James Hogan b45bacd2d0 MIPS: KVM: Fix timer IRQ race when writing CP0_Compare ... Writing CP0_Compare clears the timer interrupt pending bit (CP0_Cause.TI), but this wasn't being done atomically. If a timer interrupt raced with the write of the guest CP0_Compare, the timer interrupt could end up being pending even though the new CP0_Compare is nowhere near CP0_Count. We were already updating the hrtimer expiry with kvm_mips_update_hrtimer(), which used both kvm_mips_freeze_hrtimer() and kvm_mips_resume_hrtimer(). Close the race window by expanding out kvm_mips_update_hrtimer(), and clearing CP0_Cause.TI and setting CP0_Compare between the freeze and resume. Since the pending timer interrupt should not be cleared when CP0_Compare is written via the KVM user API, an ack argument is added to distinguish the source of the write. Fixes: e30492bbe9 ("MIPS: KVM: Rewrite count/compare timer emulation") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Cc: <stable@vger.kernel.org> # 3.16.x- Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>		2016-05-10 15:56:50 +02:00
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asm	MIPS: KVM: Fix timer IRQ race when writing CP0_Compare	2016-05-10 15:56:50 +02:00
uapi/asm	MIPS: Wire up preadv2 and pwrite2 syscalls.	2016-04-03 09:41:34 +02:00