Implement virtio-input device

sysprog21 · Aug 17, 2024 · 1ae6101 · 1ae6101
1 parent dd94f21
commit 1ae6101
Show file tree

Hide file tree

Showing 8 changed files with 891 additions and 5 deletions.
diff --git a/Makefile b/Makefile
@@ -44,6 +44,16 @@ ifeq ($(call has, VIRTIONET), 1)
     OBJS_EXTRA += virtio-net.o
 endif
 
+# virtio-input
+ENABLE_VIRTIOINPUT ?= 1
+ifneq ($(UNAME_S),Linux)
+    ENABLE_VIRTIOINPUT := 0
+endif
+$(call set-feature, VIRTIOINPUT)
+ifeq ($(call has, VIRTIOINPUT), 1)
+    OBJS_EXTRA += virtio-input.o
+endif
+
 # virtio-gpu
 ENABLE_VIRTIOGPU ?= 1
 ifneq ($(UNAME_S),Linux)

diff --git a/bitops.h b/bitops.h
@@ -0,0 +1,67 @@
+#ifndef __BITOPS_H__
+#define __BITOPS_H__
+
+#include <sys/param.h>
+
+#define BITS_PER_CHAR 8
+#define BITS_PER_LONG (BITS_PER_CHAR * sizeof(long))
+
+/* Find last bit set:
+ * the index of the last bit that's set, or 0 if value is zero.
+ */
+static inline unsigned long _flsl(unsigned long word)
+{
+    return word ? sizeof(long) * BITS_PER_CHAR - __builtin_clz(word) : 0;
+}
+
+static inline void clear_bit(unsigned long bit, unsigned long *word)
+{
+    *word &= ~(1 << bit);
+}
+
+static inline void set_bit(unsigned long bit, unsigned long *word)
+{
+    *word |= (1 << bit);
+}
+
+static inline void bitmap_clear_bit(unsigned long *map, unsigned long bit)
+{
+    clear_bit(bit % BITS_PER_LONG, &map[bit / BITS_PER_LONG]);
+}
+
+static inline void bitmap_set_bit(unsigned long *map, unsigned long bit)
+{
+    set_bit(bit % BITS_PER_LONG, &map[bit / BITS_PER_LONG]);
+}
+
+static inline unsigned long bitmap_get_bit(unsigned long *map,
+                                           unsigned long bit)
+{
+    return map[bit / BITS_PER_LONG] >> (bit % BITS_PER_LONG) & 1;
+}
+
+static inline unsigned long find_first_bit(const unsigned long *addr,
+                                           unsigned long size)
+{
+    for (unsigned long i = 0; i * BITS_PER_LONG < size; i++) {
+        if (addr[i]) {
+            return MIN(i * BITS_PER_LONG + __builtin_ffsl(addr[i]) - 1, size);
+        }
+    }
+
+    return size;
+}
+
+static inline unsigned long find_first_zero_bit(const unsigned long *addr,
+                                                unsigned long size)
+{
+    for (unsigned long i = 0; i * BITS_PER_LONG < size; i++) {
+        if (addr[i] != ~0ul) {
+            return MIN(i * BITS_PER_LONG + __builtin_ffsl(~addr[i]) - 1, size);
+        }
+    }
+
+    return size;
+}
+
+#endif
diff --git a/device.h b/device.h
@@ -222,6 +222,62 @@ void virtio_gpu_add_scanout(virtio_gpu_state_t *vgpu,
                             uint32_t height);
 #endif /* SEMU_HAS(VIRTIOGPU) */
 
+/* VirtIO Input */
+
+#if SEMU_HAS(VIRTIOINPUT)
+
+#define IRQ_VINPUT_KEYBOARD 5
+#define IRQ_VINPUT_KEYBOARD_BIT (1 << IRQ_VINPUT_KEYBOARD)
+
+#define IRQ_VINPUT_MOUSE 6
+#define IRQ_VINPUT_MOUSE_BIT (1 << IRQ_VINPUT_MOUSE)
+
+typedef struct {
+    uint32_t QueueNum;
+    uint32_t QueueDesc;
+    uint32_t QueueAvail;
+    uint32_t QueueUsed;
+    uint16_t last_avail;
+    bool ready;
+} virtio_input_queue_t;
+
+typedef struct {
+    /* feature negotiation */
+    uint32_t DeviceFeaturesSel;
+    uint32_t DriverFeatures;
+    uint32_t DriverFeaturesSel;
+    /* queue config */
+    uint32_t QueueSel;
+    virtio_input_queue_t queues[2];
+    /* status */
+    uint32_t Status;
+    uint32_t InterruptStatus;
+    /* supplied by environment */
+    uint32_t *ram;
+    /* implementation-specific */
+    int id;  // FIXME
+    void *priv;
+} virtio_input_state_t;
+
+void virtio_input_read(hart_t *vm,
+                       virtio_input_state_t *vinput,
+                       uint32_t addr,
+                       uint8_t width,
+                       uint32_t *value);
+
+void virtio_input_write(hart_t *vm,
+                        virtio_input_state_t *vinput,
+                        uint32_t addr,
+                        uint8_t width,
+                        uint32_t value);
+
+void virtio_input_init(virtio_input_state_t *vinput);
+
+void virtio_input_update_cursor(uint32_t x, uint32_t y);
+
+void virtio_input_update_key(uint32_t key, uint32_t state);
+#endif /* SEMU_HAS(VIRTIOINPUT) */
+
 /* clint */
 typedef struct {
     uint32_t msip[4096];
@@ -257,6 +313,10 @@ typedef struct {
 #endif
 #if SEMU_HAS(VIRTIOGPU)
     virtio_gpu_state_t vgpu;
+#endif
+#if SEMU_HAS(VIRTIOINPUT)
+    virtio_input_state_t vkeyboard;
+    virtio_input_state_t vmouse;
 #endif
     clint_state_t clint;
 } emu_state_t;
diff --git a/feature.h b/feature.h
@@ -17,5 +17,10 @@
 #define SEMU_FEATUREVIRTIOGPU 1
 #endif
 
+/* virtio-input */
+#ifndef SEMU_FEATUREVIRTIOINPUT
+#define SEMU_FEATUREVIRTIOINPUT 1
+#endif
+
 /* Feature test macro */
 #define SEMU_HAS(x) SEMU_FEATURE_##x
diff --git a/main.c b/main.c
@@ -85,6 +85,28 @@ static void emu_update_vgpu_interrupts(vm_t *vm)
 }
 #endif
 
+#if SEMU_HAS(VIRTIOINPUT)
+static void emu_update_vinput_keyboard_interrupts(vm_t *vm)
+{
+    emu_state_t *data = PRIV(vm->hart[0]);
+    if (data->vkeyboard.InterruptStatus)
+        data->plic.active |= IRQ_VINPUT_KEYBOARD_BIT;
+    else
+        data->plic.active &= ~IRQ_VINPUT_KEYBOARD_BIT;
+    plic_update_interrupts(vm, &data->plic);
+}
+
+static void emu_update_vinput_mouse_interrupts(vm_t *vm)
+{
+    emu_state_t *data = PRIV(vm->hart[0]);
+    if (data->vmouse.InterruptStatus)
+        data->plic.active |= IRQ_VINPUT_MOUSE_BIT;
+    else
+        data->plic.active &= ~IRQ_VINPUT_MOUSE_BIT;
+    plic_update_interrupts(vm, &data->plic);
+}
+#endif
+
 static void emu_update_timer_interrupt(hart_t *hart)
 {
     emu_state_t *data = PRIV(hart);
@@ -139,6 +161,18 @@ static void mem_load(hart_t *hart,
             virtio_gpu_read(hart, &data->vgpu, addr & 0xFFFFF, width, value);
             emu_update_vgpu_interrupts(hart->vm);
             return;
+#endif
+#if SEMU_HAS(VIRTIOINPUT)
+        case 0x45: /* virtio-input keyboard */
+            virtio_input_read(hart, &data->vkeyboard, addr & 0xFFFFF, width,
+                              value);
+            emu_update_vinput_keyboard_interrupts(hart->vm);
+            return;
+        case 0x46: /* virtio-input mouse */
+            virtio_input_read(hart, &data->vmouse, addr & 0xFFFFF, width,
+                              value);
+            emu_update_vinput_mouse_interrupts(hart->vm);
+            return;
 #endif
         }
     }
@@ -190,6 +224,18 @@ static void mem_store(hart_t *hart,
             virtio_gpu_write(hart, &data->vgpu, addr & 0xFFFFF, width, value);
             emu_update_vgpu_interrupts(hart->vm);
             return;
+#endif
+#if SEMU_HAS(VIRTIOINPUT)
+        case 0x45: /* virtio-input */
+            virtio_input_write(hart, &data->vkeyboard, addr & 0xFFFFF, width,
+                               value);
+            emu_update_vinput_keyboard_interrupts(hart->vm);
+            return;
+        case 0x46: /* virtio-input mouse */
+            virtio_input_write(hart, &data->vmouse, addr & 0xFFFFF, width,
+                               value);
+            emu_update_vinput_mouse_interrupts(hart->vm);
+            return;
 #endif
         }
     }
@@ -606,6 +652,13 @@ static int semu_start(int argc, char **argv)
     emu.vblk.ram = emu.ram;
     emu.disk = virtio_blk_init(&(emu.vblk), disk_file);
 #endif
+#if SEMU_HAS(VIRTIOINPUT)
+    emu.vkeyboard.ram = emu.ram;
+    virtio_input_init(&(emu.vkeyboard));
+
+    emu.vmouse.ram = emu.ram;
+    virtio_input_init(&(emu.vmouse));
+#endif
 #if SEMU_HAS(VIRTIOGPU)
     emu.vgpu.ram = emu.ram;
     virtio_gpu_init(&(emu.vgpu));
@@ -639,6 +692,14 @@ static int semu_start(int argc, char **argv)
                 if (emu.vgpu.InterruptStatus)
                     emu_update_vgpu_interrupts(&vm);
 #endif
+
+#if SEMU_HAS(VIRTIOINPUT)
+                if (emu.vkeyboard.InterruptStatus)
+                    emu_update_vinput_keyboard_interrupts(&vm);
+
+                if (emu.vmouse.InterruptStatus)
+                    emu_update_vinput_mouse_interrupts(&vm);
+#endif
             }
 
             emu_update_timer_interrupt(vm.hart[i]);

diff --git a/minimal.dts b/minimal.dts
@@ -72,5 +72,19 @@
             interrupts = <4>;
         };       
 #endif
+
+#if SEMU_FEATURE_VIRTIOINPUT
+        keyboard0: virtio@4500000 {
+            compatible = "virtio,mmio";
+            reg = <0x4500000 0x200>;
+            interrupts = <5>;
+        };
+
+        mouse0: virtio@4600000 {
+            compatible = "virtio,mmio";
+            reg = <0x4600000 0x200>;
+            interrupts = <6>;
+        };
+#endif
     };
 };