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2aff696b10
qemu-e2k/hw/i386/kvm/xen_evtchn.c
David Woodhouse 2aff696b10 hw/xen: Support HVM_PARAM_CALLBACK_TYPE_PCI_INTX callback 
The guest is permitted to specify an arbitrary domain/bus/device/function
and INTX pin from which the callback IRQ shall appear to have come.

In QEMU we can only easily do this for devices that actually exist, and
even that requires us "knowing" that it's a PCMachine in order to find
the PCI root bus — although that's OK really because it's always true.

We also don't get to get notified of INTX routing changes, because we
can't do that as a passive observer; if we try to register a notifier
it will overwrite any existing notifier callback on the device.

But in practice, guests using PCI_INTX will only ever use pin A on the
Xen platform device, and won't swizzle the INTX routing after they set
it up. So this is just fine.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01 09:07:50 +00:00

1358 lines
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/*
* QEMU Xen emulation: Event channel support
*
* Copyright © 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Authors: David Woodhouse <dwmw2@infradead.org>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qemu/host-utils.h"
#include "qemu/module.h"
#include "qemu/lockable.h"
#include "qemu/main-loop.h"
#include "qemu/log.h"
#include "monitor/monitor.h"
#include "monitor/hmp.h"
#include "qapi/error.h"
#include "qapi/qapi-commands-misc-target.h"
#include "qapi/qmp/qdict.h"
#include "qom/object.h"
#include "exec/target_page.h"
#include "exec/address-spaces.h"
#include "migration/vmstate.h"
#include "hw/sysbus.h"
#include "hw/xen/xen.h"
#include "hw/i386/x86.h"
#include "hw/i386/pc.h"
#include "hw/pci/pci.h"
#include "hw/irq.h"
#include "xen_evtchn.h"
#include "xen_overlay.h"
#include "sysemu/kvm.h"
#include "sysemu/kvm_xen.h"
#include <linux/kvm.h>
#include "hw/xen/interface/memory.h"
#include "hw/xen/interface/hvm/params.h"
#define TYPE_XEN_EVTCHN "xen-evtchn"
OBJECT_DECLARE_SIMPLE_TYPE(XenEvtchnState, XEN_EVTCHN)
typedef struct XenEvtchnPort {
uint32_t vcpu; /* Xen/ACPI vcpu_id */
uint16_t type; /* EVTCHNSTAT_xxxx */
uint16_t type_val; /* pirq# / virq# / remote port according to type */
} XenEvtchnPort;
/* 32-bit compatibility definitions, also used natively in 32-bit build */
struct compat_arch_vcpu_info {
unsigned int cr2;
unsigned int pad[5];
};
struct compat_vcpu_info {
uint8_t evtchn_upcall_pending;
uint8_t evtchn_upcall_mask;
uint16_t pad;
uint32_t evtchn_pending_sel;
struct compat_arch_vcpu_info arch;
struct vcpu_time_info time;
}; /* 64 bytes (x86) */
struct compat_arch_shared_info {
unsigned int max_pfn;
unsigned int pfn_to_mfn_frame_list_list;
unsigned int nmi_reason;
unsigned int p2m_cr3;
unsigned int p2m_vaddr;
unsigned int p2m_generation;
uint32_t wc_sec_hi;
};
struct compat_shared_info {
struct compat_vcpu_info vcpu_info[XEN_LEGACY_MAX_VCPUS];
uint32_t evtchn_pending[32];
uint32_t evtchn_mask[32];
uint32_t wc_version; /* Version counter: see vcpu_time_info_t. */
uint32_t wc_sec;
uint32_t wc_nsec;
struct compat_arch_shared_info arch;
};
#define COMPAT_EVTCHN_2L_NR_CHANNELS 1024
/*
* For unbound/interdomain ports there are only two possible remote
* domains; self and QEMU. Use a single high bit in type_val for that,
* and the low bits for the remote port number (or 0 for unbound).
*/
#define PORT_INFO_TYPEVAL_REMOTE_QEMU 0x8000
#define PORT_INFO_TYPEVAL_REMOTE_PORT_MASK 0x7FFF
struct XenEvtchnState {
/*< private >*/
SysBusDevice busdev;
/*< public >*/
uint64_t callback_param;
bool evtchn_in_kernel;
uint32_t callback_gsi;
QEMUBH *gsi_bh;
QemuMutex port_lock;
uint32_t nr_ports;
XenEvtchnPort port_table[EVTCHN_2L_NR_CHANNELS];
qemu_irq gsis[IOAPIC_NUM_PINS];
};
struct XenEvtchnState *xen_evtchn_singleton;
/* Top bits of callback_param are the type (HVM_PARAM_CALLBACK_TYPE_xxx) */
#define CALLBACK_VIA_TYPE_SHIFT 56
static int xen_evtchn_post_load(void *opaque, int version_id)
{
XenEvtchnState *s = opaque;
if (s->callback_param) {
xen_evtchn_set_callback_param(s->callback_param);
}
return 0;
}
static bool xen_evtchn_is_needed(void *opaque)
{
return xen_mode == XEN_EMULATE;
}
static const VMStateDescription xen_evtchn_port_vmstate = {
.name = "xen_evtchn_port",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT32(vcpu, XenEvtchnPort),
VMSTATE_UINT16(type, XenEvtchnPort),
VMSTATE_UINT16(type_val, XenEvtchnPort),
VMSTATE_END_OF_LIST()
}
};
static const VMStateDescription xen_evtchn_vmstate = {
.name = "xen_evtchn",
.version_id = 1,
.minimum_version_id = 1,
.needed = xen_evtchn_is_needed,
.post_load = xen_evtchn_post_load,
.fields = (VMStateField[]) {
VMSTATE_UINT64(callback_param, XenEvtchnState),
VMSTATE_UINT32(nr_ports, XenEvtchnState),
VMSTATE_STRUCT_VARRAY_UINT32(port_table, XenEvtchnState, nr_ports, 1,
xen_evtchn_port_vmstate, XenEvtchnPort),
VMSTATE_END_OF_LIST()
}
};
static void xen_evtchn_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->vmsd = &xen_evtchn_vmstate;
}
static const TypeInfo xen_evtchn_info = {
.name = TYPE_XEN_EVTCHN,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(XenEvtchnState),
.class_init = xen_evtchn_class_init,
};
static void gsi_assert_bh(void *opaque)
{
struct vcpu_info *vi = kvm_xen_get_vcpu_info_hva(0);
if (vi) {
xen_evtchn_set_callback_level(!!vi->evtchn_upcall_pending);
}
}
void xen_evtchn_create(void)
{
XenEvtchnState *s = XEN_EVTCHN(sysbus_create_simple(TYPE_XEN_EVTCHN,
-1, NULL));
int i;
xen_evtchn_singleton = s;
qemu_mutex_init(&s->port_lock);
s->gsi_bh = aio_bh_new(qemu_get_aio_context(), gsi_assert_bh, s);
for (i = 0; i < IOAPIC_NUM_PINS; i++) {
sysbus_init_irq(SYS_BUS_DEVICE(s), &s->gsis[i]);
}
}
void xen_evtchn_connect_gsis(qemu_irq *system_gsis)
{
XenEvtchnState *s = xen_evtchn_singleton;
int i;
if (!s) {
return;
}
for (i = 0; i < IOAPIC_NUM_PINS; i++) {
sysbus_connect_irq(SYS_BUS_DEVICE(s), i, system_gsis[i]);
}
}
static void xen_evtchn_register_types(void)
{
type_register_static(&xen_evtchn_info);
}
type_init(xen_evtchn_register_types)
static int set_callback_pci_intx(XenEvtchnState *s, uint64_t param)
{
PCMachineState *pcms = PC_MACHINE(qdev_get_machine());
uint8_t pin = param & 3;
uint8_t devfn = (param >> 8) & 0xff;
uint16_t bus = (param >> 16) & 0xffff;
uint16_t domain = (param >> 32) & 0xffff;
PCIDevice *pdev;
PCIINTxRoute r;
if (domain || !pcms) {
return 0;
}
pdev = pci_find_device(pcms->bus, bus, devfn);
if (!pdev) {
return 0;
}
r = pci_device_route_intx_to_irq(pdev, pin);
if (r.mode != PCI_INTX_ENABLED) {
return 0;
}
/*
* Hm, can we be notified of INTX routing changes? Not without
* *owning* the device and being allowed to overwrite its own
* ->intx_routing_notifier, AFAICT. So let's not.
*/
return r.irq;
}
void xen_evtchn_set_callback_level(int level)
{
XenEvtchnState *s = xen_evtchn_singleton;
if (!s) {
return;
}
/*
* We get to this function in a number of ways:
*
* • From I/O context, via PV backend drivers sending a notification to
* the guest.
*
* • From guest vCPU context, via loopback interdomain event channels
* (or theoretically even IPIs but guests don't use those with GSI
* delivery because that's pointless. We don't want a malicious guest
* to be able to trigger a deadlock though, so we can't rule it out.)
*
* • From guest vCPU context when the HVM_PARAM_CALLBACK_IRQ is being
* configured.
*
* • From guest vCPU context in the KVM exit handler, if the upcall
* pending flag has been cleared and the GSI needs to be deasserted.
*
* • Maybe in future, in an interrupt ack/eoi notifier when the GSI has
* been acked in the irqchip.
*
* Whichever context we come from if we aren't already holding the BQL
* then e can't take it now, as we may already hold s->port_lock. So
* trigger the BH to set the IRQ for us instead of doing it immediately.
*
* In the HVM_PARAM_CALLBACK_IRQ and KVM exit handler cases, the caller
* will deliberately take the BQL because they want the change to take
* effect immediately. That just leaves interdomain loopback as the case
* which uses the BH.
*/
if (!qemu_mutex_iothread_locked()) {
qemu_bh_schedule(s->gsi_bh);
return;
}
if (s->callback_gsi && s->callback_gsi < IOAPIC_NUM_PINS) {
qemu_set_irq(s->gsis[s->callback_gsi], level);
if (level) {
/* Ensure the vCPU polls for deassertion */
kvm_xen_set_callback_asserted();
}
}
}
int xen_evtchn_set_callback_param(uint64_t param)
{
XenEvtchnState *s = xen_evtchn_singleton;
struct kvm_xen_hvm_attr xa = {
.type = KVM_XEN_ATTR_TYPE_UPCALL_VECTOR,
.u.vector = 0,
};
bool in_kernel = false;
uint32_t gsi = 0;
int type = param >> CALLBACK_VIA_TYPE_SHIFT;
int ret;
if (!s) {
return -ENOTSUP;
}
/*
* We need the BQL because set_callback_pci_intx() may call into PCI code,
* and because we may need to manipulate the old and new GSI levels.
*/
assert(qemu_mutex_iothread_locked());
qemu_mutex_lock(&s->port_lock);
switch (type) {
case HVM_PARAM_CALLBACK_TYPE_VECTOR: {
xa.u.vector = (uint8_t)param,
ret = kvm_vm_ioctl(kvm_state, KVM_XEN_HVM_SET_ATTR, &xa);
if (!ret && kvm_xen_has_cap(EVTCHN_SEND)) {
in_kernel = true;
}
gsi = 0;
break;
}
case HVM_PARAM_CALLBACK_TYPE_PCI_INTX:
gsi = set_callback_pci_intx(s, param);
ret = gsi ? 0 : -EINVAL;
break;
case HVM_PARAM_CALLBACK_TYPE_GSI:
gsi = (uint32_t)param;
ret = 0;
break;
default:
/* Xen doesn't return error even if you set something bogus */
ret = 0;
break;
}
if (!ret) {
/* If vector delivery was turned *off* then tell the kernel */
if ((s->callback_param >> CALLBACK_VIA_TYPE_SHIFT) ==
HVM_PARAM_CALLBACK_TYPE_VECTOR && !xa.u.vector) {
kvm_vm_ioctl(kvm_state, KVM_XEN_HVM_SET_ATTR, &xa);
}
s->callback_param = param;
s->evtchn_in_kernel = in_kernel;
if (gsi != s->callback_gsi) {
struct vcpu_info *vi = kvm_xen_get_vcpu_info_hva(0);
xen_evtchn_set_callback_level(0);
s->callback_gsi = gsi;
if (gsi && vi && vi->evtchn_upcall_pending) {
kvm_xen_inject_vcpu_callback_vector(0, type);
}
}
}
qemu_mutex_unlock(&s->port_lock);
return ret;
}
static void inject_callback(XenEvtchnState *s, uint32_t vcpu)
{
int type = s->callback_param >> CALLBACK_VIA_TYPE_SHIFT;
kvm_xen_inject_vcpu_callback_vector(vcpu, type);
}
static void deassign_kernel_port(evtchn_port_t port)
{
struct kvm_xen_hvm_attr ha;
int ret;
ha.type = KVM_XEN_ATTR_TYPE_EVTCHN;
ha.u.evtchn.send_port = port;
ha.u.evtchn.flags = KVM_XEN_EVTCHN_DEASSIGN;
ret = kvm_vm_ioctl(kvm_state, KVM_XEN_HVM_SET_ATTR, &ha);
if (ret) {
qemu_log_mask(LOG_GUEST_ERROR, "Failed to unbind kernel port %d: %s\n",
port, strerror(ret));
}
}
static int assign_kernel_port(uint16_t type, evtchn_port_t port,
uint32_t vcpu_id)
{
CPUState *cpu = qemu_get_cpu(vcpu_id);
struct kvm_xen_hvm_attr ha;
if (!cpu) {
return -ENOENT;
}
ha.type = KVM_XEN_ATTR_TYPE_EVTCHN;
ha.u.evtchn.send_port = port;
ha.u.evtchn.type = type;
ha.u.evtchn.flags = 0;
ha.u.evtchn.deliver.port.port = port;
ha.u.evtchn.deliver.port.vcpu = kvm_arch_vcpu_id(cpu);
ha.u.evtchn.deliver.port.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL;
return kvm_vm_ioctl(kvm_state, KVM_XEN_HVM_SET_ATTR, &ha);
}
static bool valid_port(evtchn_port_t port)
{
if (!port) {
return false;
}
if (xen_is_long_mode()) {
return port < EVTCHN_2L_NR_CHANNELS;
} else {
return port < COMPAT_EVTCHN_2L_NR_CHANNELS;
}
}
static bool valid_vcpu(uint32_t vcpu)
{
return !!qemu_get_cpu(vcpu);
}
int xen_evtchn_status_op(struct evtchn_status *status)
{
XenEvtchnState *s = xen_evtchn_singleton;
XenEvtchnPort *p;
if (!s) {
return -ENOTSUP;
}
if (status->dom != DOMID_SELF && status->dom != xen_domid) {
return -ESRCH;
}
if (!valid_port(status->port)) {
return -EINVAL;
}
qemu_mutex_lock(&s->port_lock);
p = &s->port_table[status->port];
status->status = p->type;
status->vcpu = p->vcpu;
switch (p->type) {
case EVTCHNSTAT_unbound:
if (p->type_val & PORT_INFO_TYPEVAL_REMOTE_QEMU) {
status->u.unbound.dom = DOMID_QEMU;
} else {
status->u.unbound.dom = xen_domid;
}
break;
case EVTCHNSTAT_interdomain:
if (p->type_val & PORT_INFO_TYPEVAL_REMOTE_QEMU) {
status->u.interdomain.dom = DOMID_QEMU;
} else {
status->u.interdomain.dom = xen_domid;
}
status->u.interdomain.port = p->type_val &
PORT_INFO_TYPEVAL_REMOTE_PORT_MASK;
break;
case EVTCHNSTAT_pirq:
status->u.pirq = p->type_val;
break;
case EVTCHNSTAT_virq:
status->u.virq = p->type_val;
break;
}
qemu_mutex_unlock(&s->port_lock);
return 0;
}
/*
* Never thought I'd hear myself say this, but C++ templates would be
* kind of nice here.
*
* template<class T> static int do_unmask_port(T *shinfo, ...);
*/
static int do_unmask_port_lm(XenEvtchnState *s, evtchn_port_t port,
bool do_unmask, struct shared_info *shinfo,
struct vcpu_info *vcpu_info)
{
const int bits_per_word = BITS_PER_BYTE * sizeof(shinfo->evtchn_pending[0]);
typeof(shinfo->evtchn_pending[0]) mask;
int idx = port / bits_per_word;
int offset = port % bits_per_word;
mask = 1UL << offset;
if (idx >= bits_per_word) {
return -EINVAL;
}
if (do_unmask) {
/*
* If this is a true unmask operation, clear the mask bit. If
* it was already unmasked, we have nothing further to do.
*/
if (!((qatomic_fetch_and(&shinfo->evtchn_mask[idx], ~mask) & mask))) {
return 0;
}
} else {
/*
* This is a pseudo-unmask for affinity changes. We don't
* change the mask bit, and if it's *masked* we have nothing
* else to do.
*/
if (qatomic_fetch_or(&shinfo->evtchn_mask[idx], 0) & mask) {
return 0;
}
}
/* If the event was not pending, we're done. */
if (!(qatomic_fetch_or(&shinfo->evtchn_pending[idx], 0) & mask)) {
return 0;
}
/* Now on to the vcpu_info evtchn_pending_sel index... */
mask = 1UL << idx;
/* If a port in this word was already pending for this vCPU, all done. */
if (qatomic_fetch_or(&vcpu_info->evtchn_pending_sel, mask) & mask) {
return 0;
}
/* Set evtchn_upcall_pending for this vCPU */
if (qatomic_fetch_or(&vcpu_info->evtchn_upcall_pending, 1)) {
return 0;
}
inject_callback(s, s->port_table[port].vcpu);
return 0;
}
static int do_unmask_port_compat(XenEvtchnState *s, evtchn_port_t port,
bool do_unmask,
struct compat_shared_info *shinfo,
struct compat_vcpu_info *vcpu_info)
{
const int bits_per_word = BITS_PER_BYTE * sizeof(shinfo->evtchn_pending[0]);
typeof(shinfo->evtchn_pending[0]) mask;
int idx = port / bits_per_word;
int offset = port % bits_per_word;
mask = 1UL << offset;
if (idx >= bits_per_word) {
return -EINVAL;
}
if (do_unmask) {
/*
* If this is a true unmask operation, clear the mask bit. If
* it was already unmasked, we have nothing further to do.
*/
if (!((qatomic_fetch_and(&shinfo->evtchn_mask[idx], ~mask) & mask))) {
return 0;
}
} else {
/*
* This is a pseudo-unmask for affinity changes. We don't
* change the mask bit, and if it's *masked* we have nothing
* else to do.
*/
if (qatomic_fetch_or(&shinfo->evtchn_mask[idx], 0) & mask) {
return 0;
}
}
/* If the event was not pending, we're done. */
if (!(qatomic_fetch_or(&shinfo->evtchn_pending[idx], 0) & mask)) {
return 0;
}
/* Now on to the vcpu_info evtchn_pending_sel index... */
mask = 1UL << idx;
/* If a port in this word was already pending for this vCPU, all done. */
if (qatomic_fetch_or(&vcpu_info->evtchn_pending_sel, mask) & mask) {
return 0;
}
/* Set evtchn_upcall_pending for this vCPU */
if (qatomic_fetch_or(&vcpu_info->evtchn_upcall_pending, 1)) {
return 0;
}
inject_callback(s, s->port_table[port].vcpu);
return 0;
}
static int unmask_port(XenEvtchnState *s, evtchn_port_t port, bool do_unmask)
{
void *vcpu_info, *shinfo;
if (s->port_table[port].type == EVTCHNSTAT_closed) {
return -EINVAL;
}
shinfo = xen_overlay_get_shinfo_ptr();
if (!shinfo) {
return -ENOTSUP;
}
vcpu_info = kvm_xen_get_vcpu_info_hva(s->port_table[port].vcpu);
if (!vcpu_info) {
return -EINVAL;
}
if (xen_is_long_mode()) {
return do_unmask_port_lm(s, port, do_unmask, shinfo, vcpu_info);
} else {
return do_unmask_port_compat(s, port, do_unmask, shinfo, vcpu_info);
}
}
static int do_set_port_lm(XenEvtchnState *s, evtchn_port_t port,
struct shared_info *shinfo,
struct vcpu_info *vcpu_info)
{
const int bits_per_word = BITS_PER_BYTE * sizeof(shinfo->evtchn_pending[0]);
typeof(shinfo->evtchn_pending[0]) mask;
int idx = port / bits_per_word;
int offset = port % bits_per_word;
mask = 1UL << offset;
if (idx >= bits_per_word) {
return -EINVAL;
}
/* Update the pending bit itself. If it was already set, we're done. */
if (qatomic_fetch_or(&shinfo->evtchn_pending[idx], mask) & mask) {
return 0;
}
/* Check if it's masked. */
if (qatomic_fetch_or(&shinfo->evtchn_mask[idx], 0) & mask) {
return 0;
}
/* Now on to the vcpu_info evtchn_pending_sel index... */
mask = 1UL << idx;
/* If a port in this word was already pending for this vCPU, all done. */
if (qatomic_fetch_or(&vcpu_info->evtchn_pending_sel, mask) & mask) {
return 0;
}
/* Set evtchn_upcall_pending for this vCPU */
if (qatomic_fetch_or(&vcpu_info->evtchn_upcall_pending, 1)) {
return 0;
}
inject_callback(s, s->port_table[port].vcpu);
return 0;
}
static int do_set_port_compat(XenEvtchnState *s, evtchn_port_t port,
struct compat_shared_info *shinfo,
struct compat_vcpu_info *vcpu_info)
{
const int bits_per_word = BITS_PER_BYTE * sizeof(shinfo->evtchn_pending[0]);
typeof(shinfo->evtchn_pending[0]) mask;
int idx = port / bits_per_word;
int offset = port % bits_per_word;
mask = 1UL << offset;
if (idx >= bits_per_word) {
return -EINVAL;
}
/* Update the pending bit itself. If it was already set, we're done. */
if (qatomic_fetch_or(&shinfo->evtchn_pending[idx], mask) & mask) {
return 0;
}
/* Check if it's masked. */
if (qatomic_fetch_or(&shinfo->evtchn_mask[idx], 0) & mask) {
return 0;
}
/* Now on to the vcpu_info evtchn_pending_sel index... */
mask = 1UL << idx;
/* If a port in this word was already pending for this vCPU, all done. */
if (qatomic_fetch_or(&vcpu_info->evtchn_pending_sel, mask) & mask) {
return 0;
}
/* Set evtchn_upcall_pending for this vCPU */
if (qatomic_fetch_or(&vcpu_info->evtchn_upcall_pending, 1)) {
return 0;
}
inject_callback(s, s->port_table[port].vcpu);
return 0;
}
static int set_port_pending(XenEvtchnState *s, evtchn_port_t port)
{
void *vcpu_info, *shinfo;
if (s->port_table[port].type == EVTCHNSTAT_closed) {
return -EINVAL;
}
if (s->evtchn_in_kernel) {
XenEvtchnPort *p = &s->port_table[port];
CPUState *cpu = qemu_get_cpu(p->vcpu);
struct kvm_irq_routing_xen_evtchn evt;
if (!cpu) {
return 0;
}
evt.port = port;
evt.vcpu = kvm_arch_vcpu_id(cpu);
evt.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL;
return kvm_vm_ioctl(kvm_state, KVM_XEN_HVM_EVTCHN_SEND, &evt);
}
shinfo = xen_overlay_get_shinfo_ptr();
if (!shinfo) {
return -ENOTSUP;
}
vcpu_info = kvm_xen_get_vcpu_info_hva(s->port_table[port].vcpu);
if (!vcpu_info) {
return -EINVAL;
}
if (xen_is_long_mode()) {
return do_set_port_lm(s, port, shinfo, vcpu_info);
} else {
return do_set_port_compat(s, port, shinfo, vcpu_info);
}
}
static int clear_port_pending(XenEvtchnState *s, evtchn_port_t port)
{
void *p = xen_overlay_get_shinfo_ptr();
if (!p) {
return -ENOTSUP;
}
if (xen_is_long_mode()) {
struct shared_info *shinfo = p;
const int bits_per_word = BITS_PER_BYTE * sizeof(shinfo->evtchn_pending[0]);
typeof(shinfo->evtchn_pending[0]) mask;
int idx = port / bits_per_word;
int offset = port % bits_per_word;
mask = 1UL << offset;
qatomic_fetch_and(&shinfo->evtchn_pending[idx], ~mask);
} else {
struct compat_shared_info *shinfo = p;
const int bits_per_word = BITS_PER_BYTE * sizeof(shinfo->evtchn_pending[0]);
typeof(shinfo->evtchn_pending[0]) mask;
int idx = port / bits_per_word;
int offset = port % bits_per_word;
mask = 1UL << offset;
qatomic_fetch_and(&shinfo->evtchn_pending[idx], ~mask);
}
return 0;
}
static void free_port(XenEvtchnState *s, evtchn_port_t port)
{
s->port_table[port].type = EVTCHNSTAT_closed;
s->port_table[port].type_val = 0;
s->port_table[port].vcpu = 0;
if (s->nr_ports == port + 1) {
do {
s->nr_ports--;
} while (s->nr_ports &&
s->port_table[s->nr_ports - 1].type == EVTCHNSTAT_closed);
}
/* Clear pending event to avoid unexpected behavior on re-bind. */
clear_port_pending(s, port);
}
static int allocate_port(XenEvtchnState *s, uint32_t vcpu, uint16_t type,
uint16_t val, evtchn_port_t *port)
{
evtchn_port_t p = 1;
for (p = 1; valid_port(p); p++) {
if (s->port_table[p].type == EVTCHNSTAT_closed) {
s->port_table[p].vcpu = vcpu;
s->port_table[p].type = type;
s->port_table[p].type_val = val;
*port = p;
if (s->nr_ports < p + 1) {
s->nr_ports = p + 1;
}
return 0;
}
}
return -ENOSPC;
}
static bool virq_is_global(uint32_t virq)
{
switch (virq) {
case VIRQ_TIMER:
case VIRQ_DEBUG:
case VIRQ_XENOPROF:
case VIRQ_XENPMU:
return false;
default:
return true;
}
}
static int close_port(XenEvtchnState *s, evtchn_port_t port)
{
XenEvtchnPort *p = &s->port_table[port];
switch (p->type) {
case EVTCHNSTAT_closed:
return -ENOENT;
case EVTCHNSTAT_virq:
kvm_xen_set_vcpu_virq(virq_is_global(p->type_val) ? 0 : p->vcpu,
p->type_val, 0);
break;
case EVTCHNSTAT_ipi:
if (s->evtchn_in_kernel) {
deassign_kernel_port(port);
}
break;
case EVTCHNSTAT_interdomain:
if (p->type_val & PORT_INFO_TYPEVAL_REMOTE_QEMU) {
/* Not yet implemented. This can't happen! */
} else {
/* Loopback interdomain */
XenEvtchnPort *rp = &s->port_table[p->type_val];
if (!valid_port(p->type_val) || rp->type_val != port ||
rp->type != EVTCHNSTAT_interdomain) {
error_report("Inconsistent state for interdomain unbind");
} else {
/* Set the other end back to unbound */
rp->type = EVTCHNSTAT_unbound;
rp->type_val = 0;
}
}
break;
default:
break;
}
free_port(s, port);
return 0;
}
int xen_evtchn_soft_reset(void)
{
XenEvtchnState *s = xen_evtchn_singleton;
int i;
if (!s) {
return -ENOTSUP;
}
assert(qemu_mutex_iothread_locked());
QEMU_LOCK_GUARD(&s->port_lock);
for (i = 0; i < s->nr_ports; i++) {
close_port(s, i);
}
return 0;
}
int xen_evtchn_reset_op(struct evtchn_reset *reset)
{
if (reset->dom != DOMID_SELF && reset->dom != xen_domid) {
return -ESRCH;
}
return xen_evtchn_soft_reset();
}
int xen_evtchn_close_op(struct evtchn_close *close)
{
XenEvtchnState *s = xen_evtchn_singleton;
int ret;
if (!s) {
return -ENOTSUP;
}
if (!valid_port(close->port)) {
return -EINVAL;
}
qemu_mutex_lock(&s->port_lock);
ret = close_port(s, close->port);
qemu_mutex_unlock(&s->port_lock);
return ret;
}
int xen_evtchn_unmask_op(struct evtchn_unmask *unmask)
{
XenEvtchnState *s = xen_evtchn_singleton;
int ret;
if (!s) {
return -ENOTSUP;
}
if (!valid_port(unmask->port)) {
return -EINVAL;
}
qemu_mutex_lock(&s->port_lock);
ret = unmask_port(s, unmask->port, true);
qemu_mutex_unlock(&s->port_lock);
return ret;
}
int xen_evtchn_bind_vcpu_op(struct evtchn_bind_vcpu *vcpu)
{
XenEvtchnState *s = xen_evtchn_singleton;
XenEvtchnPort *p;
int ret = -EINVAL;
if (!s) {
return -ENOTSUP;
}
if (!valid_port(vcpu->port)) {
return -EINVAL;
}
if (!valid_vcpu(vcpu->vcpu)) {
return -ENOENT;
}
qemu_mutex_lock(&s->port_lock);
p = &s->port_table[vcpu->port];
if (p->type == EVTCHNSTAT_interdomain ||
p->type == EVTCHNSTAT_unbound ||
p->type == EVTCHNSTAT_pirq ||
(p->type == EVTCHNSTAT_virq && virq_is_global(p->type_val))) {
/*
* unmask_port() with do_unmask==false will just raise the event
* on the new vCPU if the port was already pending.
*/
p->vcpu = vcpu->vcpu;
unmask_port(s, vcpu->port, false);
ret = 0;
}
qemu_mutex_unlock(&s->port_lock);
return ret;
}
int xen_evtchn_bind_virq_op(struct evtchn_bind_virq *virq)
{
XenEvtchnState *s = xen_evtchn_singleton;
int ret;
if (!s) {
return -ENOTSUP;
}
if (virq->virq >= NR_VIRQS) {
return -EINVAL;
}
/* Global VIRQ must be allocated on vCPU0 first */
if (virq_is_global(virq->virq) && virq->vcpu != 0) {
return -EINVAL;
}
if (!valid_vcpu(virq->vcpu)) {
return -ENOENT;
}
qemu_mutex_lock(&s->port_lock);
ret = allocate_port(s, virq->vcpu, EVTCHNSTAT_virq, virq->virq,
&virq->port);
if (!ret) {
ret = kvm_xen_set_vcpu_virq(virq->vcpu, virq->virq, virq->port);
if (ret) {
free_port(s, virq->port);
}
}
qemu_mutex_unlock(&s->port_lock);
return ret;
}
int xen_evtchn_bind_ipi_op(struct evtchn_bind_ipi *ipi)
{
XenEvtchnState *s = xen_evtchn_singleton;
int ret;
if (!s) {
return -ENOTSUP;
}
if (!valid_vcpu(ipi->vcpu)) {
return -ENOENT;
}
qemu_mutex_lock(&s->port_lock);
ret = allocate_port(s, ipi->vcpu, EVTCHNSTAT_ipi, 0, &ipi->port);
if (!ret && s->evtchn_in_kernel) {
assign_kernel_port(EVTCHNSTAT_ipi, ipi->port, ipi->vcpu);
}
qemu_mutex_unlock(&s->port_lock);
return ret;
}
int xen_evtchn_bind_interdomain_op(struct evtchn_bind_interdomain *interdomain)
{
XenEvtchnState *s = xen_evtchn_singleton;
uint16_t type_val;
int ret;
if (!s) {
return -ENOTSUP;
}
if (interdomain->remote_dom == DOMID_QEMU) {
type_val = PORT_INFO_TYPEVAL_REMOTE_QEMU;
} else if (interdomain->remote_dom == DOMID_SELF ||
interdomain->remote_dom == xen_domid) {
type_val = 0;
} else {
return -ESRCH;
}
if (!valid_port(interdomain->remote_port)) {
return -EINVAL;
}
qemu_mutex_lock(&s->port_lock);
/* The newly allocated port starts out as unbound */
ret = allocate_port(s, 0, EVTCHNSTAT_unbound, type_val,
&interdomain->local_port);
if (ret) {
goto out;
}
if (interdomain->remote_dom == DOMID_QEMU) {
/* We haven't hooked up QEMU's PV drivers to this yet */
ret = -ENOSYS;
} else {
/* Loopback */
XenEvtchnPort *rp = &s->port_table[interdomain->remote_port];
XenEvtchnPort *lp = &s->port_table[interdomain->local_port];
if (rp->type == EVTCHNSTAT_unbound && rp->type_val == 0) {
/* It's a match! */
rp->type = EVTCHNSTAT_interdomain;
rp->type_val = interdomain->local_port;
lp->type = EVTCHNSTAT_interdomain;
lp->type_val = interdomain->remote_port;
} else {
ret = -EINVAL;
}
}
if (ret) {
free_port(s, interdomain->local_port);
}
out:
qemu_mutex_unlock(&s->port_lock);
return ret;
}
int xen_evtchn_alloc_unbound_op(struct evtchn_alloc_unbound *alloc)
{
XenEvtchnState *s = xen_evtchn_singleton;
uint16_t type_val;
int ret;
if (!s) {
return -ENOTSUP;
}
if (alloc->dom != DOMID_SELF && alloc->dom != xen_domid) {
return -ESRCH;
}
if (alloc->remote_dom == DOMID_QEMU) {
type_val = PORT_INFO_TYPEVAL_REMOTE_QEMU;
} else if (alloc->remote_dom == DOMID_SELF ||
alloc->remote_dom == xen_domid) {
type_val = 0;
} else {
return -EPERM;
}
qemu_mutex_lock(&s->port_lock);
ret = allocate_port(s, 0, EVTCHNSTAT_unbound, type_val, &alloc->port);
qemu_mutex_unlock(&s->port_lock);
return ret;
}
int xen_evtchn_send_op(struct evtchn_send *send)
{
XenEvtchnState *s = xen_evtchn_singleton;
XenEvtchnPort *p;
int ret = 0;
if (!s) {
return -ENOTSUP;
}
if (!valid_port(send->port)) {
return -EINVAL;
}
qemu_mutex_lock(&s->port_lock);
p = &s->port_table[send->port];
switch (p->type) {
case EVTCHNSTAT_interdomain:
if (p->type_val & PORT_INFO_TYPEVAL_REMOTE_QEMU) {
/*
* This is an event from the guest to qemu itself, which is
* serving as the driver domain. Not yet implemented; it will
* be hooked up to the qemu implementation of xenstore,
* console, PV net/block drivers etc.
*/
ret = -ENOSYS;
} else {
/* Loopback interdomain ports; just a complex IPI */
set_port_pending(s, p->type_val);
}
break;
case EVTCHNSTAT_ipi:
set_port_pending(s, send->port);
break;
case EVTCHNSTAT_unbound:
/* Xen will silently drop these */
break;
default:
ret = -EINVAL;
break;
}
qemu_mutex_unlock(&s->port_lock);
return ret;
}
EvtchnInfoList *qmp_xen_event_list(Error **errp)
{
XenEvtchnState *s = xen_evtchn_singleton;
EvtchnInfoList *head = NULL, **tail = &head;
void *shinfo, *pending, *mask;
int i;
if (!s) {
error_setg(errp, "Xen event channel emulation not enabled");
return NULL;
}
shinfo = xen_overlay_get_shinfo_ptr();
if (!shinfo) {
error_setg(errp, "Xen shared info page not allocated");
return NULL;
}
if (xen_is_long_mode()) {
pending = shinfo + offsetof(struct shared_info, evtchn_pending);
mask = shinfo + offsetof(struct shared_info, evtchn_mask);
} else {
pending = shinfo + offsetof(struct compat_shared_info, evtchn_pending);
mask = shinfo + offsetof(struct compat_shared_info, evtchn_mask);
}
QEMU_LOCK_GUARD(&s->port_lock);
for (i = 0; i < s->nr_ports; i++) {
XenEvtchnPort *p = &s->port_table[i];
EvtchnInfo *info;
if (p->type == EVTCHNSTAT_closed) {
continue;
}
info = g_new0(EvtchnInfo, 1);
info->port = i;
qemu_build_assert(EVTCHN_PORT_TYPE_CLOSED == EVTCHNSTAT_closed);
qemu_build_assert(EVTCHN_PORT_TYPE_UNBOUND == EVTCHNSTAT_unbound);
qemu_build_assert(EVTCHN_PORT_TYPE_INTERDOMAIN == EVTCHNSTAT_interdomain);
qemu_build_assert(EVTCHN_PORT_TYPE_PIRQ == EVTCHNSTAT_pirq);
qemu_build_assert(EVTCHN_PORT_TYPE_VIRQ == EVTCHNSTAT_virq);
qemu_build_assert(EVTCHN_PORT_TYPE_IPI == EVTCHNSTAT_ipi);
info->type = p->type;
if (p->type == EVTCHNSTAT_interdomain) {
info->remote_domain = g_strdup((p->type_val & PORT_INFO_TYPEVAL_REMOTE_QEMU) ?
"qemu" : "loopback");
info->target = p->type_val & PORT_INFO_TYPEVAL_REMOTE_PORT_MASK;
} else {
info->target = p->type_val;
}
info->vcpu = p->vcpu;
info->pending = test_bit(i, pending);
info->masked = test_bit(i, mask);
QAPI_LIST_APPEND(tail, info);
}
return head;
}
void qmp_xen_event_inject(uint32_t port, Error **errp)
{
XenEvtchnState *s = xen_evtchn_singleton;
if (!s) {
error_setg(errp, "Xen event channel emulation not enabled");
return;
}
if (!valid_port(port)) {
error_setg(errp, "Invalid port %u", port);
}
QEMU_LOCK_GUARD(&s->port_lock);
if (set_port_pending(s, port)) {
error_setg(errp, "Failed to set port %u", port);
return;
}
}
void hmp_xen_event_list(Monitor *mon, const QDict *qdict)
{
EvtchnInfoList *iter, *info_list;
Error *err = NULL;
info_list = qmp_xen_event_list(&err);
if (err) {
hmp_handle_error(mon, err);
return;
}
for (iter = info_list; iter; iter = iter->next) {
EvtchnInfo *info = iter->value;
monitor_printf(mon, "port %4u: vcpu: %d %s", info->port, info->vcpu,
EvtchnPortType_str(info->type));
if (info->type != EVTCHN_PORT_TYPE_IPI) {
monitor_printf(mon, "(");
if (info->remote_domain) {
monitor_printf(mon, "%s:", info->remote_domain);
}
monitor_printf(mon, "%d)", info->target);
}
if (info->pending) {
monitor_printf(mon, " PENDING");
}
if (info->masked) {
monitor_printf(mon, " MASKED");
}
monitor_printf(mon, "\n");
}
qapi_free_EvtchnInfoList(info_list);
}
void hmp_xen_event_inject(Monitor *mon, const QDict *qdict)
{
int port = qdict_get_int(qdict, "port");
Error *err = NULL;
qmp_xen_event_inject(port, &err);
if (err) {
hmp_handle_error(mon, err);
} else {
monitor_printf(mon, "Delivered port %d\n", port);
}
}
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