On Wed, Jan 09, 2019 at 01:54:32PM +0000, Marc Zyngier wrote: > It recently appeared that the nasty hack we use to call a HYP function > on a non-VHE system has an interesting side effect on VHE: We wrap any > such call into a hypercall, losing any form of type checking between > the caller and the callee. > > This isn't a big deal if you can guarantee to write code that is > always 100% correct, but it appears that I'm not you. > > In order to restore some sanity, let's use the following property: On > a VHE system, it is always possible to call any function directly as > they live in the same address space. We can thus always emit a direct > call, and use a static key to flip from one to the other. As a bonus, > this also sanitizes !VHE systems as we always generate code for noth s/noth/both/g Andrew Murray > revisions of the architecture. > > Marc Zyngier (3): > arm/arm64: KVM: Introduce kvm_call_hyp_ret() > arm64: KVM: Allow for direct call of HYP functions when using VHE > arm64: KVM: Drop VHE-specific HYP call stub > > arch/arm/include/asm/kvm_host.h | 3 +++ > arch/arm64/include/asm/kvm_host.h | 31 ++++++++++++++++++++++++++++++- > arch/arm64/kvm/debug.c | 2 +- > arch/arm64/kvm/hyp.S | 3 --- > arch/arm64/kvm/hyp/hyp-entry.S | 12 ------------ > virt/kvm/arm/arm.c | 2 +- > virt/kvm/arm/vgic/vgic-v3.c | 4 ++-- > 7 files changed, 37 insertions(+), 20 deletions(-) > > -- > 2.20.1 > > _______________________________________________ > kvmarm mailing list > kvmarm@xxxxxxxxxxxxxxxxxxxxx > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
