On Friday 15 November 2013 09:25 AM, Marc Zyngier wrote: > On 15/11/13 13:39, Catalin Marinas wrote: >> On Thu, Nov 14, 2013 at 07:37:44PM +0000, Santosh Shilimkar wrote: >>> Slab allocator can allocate memory beyond the lowmem watermark >>> which can lead to false failure of virt_addr_valid(). >>> >>> So drop the check. The issue was seen with percpu_alloc() >>> in KVM code which was allocating memory beyond lowmem watermark. >>> >>> Am not completly sure whether this is the right fix and if it could >>> impact any other user of virt_addr_valid(). Without this fix as >>> pointed out the KVM init was failing in my testing. >> >> Do you have a problem on arm64? There is no lowmem watermark here. > > I don't think that change is relevant for arm64. Actually, the more I > look at it, I don't think virt_addr_valid() should be touched at all. > > The real issue is the use of virt_to_phys()/virt_addr_valid() on a > percpu pointer, which is wrong and only worked by chance so far. > > I'm working on a patch to solve this. > Yep. I tried Marc's other approach and that does solve the issue. The $subject patch was any way more for getting attention to figure out right solution ;-) which I guess we have now. Regards, Santosh _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
