On Fri, 2011-12-16 at 15:02 +0800, Zang Hongyong wrote: > 于 2011/12/16,星期五 13:50, Sasha Levin 写道: > > On Fri, 2011-12-16 at 09:01 +0800, zanghongyong@xxxxxxxxxx wrote: > >> If a guest's ram_size exceeds KVM_32BIT_GAP_START, the corresponding kvm tool's > >> virtual address size should be (ram_size + KVM_32BIT_GAP_SIZE), rather than ram_size. > > You're right. > > > > There are more places than just the madvise() code which make the same > > error you've spotted (for example, the memslot allocation code), so > > instead of trying to fix all of them I'd suggest to just update ram_size > > in kvm__arch_init() before allocating everything - that should fix all > > of them at once. > > > Yes. There are other scenarios with the same error. > However ram_size sometimes means real guest ram size, and sometimes > means virtual address > size of kvm tool's user space. Shall we define a new variable? Let's keep it simple. If the user requests more than RAM than KVM_32BIT_GAP_START just increase it by KVM_32BIT_GAP_SIZE, this way mapped size == guest size always (we can madvise(MADV_DONTNEED) the gap in the mmapped ram). Since a user which requests more than KVM_32BIT_GAP_START will have to be on 64bit host anyway, there shouldn't be any issue with that. -- Sasha. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
