diff --git a/bsp/qemu-virt64-aarch64/drivers/drv_virtio.c b/bsp/qemu-virt64-aarch64/drivers/drv_virtio.c index 636b2fde8a..69b4e64ac2 100644 --- a/bsp/qemu-virt64-aarch64/drivers/drv_virtio.c +++ b/bsp/qemu-virt64-aarch64/drivers/drv_virtio.c @@ -80,7 +80,7 @@ int rt_virtio_devices_init(void) } /* Support both legacy (0x1) and modern (0x2) versions */ - if (mmio_config->version != 1 && mmio_config->version != 2) + if ((mmio_config->version < 1) || (mmio_config->version > 2)) { continue; } diff --git a/bsp/qemu-virt64-riscv/driver/drv_virtio.c b/bsp/qemu-virt64-riscv/driver/drv_virtio.c index f7bf6f2098..5a6422c3c8 100644 --- a/bsp/qemu-virt64-riscv/driver/drv_virtio.c +++ b/bsp/qemu-virt64-riscv/driver/drv_virtio.c @@ -86,7 +86,7 @@ int rt_virtio_devices_init(void) } /* Support both legacy (0x1) and modern (0x2) versions */ - if (mmio_config->version != 1 && mmio_config->version != 2) + if ((mmio_config->version < 1) || (mmio_config->version > 2)) { continue; } diff --git a/components/drivers/virtio/README.md b/components/drivers/virtio/README.md index 10278a24ed..f605b7b3a2 100644 --- a/components/drivers/virtio/README.md +++ b/components/drivers/virtio/README.md @@ -1,5 +1,7 @@ # VirtIO Driver for RT-Thread +[中文](README_zh.md) | English + ## Overview The VirtIO driver provides support for virtual I/O devices in RT-Thread, primarily used in virtualized environments like QEMU. @@ -43,17 +45,13 @@ Options: Enable individual VirtIO devices: -``` -RT-Thread Components → Device Drivers → Using VirtIO device drivers -``` - - `RT_USING_VIRTIO_BLK`: VirtIO block device support - `RT_USING_VIRTIO_NET`: VirtIO network device support - `RT_USING_VIRTIO_CONSOLE`: VirtIO console device support - `RT_USING_VIRTIO_GPU`: VirtIO GPU device support - `RT_USING_VIRTIO_INPUT`: VirtIO input device support -## Key Differences Between Legacy and Modern VirtIO +## Key Differences ### Legacy VirtIO (v0.95) - 32-bit feature negotiation @@ -66,7 +64,6 @@ RT-Thread Components → Device Drivers → Using VirtIO device drivers - Separate descriptor/driver/device queue areas - Enhanced status flow with FEATURES_OK check - Better memory alignment and atomicity guarantees -- Config generation field for atomic configuration reads ## Migration Guide @@ -94,74 +91,10 @@ The following BSPs have been updated to support both legacy and modern VirtIO: ## Reference Specifications -- [VirtIO Specification v1.0](https://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.html) -- [VirtIO Specification v1.1](https://docs.oasis-open.org/virtio/virtio/v1.1/virtio-v1.1.html) -- [VirtIO Specification v1.2](https://docs.oasis-open.org/virtio/virtio/v1.2/virtio-v1.2.html) - -## Implementation Details - -### Feature Negotiation - -Modern VirtIO uses 64-bit feature negotiation: -- Device exposes features via `device_features` register (selected by `device_features_sel`) -- Driver acknowledges features via `driver_features` register (selected by `driver_features_sel`) -- For modern devices, the driver must negotiate `VIRTIO_F_VERSION_1` (feature bit 32) - -### Queue Initialization - -**Legacy VirtIO:** -- Uses single `queue_pfn` register pointing to the start of the queue area -- Guest page size configured via `guest_page_size` - -**Modern VirtIO:** -- Uses separate registers for descriptor, driver (avail), and device (used) areas: - - `queue_desc_low`/`queue_desc_high`: Descriptor table address - - `queue_driver_low`/`queue_driver_high`: Available ring address - - `queue_device_low`/`queue_device_high`: Used ring address -- Queue activated via `queue_ready` register - -### Status Flow - -**Modern VirtIO adds FEATURES_OK check:** -1. Reset device (status = 0) -2. Set ACKNOWLEDGE and DRIVER status bits -3. Read and negotiate features -4. Write negotiated features to device -5. Set FEATURES_OK status bit -6. Re-read status to verify FEATURES_OK (device may reject features) -7. If accepted, proceed with queue setup and set DRIVER_OK - -## Troubleshooting - -### Device Not Detected - -Check that: -1. QEMU is configured with VirtIO devices -2. The VirtIO version matches your QEMU configuration -3. The device memory region is correctly mapped - -### Build Errors - -Ensure: -1. The Kconfig is properly configured -2. All VirtIO header files are included -3. The BSP supports VirtIO (check `BSP_USING_VIRTIO`) - -### Runtime Issues - -Debug tips: -1. Check device version in MMIO config -2. Verify feature negotiation succeeded -3. Check queue initialization (descriptor, avail, used ring addresses) -4. Monitor interrupt status and acknowledgment - -## Contributing - -When adding new VirtIO devices or features: -1. Support both legacy and modern versions -2. Use the helper functions for feature negotiation (`virtio_get_features`, `virtio_set_features`) -3. Use version checking (`dev->version`) for version-specific code -4. Test on both legacy and modern QEMU configurations +- [VirtIO Specification v1.2](https://docs.oasis-open.org/virtio/virtio/v1.2/virtio-v1.2.html) (Latest, 2022) +- [VirtIO Specification v1.1](https://docs.oasis-open.org/virtio/virtio/v1.1/virtio-v1.1.html) (2019) +- [VirtIO Specification v1.0](https://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.html) (2016) +- [OASIS VirtIO TC](https://www.oasis-open.org/committees/virtio/) ## License diff --git a/components/drivers/virtio/README_zh.md b/components/drivers/virtio/README_zh.md new file mode 100644 index 0000000000..d8ad9a2b63 --- /dev/null +++ b/components/drivers/virtio/README_zh.md @@ -0,0 +1,101 @@ +# RT-Thread VirtIO 驱动 + +[English](README.md) | 中文 + +## 概述 + +VirtIO 驱动为 RT-Thread 提供虚拟 I/O 设备支持,主要用于 QEMU 等虚拟化环境。 + +## 支持的版本 + +驱动现已支持传统版和现代版 VirtIO 规范: + +- **传统版 VirtIO (v0.95)**:版本字段为 0x1,兼容较旧的 QEMU 版本 +- **现代版 VirtIO (v1.0+)**:版本字段为 0x2,支持 VirtIO 1.0、1.1 和 1.2 规范 + +## 支持的设备 + +- **VirtIO 块设备 (virtio-blk)**:虚拟块设备 +- **VirtIO 网络设备 (virtio-net)**:虚拟网络接口 +- **VirtIO 控制台 (virtio-console)**:虚拟串口控制台 +- **VirtIO GPU (virtio-gpu)**:虚拟图形设备 +- **VirtIO 输入设备 (virtio-input)**:虚拟输入设备(键盘、鼠标、触摸板) + +## 配置 + +使用 `menuconfig` 配置 VirtIO 支持: + +``` +RT-Thread Components → Device Drivers → Using VirtIO device drivers +``` + +### 版本选择 + +在传统版和现代版 VirtIO 之间选择: + +``` +RT-Thread Components → Device Drivers → Using VirtIO device drivers → VirtIO Version +``` + +选项: +- **VirtIO Legacy (v0.95)**:与较旧的 QEMU 版本兼容(默认) +- **VirtIO Modern (v1.0+)**:用于较新的 QEMU 版本(2.4+),具有增强功能 + +### 设备选择 + +启用各个 VirtIO 设备: + +- `RT_USING_VIRTIO_BLK`:VirtIO 块设备支持 +- `RT_USING_VIRTIO_NET`:VirtIO 网络设备支持 +- `RT_USING_VIRTIO_CONSOLE`:VirtIO 控制台支持 +- `RT_USING_VIRTIO_GPU`:VirtIO GPU 支持 +- `RT_USING_VIRTIO_INPUT`:VirtIO 输入设备支持 + +## 主要区别 + +### 传统版 VirtIO (v0.95) +- 32 位特性协商 +- 单一队列描述符区域 +- 简单状态标志 +- 客户机页面大小配置 + +### 现代版 VirtIO (v1.0+) +- 64 位特性协商(支持更多特性) +- 独立的描述符/驱动/设备队列区域 +- 增强的状态流程,带 FEATURES_OK 检查 +- 更好的内存对齐和原子性保证 + +## 迁移指南 + +### 从传统版迁移到现代版 + +1. 更新 QEMU 命令行以使用现代版 VirtIO 设备(最新的 QEMU 版本默认使用现代版) +2. 在 menuconfig 中更改 VirtIO 版本: + ``` + RT-Thread Components → Device Drivers → Using VirtIO device drivers → VirtIO Version + → 选择 "VirtIO Modern (v1.0+)" + ``` +3. 重新构建应用程序 +4. 驱动将自动与设备协商 VERSION_1 特性 + +### 向后兼容性 + +驱动从 MMIO 配置中自动检测设备版本,并相应调整其行为。传统版(版本 0x1)和现代版(版本 0x2)设备在同一构建中都受支持。 + +## BSP 支持 + +以下 BSP 已更新以支持传统版和现代版 VirtIO: + +- `qemu-virt64-riscv`:QEMU RISC-V 64 位 +- `qemu-virt64-aarch64`:QEMU ARM64 (AArch64) + +## 规范参考 + +- [VirtIO 规范 v1.2](https://docs.oasis-open.org/virtio/virtio/v1.2/virtio-v1.2.html)(最新,2022) +- [VirtIO 规范 v1.1](https://docs.oasis-open.org/virtio/virtio/v1.1/virtio-v1.1.html)(2019) +- [VirtIO 规范 v1.0](https://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.html)(2016) +- [OASIS VirtIO 技术委员会](https://www.oasis-open.org/committees/virtio/) + +## 许可证 + +Apache-2.0 diff --git a/components/drivers/virtio/SPECIFICATIONS.md b/components/drivers/virtio/SPECIFICATIONS.md deleted file mode 100644 index eb833cda92..0000000000 --- a/components/drivers/virtio/SPECIFICATIONS.md +++ /dev/null @@ -1,194 +0,0 @@ -# VirtIO Specification References - -## Official VirtIO Specifications - -### Latest Version (v1.2) -**VirtIO 1.2 Specification** (2022-07-14) -- **Official Link**: https://docs.oasis-open.org/virtio/virtio/v1.2/virtio-v1.2.html -- **PDF**: https://docs.oasis-open.org/virtio/virtio/v1.2/csd01/virtio-v1.2-csd01.pdf -- **Status**: OASIS Committee Specification Draft 01 -- **Key Features**: - - All features from v1.1 - - New devices: Audio, File System, PMEM, RPMB, Video Encoder/Decoder, SCMI, GPIO, RDMA - - Enhanced device specifications - - Better security and performance features - -### VirtIO 1.1 Specification (2019-01-29) -- **Official Link**: https://docs.oasis-open.org/virtio/virtio/v1.1/virtio-v1.1.html -- **PDF**: https://docs.oasis-open.org/virtio/virtio/v1.1/csprd01/virtio-v1.1-csprd01.pdf -- **Status**: OASIS Committee Specification Public Review Draft 01 -- **Key Features**: - - All features from v1.0 - - Packed ring support (VIRTIO_F_RING_PACKED) - - New devices: Socket, Crypto, Signal Distribution Module, IOMMU, Memory - - Order-independent feature negotiation - -### VirtIO 1.0 Specification (2016-03-08) -- **Official Link**: https://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.html -- **PDF**: https://docs.oasis-open.org/virtio/virtio/v1.0/cs04/virtio-v1.0-cs04.pdf -- **Status**: OASIS Committee Specification 04 -- **Key Features**: - - Modern interface (version field = 0x2) - - 64-bit feature negotiation - - Separate queue descriptor/driver/device areas - - FEATURES_OK status check - - Better memory alignment requirements - -### Legacy VirtIO (v0.95) -- **Reference**: Part of Linux kernel documentation -- **Link**: https://wiki.libvirt.org/VirtIO.html -- **Status**: Legacy interface (version field = 0x1) -- **Note**: Used by older QEMU versions and some embedded systems - -## OASIS VirtIO Technical Committee - -- **Website**: https://www.oasis-open.org/committees/virtio/ -- **Charter**: Defines standard interfaces for virtual I/O devices -- **Mailing List**: virtio@lists.oasis-open.org -- **Git Repository**: https://github.com/oasis-tcs/virtio-spec - -## Implementation in RT-Thread - -RT-Thread now supports: -- ✅ **Legacy VirtIO (v0.95)**: Version field 0x1, 32-bit features, legacy queue setup -- ✅ **Modern VirtIO (v1.0+)**: Version field 0x2, 64-bit features, modern queue setup - -The implementation follows the VirtIO 1.2 specification for modern devices while maintaining backward compatibility with legacy devices. - -## Device-Specific Specifications - -### VirtIO Block Device -- **Section**: 5.2 in VirtIO 1.2 spec -- **Features**: Basic block I/O, multiple queues, discard support -- **Status**: Fully implemented in RT-Thread - -### VirtIO Network Device -- **Section**: 5.1 in VirtIO 1.2 spec -- **Features**: Ethernet interface, checksum offload, multiple queues -- **Status**: Fully implemented in RT-Thread - -### VirtIO Console Device -- **Section**: 5.3 in VirtIO 1.2 spec -- **Features**: Serial console, multiple ports, control messages -- **Status**: Fully implemented in RT-Thread - -### VirtIO GPU Device -- **Section**: 5.7 in VirtIO 1.2 spec -- **Features**: 2D graphics, scanout, resource management -- **Status**: Fully implemented in RT-Thread - -### VirtIO Input Device -- **Section**: 5.8 in VirtIO 1.2 spec -- **Features**: Keyboard, mouse, tablet input events -- **Status**: Fully implemented in RT-Thread - -## QEMU VirtIO Implementation - -### QEMU Documentation -- **VirtIO Devices**: https://qemu.readthedocs.io/en/latest/system/devices/virtio-net.html -- **MMIO Transport**: https://qemu.readthedocs.io/en/latest/specs/virtio-mmio.html - -### QEMU Version Requirements -- **Legacy VirtIO**: QEMU 1.0+ -- **Modern VirtIO**: QEMU 2.4+ (recommended 2.6+) - -### QEMU Command Line Examples - -**Legacy Mode:** -```bash -qemu-system-riscv64 -M virt \ - -device virtio-blk-device,disable-modern=on,drive=blk0 -``` - -**Modern Mode:** -```bash -qemu-system-riscv64 -M virt \ - -device virtio-blk-device,disable-legacy=on,drive=blk0 -``` - -**Auto-detect (Default):** -```bash -qemu-system-riscv64 -M virt \ - -device virtio-blk-device,drive=blk0 -``` - -## Feature Bits Reference - -### Common Features (Section 6 in VirtIO 1.2 spec) - -| Bit | Name | Description | -|-----|------|-------------| -| 24 | VIRTIO_F_NOTIFY_ON_EMPTY | Notify on empty available ring | -| 27 | VIRTIO_F_ANY_LAYOUT | Flexible descriptor layout | -| 28 | VIRTIO_F_RING_INDIRECT_DESC | Indirect descriptors | -| 29 | VIRTIO_F_RING_EVENT_IDX | Event index for notifications | -| 32 | VIRTIO_F_VERSION_1 | Compliance with VirtIO 1.0+ | -| 34 | VIRTIO_F_RING_PACKED | Packed ring layout (1.1+) | - -### Device-Specific Features - -**Block Device:** -- Bit 0: VIRTIO_BLK_F_BARRIER - Legacy barrier support -- Bit 1: VIRTIO_BLK_F_SIZE_MAX - Maximum segment size -- Bit 2: VIRTIO_BLK_F_SEG_MAX - Maximum segments -- Bit 5: VIRTIO_BLK_F_RO - Read-only device -- Bit 9: VIRTIO_BLK_F_FLUSH - Cache flush support - -**Network Device:** -- Bit 0: VIRTIO_NET_F_CSUM - Checksum offload -- Bit 1: VIRTIO_NET_F_GUEST_CSUM - Guest checksum -- Bit 5: VIRTIO_NET_F_MAC - MAC address -- Bit 6: VIRTIO_NET_F_GSO - Generic segmentation offload - -## Status Bits Reference - -| Bit | Name | Description | -|-----|------|-------------| -| 0 | ACKNOWLEDGE | Driver has found the device | -| 1 | DRIVER | Driver knows how to drive the device | -| 2 | DRIVER_OK | Driver is set up and ready | -| 3 | FEATURES_OK | Feature negotiation complete | -| 6 | NEEDS_RESET | Device experienced unrecoverable error | -| 7 | FAILED | Driver gave up on device | - -## Additional Resources - -### Linux Kernel VirtIO Implementation -- **Source**: https://github.com/torvalds/linux/tree/master/drivers/virtio -- **Documentation**: https://www.kernel.org/doc/Documentation/virtual/ - -### KVM/QEMU VirtIO -- **KVM Forum**: https://www.linux-kvm.org/page/Virtio -- **QEMU Wiki**: https://wiki.qemu.org/Features/VirtIO - -### Books and Papers -- **"Hardware Virtualization: Platforms and Applications"** - Covers VirtIO design -- **"Virtual Machines: Versatile Platforms for Systems and Processes"** - Chapter on I/O virtualization - -## RT-Thread Specific Documentation - -- **[README.md](README.md)**: RT-Thread VirtIO usage guide -- **[TESTING.md](TESTING.md)**: Testing procedures for both legacy and modern modes - -## Version History - -| Date | Version | RT-Thread Support | Notes | -|------|---------|------------------|-------| -| 2022-07-14 | 1.2 | ✅ Yes | Latest specification | -| 2019-01-29 | 1.1 | ✅ Yes | Packed ring support | -| 2016-03-08 | 1.0 | ✅ Yes | Modern interface | -| ~2013 | 0.95 | ✅ Yes | Legacy interface (default) | - -## Contact and Support - -- **RT-Thread Forum**: https://club.rt-thread.io/ -- **GitHub Issues**: https://github.com/RT-Thread/rt-thread/issues -- **VirtIO Mailing List**: virtio@lists.oasis-open.org - -## License - -VirtIO specifications are licensed under: -- OASIS Open Source License (VirtIO 1.0+) - -RT-Thread VirtIO driver is licensed under: -- Apache License 2.0 diff --git a/components/drivers/virtio/TESTING.md b/components/drivers/virtio/TESTING.md deleted file mode 100644 index b640a089c5..0000000000 --- a/components/drivers/virtio/TESTING.md +++ /dev/null @@ -1,301 +0,0 @@ -# VirtIO Testing Guide - -This guide helps you test VirtIO support on RT-Thread with both legacy and modern versions. - -## Prerequisites - -- QEMU installed (version 2.4+ for modern VirtIO support) -- RT-Thread build environment -- RISC-V or AArch64 toolchain - -## Testing Legacy VirtIO (v0.95) - -### 1. Configure RT-Thread - -```bash -cd bsp/qemu-virt64-riscv -scons --menuconfig -``` - -Navigate to: -``` -RT-Thread Components → Device Drivers → Using VirtIO device drivers → VirtIO Version -→ Select "VirtIO Legacy (v0.95)" or "VirtIO Legacy (v1.0 - alias for compatibility)" -``` - -### 2. Build - -```bash -scons -``` - -### 3. Run with QEMU (Legacy Mode) - -Force QEMU to use legacy VirtIO: - -```bash -qemu-system-riscv64 \ - -M virt \ - -kernel rtthread.bin \ - -nographic \ - -device virtio-blk-device,disable-modern=on,drive=blk0 \ - -drive if=none,id=blk0,file=sd.bin \ - -device virtio-net-device,disable-modern=on,netdev=net0 \ - -netdev user,id=net0 -``` - -### 4. Verify - -Check that VirtIO devices are detected: -``` -msh /> list_device -device type ref count ------- -------------------- ---------- -virtio-blk0 Block Device 0 -virtio-net0 Network Interface 0 -``` - -## Testing Modern VirtIO (v1.0+) - -### 1. Configure RT-Thread - -```bash -cd bsp/qemu-virt64-riscv -scons --menuconfig -``` - -Navigate to: -``` -RT-Thread Components → Device Drivers → Using VirtIO device drivers → VirtIO Version -→ Select "VirtIO Modern (v1.0+)" -``` - -### 2. Build - -```bash -scons -``` - -### 3. Run with QEMU (Modern Mode) - -Use default QEMU settings (modern VirtIO): - -```bash -qemu-system-riscv64 \ - -M virt \ - -kernel rtthread.bin \ - -nographic \ - -device virtio-blk-device,drive=blk0 \ - -drive if=none,id=blk0,file=sd.bin \ - -device virtio-net-device,netdev=net0 \ - -netdev user,id=net0 -``` - -Or explicitly enable modern mode: - -```bash -qemu-system-riscv64 \ - -M virt \ - -kernel rtthread.bin \ - -nographic \ - -device virtio-blk-device,disable-legacy=on,drive=blk0 \ - -drive if=none,id=blk0,file=sd.bin \ - -device virtio-net-device,disable-legacy=on,netdev=net0 \ - -netdev user,id=net0 -``` - -### 4. Verify - -Check that VirtIO devices are detected: -``` -msh /> list_device -device type ref count ------- -------------------- ---------- -virtio-blk0 Block Device 0 -virtio-net0 Network Interface 0 -``` - -## Testing Auto-Detection (Recommended) - -The driver can auto-detect the VirtIO version. To test this: - -### 1. Build with Default Settings - -Use the existing configuration (legacy by default): -```bash -cd bsp/qemu-virt64-riscv -scons -``` - -### 2. Test with Both QEMU Modes - -**Test 1: Legacy QEMU** -```bash -qemu-system-riscv64 -M virt -kernel rtthread.bin -nographic \ - -device virtio-blk-device,disable-modern=on,drive=blk0 \ - -drive if=none,id=blk0,file=sd.bin -``` - -**Test 2: Modern QEMU** -```bash -qemu-system-riscv64 -M virt -kernel rtthread.bin -nographic \ - -device virtio-blk-device,drive=blk0 \ - -drive if=none,id=blk0,file=sd.bin -``` - -Both should work because the driver detects the version from the MMIO config. - -## Testing Individual Devices - -### VirtIO Block Device - -```bash -# Create a test disk image -dd if=/dev/zero of=sd.bin bs=1M count=32 - -# Run QEMU with block device -qemu-system-riscv64 -M virt -kernel rtthread.bin -nographic \ - -device virtio-blk-device,drive=blk0 \ - -drive if=none,id=blk0,file=sd.bin - -# In RT-Thread shell -msh /> mkfs -t elm virtio-blk0 -msh /> mount virtio-blk0 / elm -``` - -### VirtIO Network Device - -```bash -# Run QEMU with network device -qemu-system-riscv64 -M virt -kernel rtthread.bin -nographic \ - -device virtio-net-device,netdev=net0 \ - -netdev user,id=net0,hostfwd=tcp::5555-:23 - -# In RT-Thread shell -msh /> ifconfig -``` - -### VirtIO Console - -```bash -# Run QEMU with console device -qemu-system-riscv64 -M virt -kernel rtthread.bin -nographic \ - -device virtio-serial-device \ - -chardev stdio,id=console0 \ - -device virtconsole,chardev=console0 - -# Check for virtio-console devices -msh /> list_device -``` - -### VirtIO GPU - -```bash -# Run QEMU with GPU device (requires display) -qemu-system-riscv64 -M virt -kernel rtthread.bin \ - -device virtio-gpu-device \ - -serial stdio - -# Or with VNC -qemu-system-riscv64 -M virt -kernel rtthread.bin -nographic \ - -device virtio-gpu-device \ - -vnc :0 -``` - -### VirtIO Input (Keyboard/Mouse) - -```bash -# Run QEMU with input devices -qemu-system-riscv64 -M virt -kernel rtthread.bin \ - -device virtio-keyboard-device \ - -device virtio-mouse-device \ - -device virtio-tablet-device - -# Check for input devices -msh /> list_device -``` - -## Debugging - -### Enable Debug Output - -Add debug prints to check version detection: - -```c -// In your application or driver init -rt_kprintf("VirtIO version: %d\n", virtio_dev->version); -rt_kprintf("VirtIO magic: 0x%x\n", virtio_dev->mmio_config->magic); -rt_kprintf("VirtIO device_id: %d\n", virtio_dev->mmio_config->device_id); -``` - -### Check QEMU Version - -```bash -qemu-system-riscv64 --version -``` - -Modern VirtIO requires QEMU 2.4+. - -### Check Feature Negotiation - -Add debug output in `virtio_get_features` and `virtio_set_features` to verify feature negotiation. - -## Expected Results - -### Legacy Mode (Version 1) -- `dev->version == 1` -- Features are 32-bit -- Queue uses `queue_pfn` register -- No FEATURES_OK check - -### Modern Mode (Version 2) -- `dev->version == 2` -- Features are 64-bit -- Queue uses separate desc/driver/device registers -- FEATURES_OK status check performed -- VERSION_1 feature negotiated - -## Common Issues - -### Issue: Device not detected -**Solution**: Check QEMU device configuration and memory mapping - -### Issue: Feature negotiation fails -**Solution**: Verify QEMU supports the features you're requesting - -### Issue: Queue initialization fails -**Solution**: Check memory alignment and addresses - -### Issue: Build errors -**Solution**: Ensure Kconfig is properly configured and rtconfig.h is generated - -## Performance Testing - -### Block Device Performance - -```bash -# In RT-Thread shell (with filesystem mounted) -msh /> dd if=/dev/zero of=/test.bin bs=4096 count=1000 -``` - -### Network Performance - -```bash -# Use iperf or similar tools -# Configure network and run throughput tests -``` - -## Reporting Issues - -When reporting issues, include: -1. QEMU version -2. RT-Thread configuration (legacy/modern) -3. QEMU command line -4. Error messages or unexpected behavior -5. Debug output (if enabled) - -## Reference - -- [QEMU VirtIO Documentation](https://wiki.qemu.org/Features/VirtIO) -- [VirtIO Specification](https://docs.oasis-open.org/virtio/virtio/v1.2/virtio-v1.2.html) -- [RT-Thread VirtIO README](README.md)