/*
* Reads datagrams from the data in port and dispatches them. We
* always start reading datagrams into only the first page of the
* datagram buffer. If the datagrams don't fit into one page, we
* use the maximum datagram buffer size for the remainder of the
* invocation. This is a simple heuristic for not penalizing
* small datagrams.
*
* This function assumes that it has exclusive access to the data
* in port for the duration of the call.
*/
static void vmci_dispatch_dgs(unsigned long data)
{
struct vmci_guest_device *vmci_dev = (struct vmci_guest_device *)data;
u8 *dg_in_buffer = vmci_dev->data_buffer;
struct vmci_datagram *dg;
size_t dg_in_buffer_size = VMCI_MAX_DG_SIZE;
size_t current_dg_in_buffer_size = PAGE_SIZE;
size_t remaining_bytes;
BUILD_BUG_ON(VMCI_MAX_DG_SIZE < PAGE_SIZE);
ioread8_rep(vmci_dev->iobase + VMCI_DATA_IN_ADDR,
vmci_dev->data_buffer, current_dg_in_buffer_size);
dg = (struct vmci_datagram *)dg_in_buffer;
remaining_bytes = current_dg_in_buffer_size;
while (dg->dst.resource != VMCI_INVALID_ID ||
remaining_bytes > PAGE_SIZE) {
unsigned dg_in_size;
/*
* When the input buffer spans multiple pages, a datagram can
* start on any page boundary in the buffer.
*/
if (dg->dst.resource == VMCI_INVALID_ID) {
dg = (struct vmci_datagram *)roundup(
(uintptr_t)dg + 1, PAGE_SIZE);
remaining_bytes =
(size_t)(dg_in_buffer +
current_dg_in_buffer_size -
(u8 *)dg);
continue;
}
dg_in_size = VMCI_DG_SIZE_ALIGNED(dg);
if (dg_in_size <= dg_in_buffer_size) {
int result;
/*
* If the remaining bytes in the datagram
* buffer doesn't contain the complete
* datagram, we first make sure we have enough
* room for it and then we read the reminder
* of the datagram and possibly any following
* datagrams.
*/
if (dg_in_size > remaining_bytes) {
if (remaining_bytes !=
current_dg_in_buffer_size) {
/*
* We move the partial
* datagram to the front and
* read the reminder of the
* datagram and possibly
* following calls into the
* following bytes.
*/
memmove(dg_in_buffer, dg_in_buffer +
current_dg_in_buffer_size -
remaining_bytes,
remaining_bytes);
dg = (struct vmci_datagram *)
dg_in_buffer;
}
if (current_dg_in_buffer_size !=
dg_in_buffer_size)
current_dg_in_buffer_size =
dg_in_buffer_size;
ioread8_rep(vmci_dev->iobase +
VMCI_DATA_IN_ADDR,
vmci_dev->data_buffer +
remaining_bytes,
current_dg_in_buffer_size -
remaining_bytes);
}
/*
* We special case event datagrams from the
* hypervisor.
*/
if (dg->src.context == VMCI_HYPERVISOR_CONTEXT_ID &&
dg->dst.resource == VMCI_EVENT_HANDLER) {
result = vmci_event_dispatch(dg);
} else {
result = vmci_datagram_invoke_guest_handler(dg);
}
if (result < VMCI_SUCCESS)
dev_dbg(vmci_dev->dev,
"Datagram with resource (ID=0x%x) failed (err=%d)\n",
dg->dst.resource, result);
/* On to the next datagram. */
dg = (struct vmci_datagram *)((u8 *)dg +
dg_in_size);
} else {
size_t bytes_to_skip;
/*
* Datagram doesn't fit in datagram buffer of maximal
* size. We drop it.
*/
dev_dbg(vmci_dev->dev,
"Failed to receive datagram (size=%u bytes)\n",
dg_in_size);
bytes_to_skip = dg_in_size - remaining_bytes;
if (current_dg_in_buffer_size != dg_in_buffer_size)
current_dg_in_buffer_size = dg_in_buffer_size;
for (;;) {
ioread8_rep(vmci_dev->iobase +
VMCI_DATA_IN_ADDR,
vmci_dev->data_buffer,
current_dg_in_buffer_size);
if (bytes_to_skip <= current_dg_in_buffer_size)
break;
bytes_to_skip -= current_dg_in_buffer_size;
}
dg = (struct vmci_datagram *)(dg_in_buffer +
bytes_to_skip);
}
remaining_bytes =
(size_t) (dg_in_buffer + current_dg_in_buffer_size -
(u8 *)dg);
if (remaining_bytes < VMCI_DG_HEADERSIZE) {
/* Get the next batch of datagrams. */
ioread8_rep(vmci_dev->iobase + VMCI_DATA_IN_ADDR,
vmci_dev->data_buffer,
current_dg_in_buffer_size);
dg = (struct vmci_datagram *)dg_in_buffer;
remaining_bytes = current_dg_in_buffer_size;
}
}
}
void
VMCI_ReadDatagramsFromPort(VMCIIoHandle ioHandle, // IN
VMCIIoPort dgInPort, // IN
uint8 *dgInBuffer, // IN
size_t dgInBufferSize) // IN
{
VMCIDatagram *dg;
size_t currentDgInBufferSize = PAGE_SIZE;
size_t remainingBytes;
ASSERT(dgInBufferSize >= PAGE_SIZE);
VMCI_ReadPortBytes(ioHandle, dgInPort, dgInBuffer, currentDgInBufferSize);
dg = (VMCIDatagram *)dgInBuffer;
remainingBytes = currentDgInBufferSize;
while (dg->dst.resource != VMCI_INVALID_ID || remainingBytes > PAGE_SIZE) {
unsigned dgInSize;
/*
* When the input buffer spans multiple pages, a datagram can
* start on any page boundary in the buffer.
*/
if (dg->dst.resource == VMCI_INVALID_ID) {
ASSERT(remainingBytes > PAGE_SIZE);
dg = (VMCIDatagram *)ROUNDUP((uintptr_t)dg + 1, PAGE_SIZE);
ASSERT((uint8 *)dg < dgInBuffer + currentDgInBufferSize);
remainingBytes = (size_t)(dgInBuffer + currentDgInBufferSize - (uint8 *)dg);
continue;
}
dgInSize = VMCI_DG_SIZE_ALIGNED(dg);
if (dgInSize <= dgInBufferSize) {
int result;
/*
* If the remaining bytes in the datagram buffer doesn't
* contain the complete datagram, we first make sure we have
* enough room for it and then we read the reminder of the
* datagram and possibly any following datagrams.
*/
if (dgInSize > remainingBytes) {
if (remainingBytes != currentDgInBufferSize) {
/*
* We move the partial datagram to the front and read
* the reminder of the datagram and possibly following
* calls into the following bytes.
*/
memmove(dgInBuffer, dgInBuffer + currentDgInBufferSize - remainingBytes,
remainingBytes);
dg = (VMCIDatagram *)dgInBuffer;
}
if (currentDgInBufferSize != dgInBufferSize) {
currentDgInBufferSize = dgInBufferSize;
}
VMCI_ReadPortBytes(ioHandle, dgInPort, dgInBuffer + remainingBytes,
currentDgInBufferSize - remainingBytes);
}
/* We special case event datagrams from the hypervisor. */
if (dg->src.context == VMCI_HYPERVISOR_CONTEXT_ID &&
dg->dst.resource == VMCI_EVENT_HANDLER) {
result = VMCIEvent_Dispatch(dg);
} else {
result = VMCIDatagram_InvokeGuestHandler(dg);
}
if (result < VMCI_SUCCESS) {
VMCI_DEBUG_LOG(4, (LGPFX"Datagram with resource (ID=0x%x) failed "
"(err=%d).\n", dg->dst.resource, result));
}
/* On to the next datagram. */
dg = (VMCIDatagram *)((uint8 *)dg + dgInSize);
} else {
size_t bytesToSkip;
/*
* Datagram doesn't fit in datagram buffer of maximal size. We drop it.
*/
VMCI_DEBUG_LOG(4, (LGPFX"Failed to receive datagram (size=%u bytes).\n",
dgInSize));
bytesToSkip = dgInSize - remainingBytes;
if (currentDgInBufferSize != dgInBufferSize) {
currentDgInBufferSize = dgInBufferSize;
}
for (;;) {
VMCI_ReadPortBytes(ioHandle, dgInPort, dgInBuffer, currentDgInBufferSize);
if (bytesToSkip <= currentDgInBufferSize) {
break;
}
bytesToSkip -= currentDgInBufferSize;
}
dg = (VMCIDatagram *)(dgInBuffer + bytesToSkip);
}
remainingBytes = (size_t) (dgInBuffer + currentDgInBufferSize - (uint8 *)dg);
if (remainingBytes < VMCI_DG_HEADERSIZE) {
/* Get the next batch of datagrams. */
VMCI_ReadPortBytes(ioHandle, dgInPort, dgInBuffer, currentDgInBufferSize);
dg = (VMCIDatagram *)dgInBuffer;
remainingBytes = currentDgInBufferSize;
}
}
}
