From: David Woodhouse <dwmw@amazon.co.uk>
Coverity points out (CID 1507534) that we sometimes access
env->xen_singleshot_timer_ns under the protection of
env->xen_timers_lock (eg in xen_vcpu_singleshot_timer_event()) and
sometimes not (the specific case Coverity complains about is in
do_vcpu_soft_reset()).
This isn't strictly an issue. There are two modes for the timers; if
the kernel supports the EVTCHN_SEND capability then it handles all the
timer hypercalls and delivery internally, and all we need to do is an
ioctl to get/set the next timer as part of the vCPU state. If the
kernel doesn't have that support, then we do all the emulation within
qemu, and *those* are the code paths where we actually care about the
locking.
But it doesn't hurt to be a little bit more consistent and avoid having
to explain *why* it's OK.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
On Tue, 2023-05-09 at 15:55 +0100, Peter Maydell wrote:
Hi; Coverity points out (CID 1507534) that we seem to sometimes
access env->xen_singleshot_timer_ns under the protection of
env->xen_timers_lock (eg in xen_vcpu_singleshot_timer_event())
and sometimes not (the specific case Coverity complains about is
in do_vcpu_soft_reset()). Is this a false positive, or is there
Thanks. As noted, I think it's harmless but it doesn't hurt to clean it
up a bit. I've pushed this to my tree at
https://git.infradead.org/users/dwmw2/qemu.git/shortlog/refs/heads/xenfv
on top of the other fixes that didn't make 8.0.
target/i386/kvm/xen-emu.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)