zhukeqian1@huawei.com
2020-12-03 19:02:18 +00:00

134 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2019 Arm Ltd.
#include <linux/arm-smccc.h>
#include <linux/kvm_host.h>
#include <linux/sched/stat.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 base = vcpu->arch.steal.base;
u64 last_steal = vcpu->arch.steal.last_steal;
u64 offset = offsetof(struct pvclock_vcpu_stolen_time, stolen_time);
u64 steal = 0;
int idx;
if (base == GPA_INVALID)
return;
idx = srcu_read_lock(&kvm->srcu);
if (!kvm_get_guest(kvm, base + offset, steal)) {
steal = le64_to_cpu(steal);
vcpu->arch.steal.last_steal = READ_ONCE(current->sched_info.run_delay);
steal += vcpu->arch.steal.last_steal - last_steal;
kvm_put_guest(kvm, base + offset, cpu_to_le64(steal));
}
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:
if (vcpu->arch.steal.base != GPA_INVALID)
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;
if (base == GPA_INVALID)
return base;
/*
* Start counting stolen time from the time the guest requests
* the feature enabled.
*/
vcpu->arch.steal.last_steal = current->sched_info.run_delay;
kvm_write_guest_lock(kvm, base, &init_values, sizeof(init_values));
return base;
}
bool kvm_arm_pvtime_supported(void)
{
return !!sched_info_on();
}
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 (!kvm_arm_pvtime_supported() ||
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 (!kvm_arm_pvtime_supported() ||
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:
if (kvm_arm_pvtime_supported())
return 0;
}
return -ENXIO;
}