// SPDX-License-Identifier: GPL-2.0-only
/*
* Kernel-based Virtual Machine driver for Linux
*
* AMD SVM support
*
* Copyright (C) 2006 Qumranet, Inc.
* Copyright 2010 Red Hat, Inc. and/or its affiliates.
*
* Authors:
* Yaniv Kamay <yaniv@qumranet.com>
* Avi Kivity <avi@qumranet.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kvm_types.h>
#include <linux/hashtable.h>
#include <linux/amd-iommu.h>
#include <linux/kvm_host.h>
#include <linux/kvm_irqfd.h>
#include <linux/sysfs.h>
#include <asm/irq_remapping.h>
#include <asm/msr.h>
#include "trace.h"
#include "lapic.h"
#include "x86.h"
#include "irq.h"
#include "svm.h"
/*
* Encode the arbitrary VM ID and the vCPU's _index_ into the GATag so that
* KVM can retrieve the correct vCPU from a GALog entry if an interrupt can't
* be delivered, e.g. because the vCPU isn't running. Use the vCPU's index
* instead of its ID (a.k.a. its default APIC ID), as KVM is guaranteed a fast
* lookup on the index, where as vCPUs whose index doesn't match their ID need
* to walk the entire xarray of vCPUs in the worst case scenario.
*
* For the vCPU index, use however many bits are currently allowed for the max
* guest physical APIC ID (limited by the size of the physical ID table), and
* use whatever bits remain to assign arbitrary AVIC IDs to VMs. Note, the
* size of the GATag is defined by hardware (32 bits), but is an opaque value
* as far as hardware is concerned.
*/
#define AVIC_VCPU_IDX_MASK AVIC_PHYSICAL_MAX_INDEX_MASK
#define AVIC_VM_ID_SHIFT HWEIGHT32(AVIC_PHYSICAL_MAX_INDEX_MASK)
#define AVIC_VM_ID_MASK (GENMASK(31, AVIC_VM_ID_SHIFT) >> AVIC_VM_ID_SHIFT)
#define AVIC_GATAG_TO_VMID(x) ((x >> AVIC_VM_ID_SHIFT) & AVIC_VM_ID_MASK)
#define AVIC_GATAG_TO_VCPUIDX(x) (x & AVIC_VCPU_IDX_MASK)
#define __AVIC_GATAG(vm_id, vcpu_idx) ((((vm_id) & AVIC_VM_ID_MASK) << AVIC_VM_ID_SHIFT) | \
((vcpu_idx) & AVIC_VCPU_IDX_MASK))
#define AVIC_GATAG(vm_id, vcpu_idx) \
({ \
u32 ga_tag = __AVIC_GATAG(vm_id, vcpu_idx); \
\
WARN_ON_ONCE(AVIC_GATAG_TO_VCPUIDX(ga_tag) != (vcpu_idx)); \
WARN_ON_ONCE(AVIC_GATAG_TO_VMID(ga_tag) != (vm_id)); \
ga_tag; \
})
static_assert(__AVIC_GATAG(AVIC_VM_ID_MASK, AVIC_VCPU_IDX_MASK) == -1u);
#define AVIC_AUTO_MODE -1
static int avic_param_set(const char *val, const struct kernel_param *kp)
{
if (val && sysfs_streq(val, "auto")) {
*(int *)kp->arg = AVIC_AUTO_MODE;
return 0;
}
return param_set_bint(val, kp);
}
static int avic_param_get(char *buffer, const struct kernel_param *kp)
{
int val = *(int *)kp->arg;
if (val == AVIC_AUTO_MODE)
return sysfs_emit(buffer, "N\n");
return param_get_bool(buffer, kp);
}
static const struct kernel_param_ops avic_ops = {
.flags = KERNEL_PARAM_OPS_FL_NOARG,
.set = avic_param_set,
.get = avic_param_get,
};
/*
* Enable / disable AVIC. In "auto" mode (default behavior), AVIC is enabled
