Re: fs-backend on -unstable

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

Jody Belka wrote:

> Now, the stub domain isn't actually working for me anyway, even on
> non-pvops0, but it is able to talk to the fs-backend at least. To show
> what that looks like, I've attached a couple of emails I sent off-list.



There are some known issues that affect stubdoms at the moment, since
they involve some changes made on qemu upstream I am trying to find a
solution there.

However if you want to test the latest stubdoms you can try this patch,
it works for me.

---

diff --git a/hw/ide.c b/hw/ide.c
index 7031ba1..a97c78b 100644
--- a/hw/ide.c
+++ b/hw/ide.c
@@ -1056,10 +1056,11 @@ static int dma_buf_prepare(BMDMAState *bm, int is_write)
         uint32_t addr;
         uint32_t size;
     } prd;
-    int l, len;
+    int l, len, n;
     void *mem;
     target_phys_addr_t l1;
 
+    n = s->nsector <= IDE_DMA_BUF_SECTORS ? s->nsector : IDE_DMA_BUF_SECTORS;
     qemu_iovec_init(&s->iovec, s->nsector / (TARGET_PAGE_SIZE/512) + 1);
     s->io_buffer_size = 0;
     for(;;) {
@@ -1082,6 +1083,13 @@ static int dma_buf_prepare(BMDMAState *bm, int is_write)
         l = bm->cur_prd_len;
         if (l > 0) {
             l1 = l;
+            if (l1 > IDE_DMA_BUF_SECTORS * 512)
+                l1 = IDE_DMA_BUF_SECTORS * 512;
+            if (s->io_buffer_size + l1 > IDE_DMA_BUF_SECTORS * 512) {
+                l1 = IDE_DMA_BUF_SECTORS * 512 - s->io_buffer_size;
+                if (!l1)
+                    return s->io_buffer_size != 0;
+            }
             mem = cpu_physical_memory_map(bm->cur_prd_addr, &l1, is_write);
             if (!mem) {
                 break;
@@ -1263,6 +1271,8 @@ static void ide_read_dma_cb(void *opaque, int ret)
 
     /* launch next transfer */
     n = s->nsector;
+    if (n > IDE_DMA_BUF_SECTORS)
+        n = IDE_DMA_BUF_SECTORS;
     s->io_buffer_index = 0;
     s->io_buffer_size = n * 512;
     if (dma_buf_prepare(bm, 1) == 0)
@@ -1412,6 +1422,8 @@ static void ide_write_dma_cb(void *opaque, int ret)
     }
 
     n = s->nsector;
+    if (n > IDE_DMA_BUF_SECTORS)
+        n = IDE_DMA_BUF_SECTORS;
     s->io_buffer_size = n * 512;
     /* launch next transfer */
     if (dma_buf_prepare(bm, 0) == 0)