On Mon, Jan 25, 2016 at 03:53:34PM +0000, Marc Zyngier wrote: > ARMv8.1 comes with the "Virtualization Host Extension" (VHE for > short), which enables simpler support of Type-2 hypervisors. > > This extension allows the kernel to directly run at EL2, and > significantly reduces the number of system registers shared between > host and guest, reducing the overhead of virtualization. > > In order to have the same kernel binary running on all versions of the > architecture, this series makes heavy use of runtime code patching. > > The first 20 patches massage the KVM code to deal with VHE and enable > Linux to run at EL2. The last patch catches an ugly case when VHE > capable CPUs are paired with some of their less capable siblings. This > should never happen, but hey... > > I have deliberately left out some of the more "advanced" > optimizations, as they are likely to distract the reviewer from the > core infrastructure, which is what I care about at the moment. > > A few things to note: > > - Given that the code has been almost entierely rewritten, I've > dropped all Acks from the new patches > > - GDB is currently busted on VHE systems, as it checks for version 6 > on the debug architecture, while VHE is version 7. The binutils > people are on the case. > > This has been tested on the FVP_Base_SLV-V8-A model, and based on > v4.5-rc1. I've put a branch out on: > > git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git kvm-arm64/vhe > > * From v1: > - Full rewrite now that the World Switch is written in C code. > - Dropped the "early IRQ handling" for the moment. > > Marc Zyngier (21): > arm/arm64: Add new is_kernel_in_hyp_mode predicate > arm64: Allow the arch timer to use the HYP timer > arm64: Add ARM64_HAS_VIRT_HOST_EXTN feature > arm64: KVM: Skip HYP setup when already running in HYP > arm64: KVM: VHE: Turn VTCR_EL2 setup into a reusable macro > arm64: KVM: VHE: Patch out use of HVC > arm64: KVM: VHE: Patch out kern_hyp_va > arm64: KVM: VHE: Introduce unified system register accessors > arm64: KVM: VHE: Differenciate host/guest sysreg save/restore > arm64: KVM: VHE: Split save/restore of sysregs shared between EL1 and > EL2 > arm64: KVM: VHE: Use unified system register accessors > arm64: KVM: VHE: Enable minimal sysreg save/restore > arm64: KVM: VHE: Make __fpsimd_enabled VHE aware > arm64: KVM: VHE: Implement VHE activate/deactivate_traps > arm64: KVM: VHE: Use unified sysreg accessors for timer > arm64: KVM: VHE: Add fpsimd enabling on guest access > arm64: KVM: VHE: Add alternative panic handling > arm64: KVM: Introduce hyp_alternate_value helper > arm64: KVM: Move most of the fault decoding to C > arm64: VHE: Add support for running Linux in EL2 mode > arm64: Panic when VHE and non VHE CPUs coexist These patches generally look awesome! I found some trailing white space in patch 6 and 7 that you can fix up if you care to. Thanks, -Christoffer -- 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
