Here's another batch of NV-related patches, this time bringing in most of the timer support for EL2 as well as nested guests. The code is pretty convoluted for a bunch of reasons: - FEAT_NV2 breaks the timer semantics by redirecting HW controls to memory, meaning that a guest could setup a timer and never see it firing until the next exit - We go try hard to reflect the timer state in memory, but that's not great. - With FEAT_ECV, we can finally correctly emulate the virtual timer, but this emulation is pretty costly - As a way to make things suck less, we handle timer reads as early as possible, and only defer writes to the normal trap handling - Finally, some implementations are badly broken, and require some hand-holding, irrespective of NV support. So we try and reuse the NV infrastructure to make them usable. This could be further optimised, but I'm running out of patience for this sort of HW. What this is not implementing is support for CNTPOFF_EL2. It appears that the architecture doesn't let you correctly emulate it, so I guess this will be trap/emulate for the foreseeable future. This series is on top of v6.13-rc1, and has been tested on my usual M2 setup, but also on a Snapdragon X1 Elite devkit. I would like to thank Qualcomm for the free hardware with no strings (nor support) attached! If you are feeling brave, you can run the whole thing from [1]. [1] https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/log/?h=kvm-arm64/nv-next Marc Zyngier (11): KVM: arm64: nv: Add handling of EL2-specific timer registers KVM: arm64: nv: Sync nested timer state with FEAT_NV2 KVM: arm64: nv: Publish emulated timer interrupt state in the in-memory state KVM: arm64: nv: Use FEAT_ECV to trap access to EL0 timers KVM: arm64: nv: Accelerate EL0 timer read accesses when FEAT_ECV in use KVM: arm64: nv: Acceletate EL0 counter accesses from hypervisor context KVM: arm64: Handle counter access early in non-HYP context KVM: arm64: nv: Add trap routing for CNTHCTL_EL2.EL1{NVPCT,NVVCT,TVT,TVCT} KVM: arm64: nv: Propagate CNTHCTL_EL2.EL1NV{P,V}CT bits KVM: arm64: nv: Sanitise CNTHCTL_EL2 KVM: arm64: Work around x1e's CNTVOFF_EL2 bogosity arch/arm64/include/asm/cputype.h | 2 + arch/arm64/include/asm/kvm_host.h | 2 +- arch/arm64/include/asm/sysreg.h | 4 + arch/arm64/kernel/cpu_errata.c | 8 ++ arch/arm64/kernel/image-vars.h | 3 + arch/arm64/kvm/arch_timer.c | 177 +++++++++++++++++++++--- arch/arm64/kvm/arm.c | 3 + arch/arm64/kvm/emulate-nested.c | 58 +++++++- arch/arm64/kvm/hyp/include/hyp/switch.h | 39 ++++-- arch/arm64/kvm/hyp/nvhe/timer-sr.c | 16 ++- arch/arm64/kvm/hyp/vhe/switch.c | 84 +++++++++++ arch/arm64/kvm/nested.c | 15 ++ arch/arm64/kvm/sys_regs.c | 146 ++++++++++++++++++- arch/arm64/tools/cpucaps | 1 + include/clocksource/arm_arch_timer.h | 6 + include/kvm/arm_arch_timer.h | 23 +++ 16 files changed, 546 insertions(+), 41 deletions(-) -- 2.39.2
