On Wed, Mar 10, 2021 at 05:57:33PM +0000, Quentin Perret wrote: > When memory protection is enabled, the EL2 code needs the ability to > create and manage its own page-table. To do so, introduce a new set of > hypercalls to bootstrap a memory management system at EL2. > > This leads to the following boot flow in nVHE Protected mode: > > 1. the host allocates memory for the hypervisor very early on, using > the memblock API; > > 2. the host creates a set of stage 1 page-table for EL2, installs the > EL2 vectors, and issues the __pkvm_init hypercall; > > 3. during __pkvm_init, the hypervisor re-creates its stage 1 page-table > and stores it in the memory pool provided by the host; > > 4. the hypervisor then extends its stage 1 mappings to include a > vmemmap in the EL2 VA space, hence allowing to use the buddy > allocator introduced in a previous patch; > > 5. the hypervisor jumps back in the idmap page, switches from the > host-provided page-table to the new one, and wraps up its > initialization by enabling the new allocator, before returning to > the host. > > 6. the host can free the now unused page-table created for EL2, and > will now need to issue hypercalls to make changes to the EL2 stage 1 > mappings instead of modifying them directly. > > Note that for the sake of simplifying the review, this patch focuses on > the hypervisor side of things. In other words, this only implements the > new hypercalls, but does not make use of them from the host yet. The > host-side changes will follow in a subsequent patch. > > Credits to Will for __pkvm_init_switch_pgd. > > Co-authored-by: Will Deacon <will@xxxxxxxxxx> > Signed-off-by: Will Deacon <will@xxxxxxxxxx> > Signed-off-by: Quentin Perret <qperret@xxxxxxxxxx> > --- > arch/arm64/include/asm/kvm_asm.h | 4 + > arch/arm64/include/asm/kvm_host.h | 7 + > arch/arm64/include/asm/kvm_hyp.h | 8 ++ > arch/arm64/include/asm/kvm_pgtable.h | 2 + > arch/arm64/kernel/image-vars.h | 16 +++ > arch/arm64/kvm/hyp/Makefile | 2 +- > arch/arm64/kvm/hyp/include/nvhe/mm.h | 71 ++++++++++ > arch/arm64/kvm/hyp/nvhe/Makefile | 4 +- > arch/arm64/kvm/hyp/nvhe/hyp-init.S | 27 ++++ > arch/arm64/kvm/hyp/nvhe/hyp-main.c | 49 +++++++ > arch/arm64/kvm/hyp/nvhe/mm.c | 173 +++++++++++++++++++++++ > arch/arm64/kvm/hyp/nvhe/setup.c | 197 +++++++++++++++++++++++++++ > arch/arm64/kvm/hyp/pgtable.c | 2 - > arch/arm64/kvm/hyp/reserved_mem.c | 92 +++++++++++++ > arch/arm64/mm/init.c | 3 + > 15 files changed, 652 insertions(+), 5 deletions(-) > create mode 100644 arch/arm64/kvm/hyp/include/nvhe/mm.h > create mode 100644 arch/arm64/kvm/hyp/nvhe/mm.c > create mode 100644 arch/arm64/kvm/hyp/nvhe/setup.c > create mode 100644 arch/arm64/kvm/hyp/reserved_mem.c Acked-by: Will Deacon <will@xxxxxxxxxx> Will _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
