This fixes two design flaws in hv_uio_generic.
Since hv_uio_probe is called from vmbus_probe with lock held
it potentially can cause sleep in an atomic section because
vmbus_open will wait for response from host.
The hv_uio_generic driver could not handle applications
exiting and restarting because the vmbus channel was
persistent. Change the semantics so that the buffers are
allocated on probe, but not attached to host until
device is opened.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ring buffer is contiguous IOVA and is mapped via phys addr
for sysfs file. Use same method for the UIO mapping.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Avoid going from struct page to virt address (and back) by just
keeping pointer to the allocated pages instead of virt address.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
DEBUG is leftover from the development phase, remove it.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When using DPDK there is significant performance boost by using
the largest possible send and receive buffer area.
Unfortunately, with UIO model there is not a good way to configure
this at run time. But it is okay to have a bigger buffer available
even if application only decides to use a smaller piece of it.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For those without any license text present or short reference
to GPL, add SPDX tag.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The fault method of handling subchannel ring, did not work correctly
(it only worked for the first page).
Since ring buffer is physically contiguous, using the vm helper
function is simpler and handles more cases.
Fixes: 37b96a4931 ("uio_hv_generic: support sub-channels")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Need to mask the correct sub-channel in the callback from VMBUS
isr. Otherwise, can get in to infinite interrupt storm.
Fixes: 37b96a4931 ("uio_hv_generic: support sub-channels")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The primary channel also needs a ring buffer attribute. This allows
application to check if kernel supports uio sub channels, and also
makes all channels use consistent API.
Fixes: 37b96a4931 ("uio_hv_generic: support sub-channels")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The original code had ring size as a module parameter, but
then it was made a fixed value. The code to set the size of
the ring buffer binary file was lost in the transistion.
The size is needed by user mode driver to know the size of
the ring buffer.
Fixes: 37b96a4931 ("uio_hv_generic: support sub-channels")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use sysfs to allow supporting sub-channels. The userspace application
makes request to host to create sub-channels and the UIO kernel
driver populates the sysfs per-channel directory with a binary
attribute file that can be used to read/write ring.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In commit 72d1465789 ("uio_hv_generic: fix type mismatch warnings"),
I addressed some warnings that show up with CONFIG_X86_PAE, now a new
change has added more of the same:
drivers/uio/uio_hv_generic.c: In function 'hv_uio_probe':
drivers/uio/uio_hv_generic.c:205:5: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
drivers/uio/uio_hv_generic.c:225:5: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
The fix is the same as before, casting to uintptr_t as an intermediate.
Fixes: e7d214642a ("uio_hv_generic: create send and receive buffers")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I moved the virt_to_phys() conversion into hv_uio_probe() as part of
a warning fix. Stephen's cleanup to remove the private mmap() function
seems reasonable, but part of it reverted the change that I did to
hide the warnings, so they are back now:
drivers/uio/uio_hv_generic.c: In function 'hv_uio_probe':
drivers/uio/uio_hv_generic.c:123:5: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
drivers/uio/uio_hv_generic.c:130:5: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
drivers/uio/uio_hv_generic.c:136:5: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
The type mismatch is now the result of the uio_mmap() definition, and
the best way I see from here is to shut them up with a uintptr_t cast.
Fixes: 9c40546c01 ("uio_hv_generic: use standard mmap for resources")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When host rescinds the device, the UIO driver will clear the interrupt
state and notify application. The read (or write) on the interrupt FD
will then fail with -EIO. This is simpler than adding lots extra uevent
stuff inside UIO.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In order for userspace application to signal host, it needs the
host to support the monitor page property. Check for the flag
and fail if this is not supported.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Map in receive and send buffers for networking in UIO device.
These buffers are special and need to be setup by kernel
API's; userspace can not do it.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The UIO IRQ handler doesn't need to be called from a tasklet.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The generic UIO mmap should work for us.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The suggested method for configuration does not work with
current kernels. Paths and ids changed.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change the simple boolean batched_reading into a tri-value.
For future NAPI support in netvsc driver, the callback needs to
occur directly in interrupt handler.
Batched mode is also changed to disable host interrupts immediately
in interrupt routine (to avoid unnecessary host signals), and the
tasklet is rescheduled if more data is detected.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gcc warns about the newly added driver when phys_addr_t is wider than
a pointer:
drivers/uio/uio_hv_generic.c: In function 'hv_uio_mmap':
drivers/uio/uio_hv_generic.c:71:17: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
virt_to_phys((void *)info->mem[mi].addr) >> PAGE_SHIFT,
drivers/uio/uio_hv_generic.c: In function 'hv_uio_probe':
drivers/uio/uio_hv_generic.c:140:5: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
= (phys_addr_t)dev->channel->ringbuffer_pages;
drivers/uio/uio_hv_generic.c:147:3: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
(phys_addr_t)vmbus_connection.int_page;
drivers/uio/uio_hv_generic.c:153:3: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
(phys_addr_t)vmbus_connection.monitor_pages[1];
I can't see why we store a virtual address in a phys_addr_t here,
as the only user of that variable converts it into a physical
address anyway, so this moves the conversion to where it logically
fits according to the types.
Fixes: 95096f2fbd ("uio-hv-generic: new userspace i/o driver for VMBus")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is a new driver to enable userspace networking on VMBus.
It is based largely on the similar driver that already exists
for PCI, and earlier work done by Brocade to support DPDK.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
