Anthony Liguori wrote: > Now that we have userspace memory allocation, I wanted to play with > ballooning. > The idea is that when a guest "balloons" down, we simply unpin the underlying > physical memory and the host kernel may or may not swap it. To reclaim > ballooned memory, the guest can just start using it and we'll pin it on > demand. > > The following patch is a stab at providing the right infrastructure for > pinning > and automatic repinning. I don't have a lot of comfort in the MMU code so I > thought I'd get some feedback before going much further. > > gpa_to_hpa is a little awkward to hook, but it seems like the right place in > the > code. I'm most uncertain about the SMP safety of the unpinning. Presumably, > I have to hold the kvm lock around the mmu_unshadow and page_cache release to > ensure that another VCPU doesn't fault the page back in after mmu_unshadow? > >
One we have true swapping capabilities (which imply ability for the kernel to remove a page from the shadow page tables) you can unpin by calling munmap() or madvise(MADV_REMOVE) on the pages to be unpinned. Other than that the approach seems right. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. ------------------------------------------------------------------------- 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
