/**
* @brief Interrupt filter routine for VMBUS.
*
* The purpose of this routine is to determine the type of VMBUS protocol
* message to process - an event or a channel message.
*/
static inline int
hv_vmbus_isr(void *unused)
{
int cpu;
hv_vmbus_message* msg;
hv_vmbus_synic_event_flags* event;
void* page_addr;
cpu = PCPU_GET(cpuid);
/*
* The Windows team has advised that we check for events
* before checking for messages. This is the way they do it
* in Windows when running as a guest in Hyper-V
*/
page_addr = hv_vmbus_g_context.syn_ic_event_page[cpu];
event = (hv_vmbus_synic_event_flags*)
page_addr + HV_VMBUS_MESSAGE_SINT;
if ((hv_vmbus_protocal_version == HV_VMBUS_VERSION_WS2008) ||
(hv_vmbus_protocal_version == HV_VMBUS_VERSION_WIN7)) {
/* Since we are a child, we only need to check bit 0 */
if (synch_test_and_clear_bit(0, &event->flags32[0])) {
swi_sched(hv_vmbus_g_context.event_swintr[cpu], 0);
}
} else {
/*
* On host with Win8 or above, we can directly look at
* the event page. If bit n is set, we have an interrupt
* on the channel with id n.
* Directly schedule the event software interrupt on
* current cpu.
*/
swi_sched(hv_vmbus_g_context.event_swintr[cpu], 0);
}
/* Check if there are actual msgs to be process */
page_addr = hv_vmbus_g_context.syn_ic_msg_page[cpu];
msg = (hv_vmbus_message*) page_addr + HV_VMBUS_MESSAGE_SINT;
if (msg->header.message_type != HV_MESSAGE_TYPE_NONE) {
swi_sched(hv_vmbus_g_context.msg_swintr[cpu], 0);
}
return FILTER_HANDLED;
}
/**
* @brief Interrupt filter routine for VMBUS.
*
* The purpose of this routine is to determine the type of VMBUS protocol
* message to process - an event or a channel message.
* As this is an interrupt filter routine, the function runs in a very
* restricted envinronment. From the manpage for bus_setup_intr(9)
*
* In this restricted environment, care must be taken to account for all
* races. A careful analysis of races should be done as well. It is gener-
* ally cheaper to take an extra interrupt, for example, than to protect
* variables with spinlocks. Read, modify, write cycles of hardware regis-
* ters need to be carefully analyzed if other threads are accessing the
* same registers.
*/
static int
hv_vmbus_isr(void *unused)
{
int cpu;
hv_vmbus_message* msg;
hv_vmbus_synic_event_flags* event;
void* page_addr;
cpu = PCPU_GET(cpuid);
/* (Temporary limit) */
KASSERT(cpu == 0, ("hv_vmbus_isr: Interrupt on CPU other than zero"));
/*
* The Windows team has advised that we check for events
* before checking for messages. This is the way they do it
* in Windows when running as a guest in Hyper-V
*/
page_addr = hv_vmbus_g_context.syn_ic_event_page[cpu];
event = (hv_vmbus_synic_event_flags*)
page_addr + HV_VMBUS_MESSAGE_SINT;
/* Since we are a child, we only need to check bit 0 */
if (synch_test_and_clear_bit(0, &event->flags32[0])) {
swi_sched(event_swintr, 0);
}
/* Check if there are actual msgs to be process */
page_addr = hv_vmbus_g_context.syn_ic_msg_page[cpu];
msg = (hv_vmbus_message*) page_addr + HV_VMBUS_MESSAGE_SINT;
if (msg->header.message_type != HV_MESSAGE_TYPE_NONE) {
swi_sched(msg_swintr, 0);
}
return FILTER_HANDLED;
}
/**
* @brief Interrupt filter routine for VMBUS.
*
* The purpose of this routine is to determine the type of VMBUS protocol
* message to process - an event or a channel message.
*/
static inline int
hv_vmbus_isr(struct trapframe *frame)
{
int cpu;
hv_vmbus_message* msg;
hv_vmbus_synic_event_flags* event;
void* page_addr;
cpu = PCPU_GET(cpuid);
/*
* The Windows team has advised that we check for events
* before checking for messages. This is the way they do it
* in Windows when running as a guest in Hyper-V
*/
page_addr = hv_vmbus_g_context.syn_ic_event_page[cpu];
event = (hv_vmbus_synic_event_flags*)
page_addr + HV_VMBUS_MESSAGE_SINT;
if ((hv_vmbus_protocal_version == HV_VMBUS_VERSION_WS2008) ||
(hv_vmbus_protocal_version == HV_VMBUS_VERSION_WIN7)) {
/* Since we are a child, we only need to check bit 0 */
if (synch_test_and_clear_bit(0, &event->flags32[0])) {
swi_sched(hv_vmbus_g_context.event_swintr[cpu], 0);
}
} else {
/*
* On host with Win8 or above, we can directly look at
* the event page. If bit n is set, we have an interrupt
* on the channel with id n.
* Directly schedule the event software interrupt on
* current cpu.
*/
swi_sched(hv_vmbus_g_context.event_swintr[cpu], 0);
}
/* Check if there are actual msgs to be process */
page_addr = hv_vmbus_g_context.syn_ic_msg_page[cpu];
msg = (hv_vmbus_message*) page_addr + HV_VMBUS_MESSAGE_SINT;
/* we call eventtimer process the message */
if (msg->header.message_type == HV_MESSAGE_TIMER_EXPIRED) {
msg->header.message_type = HV_MESSAGE_TYPE_NONE;
/*
* Make sure the write to message_type (ie set to
* HV_MESSAGE_TYPE_NONE) happens before we read the
* message_pending and EOMing. Otherwise, the EOMing will
* not deliver any more messages
* since there is no empty slot
*/
wmb();
if (msg->header.message_flags.u.message_pending) {
/*
* This will cause message queue rescan to possibly
* deliver another msg from the hypervisor
*/
wrmsr(HV_X64_MSR_EOM, 0);
}
hv_et_intr(frame);
return (FILTER_HANDLED);
}
if (msg->header.message_type != HV_MESSAGE_TYPE_NONE) {
swi_sched(hv_vmbus_g_context.msg_swintr[cpu], 0);
}
return (FILTER_HANDLED);
}
