Originally, timers were ticks based, and it made sense to
add ticks to current time to know when to trigger an alarm.
But since commit:
7447545 change all other clock references to use nanosecond resolution accessors
All timers use nanoseconds and we need to convert ticks to nanoseconds, by
doing something like:
y = muldiv64(x, get_ticks_per_sec(), PCI_FREQUENCY)
where x is the number of device ticks and y the number of system ticks.
y is used as nanoseconds in timer functions,
it works because 1 tick is 1 nanosecond.
(get_ticks_per_sec() is 10^9)
But as PCI frequency is 33 MHz, we can also do:
y = x * 30; /* 33 MHz PCI period is 30 ns */
Which is much more simple.
This implies a 33.333333 MHz PCI frequency,
but this is correct.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
We use muldiv64() to compute the time to wait:
timeout = muldiv64(get_ticks_per_sec(), timeout, 33000000);
but get_ticks_per_sec() is 10^9 (30 bit value) and timeout
is a 35 bit value.
Whereas muldiv64 is:
uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)
So we loose 3 bits of timeout.
Swapping get_ticks_per_sec() and timeout fixes it.
We can also replace it by a multiplication by 30 ns,
but this changes PCI clock frequency from 33MHz to 33.333333MHz
and we need to do this on all the QEMU PCI devices (later...)
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
If the guest programs a sufficiently large timeout value an integer
overflow can occur in i6300esb_restart_timer(). e.g. if the maximum
possible timer preload value of 0xfffff is programmed then we end up with
the calculation:
timeout = get_ticks_per_sec() * (0xfffff << 15) / 33000000;
get_ticks_per_sec() returns 1000000000 (10^9) giving:
10^9 * (0xfffff * 2^15) == 0x1dcd632329b000000 (65 bits)
Obviously the division by 33MHz brings it back under 64-bits, but the
overflow has already occurred.
Since signed integer overflow has undefined behaviour in C, in theory this
could be arbitrarily bad. In practice, the overflowed value wraps around
to something negative, causing the watchdog to immediately expire, killing
the guest, which is still fairly bad.
The bug can be triggered by running a Linux guest, loading the i6300esb
driver with parameter "heartbeat=2046" and opening /dev/watchdog. The
watchdog will trigger as soon as the device is opened.
This patch corrects the problem by using muldiv64(), which effectively
allows a 128-bit intermediate value between the multiplication and
division.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <1427075508-12099-3-git-send-email-david@gibson.dropbear.id.au>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The IO operations for the i6300esb watchdog timer are marked as
DEVICE_NATIVE_ENDIAN. This is not correct, and - as a PCI device - should
be DEVICE_LITTLE_ENDIAN.
This allows i6300esb to work on ppc targets (yes, using an Intel ICH
derived device on ppc is a bit odd, but the driver exists on the guest
and there's no more obviously suitable watchdog device).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <1427075508-12099-2-git-send-email-david@gibson.dropbear.id.au>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Convert the device models where initialization obviously can't fail.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
The function is empty after the previous patch, so remove it.
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
After previous Peter patch, they are redundant. This way we don't
assign them except when needed. Once there, there were lots of case
where the ".fields" indentation was wrong:
.fields = (VMStateField []) {
and
.fields = (VMStateField []) {
Change all the combinations to:
.fields = (VMStateField[]){
The biggest problem (appart from aesthetics) was that checkpatch complained
when we copy&pasted the code from one place to another.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
This is an autogenerated patch using scripts/switch-timer-api.
Switch the entire code base to using the new timer API.
Note this patch may introduce some line length issues.
Signed-off-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The category will be used to sort the devices displayed in
the command line help.
Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
Message-id: 1375107465-25767-4-git-send-email-marcel.a@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
When this VMSD was introduced it's version fields were set to
sizeof(I6300State), making them essentially random from build to build,
version to version.
To fix this, we lock in a high version id and low minimum version id to
support old->new migration from all prior versions of this device's
state. This should work since the device state has not changed since
its introduction.
The potentially breaks migration from 1.5+ to 1.5, but since the
versioning was essentially random prior to this patch, new->old
migration was not consistently functional to begin with.
Reported-by: Nicholas Thomas <nick@bytemark.co.uk>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-stable@nongnu.org
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
