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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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58772e9a3d
Allow user space to inform the KVM host where in the physical memory map the paravirtualized time structures should be located. User space can set an attribute on the VCPU providing the IPA base address of the stolen time structure for that VCPU. This must be repeated for every VCPU in the VM. The address is given in terms of the physical address visible to the guest and must be 64 byte aligned. The guest will discover the address via a hypercall. Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
132 lines
2.8 KiB
C
132 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2019 Arm Ltd.
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#include <linux/arm-smccc.h>
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#include <linux/kvm_host.h>
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#include <asm/kvm_mmu.h>
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#include <asm/pvclock-abi.h>
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#include <kvm/arm_hypercalls.h>
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void kvm_update_stolen_time(struct kvm_vcpu *vcpu)
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{
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struct kvm *kvm = vcpu->kvm;
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u64 steal;
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__le64 steal_le;
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u64 offset;
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int idx;
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u64 base = vcpu->arch.steal.base;
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if (base == GPA_INVALID)
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return;
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/* Let's do the local bookkeeping */
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steal = vcpu->arch.steal.steal;
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steal += current->sched_info.run_delay - vcpu->arch.steal.last_steal;
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vcpu->arch.steal.last_steal = current->sched_info.run_delay;
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vcpu->arch.steal.steal = steal;
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steal_le = cpu_to_le64(steal);
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idx = srcu_read_lock(&kvm->srcu);
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offset = offsetof(struct pvclock_vcpu_stolen_time, stolen_time);
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kvm_put_guest(kvm, base + offset, steal_le, u64);
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srcu_read_unlock(&kvm->srcu, idx);
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}
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long kvm_hypercall_pv_features(struct kvm_vcpu *vcpu)
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{
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u32 feature = smccc_get_arg1(vcpu);
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long val = SMCCC_RET_NOT_SUPPORTED;
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switch (feature) {
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case ARM_SMCCC_HV_PV_TIME_FEATURES:
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case ARM_SMCCC_HV_PV_TIME_ST:
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val = SMCCC_RET_SUCCESS;
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break;
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}
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return val;
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}
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gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu)
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{
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struct pvclock_vcpu_stolen_time init_values = {};
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struct kvm *kvm = vcpu->kvm;
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u64 base = vcpu->arch.steal.base;
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int idx;
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if (base == GPA_INVALID)
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return base;
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/*
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* Start counting stolen time from the time the guest requests
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* the feature enabled.
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*/
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vcpu->arch.steal.steal = 0;
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vcpu->arch.steal.last_steal = current->sched_info.run_delay;
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idx = srcu_read_lock(&kvm->srcu);
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kvm_write_guest(kvm, base, &init_values, sizeof(init_values));
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srcu_read_unlock(&kvm->srcu, idx);
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return base;
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}
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int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu,
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struct kvm_device_attr *attr)
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{
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u64 __user *user = (u64 __user *)attr->addr;
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struct kvm *kvm = vcpu->kvm;
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u64 ipa;
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int ret = 0;
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int idx;
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if (attr->attr != KVM_ARM_VCPU_PVTIME_IPA)
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return -ENXIO;
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if (get_user(ipa, user))
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return -EFAULT;
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if (!IS_ALIGNED(ipa, 64))
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return -EINVAL;
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if (vcpu->arch.steal.base != GPA_INVALID)
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return -EEXIST;
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/* Check the address is in a valid memslot */
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idx = srcu_read_lock(&kvm->srcu);
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if (kvm_is_error_hva(gfn_to_hva(kvm, ipa >> PAGE_SHIFT)))
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ret = -EINVAL;
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srcu_read_unlock(&kvm->srcu, idx);
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if (!ret)
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vcpu->arch.steal.base = ipa;
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return ret;
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}
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int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu,
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struct kvm_device_attr *attr)
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{
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u64 __user *user = (u64 __user *)attr->addr;
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u64 ipa;
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if (attr->attr != KVM_ARM_VCPU_PVTIME_IPA)
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return -ENXIO;
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ipa = vcpu->arch.steal.base;
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if (put_user(ipa, user))
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return -EFAULT;
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return 0;
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}
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int kvm_arm_pvtime_has_attr(struct kvm_vcpu *vcpu,
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struct kvm_device_attr *attr)
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{
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switch (attr->attr) {
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case KVM_ARM_VCPU_PVTIME_IPA:
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return 0;
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}
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return -ENXIO;
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}
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