src/dev/arm/vio_mmio.cc - public/gem5 - Git at Google

 /*
  * Copyright (c) 2016-2018 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
  * not be construed as granting a license to any other intellectual
  * property including but not limited to intellectual property relating
  * to a hardware implementation of the functionality of the software
  * licensed hereunder.  You may use the software subject to the license
  * terms below provided that you ensure that this notice is replicated
  * unmodified and in its entirety in all distributions of the software,
  * modified or unmodified, in source code or in binary form.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met: redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer;
  * redistributions in binary form must reproduce the above copyright
  * notice, this list of conditions and the following disclaimer in the
  * documentation and/or other materials provided with the distribution;
  * neither the name of the copyright holders nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "dev/arm/vio_mmio.hh"

 #include "debug/VIOIface.hh"
 #include "dev/arm/base_gic.hh"
 #include "mem/packet_access.hh"
 #include "params/MmioVirtIO.hh"

 MmioVirtIO::MmioVirtIO(const MmioVirtIOParams *params)
     : BasicPioDevice(params, params->pio_size),
       hostFeaturesSelect(0), guestFeaturesSelect(0), pageSize(0),
       interruptStatus(0), vio(*params->vio),
       interrupt(params->interrupt->get())
 {
     fatal_if(!interrupt, "No MMIO VirtIO interrupt specified\n");

     vio.registerKickCallback([this]() { kick(); });
 }

 MmioVirtIO::~MmioVirtIO()
 {
 }

 Tick
 MmioVirtIO::read(PacketPtr pkt)
 {
     const Addr offset = pkt->getAddr() - pioAddr;
     const unsigned size(pkt->getSize());

     DPRINTF(VIOIface, "Reading %u bytes @ 0x%x:\n", size, offset);

     // Forward device configuration writes to the device VirtIO model
     if (offset >= OFF_CONFIG) {
         vio.readConfig(pkt, offset - OFF_CONFIG);
         return 0;
     }

     panic_if(size != 4, "Unexpected read size: %u\n", size);

     const uint32_t value = read(offset);
     DPRINTF(VIOIface, "    value: 0x%x\n", value);
     pkt->makeResponse();
     pkt->setLE<uint32_t>(value);

     return 0;
 }

 uint32_t
 MmioVirtIO::read(Addr offset)
 {
     switch(offset) {
       case OFF_MAGIC:
         return MAGIC;

       case OFF_VERSION:
         return VERSION;

       case OFF_DEVICE_ID:
         return vio.deviceId;

       case OFF_VENDOR_ID:
         return VENDOR_ID;

       case OFF_HOST_FEATURES:
         // We only implement 32 bits of this register
         if (hostFeaturesSelect == 0)
             return vio.deviceFeatures;
         else
             return 0;

       case OFF_HOST_FEATURES_SELECT:
         return hostFeaturesSelect;

       case OFF_GUEST_FEATURES:
         // We only implement 32 bits of this register
         if (guestFeaturesSelect == 0)
             return vio.getGuestFeatures();
         else
             return 0;

       case OFF_GUEST_FEATURES_SELECT:
         return hostFeaturesSelect;

       case OFF_GUEST_PAGE_SIZE:
         return pageSize;

       case OFF_QUEUE_SELECT:
         return vio.getQueueSelect();

       case OFF_QUEUE_NUM_MAX:
         return vio.getQueueSize();

       case OFF_QUEUE_NUM:
         // TODO: We don't support queue resizing, so ignore this for now.
         return vio.getQueueSize();

       case OFF_QUEUE_ALIGN:
         // TODO: Implement this once we support other alignment sizes
         return VirtQueue::ALIGN_SIZE;

       case OFF_QUEUE_PFN:
         return vio.getQueueAddress();

       case OFF_INTERRUPT_STATUS:
         return interruptStatus;

       case OFF_STATUS:
         return vio.getDeviceStatus();

         // Write-only registers
       case OFF_QUEUE_NOTIFY:
       case OFF_INTERRUPT_ACK:
         warn("Guest is trying to read to write-only register 0x%\n",
              offset);
         return 0;

       default:
         panic("Unhandled read offset (0x%x)\n", offset);
     }
 }

 Tick
 MmioVirtIO::write(PacketPtr pkt)
 {
     const Addr offset = pkt->getAddr() - pioAddr;
     const unsigned size(pkt->getSize());

     DPRINTF(VIOIface, "Writing %u bytes @ 0x%x:\n", size, offset);

     // Forward device configuration writes to the device VirtIO model
     if (offset >= OFF_CONFIG) {
         vio.writeConfig(pkt, offset - OFF_CONFIG);
         return 0;
     }

     panic_if(size != 4, "Unexpected write size @ 0x%x: %u\n", offset, size);
     DPRINTF(VIOIface, "    value: 0x%x\n", pkt->getLE<uint32_t>());
     pkt->makeResponse();
     write(offset, pkt->getLE<uint32_t>());
     return 0;
 }

 void
 MmioVirtIO::write(Addr offset, uint32_t value)
 {
     switch(offset) {
       case OFF_HOST_FEATURES_SELECT:
         hostFeaturesSelect = value;
         return;

       case OFF_GUEST_FEATURES:
         if (guestFeaturesSelect == 0) {
             vio.setGuestFeatures(value);
         } else if (value != 0) {
             warn("Setting unimplemented guest features register %u: %u\n",
                  guestFeaturesSelect, value);
         }
         return;

       case OFF_GUEST_FEATURES_SELECT:
         guestFeaturesSelect = value;
         return;

       case OFF_GUEST_PAGE_SIZE:
         // TODO: We only support 4096 byte pages at the moment
         panic_if(value != VirtQueue::ALIGN_SIZE,
                  "Unhandled VirtIO page size: %u", value);
         pageSize = value;
         return;

       case OFF_QUEUE_SELECT:
         vio.setQueueSelect(value);
         return;

       case OFF_QUEUE_NUM:
         // TODO: We don't support queue resizing, so ignore this for now.
         warn_once("Ignoring queue resize hint. Requested size: %u\n", value);
         return;

       case OFF_QUEUE_ALIGN:
         // TODO: We currently only support the hard-coded 4k alignment used
         // in legacy VirtIO.
         panic_if(value != VirtQueue::ALIGN_SIZE,
                  "Unhandled VirtIO alignment size: %u", value);
         return;

       case OFF_QUEUE_PFN:
         vio.setQueueAddress(value);
         return;

       case OFF_QUEUE_NOTIFY:
         vio.onNotify(value);
         return;

       case OFF_INTERRUPT_ACK:
         setInterrupts(interruptStatus & (~value));
         return;

       case OFF_STATUS:
         panic_if(value > 0xff, "Unexpected status: 0x%x\n", value);
         vio.setDeviceStatus(value);
         return;

         /* Read-only registers */
       case OFF_MAGIC:
       case OFF_VERSION:
       case OFF_DEVICE_ID:
       case OFF_VENDOR_ID:
       case OFF_HOST_FEATURES:
       case OFF_QUEUE_NUM_MAX:
       case OFF_INTERRUPT_STATUS:
         warn("Guest is trying to write to read-only register 0x%\n",
              offset);
         return;

       default:
         panic("Unhandled read offset (0x%x)\n", offset);
     }
 }

 void
 MmioVirtIO::kick()
 {
     DPRINTF(VIOIface, "kick(): Sending interrupt...\n");
     setInterrupts(interruptStatus | INT_USED_RING);
 }

 void
 MmioVirtIO::setInterrupts(uint32_t value)
 {
     const uint32_t old_ints = interruptStatus;
     interruptStatus = value;

     if (!old_ints && interruptStatus) {
         interrupt->raise();
     } else if (old_ints && !interruptStatus) {
         interrupt->clear();
     }
 }


 MmioVirtIO *
 MmioVirtIOParams::create()
 {
     return new MmioVirtIO(this);
 }
	/*
	* Copyright (c) 2016-2018 ARM Limited
	* All rights reserved
	*
	* The license below extends only to copyright in the software and shall
	* not be construed as granting a license to any other intellectual
	* property including but not limited to intellectual property relating
	* to a hardware implementation of the functionality of the software
	* licensed hereunder. You may use the software subject to the license
	* terms below provided that you ensure that this notice is replicated
	* unmodified and in its entirety in all distributions of the software,
	* modified or unmodified, in source code or in binary form.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met: redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer;
	* redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution;
	* neither the name of the copyright holders nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "dev/arm/vio_mmio.hh"

	#include "debug/VIOIface.hh"
	#include "dev/arm/base_gic.hh"
	#include "mem/packet_access.hh"
	#include "params/MmioVirtIO.hh"

	MmioVirtIO::MmioVirtIO(const MmioVirtIOParams *params)
	: BasicPioDevice(params, params->pio_size),
	hostFeaturesSelect(0), guestFeaturesSelect(0), pageSize(0),
	interruptStatus(0), vio(*params->vio),
	interrupt(params->interrupt->get())
	{
	fatal_if(!interrupt, "No MMIO VirtIO interrupt specified\n");

	vio.registerKickCallback([this]() { kick(); });
	}

	MmioVirtIO::~MmioVirtIO()
	{
	}

	Tick
	MmioVirtIO::read(PacketPtr pkt)
	{
	const Addr offset = pkt->getAddr() - pioAddr;
	const unsigned size(pkt->getSize());

	DPRINTF(VIOIface, "Reading %u bytes @ 0x%x:\n", size, offset);

	// Forward device configuration writes to the device VirtIO model
	if (offset >= OFF_CONFIG) {
	vio.readConfig(pkt, offset - OFF_CONFIG);
	return 0;
	}

	panic_if(size != 4, "Unexpected read size: %u\n", size);

	const uint32_t value = read(offset);
	DPRINTF(VIOIface, " value: 0x%x\n", value);
	pkt->makeResponse();
	pkt->setLE<uint32_t>(value);

	return 0;
	}

	uint32_t
	MmioVirtIO::read(Addr offset)
	{
	switch(offset) {
	case OFF_MAGIC:
	return MAGIC;

	case OFF_VERSION:
	return VERSION;

	case OFF_DEVICE_ID:
	return vio.deviceId;

	case OFF_VENDOR_ID:
	return VENDOR_ID;

	case OFF_HOST_FEATURES:
	// We only implement 32 bits of this register
	if (hostFeaturesSelect == 0)
	return vio.deviceFeatures;
	else
	return 0;

	case OFF_HOST_FEATURES_SELECT:
	return hostFeaturesSelect;

	case OFF_GUEST_FEATURES:
	// We only implement 32 bits of this register
	if (guestFeaturesSelect == 0)
	return vio.getGuestFeatures();
	else
	return 0;

	case OFF_GUEST_FEATURES_SELECT:
	return hostFeaturesSelect;

	case OFF_GUEST_PAGE_SIZE:
	return pageSize;

	case OFF_QUEUE_SELECT:
	return vio.getQueueSelect();

	case OFF_QUEUE_NUM_MAX:
	return vio.getQueueSize();

	case OFF_QUEUE_NUM:
	// TODO: We don't support queue resizing, so ignore this for now.
	return vio.getQueueSize();

	case OFF_QUEUE_ALIGN:
	// TODO: Implement this once we support other alignment sizes
	return VirtQueue::ALIGN_SIZE;

	case OFF_QUEUE_PFN:
	return vio.getQueueAddress();

	case OFF_INTERRUPT_STATUS:
	return interruptStatus;

	case OFF_STATUS:
	return vio.getDeviceStatus();

	// Write-only registers
	case OFF_QUEUE_NOTIFY:
	case OFF_INTERRUPT_ACK:
	warn("Guest is trying to read to write-only register 0x%\n",
	offset);
	return 0;

	default:
	panic("Unhandled read offset (0x%x)\n", offset);
	}
	}

	Tick
	MmioVirtIO::write(PacketPtr pkt)
	{
	const Addr offset = pkt->getAddr() - pioAddr;
	const unsigned size(pkt->getSize());

	DPRINTF(VIOIface, "Writing %u bytes @ 0x%x:\n", size, offset);

	// Forward device configuration writes to the device VirtIO model
	if (offset >= OFF_CONFIG) {
	vio.writeConfig(pkt, offset - OFF_CONFIG);
	return 0;
	}

	panic_if(size != 4, "Unexpected write size @ 0x%x: %u\n", offset, size);
	DPRINTF(VIOIface, " value: 0x%x\n", pkt->getLE<uint32_t>());
	pkt->makeResponse();
	write(offset, pkt->getLE<uint32_t>());
	return 0;
	}

	void
	MmioVirtIO::write(Addr offset, uint32_t value)
	{
	switch(offset) {
	case OFF_HOST_FEATURES_SELECT:
	hostFeaturesSelect = value;
	return;

	case OFF_GUEST_FEATURES:
	if (guestFeaturesSelect == 0) {
	vio.setGuestFeatures(value);
	} else if (value != 0) {
	warn("Setting unimplemented guest features register %u: %u\n",
	guestFeaturesSelect, value);
	}
	return;

	case OFF_GUEST_FEATURES_SELECT:
	guestFeaturesSelect = value;
	return;

	case OFF_GUEST_PAGE_SIZE:
	// TODO: We only support 4096 byte pages at the moment
	panic_if(value != VirtQueue::ALIGN_SIZE,
	"Unhandled VirtIO page size: %u", value);
	pageSize = value;
	return;

	case OFF_QUEUE_SELECT:
	vio.setQueueSelect(value);
	return;

	case OFF_QUEUE_NUM:
	// TODO: We don't support queue resizing, so ignore this for now.
	warn_once("Ignoring queue resize hint. Requested size: %u\n", value);
	return;

	case OFF_QUEUE_ALIGN:
	// TODO: We currently only support the hard-coded 4k alignment used
	// in legacy VirtIO.
	panic_if(value != VirtQueue::ALIGN_SIZE,
	"Unhandled VirtIO alignment size: %u", value);
	return;

	case OFF_QUEUE_PFN:
	vio.setQueueAddress(value);
	return;

	case OFF_QUEUE_NOTIFY:
	vio.onNotify(value);
	return;

	case OFF_INTERRUPT_ACK:
	setInterrupts(interruptStatus & (~value));
	return;

	case OFF_STATUS:
	panic_if(value > 0xff, "Unexpected status: 0x%x\n", value);
	vio.setDeviceStatus(value);
	return;

	/* Read-only registers */
	case OFF_MAGIC:
	case OFF_VERSION:
	case OFF_DEVICE_ID:
	case OFF_VENDOR_ID:
	case OFF_HOST_FEATURES:
	case OFF_QUEUE_NUM_MAX:
	case OFF_INTERRUPT_STATUS:
	warn("Guest is trying to write to read-only register 0x%\n",
	offset);
	return;

	default:
	panic("Unhandled read offset (0x%x)\n", offset);
	}
	}

	void
	MmioVirtIO::kick()
	{
	DPRINTF(VIOIface, "kick(): Sending interrupt...\n");
	setInterrupts(interruptStatus \| INT_USED_RING);
	}

	void
	MmioVirtIO::setInterrupts(uint32_t value)
	{
	const uint32_t old_ints = interruptStatus;
	interruptStatus = value;

	if (!old_ints && interruptStatus) {
	interrupt->raise();
	} else if (old_ints && !interruptStatus) {
	interrupt->clear();
	}
	}


	MmioVirtIO *
	MmioVirtIOParams::create()
	{
	return new MmioVirtIO(this);
	}