[dev][virtio] add no kernel VM workaround

Also add stride to the mmio detect routine. Not all virtio apertures are
tightly packed as they are on arm.

dev/virtio/block/virtio-block.c

@@ -7,6 +7,7 @@
  */
 #include <dev/virtio/block.h>
 
+#include <stdlib.h>
 #include <lk/debug.h>
 #include <assert.h>
 #include <lk/trace.h>
@@ -16,9 +17,12 @@
 #include <kernel/thread.h>
 #include <kernel/event.h>
 #include <kernel/mutex.h>
-#include <kernel/vm.h>
 #include <lib/bio.h>
 
+#if WITH_KERNEL_VM
+#include <kernel/vm.h>
+#endif
+
 #define LOCAL_TRACE 0
 
 struct virtio_blk_config {
@@ -98,7 +102,7 @@ status_t virtio_block_init(struct virtio_device *dev, uint32_t host_features) {
 #if WITH_KERNEL_VM
     bdev->blk_req_phys = vaddr_to_paddr(bdev->blk_req);
 #else
-    bdev->blk_freq_phys = (uint64_t)(uintptr_t)bdev->blk_req;
+    bdev->blk_req_phys = (uint64_t)(uintptr_t)bdev->blk_req;
 #endif
     LTRACEF("blk_req structure at %p (0x%lx phys)\n", bdev->blk_req, bdev->blk_req_phys);
 
@@ -189,8 +193,6 @@ ssize_t virtio_block_read_write(struct virtio_device *dev, void *buf, off_t offs
 
     uint16_t i;
     struct vring_desc *desc;
-    paddr_t pa;
-    vaddr_t va = (vaddr_t)buf;
 
     LTRACEF("dev %p, buf %p, offset 0x%llx, len %zu\n", dev, buf, offset, len);
 
@@ -219,7 +221,8 @@ ssize_t virtio_block_read_write(struct virtio_device *dev, void *buf, off_t offs
     desc = virtio_desc_index_to_desc(dev, 0, desc->next);
 #if WITH_KERNEL_VM
     /* translate the first buffer */
-    pa = vaddr_to_paddr((void *)va);
+    vaddr_t va = (vaddr_t)buf;
+    paddr_t pa = vaddr_to_paddr((void *)va);
     desc->addr = (uint64_t)pa;
     /* desc->len is filled in below */
 #else

dev/virtio/gpu/virtio-gpu.c

@@ -7,6 +7,7 @@
  */
 #include <dev/virtio/gpu.h>
 
+#include <stdlib.h>
 #include <lk/debug.h>
 #include <assert.h>
 #include <lk/trace.h>
@@ -17,9 +18,12 @@
 #include <kernel/thread.h>
 #include <kernel/event.h>
 #include <kernel/mutex.h>
-#include <kernel/vm.h>
 #include <dev/display.h>
 
+#if WITH_KERNEL_VM
+#include <kernel/vm.h>
+#endif
+
 #include "virtio_gpu.h"
 
 #define LOCAL_TRACE 0
@@ -208,7 +212,11 @@ static status_t attach_backing(struct virtio_gpu_dev *gdev, uint32_t resource_id
     req.req.nr_entries = 1;
 
     paddr_t pa;
+#if WITH_KERNEL_VM
     pa = vaddr_to_paddr(ptr);
+#else
+    pa = (paddr_t)ptr;
+#endif
     req.mem.addr = pa;
     req.mem.length = buf_len;
 
@@ -356,7 +364,11 @@ status_t virtio_gpu_start(struct virtio_device *dev) {
 
     /* attach a backing store to the resource */
     size_t len = gdev->pmode.r.width * gdev->pmode.r.height * 4;
+#if WITH_KERNEL_VM
     gdev->fb = pmm_alloc_kpages(ROUNDUP(len, PAGE_SIZE) / PAGE_SIZE, NULL);
+#else
+    gdev->fb = memalign(PAGE_SIZE, ROUNDUP(len, PAGE_SIZE));
+#endif
     if (!gdev->fb) {
         TRACEF("failed to allocate framebuffer, wanted 0x%zx bytes\n", len);
         return ERR_NO_MEMORY;

dev/virtio/include/dev/virtio.h

@@ -15,7 +15,7 @@
 
 /* detect a virtio mmio hardware block
  * returns number of devices found */
-int virtio_mmio_detect(void *ptr, uint count, const uint irqs[]);
+int virtio_mmio_detect(void *ptr, uint count, const uint irqs[], size_t stride);
 
 #define MAX_VIRTIO_RINGS 4
 

dev/virtio/net/virtio-net.c

@@ -7,6 +7,7 @@
  */
 #include <dev/virtio/net.h>
 
+#include <stdlib.h>
 #include <lk/debug.h>
 #include <assert.h>
 #include <lk/trace.h>
@@ -17,7 +18,6 @@
 #include <kernel/thread.h>
 #include <kernel/event.h>
 #include <kernel/spinlock.h>
-#include <kernel/vm.h>
 #include <lib/pktbuf.h>
 #include <lib/minip.h>
 

dev/virtio/virtio.c

@@ -19,8 +19,10 @@
 #include <lk/pow2.h>
 #include <lk/init.h>
 #include <kernel/thread.h>
-#include <kernel/vm.h>
 #include <platform/interrupts.h>
+#if WITH_KERNEL_VM
+#include <kernel/vm.h>
+#endif
 
 #include "virtio_priv.h"
 
@@ -109,7 +111,7 @@ static enum handler_return virtio_mmio_irq(void *arg) {
     return ret;
 }
 
-int virtio_mmio_detect(void *ptr, uint count, const uint irqs[]) {
+int virtio_mmio_detect(void *ptr, uint count, const uint irqs[], size_t stride) {
     LTRACEF("ptr %p, count %u\n", ptr, count);
 
     DEBUG_ASSERT(ptr);
@@ -123,7 +125,7 @@ int virtio_mmio_detect(void *ptr, uint count, const uint irqs[]) {
 
     int found = 0;
     for (uint i = 0; i < count; i++) {
-        volatile struct virtio_mmio_config *mmio = (struct virtio_mmio_config *)((uint8_t *)ptr + i * 0x200);
+        volatile struct virtio_mmio_config *mmio = (struct virtio_mmio_config *)((uint8_t *)ptr + i * stride);
         struct virtio_device *dev = &devices[i];
 
         dev->index = i;
@@ -132,8 +134,8 @@ int virtio_mmio_detect(void *ptr, uint count, const uint irqs[]) {
         mask_interrupt(irqs[i]);
         register_int_handler(irqs[i], &virtio_mmio_irq, (void *)dev);
 
-        LTRACEF("looking at magic 0x%x version 0x%x did 0x%x vid 0x%x\n",
-                mmio->magic, mmio->version, mmio->device_id, mmio->vendor_id);
+        LTRACEF("looking at %p: magic 0x%x version 0x%x did 0x%x vid 0x%x\n",
+                mmio, mmio->magic, mmio->version, mmio->device_id, mmio->vendor_id);
 
         if (mmio->magic != VIRTIO_MMIO_MAGIC) {
             continue;
@@ -283,7 +285,7 @@ void virtio_submit_chain(struct virtio_device *dev, uint ring_index, uint16_t de
     struct vring_avail *avail = dev->ring[ring_index].avail;
 
     avail->ring[avail->idx & dev->ring[ring_index].num_mask] = desc_index;
-    DSB;
+    mb();
     avail->idx++;
 
 #if LOCAL_TRACE
@@ -295,7 +297,7 @@ void virtio_kick(struct virtio_device *dev, uint ring_index) {
     LTRACEF("dev %p, ring %u\n", dev, ring_index);
 
     dev->mmio_config->queue_notify = ring_index;
-    DSB;
+    mb();
 }
 
 status_t virtio_alloc_ring(struct virtio_device *dev, uint index, uint16_t len) {