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| author | Michael Ellerman <mpe@ellerman.id.au> | 2018-10-17 23:39:41 +1100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-24 08:21:08 +0100 |
| commit | e2a37708cfca2e9815fc9a2456263b4fbbcfc367 (patch) | |
| tree | 2caf8562d33f752507ccca5b3f3fc02889d59d6e | |
| parent | ff36ace6c107a3abe90f08e1712650a207eb7327 (diff) | |
powerpc/time: Fix clockevent_decrementer initalisation for PR KVM
[ Upstream commit b4d16ab58c41ff0125822464bdff074cebd0fe47 ]
In the recent commit 8b78fdb045de ("powerpc/time: Use
clockevents_register_device(), fixing an issue with large
decrementer") we changed the way we initialise the decrementer
clockevent(s).
We no longer initialise the mult & shift values of
decrementer_clockevent itself.
This has the effect of breaking PR KVM, because it uses those values
in kvmppc_emulate_dec(). The symptom is guest kernels spin forever
mid-way through boot.
For now fix it by assigning back to decrementer_clockevent the mult
and shift values.
Fixes: 8b78fdb045de ("powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/powerpc/kernel/time.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 6a1f0a084ca3..7707990c4c16 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -988,6 +988,10 @@ static void register_decrementer_clockevent(int cpu) printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n", dec->name, dec->mult, dec->shift, cpu); + + /* Set values for KVM, see kvm_emulate_dec() */ + decrementer_clockevent.mult = dec->mult; + decrementer_clockevent.shift = dec->shift; } static void enable_large_decrementer(void) |