Avi Kivity wrote: > Anthony Liguori wrote: >>> >>>> static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu) >>>> { >>>> int r; >>>> >>>> kvm_mmu_free_some_pages(vcpu); >>>> r = mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache, >>>> pte_chain_cache, 4); >>>> if (r) >>>> goto out; >>>> r = mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache, >>>> rmap_desc_cache, 1); >>>> if (r) >>>> goto out; >>>> r = mmu_topup_memory_cache_page(&vcpu->mmu_page_cache, 8); >>>> if (r) >>>> goto out; >>>> r = mmu_topup_memory_cache(&vcpu->mmu_page_header_cache, >>>> mmu_page_header_cache, 4); >>>> out: >>>> return r; >>>> } >>> >>> >>> These are the (4, 1, 8, 4) values in the call to >>> mmu_topup_memory_cache. Perhaps one of them is too low. >> >> Sure. Would this be affected at all by your tpr patch? > > I believe not, but the code doesn't care what I believe. > >> IIUC, if this is the problem, it should be reproducible with the >> latest git too? > > One difference is that the tpr patch disables nx. That causes Windows > to go into 32-bit paging mode (nice that it has both pae and nonpae in > the same kernel), which may change things. > > You can try booting your host with nx disabled to get the same effect > (or disable nx cpuid in kvm).
I've disabled NX in KVM and that didn't reproduce the issue in the current git. If I double all of the memory caches, I can't seem to reproduce. However, as soon as I reduce rmap_desc_cache down to 1, I can reproduce. I'll try to see if just setting the rmap_desc_cache line to 2 is enough to make the problem go away. How can the guest provoke this BUG() based on the cache size? Should the cache size only affect performance? Regards, Anthony Liguori ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel