The block layer may signal an immediate error on an asynchronous request
by returning NULL. The DMA API did not handle this correctly, returning
an AIO request which would never complete (and which would crash if
cancelled).
Fix by detecting the failure and propagating it.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6893 c046a42c-6fe2-441c-8c8c-71466251a162
Use the dedicated dma aiocb to store intermediate state for dma block
transactions.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6874 c046a42c-6fe2-441c-8c8c-71466251a162
Move the dma helpers to a private aio pool, and implement a cancellation
method for them. Should prevent issues when cancelling I/O while dma is
in progress.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6872 c046a42c-6fe2-441c-8c8c-71466251a162
These helpers perform read/write requests on entire scatter/gather lists,
relieving the device emulation code from mapping and unmapping physical
memory, and from looping when map resources are exhausted.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6524 c046a42c-6fe2-441c-8c8c-71466251a162
Scatter-gather lists are used extensively in dma-capable devices; a
single data structure allows more code reuse later on.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6522 c046a42c-6fe2-441c-8c8c-71466251a162
