OSv can only be built on a 64-bit Linux distribution - otherwise the
compiler will not (by default, at least) generate 64-bit code, and we
won't be able to run the 64-guest needed for building the ZFS filesystem.

Make this requirement explicit in README.md.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

While (unfortunately) C++ doesn't support designated initializers, and the
compiler rejects them, one instance has survived in xenbus.  Strangely,
gcc 4.8.2 generates correct code, while gcc 4.8.0 fails with an internal
compiler error, instead of both of them rejecting the code.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Without this, only even megabytes are accessible, and accesses to odd megabytes
hit the even megabytes.  For example address 0x312345 is aliased to address
0x212345.

Enable the A20 gate to prevent this.

Fixes boot on VMware.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Now that total is long casting to float may cause precision loss.

Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

As pointed out by Tomek, the call to printStackTrace() will already
print out the exception message.

Drop the "uncaught exception" messages to simplify things.

Acked-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

This is useful to notify us that something goes wrong.

Reviewed-by: Tomasz Grabiec <tgrabiec@gmail.com>
Signed-off-by: Asias He <asias@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

bytes_written can overflow while testing on a fast device.

Reviewed-by: Tomasz Grabiec <tgrabiec@gmail.com>
Signed-off-by: Asias He <asias@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Start using tprintf as in drivers/pci.cc, for example, and switch to
'error' severity to disable early boot ACPI messages.

Eventually, core/debug.cc needs to be more dynamically configured but
for now it's good enough to use a standardized API and make the output
silent by default.

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

The uncaught exception handler did not state what the exception is.

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

tst-commands.so and tst-fsx.so were missing.

Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Add additional error patterns to test.py:
1) For tests that are missing. Without it test.py was reporting the
   missing tests as PASSED.
2) For tests that fail with a critical errors like missing symbols.
   Without it the "make check" was hanging silently leaving u dazed
   and confused.
3) For tests that return non-zero status:
       a) Those that use exit().
       b) Those that user return xx.

Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Indicate to the virtual hardware that our stack supports UDP fragmentation
offload.

This improves performance by a factor of about 3.3 (from ~20Gbps to ~66Gbps)
running the netperf UDP STREAM test.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

We reported the size of the last buffer in the packet, rather than the size
of the complete packet.

Fix to report the total size.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

With indirect descriptor, we can queue more buffers in the queue.
Indirect descriptor helps block device by making the large request does
not consume the entire ring and making the queue depth deeper. Indirect
descriptor does not help net device because it makes the queue longer so
it adds latency. The tests show that indirect descriptor makes blk
faster and there is no real measurable degradation on net. Also the
indirect will turn on only when we are short of descriptors.

This patch only enables indirect descriptor for vblk and vscsi. vnet is
not enabled.

1) vblk
Before: 340MB/s
After:  350MB/s

2) vscsi
Before: 320MB/s
After:  410MB/s

Signed-off-by: Asias He <asias@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

VIRTIO_RING_F_INDIRECT_DESC belongs to the base features bits. No need
to specify it in net driver.

Signed-off-by: Asias He <asias@cloudius-systems.com>
Reviewed-by: Dor Laor <dor@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

operate_range() has it already.

Signed-off-by: Gleb Natapov <gleb@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

If permissions are elevated another cpu will fault and will see new
permission after page walk.

Signed-off-by: Gleb Natapov <gleb@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Page cannot be freed before remote tlbs are flushed since if
remote cpu has the page in its tlb and the page is reallocated
for some other purposes remote cpu can still access the page through
tlb and corrupt its content. Think about two threads running on two
different cpus: first one writes to a virtual address constantly and
second unmaps the virtual address. Physical page, virtual address is
mapped to, cannot be freed before both cpus tlb are flushed.

Signed-off-by: Gleb Natapov <gleb@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Add constexpr to make sure they are evaluated in compile time if
possible. Compiler will probably do it anyway though.

Signed-off-by: Gleb Natapov <gleb@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Implement page_mapper variant for virt_to_phys mapping.  map_level class
now hold a reference to page_mapper since page_mapper state needs to be
preserved over function calls.

Signed-off-by: Gleb Natapov <gleb@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

This is pretty straightforward: provide page_mapper variant for each of
those operations, remove unused pt walker.

Signed-off-by: Gleb Natapov <gleb@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

This patch implements generic page table walker that traverse page table
levels in compile time. It accepts page_mapper class, that controls
various aspects of page traversing, as a parameter.  page_table_operation
controls whether non present intermediate page should be allocated,
how to handle leaf small/huge pages, whether to split huge pages, how to
handle sub area of a huge page in case splitting is disabled and whether
walker should loop over multiple page entries.

linear_map_level() is modified to use new page walker.

Signed-off-by: Gleb Natapov <gleb@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Move code that will be needed by unified page walker. No changes to
generated code.

Signed-off-by: Gleb Natapov <gleb@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Backported from FreeBSD r242252.

Improves netperf by about 10%.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

This is more useful if there is no ordering between the two numbers (either
one can be ahead).

Change BYTES_THIS_ACK to return unsigned, to prevent an unsigned division from
turning into a signed division.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Add comparison operators that use modulo arithmetic to order sequence
numbers, and use them to replace SEQ_LT() and friends, increasing code
readability.

As a consequence std::min() and std::max() can be used instead of SEQ_MIN()
and SEQ_MAX().

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

tcp sequence numbers are similar to integers, but have different comparison
operations.  Separate them into a class so we don't mix the two.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

inline functions can be overloaded and are less nasty than macros in other
ways (like evaluating their arguments only once).

Note we can't touch ntohl() itself, since it is defined to be an out-of-line
function by libc.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

This patch fixes two places where tst-mmap.cc doesn't munmap() everything
it mmap()ed. This only makes a difference if doing leak detection on
tst-mmap.cc to see if our page-table handling code leaked memory.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

select() previously returned EINVAL only when nfds > FD_SETSIZE+1. The
right test is nfds > FD_SETSIZE, i.e., for nfds = FD_SETSIZE+1 this is also
an error.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Helps making bsd header changes that xen includes.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

We use sched::thread::attr to pass parameters to sched::thread creation,
i.e., create a thread with non-default stack parameters, pinned to a
particular CPU, or a detached thread.

Previously we had constructors taking many combinations of stack size
(integer), pinned cpu (cpu*) and detached (boolean), and doing "the
right thing". However, this makes the code hard to read (what does
attr(4096) specify?) and the constructors hard to expand with new
parameters.

Replace the attr() constructors with the so-called "named parameter"
idiom: attr now only has a null constructor attr(), and one modifies
it with calls to pin(cpu*), detach(), or stack(size).

For example,
    attr()                                  // default attributes
    attr().pin(sched::cpus[0])              // pin to cpu 0
    attr().stack(4096).pin(sched::cpus[0])  // pin and non-default stack
    and so on.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

This patch applies bugfix published on FreeBSD list at Feb 2013:
http://lists.freebsd.org/pipermail/svn-src-stable-9/2013-February/003928.html



LRO mechanism is broken on systems without IP checksum verification offload.
Due to improper checksum verification RX packets omit LRO path and go
directly to TCP stack which is not good for performance.

EC2 Xen is one example of such a system.
This bug is one of the reasons we see bad performance on Amazon.

Some test results w/ and w/o the fix:

Buffer size    Before         After          Improvement %
TCP TX
32             557.52         1386.28        149
64             552.38         1385.99        151
128            546.43         1401.46        156
256            565.25         1382.28        145
512            557.32         1375.23        147
1024           549.71         1356.69        147
2048           551.11         1371.92        149
4096           556.13         1383.67        149
8192           559.49         1364.05        144
16384          567.25         1366.48        141
32768          546.18         1366.63        150
65536          553.4          1353.87        145

TCP RX
32             107.37         105.48         -2
64             187.56         179.9          -4
128            297.16         301.71         2
256            300.47         503.92         68
512            294.76         826.13         180
1024           299.95         1916.69        539
2048           287.04         1924.44        570
4096           300.78         1929.37        541
8192           304.52         1934.02        535
16384          305.04         1957.54        542
32768          309            1921.84        522
65536          296.48         1935.41        553

Still we are pretty far from Linux, there are other problems to be fixed.

Signed-off-by: Dmitry Fleytman <dmitry@daynix.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

I saw this Abort:

35.159 Mb/s
50.230 Mb/s
46.648 Mb/s
68.850 Mb/s
Wrote 613.418 MB in 10.00 s
Aborted

The backtrace says:

  (gdb) bt
  #0  0x000000000035bb82 in halt_no_interrupts () at
  /home/asias/src/cloudius-systems/osv/arch/x64/processor.hh:241
  #1  osv::halt () at
  /home/asias/src/cloudius-systems/osv/core/power.cc:28
  #2  0x0000000000218142 in abort (msg=msg@entry=0x55197f "Aborted\n") at
  /home/asias/src/cloudius-systems/osv/runtime.cc:89
  #3  0x000000000021816e in abort () at
  /home/asias/src/cloudius-systems/osv/runtime.cc:79
  #4  0x000000000039eaa2 in osv::generate_signal (siginfo=...,
  ef=0xffffc0003eb56008) at
  /home/asias/src/cloudius-systems/osv/libc/signal.cc:58
  #5  0x000000000039eb0c in osv::handle_segmentation_fault
  (addr=<optimized out>, ef=<optimized out>) at
  /home/asias/src/cloudius-systems/osv/libc/signal.cc:73
  #6  0x000000000030b45c in mmu::vm_sigsegv
  (addr=addr@entry=17592186060800, ef=ef@entry=0xffffc0003eb56008) at
  /home/asias/src/cloudius-systems/osv/core/mmu.cc:763
  #7  0x000000000030b54b in mmu::vm_fault (addr=<optimized out>,
  addr@entry=17592186061840, ef=ef@entry=0xffffc0003eb56008)
      at /home/asias/src/cloudius-systems/osv/core/mmu.cc:773
  #8  0x000000000032bff5 in page_fault (ef=0xffffc0003eb56008) at
  /home/asias/src/cloudius-systems/osv/arch/x64/mmu.cc:35
  #9  <signal handler called>
  #10 0x0000100000004410 in ?? ()
  #11 0x000000000031e5fd in virtio::blk::req_done
  (this=0xffffc0003eddb800) at
  /home/asias/src/cloudius-systems/osv/drivers/virtio-blk.

Wait until all the bio are done to fix this use after free.

This patch also make the test to measure completed writes instead of
submitted writes.

Reviewed-by: Tomasz Grabiec <tgrabiec@gmail.com>
Signed-off-by: Asias He <asias@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

We were missing the prerequisite qemu-img (needed for qemu-nbd, used
during our build) and of course qemu-system-x86 (we run the guest as
part of the build, to have it write files into the ZFS image).

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>