Kernel: Add base support for VirtConsole (VirtIO based consoles)

Based on pull #3236 by tomuta, this is still very much WIP but will
eventually allow us to switch from the considerably slower method of
knocking on port 0xe9 for each character

Co-authored-by: Tom <tomut@yahoo.com>
Co-authored-by: Sahan <sahan.h.fernando@gmail.com>

Kernel/CMakeLists.txt

@@ -42,6 +42,7 @@ set(KERNEL_SOURCES
     Devices/USB/UHCIController.cpp
     VirtIO/VirtIO.cpp
     VirtIO/VirtIOQueue.cpp
+    VirtIO/VirtIOConsole.cpp
     Devices/VMWareBackdoor.cpp
     Devices/ZeroDevice.cpp
     Devices/HID/I8042Controller.cpp

Kernel/VirtIO/VirtIO.cpp

@@ -25,6 +25,7 @@
  */
 
 #include <Kernel/VirtIO/VirtIO.h>
+#include <Kernel/VirtIO/VirtIOConsole.h>
 
 namespace Kernel {
 
@@ -35,6 +36,11 @@ void VirtIO::detect()
             return;
         if (id.vendor_id != VIRTIO_PCI_VENDOR_ID)
             return;
+        switch (id.device_id) {
+        case VIRTIO_CONSOLE_PCI_DEVICE_ID:
+            [[maybe_unused]] auto& unused = adopt(*new VirtIOConsole(address)).leak_ref();
+            break;
+        }
     });
 }
 

Kernel/VirtIO/VirtIOConsole.cpp

@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 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 HOLDER 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 <Kernel/VirtIO/VirtIOConsole.h>
+
+namespace Kernel {
+
+VirtIOConsole::VirtIOConsole(PCI::Address address)
+    : CharacterDevice(229, 0)
+    , VirtIODevice(address, "VirtIOConsole")
+{
+    if (auto* cfg = get_device_config()) {
+        bool success = negotiate_features([&](u64 supported_features) {
+            u64 negotiated = 0;
+            if (is_feature_set(supported_features, VIRTIO_CONSOLE_F_SIZE))
+                dbgln("VirtIOConsole: Console size is not yet supported!");
+            if (is_feature_set(supported_features, VIRTIO_CONSOLE_F_MULTIPORT))
+                dbgln("VirtIOConsole: Multi port is not yet supported!");
+            return negotiated;
+        });
+        if (success) {
+            u32 max_nr_ports = 0;
+            u16 cols = 0, rows = 0;
+            read_config_atomic([&]() {
+                if (is_feature_accepted(VIRTIO_CONSOLE_F_SIZE)) {
+                    cols = config_read16(cfg, 0x0);
+                    rows = config_read16(cfg, 0x2);
+                }
+                if (is_feature_accepted(VIRTIO_CONSOLE_F_MULTIPORT)) {
+                    max_nr_ports = config_read32(cfg, 0x4);
+                }
+            });
+            dbgln("VirtIOConsole: cols: {}, rows: {}, max nr ports {}", cols, rows, max_nr_ports);
+            set_requested_queue_count(2 + max_nr_ports * 2); // base receiveq/transmitq for port0 + 2 per every additional port
+            success = finish_init();
+        }
+        if (success) {
+            m_receive_queue = get_queue(RECEIVEQ);
+            m_receive_queue->on_data_available = [&]() {
+                dbgln("VirtIOConsole: receive_queue on_data_available");
+            };
+            m_send_queue = get_queue(TRANSMITQ);
+            m_send_queue->on_data_available = [&]() {
+                dbgln("VirtIOConsole: send_queue on_data_available");
+            };
+            dbgln("TODO: Populate receive queue with a receive buffer");
+        }
+    }
+}
+
+VirtIOConsole::~VirtIOConsole()
+{
+}
+
+void VirtIOConsole::handle_device_config_change()
+{
+    dbgln("VirtIOConsole: Handle device config change");
+}
+
+bool VirtIOConsole::can_read(const FileDescription&, size_t) const
+{
+    return false;
+}
+
+KResultOr<size_t> VirtIOConsole::read(FileDescription&, u64, [[maybe_unused]] UserOrKernelBuffer& data, size_t size)
+{
+    if (!size)
+        return 0;
+
+    return 1;
+}
+
+bool VirtIOConsole::can_write(const FileDescription&, size_t) const
+{
+    return true;
+}
+
+KResultOr<size_t> VirtIOConsole::write(FileDescription&, u64, const UserOrKernelBuffer& data, size_t size)
+{
+    if (!size)
+        return 0;
+
+    dbgln("VirtIOConsole: Write with size {}, kernel: {}", size, data.is_kernel_buffer());
+
+    ssize_t nread = data.read_buffered<256>(size, [&](const u8* bytes, size_t bytes_count) {
+        supply_buffer_and_notify(TRANSMITQ, bytes, bytes_count, BufferType::DeviceReadable);
+        return (ssize_t)bytes_count;
+    });
+
+    if (nread < 0)
+        return Kernel::KResult((ErrnoCode)-nread);
+    return (size_t)nread;
+}
+
+}

Kernel/VirtIO/VirtIOConsole.h

@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 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 HOLDER 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.
+ */
+
+#pragma once
+
+#include <Kernel/Devices/CharacterDevice.h>
+#include <Kernel/VirtIO/VirtIO.h>
+
+namespace Kernel {
+
+#define VIRTIO_CONSOLE_PCI_DEVICE_ID 0x1003
+
+#define VIRTIO_CONSOLE_F_SIZE (1 << 0)
+#define VIRTIO_CONSOLE_F_MULTIPORT (1 << 1)
+#define VIRTIO_CONSOLE_F_EMERG_WRITE (1 << 2)
+
+#define RECEIVEQ 0
+#define TRANSMITQ 1
+
+class VirtIOConsole final : public CharacterDevice
+    , public VirtIODevice {
+public:
+    VirtIOConsole(PCI::Address);
+    virtual ~VirtIOConsole() override;
+
+private:
+    virtual const char* class_name() const override { return m_class_name; }
+
+    virtual bool can_read(const FileDescription&, size_t) const override;
+    virtual KResultOr<size_t> read(FileDescription&, u64, UserOrKernelBuffer&, size_t) override;
+    virtual bool can_write(const FileDescription&, size_t) const override;
+    virtual KResultOr<size_t> write(FileDescription&, u64, const UserOrKernelBuffer&, size_t) override;
+
+    virtual mode_t required_mode() const override { return 0666; }
+
+    virtual void handle_device_config_change() override;
+    virtual String device_name() const override { return String::formatted("hvc{}", minor()); }
+
+    VirtIOQueue* m_receive_queue { nullptr };
+    VirtIOQueue* m_send_queue { nullptr };
+};
+
+}