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. [...] > arch/arm/include/asm/virt.h | 5 ++ > arch/arm/kvm/arm.c | 151 +++++++++++++++++++------------ > arch/arm/kvm/mmu.c | 7 ++ > arch/arm64/Kconfig | 13 +++ > arch/arm64/include/asm/cpufeature.h | 3 +- > arch/arm64/include/asm/kvm_arm.h | 1 + > arch/arm64/include/asm/kvm_emulate.h | 3 + > arch/arm64/include/asm/kvm_mmu.h | 34 ++++++- > arch/arm64/include/asm/virt.h | 27 ++++++ > arch/arm64/kernel/asm-offsets.c | 3 - > arch/arm64/kernel/cpufeature.c | 15 +++- > arch/arm64/kernel/head.S | 51 ++++++++++- > arch/arm64/kernel/smp.c | 3 + > arch/arm64/kvm/hyp-init.S | 18 +--- > arch/arm64/kvm/hyp.S | 7 ++ > arch/arm64/kvm/hyp/entry.S | 6 ++ > arch/arm64/kvm/hyp/hyp-entry.S | 107 +++++++--------------- > arch/arm64/kvm/hyp/hyp.h | 119 ++++++++++++++++++++++-- > arch/arm64/kvm/hyp/switch.c | 170 +++++++++++++++++++++++++++++++---- > arch/arm64/kvm/hyp/sysreg-sr.c | 147 ++++++++++++++++++++---------- > arch/arm64/kvm/hyp/timer-sr.c | 10 +-- > drivers/clocksource/arm_arch_timer.c | 96 ++++++++++++-------- > 22 files changed, 724 insertions(+), 272 deletions(-) Have you tried hw_breakpoint/perf/ptrace with these changes? I was under the impression that the debug architecture was aware of E2H and did need some changes made. I know you say that GDB is broken anyway, but we should check that the kernel does the right thing if userspace pokes it the right way. Will -- 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
