When KVM paravirtual clock isn't available (e.g., on Xen or on plain Qemu),
we used the HPET clock. Our HPET clock driver rolled back the clock
(clock::get()->time()) once every 42 seconds, causing strange things like
a scheduler assertion when the clock jumps back.

The problem is that we read just 32 bits out of the 64 bits of the HPET
counter. This means that we roll back the clock once every 2^32 ticks,
and with the 10ns tick (which seems to be case in Qemu), this means about
42 seconds.

Douglas Adams would have liked this bug ;-)

Fixed the code, and removed overly-optimistic comment which stated the
rollback should take years.

Added an assertion that the HPET really has a 64-bit counter; Intel's HPET
specification from 2004 already specify that a 64-bit counter is recommended,
and both Qemu and Xen do implement a 64-bit counter. If we had to deal
with a 32-bit counter, we would need to write a handler for the interrupt
that the HPET sends every time the counter wraps around.

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

Add a new virtio::probe() helper function to simplify virtio driver
probing.

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

This patch causes incorrect usage of percpu<>/PERCPU() to cause
compilation errors instead of silent runtime corruptions.

Thanks to Dmitry for first noticing this issue in xen_intr.cc (see his
separate patch), and to Avi for suggesting a compile-time fix.

With this patch:

1. Using percpu<...> to *define* a per-cpu variable fails compilation.
   Instead, PERCPU(...) must be used for the definition, which is important
   because it places the variable in the ".percpu" section.

2. If a *declaration* is needed additionally (e.g., for a static class
   member), percpu<...> must be used, not PERCPU().
   Trying to use PERCPU() for declaration will cause a compilation error.

3. PERCPU() only works on statically-constructed objects - global variables,
   static function-variables and static class-members. Trying to use it
   on a dynamically-constructed object - stack variable, class field,
   or operator new - will cause a compilation error.

With this patch, the bug in xen_intr.cc would have been caught at
compile time.

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

prio.hh defines various initialization priorities. The actual numbers
don't matter, just the order between them. But when we add too many
priorities between existing ones, we may hit a need to renumber. This
is plain ugly, and reminds me of Basic programming ;-)

So this patch switches to an enum (enum class, actually).
We now just have a list of priority names in order, with no numbers.

It would have been straightforward, if it weren't for a bug in GCC
(see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59211

) where the
"init_priority" attribute doesn't accept the enum (while the "constructor"
attribute does). Luckily, a simple workaround - explicitly casting to
int - works.

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

condvar_wait() expects an absolute time, not a duration.

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

Add the explanation by Avi Kivity to AcpiOsUnmapMemory() to explain why
it's a no-op.

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

Due to incorrect mapping logic ACPI tables longer than PAGE_SIZE
mapped partially and to wrong base address. As a result system crashed
on ACPI tables checksum verification.

Found when running on EC2 HVM instances, the problematic table was:
ACPI: DSDT 0xfc002c40 0321F (v02    Xen      HVM 00000000 INTL 20090220)

Signed-off-by: Dmitry Fleytman <dmitry@daynix.com>

Use the initialization sequence specified in 10.1.2.2 ("ACPICA
Initialization With Early ACPI Table Access") from ACPICA reference
manual.

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

Use mmu:isreadable() to actually check if a memory region is readable in
AcpiOsReadable().

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

Switch to console::write_ll() in AcpiOsPrintf() and AcpiOsvPrintf() to
make ACPI boot-time output readable:

  [penberg@localhost osv]$ ./scripts/run.py
  ACPI: RSDP 0xfd8d0 00014 (v00 BOCHS )
  ACPI: RSDT 0x3fffe380 00034 (v01 BOCHS  BXPCRSDT 00000001 BXPC 00000001)
  ACPI: FACP 0x3fffff80 00074 (v01 BOCHS  BXPCFACP 00000001 BXPC 00000001)
  ACPI: DSDT 0x3fffe3c0 011A9 (v01   BXPC   BXDSDT 00000001 INTL 20100528)
  ACPI: FACS 0x3fffff40 00040
  ACPI: SSDT 0x3ffff6e0 00858 (v01 BOCHS  BXPCSSDT 00000001 BXPC 00000001)
  ACPI: APIC 0x3ffff5b0 00090 (v01 BOCHS  BXPCAPIC 00000001 BXPC 00000001)
  ACPI: HPET 0x3ffff570 00038 (v01 BOCHS  BXPCHPET 00000001 BXPC 00000001)
  acpi 0 apic 0
  acpi 1 apic 1
  acpi 2 apic 2
  acpi 3 apic 3
  APIC base fee00000
  OSv v0.02-64-ga556eab Copyright 2013 Cloudius Systems
  locale works
  ACPI: RSDP 0xfd8d0 00014 (v00 BOCHS )
  ACPI: RSDT 0x3fffe380 00034 (v01 BOCHS  BXPCRSDT 00000001 BXPC 00000001)
  ACPI: FACP 0x3fffff80 00074 (v01 BOCHS  BXPCFACP 00000001 BXPC 00000001)
  ACPI: DSDT 0x3fffe3c0 011A9 (v01   BXPC   BXDSDT 00000001 INTL 20100528)
  ACPI: FACS 0x3fffff40 00040
  ACPI: SSDT 0x3ffff6e0 00858 (v01 BOCHS  BXPCSSDT 00000001 BXPC 00000001)
  ACPI: APIC 0x3ffff5b0 00090 (v01 BOCHS  BXPCAPIC 00000001 BXPC 00000001)
  ACPI: HPET 0x3ffff570 00038 (v01 BOCHS  BXPCHPET 00000001 BXPC 00000001)
  ACPI: All ACPI Tables successfully acquired

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

The sched::timer set() function expects an absolute time value. Fix an
incorret use of it AcpiOsWaitSemaphore().

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Spotted by GCC with '-Wformat=1':

../../drivers/xenfront-xenbus.cc: In function ‘XenbusState xenbus_get_state(device_t)’:
../../drivers/xenfront-xenbus.cc:219:80: warning: format ‘%d’ expects argument of type ‘int*’, but argument 6 has type ‘XenbusState* {aka xenbus_state*}’ [-Wformat=]
     xs_scanf(XST_NIL, dev->get_node_path().c_str(), "state", NULL, "%d", &state);

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

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

The initialization is done a this time so everything needed is ready.

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

These are the two missing functions for ACPICA be able to initialize fully.

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Start to fill the missing ACPICA OSv primitives in order to be able to fully
initialize ACPICA for use in drivers probe functions.

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Or Cohen <orc@fewbytes.com>

Spotted by Clang:

../../drivers/vga.hh:15:18: error: 'VGAConsole::write' hides overloaded virtual function
      [-Werror,-Woverloaded-virtual]
    virtual void write(const char *str);
                 ^
../../drivers/console.hh:16:18: note: hidden overloaded virtual function 'Console::write'
      declared here: different number of parameters (2 vs 1)
    virtual void write(const char *str, size_t len) = 0;
                 ^

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

We have _KERNEL defines scattered throughout the code, which makes
understanding it difficult.

Define it just once, and adjust the source to build.

We define it in an overridable variable, so that non-kernel imported code
can undo it.

Switch to size_t type for ->bio_bcount in struct bio and clean up
virtio-blk signedness casts.

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

This patch adds interrupt (by default ctrl-C) and quit (by default ctrl-\)
handling to the console driver, when the ISIG termios flag is enabled (and
this patch enables this flag by default). The application can change these
characters or disable ISIG with ioctls, exactly as in Unix.

The ^C character sends a SIGINT to the (only) process, and ^\ sends SIGQUIT.
By default both abort OSv, but when running Java we get a much more
interesting SIGQUIT handler - it shows a trace of all running threads
and other information.

Note that our line-discipline code currently sits in the console driver
(we do not have ptys yet), so it only applies to the console, not to
SSH connections or the likes.

Also note that by default (before the patch to issue #49), qemu will catch
the ^C and ^\ and won't even pass them to OSv, so apply the patch to #49
(or change the interrupt or quit characters) to see this feature working.

This patch relates to issue #53.

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

The page_size constant is not used in the code so lets just remove it.

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

Make kvmclock::probe() easier to follow by simplifying the processor
feature checks.

Cc: Venkatesh Srinivas <venkateshs@google.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Older versions of KVM and user VMMs expose kvmclock MSRs at different
MSR offsets. Detect the old flag in kvmclock::probe() and use the old
MSRs if they are the only ones available.

Signed-off-by: Venkatesh Srinivas <venkateshs@google.com>
Signed-off-by: Glauber Costa <glommer@cloudius-systems.com>

  1. MSI-X printous fixed
  2. Duplicate EOLs removed

Signed-off-by: Dmitry Fleytman <dmitry@daynix.com>

Switch to the mmu::page_size constant instead of inventing our own.

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

The 'offset' variable is first assigned to "bio->bio_offset" and then
immediately overwritten with "bio->bio_data & 0xfff". Fix that up.

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

Fix few minor but annoying coding style issues in drivers/virtio-blk.cc.

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

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

Add Cloudius copyright and license statement to drivers/*.

A couple of header files were based on Linux's BSD-licensed header files
(e.g., include/uapi/linux/virtio_net.h) so they included the BSD license,
but not any copyright statement, so we can just replace that by our own
statement of the BSD license.

I've made the mistake of presenting the counter value directly instead of
converting it to nanoseconds. We need to do that, by grabbing the period from
the device and using it.

Since hpet is already our slow fallback anyway, I am using simple
multiplication and not bothering with complex mult / shift stuff.

The Xen hypervisor not always initialize its pages. The BSD drivers will
however assume they are zeroed, and so things may break if they are not
(misterious flag tests suddenly being true, for instance).

Initialize manually the data we have just received from malloc when we deal
with softc.

This patch implements GSI interrupt support for Xen bus.
Needed in Xen environments w/o vector callbacks for HVM.
One example of such an environment is Amazon EC2.

I would like to call read_partition_table automatically from device_register,
which would guarantee that every device that comes up have its partitions
scanned. Although totally possible on KVM, it is not possible on Xen, due to
the assynchronous nature of the bringup protocol: the device is exposed and
created in a moment where IO is not yet possible, so reading the partition
table will fail. Just read them both from the drivers when we are sure the
driver is ready.

To support multiple partitions to a disk, I found it easier to add a
post-processing offset calculation to the bio just before calling the strategy.

The reason is, we have many (really many) entry points for bio preparation
(pre-strategy) and only two entry points for the strategy itself (the drivers).
Since multiplex_strategy is a good thing to be used even for virtio (although I
am not converting it now), since it allows for arbitrary sized requests, we
could very well reduce it to just one.

At this moment, the offset is always 0 and everything works as before.

Currently we get it from the private data, but since I plan to use the same
private data for all partitions, we need a unique value, that already exists in
the device. So use it.

This patch implement the HPET clock driver, that should work as a fallback for
both Xen and KVM, in case the paravirtual clock is not present. This is
unfortunately the situation for all HVM guests running on EC2, so support for
this is paramount. I have tested on KVM forcing the kvmclock to disappear, and
it seems to work all right.

Right now we are doing it right before we parse the MADT, but this is by far
not MADT specific. Other users are planned, and the best way to resolve the
disputes is to have it in a separate constructor