linux/arch/x86/kvm/irq_comm.c
Vitaly Kuznetsov b4f69df0f6 KVM: x86: Make Hyper-V emulation optional
Hyper-V emulation in KVM is a fairly big chunk and in some cases it may be
desirable to not compile it in to reduce module sizes as well as the attack
surface. Introduce CONFIG_KVM_HYPERV option to make it possible.

Note, there's room for further nVMX/nSVM code optimizations when
!CONFIG_KVM_HYPERV, this will be done in follow-up patches.

Reorganize Makefile a bit so all CONFIG_HYPERV and CONFIG_KVM_HYPERV files
are grouped together.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Tested-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Link: https://lore.kernel.org/r/20231205103630.1391318-13-vkuznets@redhat.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-12-07 09:34:57 -08:00

450 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* irq_comm.c: Common API for in kernel interrupt controller
* Copyright (c) 2007, Intel Corporation.
*
* Authors:
* Yaozu (Eddie) Dong <Eddie.dong@intel.com>
*
* Copyright 2010 Red Hat, Inc. and/or its affiliates.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kvm_host.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/rculist.h>
#include <trace/events/kvm.h>
#include "irq.h"
#include "ioapic.h"
#include "lapic.h"
#include "hyperv.h"
#include "x86.h"
#include "xen.h"
static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
struct kvm *kvm, int irq_source_id, int level,
bool line_status)
{
struct kvm_pic *pic = kvm->arch.vpic;
return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
}
static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
struct kvm *kvm, int irq_source_id, int level,
bool line_status)
{
struct kvm_ioapic *ioapic = kvm->arch.vioapic;
return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
line_status);
}
int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
struct kvm_lapic_irq *irq, struct dest_map *dest_map)
{
int r = -1;
struct kvm_vcpu *vcpu, *lowest = NULL;
unsigned long i, dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)];
unsigned int dest_vcpus = 0;
if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
return r;
if (irq->dest_mode == APIC_DEST_PHYSICAL &&
irq->dest_id == 0xff && kvm_lowest_prio_delivery(irq)) {
pr_info("apic: phys broadcast and lowest prio\n");
irq->delivery_mode = APIC_DM_FIXED;
}
memset(dest_vcpu_bitmap, 0, sizeof(dest_vcpu_bitmap));
kvm_for_each_vcpu(i, vcpu, kvm) {
if (!kvm_apic_present(vcpu))
continue;
if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
irq->dest_id, irq->dest_mode))
continue;
if (!kvm_lowest_prio_delivery(irq)) {
if (r < 0)
r = 0;
r += kvm_apic_set_irq(vcpu, irq, dest_map);
} else if (kvm_apic_sw_enabled(vcpu->arch.apic)) {
if (!kvm_vector_hashing_enabled()) {
if (!lowest)
lowest = vcpu;
else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
lowest = vcpu;
} else {
__set_bit(i, dest_vcpu_bitmap);
dest_vcpus++;
}
}
}
if (dest_vcpus != 0) {
int idx = kvm_vector_to_index(irq->vector, dest_vcpus,
dest_vcpu_bitmap, KVM_MAX_VCPUS);
lowest = kvm_get_vcpu(kvm, idx);
}
if (lowest)
r = kvm_apic_set_irq(lowest, irq, dest_map);
return r;
}
void kvm_set_msi_irq(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
struct kvm_lapic_irq *irq)
{
struct msi_msg msg = { .address_lo = e->msi.address_lo,
.address_hi = e->msi.address_hi,
.data = e->msi.data };
trace_kvm_msi_set_irq(msg.address_lo | (kvm->arch.x2apic_format ?
(u64)msg.address_hi << 32 : 0), msg.data);
irq->dest_id = x86_msi_msg_get_destid(&msg, kvm->arch.x2apic_format);
irq->vector = msg.arch_data.vector;
irq->dest_mode = kvm_lapic_irq_dest_mode(msg.arch_addr_lo.dest_mode_logical);
irq->trig_mode = msg.arch_data.is_level;
irq->delivery_mode = msg.arch_data.delivery_mode << 8;
irq->msi_redir_hint = msg.arch_addr_lo.redirect_hint;
irq->level = 1;
irq->shorthand = APIC_DEST_NOSHORT;
}
EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
static inline bool kvm_msi_route_invalid(struct kvm *kvm,
struct kvm_kernel_irq_routing_entry *e)
{
return kvm->arch.x2apic_format && (e->msi.address_hi & 0xff);
}
int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
struct kvm *kvm, int irq_source_id, int level, bool line_status)
{
struct kvm_lapic_irq irq;
if (kvm_msi_route_invalid(kvm, e))
return -EINVAL;
if (!level)
return -1;
kvm_set_msi_irq(kvm, e, &irq);
return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
}
#ifdef CONFIG_KVM_HYPERV
static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
struct kvm *kvm, int irq_source_id, int level,
bool line_status)
{
if (!level)
return -1;
return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
}
#endif
int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
struct kvm *kvm, int irq_source_id, int level,
bool line_status)
{
struct kvm_lapic_irq irq;
int r;
switch (e->type) {
#ifdef CONFIG_KVM_HYPERV
case KVM_IRQ_ROUTING_HV_SINT:
return kvm_hv_set_sint(e, kvm, irq_source_id, level,
line_status);
#endif
case KVM_IRQ_ROUTING_MSI:
if (kvm_msi_route_invalid(kvm, e))
return -EINVAL;
kvm_set_msi_irq(kvm, e, &irq);
if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
return r;
break;
#ifdef CONFIG_KVM_XEN
case KVM_IRQ_ROUTING_XEN_EVTCHN:
if (!level)
return -1;
return kvm_xen_set_evtchn_fast(&e->xen_evtchn, kvm);
#endif
default:
break;
}
return -EWOULDBLOCK;
}
int kvm_request_irq_source_id(struct kvm *kvm)
{
unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
int irq_source_id;
mutex_lock(&kvm->irq_lock);
irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
if (irq_source_id >= BITS_PER_LONG) {
pr_warn("exhausted allocatable IRQ sources!\n");
irq_source_id = -EFAULT;
goto unlock;
}
ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
set_bit(irq_source_id, bitmap);
unlock:
mutex_unlock(&kvm->irq_lock);
return irq_source_id;
}
void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
{
ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
mutex_lock(&kvm->irq_lock);
if (irq_source_id < 0 ||
irq_source_id >= BITS_PER_LONG) {
pr_err("IRQ source ID out of range!\n");
goto unlock;
}
clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
if (!irqchip_kernel(kvm))
goto unlock;
kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
kvm_pic_clear_all(kvm->arch.vpic, irq_source_id);
unlock:
mutex_unlock(&kvm->irq_lock);
}
void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
struct kvm_irq_mask_notifier *kimn)
{
mutex_lock(&kvm->irq_lock);
kimn->irq = irq;
hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
mutex_unlock(&kvm->irq_lock);
}
void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
struct kvm_irq_mask_notifier *kimn)
{
mutex_lock(&kvm->irq_lock);
hlist_del_rcu(&kimn->link);
mutex_unlock(&kvm->irq_lock);
synchronize_srcu(&kvm->irq_srcu);
}
void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
bool mask)
{
struct kvm_irq_mask_notifier *kimn;
int idx, gsi;
idx = srcu_read_lock(&kvm->irq_srcu);
gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
if (gsi != -1)
hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
if (kimn->irq == gsi)
kimn->func(kimn, mask);
srcu_read_unlock(&kvm->irq_srcu, idx);
}
bool kvm_arch_can_set_irq_routing(struct kvm *kvm)
{
return irqchip_in_kernel(kvm);
}
int kvm_set_routing_entry(struct kvm *kvm,
struct kvm_kernel_irq_routing_entry *e,
const struct kvm_irq_routing_entry *ue)
{
/* We can't check irqchip_in_kernel() here as some callers are
* currently initializing the irqchip. Other callers should therefore
* check kvm_arch_can_set_irq_routing() before calling this function.
*/
switch (ue->type) {
case KVM_IRQ_ROUTING_IRQCHIP:
if (irqchip_split(kvm))
return -EINVAL;
e->irqchip.pin = ue->u.irqchip.pin;
switch (ue->u.irqchip.irqchip) {
case KVM_IRQCHIP_PIC_SLAVE:
e->irqchip.pin += PIC_NUM_PINS / 2;
fallthrough;
case KVM_IRQCHIP_PIC_MASTER:
if (ue->u.irqchip.pin >= PIC_NUM_PINS / 2)
return -EINVAL;
e->set = kvm_set_pic_irq;
break;
case KVM_IRQCHIP_IOAPIC:
if (ue->u.irqchip.pin >= KVM_IOAPIC_NUM_PINS)
return -EINVAL;
e->set = kvm_set_ioapic_irq;
break;
default:
return -EINVAL;
}
e->irqchip.irqchip = ue->u.irqchip.irqchip;
break;
case KVM_IRQ_ROUTING_MSI:
e->set = kvm_set_msi;
e->msi.address_lo = ue->u.msi.address_lo;
e->msi.address_hi = ue->u.msi.address_hi;
e->msi.data = ue->u.msi.data;
if (kvm_msi_route_invalid(kvm, e))
return -EINVAL;
break;
#ifdef CONFIG_KVM_HYPERV
case KVM_IRQ_ROUTING_HV_SINT:
e->set = kvm_hv_set_sint;
e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
e->hv_sint.sint = ue->u.hv_sint.sint;
break;
#endif
#ifdef CONFIG_KVM_XEN
case KVM_IRQ_ROUTING_XEN_EVTCHN:
return kvm_xen_setup_evtchn(kvm, e, ue);
#endif
default:
return -EINVAL;
}
return 0;
}
bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
struct kvm_vcpu **dest_vcpu)
{
int r = 0;
unsigned long i;
struct kvm_vcpu *vcpu;
if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
return true;
kvm_for_each_vcpu(i, vcpu, kvm) {
if (!kvm_apic_present(vcpu))
continue;
if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
irq->dest_id, irq->dest_mode))
continue;
if (++r == 2)
return false;
*dest_vcpu = vcpu;
}
return r == 1;
}
EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
#define IOAPIC_ROUTING_ENTRY(irq) \
{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP, \
.u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
#define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
#define PIC_ROUTING_ENTRY(irq) \
{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP, \
.u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
#define ROUTING_ENTRY2(irq) \
IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
static const struct kvm_irq_routing_entry default_routing[] = {
ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
};
int kvm_setup_default_irq_routing(struct kvm *kvm)
{
return kvm_set_irq_routing(kvm, default_routing,
ARRAY_SIZE(default_routing), 0);
}
static const struct kvm_irq_routing_entry empty_routing[] = {};
int kvm_setup_empty_irq_routing(struct kvm *kvm)
{
return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
}
void kvm_arch_post_irq_routing_update(struct kvm *kvm)
{
if (!irqchip_split(kvm))
return;
kvm_make_scan_ioapic_request(kvm);
}
void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
ulong *ioapic_handled_vectors)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_kernel_irq_routing_entry *entry;
struct kvm_irq_routing_table *table;
u32 i, nr_ioapic_pins;
int idx;
idx = srcu_read_lock(&kvm->irq_srcu);
table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
kvm->arch.nr_reserved_ioapic_pins);
for (i = 0; i < nr_ioapic_pins; ++i) {
hlist_for_each_entry(entry, &table->map[i], link) {
struct kvm_lapic_irq irq;
if (entry->type != KVM_IRQ_ROUTING_MSI)
continue;
kvm_set_msi_irq(vcpu->kvm, entry, &irq);
if (irq.trig_mode &&
(kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
irq.dest_id, irq.dest_mode) ||
kvm_apic_pending_eoi(vcpu, irq.vector)))
__set_bit(irq.vector, ioapic_handled_vectors);
}
}
srcu_read_unlock(&kvm->irq_srcu, idx);
}
void kvm_arch_irq_routing_update(struct kvm *kvm)
{
#ifdef CONFIG_KVM_HYPERV
kvm_hv_irq_routing_update(kvm);
#endif
}