Here is the KVM implementation for the proposed PAPR extension which allows the runtime resizing of a PAPR guest's Hashed Page Table (HPT). Using this requires a guest kernel with support for the extension. Patches for guest side support in Linux were posted earlier: https://lists.ozlabs.org/pipermail/linuxppc-dev/2016-December/152164.html It also requires userspace (i.e. qemu) to intercept the HPT resizing hypercalls and invoke the KVM ioctl()s to implement them. This is done instead of having KVM direclty intercept the hypercalls, so that userspace can, if useful, impose additional restrictions on resizes: for example it could refuse them entirely if policy for the VM precludes resizing, or it could limit the size of HPT the guest can request to meet resource limits. Patches to implement the userspace part of HPT resizing are proposed for qemu-2.9, and can be found at: https://github.com/dgibson/qemu/tree/hpt-resize I'm posting these now, in the hopes that both these and the corresponding guest side patches can be staged and merged for the 4.11 window. Changes in v2: * Use a more normal and straightforward encoding of the capability flags * Add information to Documentation/virtual/kvm/api.txt * Assorted minor cleanups based on review comments David Gibson (11): Documentation: Correct duplicate section number in kvm/api.txt powerpc/kvm: HPT resizing documentation and reserved numbers powerpc/kvm: Rename kvm_alloc_hpt() for clarity powerpc/kvm: Gather HPT related variables into sub-structure powerpc/kvm: Don't store values derivable from HPT order powerpc/kvm: Split HPT allocation from activation powerpc/kvm: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size powerpc/kvm: Create kvmppc_unmap_hpte_helper() powerpc/kvm: Outline of KVM-HV HPT resizing implementation powerpc/kvm: KVM-HV HPT resizing implementation powerpc/kvm: Advertise availablity of HPT resizing on KVM HV Documentation/virtual/kvm/api.txt | 111 +++++- arch/powerpc/include/asm/kvm_book3s_64.h | 16 + arch/powerpc/include/asm/kvm_host.h | 21 +- arch/powerpc/include/asm/kvm_ppc.h | 15 +- arch/powerpc/kvm/book3s_64_mmu_hv.c | 625 +++++++++++++++++++++++++------ arch/powerpc/kvm/book3s_hv.c | 50 ++- arch/powerpc/kvm/book3s_hv_builtin.c | 8 +- arch/powerpc/kvm/book3s_hv_rm_mmu.c | 62 +-- arch/powerpc/kvm/powerpc.c | 3 + include/uapi/linux/kvm.h | 11 + 10 files changed, 741 insertions(+), 181 deletions(-) -- 2.9.3 -- 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
