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-rw-r--r--arch/arm64/kvm/pvtime.c133
1 files changed, 133 insertions, 0 deletions
diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c
new file mode 100644
index 000000000..78a09f7a6
--- /dev/null
+++ b/arch/arm64/kvm/pvtime.c
@@ -0,0 +1,133 @@
+// 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;
+}