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-rw-r--r--tools/src/hv_virtio.c308
1 files changed, 308 insertions, 0 deletions
diff --git a/tools/src/hv_virtio.c b/tools/src/hv_virtio.c
new file mode 100644
index 0000000..abe4582
--- /dev/null
+++ b/tools/src/hv_virtio.c
@@ -0,0 +1,308 @@
+/* SPDX-License-Identifier: MIT */
+
+#include "hv.h"
+#include "aic.h"
+#include "iodev.h"
+#include "malloc.h"
+
+#define MAGIC 0x000
+#define VERSION 0x004
+#define DEVID 0x008
+#define VENDID 0x00c
+#define FEAT_HOST 0x010
+#define FEAT_HOST_SEL 0x014
+#define FEAT_GUEST 0x020
+#define FEAT_GUEST_SEL 0x024
+
+#define QSEL 0x030
+#define QMAX 0x034
+#define QSIZE 0x038
+#define QREADY 0x044
+#define QNOTIFY 0x050
+
+#define QDESC 0x080
+#define QGUESTAREA 0x090
+#define QHOSTAREA 0x0a0
+
+#define IRQ_STATUS 0x060
+#define USED_BUFFER BIT(0)
+#define CFG_CHANGE BIT(1)
+#define IRQ_ACK 0x064
+#define DEV_STATUS 0x070
+
+#define DESC_NEXT BIT(0)
+#define DESC_WRITE BIT(1)
+
+struct availring {
+ u16 flags;
+ u16 idx;
+ u16 ring[];
+};
+
+struct usedring {
+ u16 flags;
+ u16 idx;
+ struct {
+ u32 id;
+ u32 len;
+ } ring[];
+};
+
+struct desc {
+ u64 addr;
+ u32 len;
+ u16 flags;
+ u16 id;
+};
+
+struct virtio_q {
+ struct virtio_dev *host;
+ int idx;
+ u32 max;
+ u32 size;
+ bool ready;
+ struct desc *desc;
+
+ u16 avail_seen;
+ struct availring *avail;
+ struct usedring *used;
+
+ u64 area_regs[(QHOSTAREA + 8 - QDESC) / 4];
+};
+
+struct virtio_conf {
+ s32 irq;
+ u32 devid;
+ u64 feats;
+ u32 num_qus;
+ void *config;
+ u64 config_len;
+ u8 verbose;
+} PACKED;
+
+struct virtio_dev {
+ struct virtio_dev *next;
+ u64 base;
+ int irq;
+ int num_qus;
+ u32 devid;
+ u64 feats;
+ uint8_t *config;
+ size_t config_len;
+ bool verbose;
+
+ u32 feat_host_sel;
+ u32 status;
+ u32 irqstatus;
+
+ struct virtio_q *currq;
+ struct virtio_q qs[];
+};
+
+static struct virtio_dev *devlist;
+
+static void notify_avail(struct exc_info *ctx, struct virtio_q *q, int idx)
+{
+ struct desc *d = &q->desc[idx];
+ struct {
+ u64 devbase;
+ u16 qu;
+ u16 idx;
+ u32 pad;
+ u64 descbase;
+ } PACKED info = {
+ q->host->base, q->idx, idx, 0, (u64)q->desc,
+ };
+
+ if (q->host->verbose)
+ printf("virtio @ %lx: available %s buffer at %lx, size %x, flags %x\n", q->host->base,
+ (d->flags & DESC_WRITE) ? "device" : "driver", d->addr, d->len, d->flags);
+
+ hv_exc_proxy(ctx, START_HV, HV_VIRTIO, &info);
+}
+
+static void notify_buffers(struct exc_info *ctx, struct virtio_dev *dev, u32 qidx)
+{
+ struct virtio_q *q = &dev->qs[qidx];
+ struct availring *avail = q->avail;
+
+ if (qidx >= (u32)dev->num_qus)
+ return;
+
+ for (; avail->idx != q->avail_seen; q->avail_seen++)
+ notify_avail(ctx, q, avail->ring[q->avail_seen % q->size]);
+}
+
+static struct virtio_dev *dev_by_base(u64 base)
+{
+ struct virtio_dev *dev;
+
+ for (dev = devlist; dev; dev = dev->next)
+ if (dev->base == base)
+ break;
+
+ return dev;
+}
+
+void virtio_put_buffer(u64 base, int qu, u32 id, u32 len)
+{
+ struct virtio_dev *dev = dev_by_base(base);
+ struct virtio_q *q;
+ struct usedring *used;
+
+ if (!dev) {
+ printf("virtio_put_buffer: no device at %lx\n", base);
+ return;
+ }
+
+ q = &dev->qs[qu];
+ used = q->used;
+
+ used->ring[used->idx % q->size].id = id;
+ used->ring[used->idx % q->size].len = len;
+ used->idx++;
+
+ dev->irqstatus |= USED_BUFFER;
+ aic_set_sw(dev->irq, true);
+}
+
+static bool handle_virtio(struct exc_info *ctx, u64 addr, u64 *val, bool write, int width)
+{
+ struct virtio_dev *dev;
+ struct virtio_q *q;
+ UNUSED(ctx);
+ UNUSED(width);
+
+ dev = dev_by_base(addr & ~0xfff);
+ if (!dev)
+ return false;
+
+ addr &= 0xfff;
+
+ if (write) {
+ if (dev->verbose)
+ printf("virtio @ %lx: W 0x%lx <- 0x%lx (%d)\n", dev->base, addr, *val, width);
+
+ switch (addr) {
+ case DEV_STATUS:
+ dev->status = *val;
+ break;
+ case QSEL:
+ if (((int)*val) <= dev->num_qus)
+ dev->currq = &dev->qs[*val];
+ else
+ dev->currq = NULL;
+ break;
+ case QNOTIFY:
+ notify_buffers(ctx, dev, *val);
+ break;
+ case FEAT_HOST_SEL:
+ dev->feat_host_sel = *val;
+ break;
+ case IRQ_ACK:
+ dev->irqstatus &= ~(*val);
+ if (!dev->irqstatus)
+ aic_set_sw(dev->irq, false);
+ break;
+ }
+
+ q = dev->currq;
+ if (!q)
+ return true;
+
+ switch (addr) {
+ case QSIZE:
+ q->size = *val;
+ break;
+ case QREADY:
+ q->ready = *val & 1;
+ break;
+ case QDESC ... QHOSTAREA + 4:
+ addr -= QDESC;
+ addr /= 4;
+ q->area_regs[addr] = *val;
+
+ q->desc = (void *)(q->area_regs[1] << 32 | q->area_regs[0]);
+ q->avail = (void *)(q->area_regs[5] << 32 | q->area_regs[4]);
+ q->used = (void *)(q->area_regs[9] << 32 | q->area_regs[8]);
+ break;
+ }
+ } else {
+ switch (addr) {
+ case MAGIC:
+ *val = 0x74726976;
+ break;
+ case VERSION:
+ *val = 2;
+ break;
+ case DEVID:
+ *val = dev->devid;
+ break;
+ case DEV_STATUS:
+ *val = dev->status;
+ break;
+ case FEAT_HOST:
+ *val = dev->feats >> (dev->feat_host_sel * 32);
+ break;
+ case IRQ_STATUS:
+ *val = dev->irqstatus;
+ break;
+ case 0x100 ... 0x1000:
+ if (addr - 0x100 < dev->config_len)
+ *val = dev->config[addr - 0x100];
+ else
+ *val = 0;
+ break;
+ default:
+ q = dev->currq;
+ if (!q) {
+ *val = 0;
+ goto rdone;
+ }
+ }
+
+ switch (addr) {
+ case QMAX:
+ *val = q->max;
+ break;
+ case QREADY:
+ *val = q->ready;
+ break;
+ }
+ rdone:
+ if (dev->verbose)
+ printf("virtio @ %lx: R 0x%lx -> 0x%lx (%d)\n", dev->base, addr, *val, width);
+ };
+
+ return true;
+}
+
+void hv_map_virtio(u64 base, struct virtio_conf *conf)
+{
+ struct virtio_dev *dev;
+ int i;
+
+ dev = malloc(sizeof(*dev) + sizeof(struct virtio_q) * conf->num_qus);
+ dev->num_qus = conf->num_qus;
+ dev->base = base;
+ dev->irq = conf->irq;
+ dev->devid = conf->devid;
+ dev->currq = NULL;
+ dev->feats = conf->feats | BIT(32); /* always set: VIRTIO_F_VERSION_1 */
+ dev->config = conf->config;
+ dev->config_len = conf->config_len;
+ dev->verbose = conf->verbose;
+ for (i = 0; i < dev->num_qus; i++) {
+ dev->qs[i].host = dev;
+ dev->qs[i].idx = i;
+ dev->qs[i].max = 256;
+ dev->qs[i].avail_seen = 0;
+ dev->qs[i].ready = 0;
+ }
+
+ if (devlist)
+ dev->next = devlist;
+ devlist = dev;
+
+ hv_map_hook(base, handle_virtio, 0x1000);
+}
generated by cgit v1.2.1 (git 2.18.0) at 2026-01-14 08:52:08 +0000