We have to set the cssid to 0, otherwise the stsch code will
return an operand exception without the m bit. In the same way
we should set m=0.
This case was triggered in some cases during reboot, if for some
reason the location of blk_schid.cssid contains 1 and m was 0.
Turns out that the qemu elf loader does not zero out the bss section
on reboot.
The symptom was an dump of the old kernel with several areas
overwritten. The bootloader does not register a program check
handler, so bios exception jumped back into the old kernel.
Lets just use a local struct with a designed initializer. That
will guarantee that all other subelements are initialized to 0.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
The current code does not initialize next_idx in the virtio ring.
As the ccw bios will always use guest memory at a fixed location,
this queue might != 0 after a reboot.
Lets make the initialization explicit.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
The guest side must not manipulate the index for the used buffers. Instead,
remember the state of the used buffer locally and wait until it has moved.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
We now take the subchannel set id also into account to find the boot device.
If we want to use a subchannel set other than the default set 0, we first
need to enable the mss facility.
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
With the ccw ipl code sometimes an error message like
"virtio: trying to map MMIO memory" or
"Guest moved used index from %u to %u" appeared. Turns out
that the ccw bios did not zero out the vring, which might
cause stale values in avail->idx and friends, especially
on reboot.
Lets zero out the relevant fields. To activate the patch we
need to rebuild s390-ccw.img as well.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1369309901-418-1-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Use the passed device, if there is no device, use the first applicable device.
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Ask the host about the configuration instead of guessing it.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Try to handle at least some of the errors that may happen.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
- Use tpi + tsch to get interrupts.
- Return an error if the irb indicates problems.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
stsch is the canonical way to detect devices. As a bonus, we can
abort the loop if we get cc 3, and we need to check only the valid
devices (dnv set).
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Lets fix this gcc warning:
virtio.c: In function ‘vring_send_buf’:
virtio.c:125:35: error: operation on ‘vr->next_idx’ may be undefined
[-Werror=sequence-point]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
We have to call strip with s390-ccw.elf as input and
s390-ccw.img as output
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
dont waste cpu power on an error condition. Lets stop the guest
with a disabled wait.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This patch adds a makefile, so we can build our ccw firmware. Also
add the resulting binaries to .gitignore, so that nobody is annoyed
they might be in the tree.
Signed-off-by: Alexander Graf <agraf@suse.de>
On s390, there is an architected boot map format that we can read to
boot a certain entry off the disk. Implement a simple reader for this
that always boots the first (default) entry.
Signed-off-by: Alexander Graf <agraf@suse.de>
Like all great programs, we have to call between different functions in
different object files. And all of them need a common ground of defines.
Provide a file that provides these defines.
Signed-off-by: Alexander Graf <agraf@suse.de>
In order to boot, we need to be able to access a virtio-blk device through
the CCW bus. Implement support for this.
Signed-off-by: Alexander Graf <agraf@suse.de>
In order to communicate with the user, we need an I/O mechanism that he
can read. Implement SCLP ASCII support, which happens to be the default
in the s390 ccw machine.
This file is missing read support for now. It can only print messages.
Signed-off-by: Alexander Graf <agraf@suse.de>
This C file is the main driving piece of the s390 ccw firmware. It
provides a search for a workable block device, sets it as the default
to boot off of and boots from it.
Signed-off-by: Alexander Graf <agraf@suse.de>
We want to write most of our code in C, so add a small assembly
stub that jumps straight into C code for us to continue booting.
Signed-off-by: Alexander Graf <agraf@suse.de>
