On Wed, May 13, 2015 at 01:31:51PM +0200, Andrew Jones wrote: > Introduce a new memory region flag, KVM_MEM_UNCACHED, which is > needed by ARM. This flag informs KVM that the given memory region > is typically mapped by the guest as non-cacheable. KVM for ARM > then ensures that that memory is indeed mapped non-cacheable by > the guest, and also remaps that region as non-cacheable for > userspace, allowing them both to maintain a coherent view. > > Changes since v1: > 1) don't pin pages [Paolo] > 2) ensure the guest maps the memory non-cacheable [me] > 3) clean up memslot flag documentation [Christoffer] Forgot to (4): switch from setting userspace's mapping to device memory to normal, non-cacheable. Using device memory caused a problem that Alex Graf found, and Peter Maydell suggested using normal, non-cacheable instead. > changes 1 and 2 effectively redesigned/rewrote v1. Find v1 here > http://www.spinics.net/lists/kvm-arm/msg14022.html > > The QEMU series for v1 hasn't really changed. Only the linux > header hack needed to bump KVM_CAP_UNCACHED_MEM from 107 to > 116. Find the series here > http://www.spinics.net/lists/kvm-arm/msg14026.html > > Testing: > This series still needs lots of testing, but I thought I'd > kick it to the list early, as there's been recent interest > in solving this problem, and I'd like to get test results > and opinions on this approach from others sooner than later. > I've tested with AAVMF (UEFI for AArch64 mach-virt guests). > AAVMF has a kludge in it to avoid the coherency problem. > I've tested both with and without that kludge active. Both > worked for me (almost). Sometimes with the non-kludged > version I was still able to see a bit of corruption in > grub's output after edk2 loaded it - not much, and not always, > but something. Anyway, it's quite frustrating, as I'm not sure > what I'm missing... > > This series applies to Linus' 110bc76729d4, but I tested with > a version backported to the current RHELSA kernel. > > Thanks for reviews and testing! > > drew > > > Andrew Jones (3): > arm/arm64: pageattr: add set_memory_nc > KVM: promote KVM_MEMSLOT_INCOHERENT to uapi > arm/arm64: KVM: implement 'uncached' mem coherency > > Documentation/virtual/kvm/api.txt | 20 ++++++++++++------ > arch/arm/include/asm/cacheflush.h | 1 + > arch/arm/include/asm/kvm_mmu.h | 5 ++++- > arch/arm/include/asm/pgtable-3level.h | 1 + > arch/arm/include/asm/pgtable.h | 1 + > arch/arm/include/uapi/asm/kvm.h | 1 + > arch/arm/kvm/arm.c | 1 + > arch/arm/kvm/mmu.c | 39 ++++++++++++++++++++++------------- > arch/arm/mm/pageattr.c | 7 +++++++ > arch/arm64/include/asm/cacheflush.h | 1 + > arch/arm64/include/asm/kvm_mmu.h | 5 ++++- > arch/arm64/include/asm/memory.h | 1 + > arch/arm64/include/asm/pgtable.h | 1 + > arch/arm64/include/uapi/asm/kvm.h | 1 + > arch/arm64/mm/pageattr.c | 8 +++++++ > include/linux/kvm_host.h | 1 - > include/uapi/linux/kvm.h | 2 ++ > virt/kvm/kvm_main.c | 7 ++++++- > 18 files changed, 79 insertions(+), 24 deletions(-) > > -- > 2.1.0 > > _______________________________________________ > kvmarm mailing list > kvmarm@xxxxxxxxxxxxxxxxxxxxx > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
