This commit supplements the various I/O signal handlers of the VFS
plugins with calls of the new 'Vfs::Env::User::wakeup_vfs_user'
interface, which will subsequently replace the old 'Io_progress_handler'
(issue #4697).
Issue #4706
The 'blocked_handles' queue was used to notify the VFS user via the
'io_progress_response' mechanism. This is now covered by the
'wakeup_vfs_user' interface introduced in issue #4697.
Issue #4706
Information about PS/2 and PIT where moved to app/pci_decode in the
following commit.
pci_decode: report devices from ACPI info
We still provide an empty <devices> node as the file itself is used by
platform agnostic run scripts.
When running on x86, and riscv never enter the kernel for cache maintainance,
but use the dummy implementation of the generic base library instead.
On ARMv8 it is not necessary to enter privileged mode for cache cleaning, and
unification of instruction/data cache, but only for invalidating cache lines
at all levels, which is necessary for the use cases, where this function it
needed (coherency of DMA memory).
Fixgenodelabs/genode#4339
This call is used to query the cache line size of the underlying CPU.
For now it is only implemented and used by 'arm_v8' platforms.
It does not distinguish between D-/I-cache sizes and always uses the
smallest size. Furthermore it does not account for any discrepancy
in 'big.little' CPUs.
Issue #4339.
To prevent the kernel to deadlock, or call itself with a syscall when
using a lock potentially hold by a core thread, the log console's
backend for core (hw) gets replaced by a specific variant that checks
whether it runs in the kernel context before using the mutex.
Fixgenodelabs/genode#3280
When a domain receives a new dynamic router IP address and that domain has
active connection states (TCP/UDP/ICMP) from another domain with NAT applied,
the connection states used to stay active while becoming obsolete. They
become obsolete because their identification and their packet processor
use the old routers IP address due to NAT.
One consequence was that connections became dysfunctional when the server
domain received a new dynamic router IP address. Request packets were still
routed from client to server, but when entering the server, their source IP
address was the outdated router address. Consequently, the server responses
used the outdated address as destination and the router dropped the responses
because it did not know this address anymore.
This commit fixes the problem by letting a domain destroy all its connection
states that were initiated from within other domains whenever it detaches from
its current IP configuration.
Strictly speaking, it is not necessary to destroy all connection states, only
those that the domain applies NAT to. However, the Genode AVL tree is not built
for removing a selection of nodes and trying to do it anyways is complicated.
So, for now, we simply destroy all connection states.
Note that the other way around was handled correctly already. When a domain
detaches from its IP config, all interfaces of that domain destroy all the
connection states they created (towards other domains).
Fixes#4696
If the IP config does not change on updates to the router IP config of a domain
change (a common case on DHCP RENEW), prevent detaching from the old config and
attaching to the new one. Because this would not only create unnecessary CPU
overhead but also force all clients at all interfaces that are listening to
this config (via config attribute 'dns_config_from') to restart their
networking (re-do DHCP).
Ref #4696
Check 'pv == nullptr' in 'ShClSvcImplWriteData' and return
VERR_INVALID_POINTER if invalid (as is done, for example, in the X11
implementation).
issue #4666
By adding a 'write_ready' interface following the lines of the existing
'read_ready', VFS plugins become able to propagate the (de-)saturation
of I/O buffers to the VFS user. This information is important when using
a non-blocking file descriptor for writing into a TCP socket. Once the
application observes EAGAIN, it expects a subsequent 'select' call to
return as soon as new I/O buffer space becomes available.
Before this patch, the select call would always return under this
condition, causing an unnecessarily busy write loop.
Issue #4697
The new interface is meant to replace the 'Vfs::Io_response_handler'.
In contrast to the 'Io_response_handler', which had to be called
on a 'Vfs_handle', the new interface does not require any specific
'Vfs_handle'. It is merely meant to prompt the VFS user (like the libc)
to re-attempt stalled I/O operations but it does not provide any
immediate hint, about which of the handles have become ready for
reading/writing.
Issue #4697
This patch removes the 'Insufficient_buffer' exception by returning the
WRITE_ERR_WOULD_BLOCK result value instead. It also eliminates the
superfluous WRITE_ERR_AGAIN and WRITE_ERR_INTERRUPT codes.
Issue #4697
The original size of 16K impedes the batched processing of network
packets. Changing the value to 256K reduces the number of context
switches when downloading large files and thereby improves the
throughput by more than 25% (base-hw on qemu_x86_64, using fetchurl
to download a file of 100 MiB via the NIC router from lighttpd).
Issue #4697
This patch fosters the batching of network packets transferred by the
lwIP stack over the NIC connection. It replaces the eager submission of
the packet-stream's data-flow signals by explicit wakeup notifications.
The commit also increases the NIC session's buffer size from 128 to 1024
packets.
Issue #4697
...and tighten constness in adjacent code parts.
The VFS-internal synchronization via mutexes is no longer needed because
the access to the VFS is serialized by the VFS client, i.e., the libc.
Issue #4697
Since the lwip library is used only by the vfs_lwip plugin, this patch
moves the Genode-specific support code local to the VFS plugin, easing
further simplification and allowing for a tighter integration with the
VFS plugin.
The recipes for api/lwip and src/vfs_lwip stay separate as both parts
use different licenses.
Issue #4697
This networking scenario is useful for analysing and optimizing the
interplay of the VFS, libc, TCP/IP, and the NIC router. It downloads a
file via fetchurl from lighttpd, both of which are hosted on a virtual
network.
Issue #4697
This patch facilitates the batching of I/O operations in the VFS library
by replacing the implicit wakeup of remote peer (via the traditional
packet-stream interface like 'submit_packet') by explicit wakeup
signalling.
The wakeup signalling is triggered not before the VFS user settles down.
E.g., for libc-based applications, this is the case if the libc goes
idle, waiting for external I/O.
In the case of a busy writer to a non-blocking file descriptor or socket
(e.g., lighttpd), the remote peers are woken up once a write operation
yields an out-count of 0.
The deferring of wakeup signals is accommodated by the new 'Remote_io'
mechanism (vfs/remote_io.h) that is designated to be used by all VFS
plugins that interact with asynchronous Genode services for I/O.
Issue #4697
This test reveals the patters of the batching of consecutive write
operations on a file-system session. It issues 100 writes of one byte
each, which should ideally result in large batches of operations
submitted to the file-system session at once.
The run script performs the write operations through a chain of two VFS
servers, thereby exercising the write batching of both the libc and the
intermediate VFS server.
Issue #4697
