Hello,
I am trying to connect at least 33 block devices via Qemu to
HelenOS, but there are multiple problems:
pci-ide: not enough devices supported
virtio-blk: possible, but currently having some perf issues [A]
usb-mass-storage: possible, but too slow
ahci: not working [B]
[A] virtio-blk:
In my previous mail I proposed a speedup to virtio-blk, the problem is,
that even though there is an expected speedup of up to 120x when writing
due to processing multiple blocks in one request, now every request, even
with 1 block takes the same amount of time as using the full bandwidth.
Why could that be?
[B] AHCI not working:
setup: relevant qemu arguments:
qemu-system-x86_64 \
[...]
-device ahci,id=ahci0 \
-drive file=/dev/sde,if=none,id=drive0 \
-device ide-hd,drive=drive0,bus=ahci0.0
1. there is a null deref always triggered in:
`uspace/drv/block/ahci/ahci.c::ahci_sata_create()`
fix:
diff --git a/uspace/drv/block/ahci/ahci.c b/uspace/drv/block/ahci/ahci.c
index acd9cd56e..26820bdb9 100644
--- a/uspace/drv/block/ahci/ahci.c
+++ b/uspace/drv/block/ahci/ahci.c
@@ -1074,6 +1074,8 @@ static errno_t ahci_sata_create(ahci_dev_t *ahci,
ddf_dev_t *dev,
goto error;
}
+ fun = sata->fun;
+
ddf_fun_set_ops(fun, &ahci_ops);
rc = ddf_fun_bind(fun);
2. even after fixing this, it still doesn't work. After starting /srv/bd/sata_bd
the server successfully finds the drv and opens a bd interface at bd/ahci_0,
but when trying to read from it: `blkdump bd/ahci_0`, the server crashes.
I think it is at
https://github.com/HelenOS/helenos/blob/master/uspace/lib/drv/generic/remote_ahci.c#L159
because this assertion triggers the crash:
[/srv/bd/sata_bd(40)] Assertion failed (area->magic == 0xBEEFCAFEU) in task 40,
file "../../helenraid/uspace/lib/c/generic/malloc.c", line 283.
which is called in free() in async_wait_for().
Also I have vbd server turned off as it was crashing the device right away,
I wanted to
manually crash it with blkdump, but its the same.
Are there other ways to connect at least 33 block devices via Qemu to HelenOS?
I will greatly appreciate any help with this.
--
Miroslav Cimerman
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