qemu/hw/hyperv/hyperv.c

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/*
* Hyper-V guest/hypervisor interaction
*
* Copyright (c) 2015-2018 Virtuozzo International GmbH.
*
* 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/main-loop.h"
#include "qemu/module.h"
#include "qapi/error.h"
#include "exec/address-spaces.h"
#include "sysemu/kvm.h"
#include "qemu/bitops.h"
#include "qemu/error-report.h"
#include "qemu/lockable.h"
#include "qemu/queue.h"
#include "qemu/rcu.h"
#include "qemu/rcu_queue.h"
#include "hw/hyperv/hyperv.h"
#include "qom/object.h"
struct SynICState {
DeviceState parent_obj;
CPUState *cs;
bool enabled;
hwaddr msg_page_addr;
hwaddr event_page_addr;
MemoryRegion msg_page_mr;
MemoryRegion event_page_mr;
struct hyperv_message_page *msg_page;
struct hyperv_event_flags_page *event_page;
};
#define TYPE_SYNIC "hyperv-synic"
OBJECT_DECLARE_SIMPLE_TYPE(SynICState, SYNIC)
static bool synic_enabled;
bool hyperv_is_synic_enabled(void)
{
return synic_enabled;
}
static SynICState *get_synic(CPUState *cs)
{
return SYNIC(object_resolve_path_component(OBJECT(cs), "synic"));
}
static void synic_update(SynICState *synic, bool enable,
hwaddr msg_page_addr, hwaddr event_page_addr)
{
synic->enabled = enable;
if (synic->msg_page_addr != msg_page_addr) {
if (synic->msg_page_addr) {
memory_region_del_subregion(get_system_memory(),
&synic->msg_page_mr);
}
if (msg_page_addr) {
memory_region_add_subregion(get_system_memory(), msg_page_addr,
&synic->msg_page_mr);
}
synic->msg_page_addr = msg_page_addr;
}
if (synic->event_page_addr != event_page_addr) {
if (synic->event_page_addr) {
memory_region_del_subregion(get_system_memory(),
&synic->event_page_mr);
}
if (event_page_addr) {
memory_region_add_subregion(get_system_memory(), event_page_addr,
&synic->event_page_mr);
}
synic->event_page_addr = event_page_addr;
}
}
void hyperv_synic_update(CPUState *cs, bool enable,
hwaddr msg_page_addr, hwaddr event_page_addr)
{
SynICState *synic = get_synic(cs);
if (!synic) {
return;
}
synic_update(synic, enable, msg_page_addr, event_page_addr);
}
static void synic_realize(DeviceState *dev, Error **errp)
{
Object *obj = OBJECT(dev);
SynICState *synic = SYNIC(dev);
char *msgp_name, *eventp_name;
uint32_t vp_index;
/* memory region names have to be globally unique */
vp_index = hyperv_vp_index(synic->cs);
msgp_name = g_strdup_printf("synic-%u-msg-page", vp_index);
eventp_name = g_strdup_printf("synic-%u-event-page", vp_index);
memory_region_init_ram(&synic->msg_page_mr, obj, msgp_name,
sizeof(*synic->msg_page), &error_abort);
memory_region_init_ram(&synic->event_page_mr, obj, eventp_name,
sizeof(*synic->event_page), &error_abort);
synic->msg_page = memory_region_get_ram_ptr(&synic->msg_page_mr);
synic->event_page = memory_region_get_ram_ptr(&synic->event_page_mr);
g_free(msgp_name);
g_free(eventp_name);
}
static void synic_reset(DeviceState *dev)
{
SynICState *synic = SYNIC(dev);
memset(synic->msg_page, 0, sizeof(*synic->msg_page));
memset(synic->event_page, 0, sizeof(*synic->event_page));
synic_update(synic, false, 0, 0);
}
static void synic_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = synic_realize;
dc->reset = synic_reset;
dc->user_creatable = false;
}
void hyperv_synic_add(CPUState *cs)
{
Object *obj;
SynICState *synic;
obj = object_new(TYPE_SYNIC);
synic = SYNIC(obj);
synic->cs = cs;
qom: Drop parameter @errp of object_property_add() & friends The only way object_property_add() can fail is when a property with the same name already exists. Since our property names are all hardcoded, failure is a programming error, and the appropriate way to handle it is passing &error_abort. Same for its variants, except for object_property_add_child(), which additionally fails when the child already has a parent. Parentage is also under program control, so this is a programming error, too. We have a bit over 500 callers. Almost half of them pass &error_abort, slightly fewer ignore errors, one test case handles errors, and the remaining few callers pass them to their own callers. The previous few commits demonstrated once again that ignoring programming errors is a bad idea. Of the few ones that pass on errors, several violate the Error API. The Error ** argument must be NULL, &error_abort, &error_fatal, or a pointer to a variable containing NULL. Passing an argument of the latter kind twice without clearing it in between is wrong: if the first call sets an error, it no longer points to NULL for the second call. ich9_pm_add_properties(), sparc32_ledma_realize(), sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize() are wrong that way. When the one appropriate choice of argument is &error_abort, letting users pick the argument is a bad idea. Drop parameter @errp and assert the preconditions instead. There's one exception to "duplicate property name is a programming error": the way object_property_add() implements the magic (and undocumented) "automatic arrayification". Don't drop @errp there. Instead, rename object_property_add() to object_property_try_add(), and add the obvious wrapper object_property_add(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200505152926.18877-15-armbru@redhat.com> [Two semantic rebase conflicts resolved]
2020-05-05 18:29:22 +03:00
object_property_add_child(OBJECT(cs), "synic", obj);
object_unref(obj);
qdev_realize(DEVICE(obj), NULL, &error_abort);
synic_enabled = true;
}
void hyperv_synic_reset(CPUState *cs)
{
SynICState *synic = get_synic(cs);
if (synic) {
device_legacy_reset(DEVICE(synic));
}
}
static const TypeInfo synic_type_info = {
.name = TYPE_SYNIC,
.parent = TYPE_DEVICE,
.instance_size = sizeof(SynICState),
.class_init = synic_class_init,
};
static void synic_register_types(void)
{
type_register_static(&synic_type_info);
}
type_init(synic_register_types)
/*
* KVM has its own message producers (SynIC timers). To guarantee
* serialization with both KVM vcpu and the guest cpu, the messages are first
* staged in an intermediate area and then posted to the SynIC message page in
* the vcpu thread.
*/
typedef struct HvSintStagedMessage {
/* message content staged by hyperv_post_msg */
struct hyperv_message msg;
/* callback + data (r/o) to complete the processing in a BH */
HvSintMsgCb cb;
void *cb_data;
/* message posting status filled by cpu_post_msg */
int status;
/* passing the buck: */
enum {
/* initial state */
HV_STAGED_MSG_FREE,
/*
* hyperv_post_msg (e.g. in main loop) grabs the staged area (FREE ->
* BUSY), copies msg, and schedules cpu_post_msg on the assigned cpu
*/
HV_STAGED_MSG_BUSY,
/*
* cpu_post_msg (vcpu thread) tries to copy staged msg to msg slot,
* notify the guest, records the status, marks the posting done (BUSY
* -> POSTED), and schedules sint_msg_bh BH
*/
HV_STAGED_MSG_POSTED,
/*
* sint_msg_bh (BH) verifies that the posting is done, runs the
* callback, and starts over (POSTED -> FREE)
*/
} state;
} HvSintStagedMessage;
struct HvSintRoute {
uint32_t sint;
SynICState *synic;
int gsi;
EventNotifier sint_set_notifier;
EventNotifier sint_ack_notifier;
HvSintStagedMessage *staged_msg;
unsigned refcount;
};
static CPUState *hyperv_find_vcpu(uint32_t vp_index)
{
CPUState *cs = qemu_get_cpu(vp_index);
assert(hyperv_vp_index(cs) == vp_index);
return cs;
}
/*
* BH to complete the processing of a staged message.
*/
static void sint_msg_bh(void *opaque)
{
HvSintRoute *sint_route = opaque;
HvSintStagedMessage *staged_msg = sint_route->staged_msg;
if (qatomic_read(&staged_msg->state) != HV_STAGED_MSG_POSTED) {
/* status nor ready yet (spurious ack from guest?), ignore */
return;
}
staged_msg->cb(staged_msg->cb_data, staged_msg->status);
staged_msg->status = 0;
/* staged message processing finished, ready to start over */
qatomic_set(&staged_msg->state, HV_STAGED_MSG_FREE);
/* drop the reference taken in hyperv_post_msg */
hyperv_sint_route_unref(sint_route);
}
/*
* Worker to transfer the message from the staging area into the SynIC message
* page in vcpu context.
*/
static void cpu_post_msg(CPUState *cs, run_on_cpu_data data)
{
HvSintRoute *sint_route = data.host_ptr;
HvSintStagedMessage *staged_msg = sint_route->staged_msg;
SynICState *synic = sint_route->synic;
struct hyperv_message *dst_msg;
bool wait_for_sint_ack = false;
assert(staged_msg->state == HV_STAGED_MSG_BUSY);
if (!synic->enabled || !synic->msg_page_addr) {
staged_msg->status = -ENXIO;
goto posted;
}
dst_msg = &synic->msg_page->slot[sint_route->sint];
if (dst_msg->header.message_type != HV_MESSAGE_NONE) {
dst_msg->header.message_flags |= HV_MESSAGE_FLAG_PENDING;
staged_msg->status = -EAGAIN;
wait_for_sint_ack = true;
} else {
memcpy(dst_msg, &staged_msg->msg, sizeof(*dst_msg));
staged_msg->status = hyperv_sint_route_set_sint(sint_route);
}
memory_region_set_dirty(&synic->msg_page_mr, 0, sizeof(*synic->msg_page));
posted:
qatomic_set(&staged_msg->state, HV_STAGED_MSG_POSTED);
/*
* Notify the msg originator of the progress made; if the slot was busy we
* set msg_pending flag in it so it will be the guest who will do EOM and
* trigger the notification from KVM via sint_ack_notifier
*/
if (!wait_for_sint_ack) {
aio_bh_schedule_oneshot(qemu_get_aio_context(), sint_msg_bh,
sint_route);
}
}
/*
* Post a Hyper-V message to the staging area, for delivery to guest in the
* vcpu thread.
*/
int hyperv_post_msg(HvSintRoute *sint_route, struct hyperv_message *src_msg)
{
HvSintStagedMessage *staged_msg = sint_route->staged_msg;
assert(staged_msg);
/* grab the staging area */
if (qatomic_cmpxchg(&staged_msg->state, HV_STAGED_MSG_FREE,
HV_STAGED_MSG_BUSY) != HV_STAGED_MSG_FREE) {
return -EAGAIN;
}
memcpy(&staged_msg->msg, src_msg, sizeof(*src_msg));
/* hold a reference on sint_route until the callback is finished */
hyperv_sint_route_ref(sint_route);
/* schedule message posting attempt in vcpu thread */
async_run_on_cpu(sint_route->synic->cs, cpu_post_msg,
RUN_ON_CPU_HOST_PTR(sint_route));
return 0;
}
static void sint_ack_handler(EventNotifier *notifier)
{
HvSintRoute *sint_route = container_of(notifier, HvSintRoute,
sint_ack_notifier);
event_notifier_test_and_clear(notifier);
/*
* the guest consumed the previous message so complete the current one with
* -EAGAIN and let the msg originator retry
*/
aio_bh_schedule_oneshot(qemu_get_aio_context(), sint_msg_bh, sint_route);
}
/*
* Set given event flag for a given sint on a given vcpu, and signal the sint.
*/
int hyperv_set_event_flag(HvSintRoute *sint_route, unsigned eventno)
{
int ret;
SynICState *synic = sint_route->synic;
unsigned long *flags, set_mask;
unsigned set_idx;
if (eventno > HV_EVENT_FLAGS_COUNT) {
return -EINVAL;
}
if (!synic->enabled || !synic->event_page_addr) {
return -ENXIO;
}
set_idx = BIT_WORD(eventno);
set_mask = BIT_MASK(eventno);
flags = synic->event_page->slot[sint_route->sint].flags;
if ((qatomic_fetch_or(&flags[set_idx], set_mask) & set_mask) != set_mask) {
memory_region_set_dirty(&synic->event_page_mr, 0,
sizeof(*synic->event_page));
ret = hyperv_sint_route_set_sint(sint_route);
} else {
ret = 0;
}
return ret;
}
HvSintRoute *hyperv_sint_route_new(uint32_t vp_index, uint32_t sint,
HvSintMsgCb cb, void *cb_data)
{
HvSintRoute *sint_route;
EventNotifier *ack_notifier;
int r, gsi;
CPUState *cs;
SynICState *synic;
cs = hyperv_find_vcpu(vp_index);
if (!cs) {
return NULL;
}
synic = get_synic(cs);
if (!synic) {
return NULL;
}
sint_route = g_new0(HvSintRoute, 1);
r = event_notifier_init(&sint_route->sint_set_notifier, false);
if (r) {
goto err;
}
ack_notifier = cb ? &sint_route->sint_ack_notifier : NULL;
if (ack_notifier) {
sint_route->staged_msg = g_new0(HvSintStagedMessage, 1);
sint_route->staged_msg->cb = cb;
sint_route->staged_msg->cb_data = cb_data;
r = event_notifier_init(ack_notifier, false);
if (r) {
goto err_sint_set_notifier;
}
event_notifier_set_handler(ack_notifier, sint_ack_handler);
}
gsi = kvm_irqchip_add_hv_sint_route(kvm_state, vp_index, sint);
if (gsi < 0) {
goto err_gsi;
}
r = kvm_irqchip_add_irqfd_notifier_gsi(kvm_state,
&sint_route->sint_set_notifier,
ack_notifier, gsi);
if (r) {
goto err_irqfd;
}
sint_route->gsi = gsi;
sint_route->synic = synic;
sint_route->sint = sint;
sint_route->refcount = 1;
return sint_route;
err_irqfd:
kvm_irqchip_release_virq(kvm_state, gsi);
err_gsi:
if (ack_notifier) {
event_notifier_set_handler(ack_notifier, NULL);
event_notifier_cleanup(ack_notifier);
g_free(sint_route->staged_msg);
}
err_sint_set_notifier:
event_notifier_cleanup(&sint_route->sint_set_notifier);
err:
g_free(sint_route);
return NULL;
}
void hyperv_sint_route_ref(HvSintRoute *sint_route)
{
sint_route->refcount++;
}
void hyperv_sint_route_unref(HvSintRoute *sint_route)
{
if (!sint_route) {
return;
}
assert(sint_route->refcount > 0);
if (--sint_route->refcount) {
return;
}
kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state,
&sint_route->sint_set_notifier,
sint_route->gsi);
kvm_irqchip_release_virq(kvm_state, sint_route->gsi);
if (sint_route->staged_msg) {
event_notifier_set_handler(&sint_route->sint_ack_notifier, NULL);
event_notifier_cleanup(&sint_route->sint_ack_notifier);
g_free(sint_route->staged_msg);
}
event_notifier_cleanup(&sint_route->sint_set_notifier);
g_free(sint_route);
}
int hyperv_sint_route_set_sint(HvSintRoute *sint_route)
{
return event_notifier_set(&sint_route->sint_set_notifier);
}
typedef struct MsgHandler {
struct rcu_head rcu;
QLIST_ENTRY(MsgHandler) link;
uint32_t conn_id;
HvMsgHandler handler;
void *data;
} MsgHandler;
typedef struct EventFlagHandler {
struct rcu_head rcu;
QLIST_ENTRY(EventFlagHandler) link;
uint32_t conn_id;
EventNotifier *notifier;
} EventFlagHandler;
static QLIST_HEAD(, MsgHandler) msg_handlers;
static QLIST_HEAD(, EventFlagHandler) event_flag_handlers;
static QemuMutex handlers_mutex;
static void __attribute__((constructor)) hv_init(void)
{
QLIST_INIT(&msg_handlers);
QLIST_INIT(&event_flag_handlers);
qemu_mutex_init(&handlers_mutex);
}
int hyperv_set_msg_handler(uint32_t conn_id, HvMsgHandler handler, void *data)
{
int ret;
MsgHandler *mh;
QEMU_LOCK_GUARD(&handlers_mutex);
QLIST_FOREACH(mh, &msg_handlers, link) {
if (mh->conn_id == conn_id) {
if (handler) {
ret = -EEXIST;
} else {
QLIST_REMOVE_RCU(mh, link);
g_free_rcu(mh, rcu);
ret = 0;
}
return ret;
}
}
if (handler) {
mh = g_new(MsgHandler, 1);
mh->conn_id = conn_id;
mh->handler = handler;
mh->data = data;
QLIST_INSERT_HEAD_RCU(&msg_handlers, mh, link);
ret = 0;
} else {
ret = -ENOENT;
}
return ret;
}
uint16_t hyperv_hcall_post_message(uint64_t param, bool fast)
{
uint16_t ret;
hwaddr len;
struct hyperv_post_message_input *msg;
MsgHandler *mh;
if (fast) {
return HV_STATUS_INVALID_HYPERCALL_CODE;
}
if (param & (__alignof__(*msg) - 1)) {
return HV_STATUS_INVALID_ALIGNMENT;
}
len = sizeof(*msg);
msg = cpu_physical_memory_map(param, &len, 0);
if (len < sizeof(*msg)) {
ret = HV_STATUS_INSUFFICIENT_MEMORY;
goto unmap;
}
if (msg->payload_size > sizeof(msg->payload)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
goto unmap;
}
ret = HV_STATUS_INVALID_CONNECTION_ID;
WITH_RCU_READ_LOCK_GUARD() {
QLIST_FOREACH_RCU(mh, &msg_handlers, link) {
if (mh->conn_id == (msg->connection_id & HV_CONNECTION_ID_MASK)) {
ret = mh->handler(msg, mh->data);
break;
}
}
}
unmap:
cpu_physical_memory_unmap(msg, len, 0, 0);
return ret;
}
static int set_event_flag_handler(uint32_t conn_id, EventNotifier *notifier)
{
int ret;
EventFlagHandler *handler;
QEMU_LOCK_GUARD(&handlers_mutex);
QLIST_FOREACH(handler, &event_flag_handlers, link) {
if (handler->conn_id == conn_id) {
if (notifier) {
ret = -EEXIST;
} else {
QLIST_REMOVE_RCU(handler, link);
g_free_rcu(handler, rcu);
ret = 0;
}
return ret;
}
}
if (notifier) {
handler = g_new(EventFlagHandler, 1);
handler->conn_id = conn_id;
handler->notifier = notifier;
QLIST_INSERT_HEAD_RCU(&event_flag_handlers, handler, link);
ret = 0;
} else {
ret = -ENOENT;
}
return ret;
}
static bool process_event_flags_userspace;
int hyperv_set_event_flag_handler(uint32_t conn_id, EventNotifier *notifier)
{
if (!process_event_flags_userspace &&
!kvm_check_extension(kvm_state, KVM_CAP_HYPERV_EVENTFD)) {
process_event_flags_userspace = true;
warn_report("Hyper-V event signaling is not supported by this kernel; "
"using slower userspace hypercall processing");
}
if (!process_event_flags_userspace) {
struct kvm_hyperv_eventfd hvevfd = {
.conn_id = conn_id,
.fd = notifier ? event_notifier_get_fd(notifier) : -1,
.flags = notifier ? 0 : KVM_HYPERV_EVENTFD_DEASSIGN,
};
return kvm_vm_ioctl(kvm_state, KVM_HYPERV_EVENTFD, &hvevfd);
}
return set_event_flag_handler(conn_id, notifier);
}
uint16_t hyperv_hcall_signal_event(uint64_t param, bool fast)
{
EventFlagHandler *handler;
if (unlikely(!fast)) {
hwaddr addr = param;
if (addr & (__alignof__(addr) - 1)) {
return HV_STATUS_INVALID_ALIGNMENT;
}
param = ldq_phys(&address_space_memory, addr);
}
/*
* Per spec, bits 32-47 contain the extra "flag number". However, we
* have no use for it, and in all known usecases it is zero, so just
* report lookup failure if it isn't.
*/
if (param & 0xffff00000000ULL) {
return HV_STATUS_INVALID_PORT_ID;
}
/* remaining bits are reserved-zero */
if (param & ~HV_CONNECTION_ID_MASK) {
return HV_STATUS_INVALID_HYPERCALL_INPUT;
}
RCU_READ_LOCK_GUARD();
QLIST_FOREACH_RCU(handler, &event_flag_handlers, link) {
if (handler->conn_id == param) {
event_notifier_set(handler->notifier);
return 0;
}
}
return HV_STATUS_INVALID_CONNECTION_ID;
}