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2024-05-03Merge branch kvm-arm64/lpi-xa-cache into kvmarm-master/nextMarc Zyngier
* kvm-arm64/lpi-xa-cache: : . : New and improved LPI translation cache from Oliver Upton. : : From the cover letter: : : "As discussed [*], here is the new take on the LPI translation cache, : migrating to an xarray indexed by (devid, eventid) per ITS. : : The end result is quite satisfying, as it becomes possible to rip out : other nasties such as the lpi_list_lock. To that end, patches 2-6 aren't : _directly_ related to the translation cache cleanup, but instead are : done to enable the cleanups at the end of the series. : : I changed out my test machine from the last time so the baseline has : moved a bit, but here are the results from the vgic_lpi_stress test: : : +----------------------------+------------+-------------------+ : | Configuration | v6.8-rc1 | v6.8-rc1 + series | : +----------------------------+------------+-------------------+ : | -v 1 -d 1 -e 1 -i 1000000 | 2063296.81 | 1362602.35 | : | -v 16 -d 16 -e 16 -i 10000 | 610678.33 | 5200910.01 | : | -v 16 -d 16 -e 17 -i 10000 | 678361.53 | 5890675.51 | : | -v 32 -d 32 -e 1 -i 100000 | 580918.96 | 8304552.67 | : | -v 1 -d 1 -e 17 -i 1000 | 1512443.94 | 1425953.8 | : +----------------------------+------------+-------------------+ : : Unlike last time, no dramatic regressions at any performance point. The : regression on a single interrupt stream is to be expected, as the : overheads of SRCU and two tree traversals (kvm_io_bus_get_dev(), : translation cache xarray) are likely greater than that of a linked-list : with a single node." : . KVM: selftests: Add stress test for LPI injection KVM: selftests: Use MPIDR_HWID_BITMASK from cputype.h KVM: selftests: Add helper for enabling LPIs on a redistributor KVM: selftests: Add a minimal library for interacting with an ITS KVM: selftests: Add quadword MMIO accessors KVM: selftests: Standardise layout of GIC frames KVM: selftests: Align with kernel's GIC definitions KVM: arm64: vgic-its: Get rid of the lpi_list_lock KVM: arm64: vgic-its: Rip out the global translation cache KVM: arm64: vgic-its: Use the per-ITS translation cache for injection KVM: arm64: vgic-its: Spin off helper for finding ITS by doorbell addr KVM: arm64: vgic-its: Maintain a translation cache per ITS KVM: arm64: vgic-its: Scope translation cache invalidations to an ITS KVM: arm64: vgic-its: Get rid of vgic_copy_lpi_list() KVM: arm64: vgic-debug: Use an xarray mark for debug iterator KVM: arm64: vgic-its: Walk LPI xarray in vgic_its_cmd_handle_movall() KVM: arm64: vgic-its: Walk LPI xarray in vgic_its_invall() KVM: arm64: vgic-its: Walk LPI xarray in its_sync_lpi_pending_table() KVM: Treat the device list as an rculist Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-03Merge branch kvm-arm64/nv-eret-pauth into kvmarm-master/nextMarc Zyngier
* kvm-arm64/nv-eret-pauth: : . : Add NV support for the ERETAA/ERETAB instructions. From the cover letter: : : "Although the current upstream NV support has *some* support for : correctly emulating ERET, that support is only partial as it doesn't : support the ERETAA and ERETAB variants. : : Supporting these instructions was cast aside for a long time as it : involves implementing some form of PAuth emulation, something I wasn't : overly keen on. But I have reached a point where enough of the : infrastructure is there that it actually makes sense. So here it is!" : . KVM: arm64: nv: Work around lack of pauth support in old toolchains KVM: arm64: Drop trapping of PAuth instructions/keys KVM: arm64: nv: Advertise support for PAuth KVM: arm64: nv: Handle ERETA[AB] instructions KVM: arm64: nv: Add emulation for ERETAx instructions KVM: arm64: nv: Add kvm_has_pauth() helper KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0 KVM: arm64: nv: Handle HCR_EL2.{API,APK} independently KVM: arm64: nv: Honor HFGITR_EL2.ERET being set KVM: arm64: nv: Fast-track 'InHost' exception returns KVM: arm64: nv: Add trap forwarding for ERET and SMC KVM: arm64: nv: Configure HCR_EL2 for FEAT_NV2 KVM: arm64: nv: Drop VCPU_HYP_CONTEXT flag KVM: arm64: Constraint PAuth support to consistent implementations KVM: arm64: Add helpers for ESR_ELx_ERET_ISS_ERET* KVM: arm64: Harden __ctxt_sys_reg() against out-of-range values Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-03Merge branch kvm-arm64/host_data into kvmarm-master/nextMarc Zyngier
* kvm-arm64/host_data: : . : Rationalise the host-specific data to live as part of the per-CPU state. : : From the cover letter: : : "It appears that over the years, we have accumulated a lot of cruft in : the kvm_vcpu_arch structure. Part of the gunk is data that is strictly : host CPU specific, and this result in two main problems: : : - the structure itself is stupidly large, over 8kB. With the : arch-agnostic kvm_vcpu, we're above 10kB, which is insane. This has : some ripple effects, as we need physically contiguous allocation to : be able to map it at EL2 for !VHE. There is more to it though, as : some data structures, although per-vcpu, could be allocated : separately. : : - We lose track of the life-cycle of this data, because we're : guaranteed that it will be around forever and we start relying on : wrong assumptions. This is becoming a maintenance burden. : : This series rectifies some of these things, starting with the two main : offenders: debug and FP, a lot of which gets pushed out to the per-CPU : host structure. Indeed, their lifetime really isn't that of the vcpu, : but tied to the physical CPU the vpcu runs on. : : This results in a small reduction of the vcpu size, but mainly a much : clearer understanding of the life-cycle of these structures." : . KVM: arm64: Move management of __hyp_running_vcpu to load/put on VHE KVM: arm64: Exclude FP ownership from kvm_vcpu_arch KVM: arm64: Exclude host_fpsimd_state pointer from kvm_vcpu_arch KVM: arm64: Exclude mdcr_el2_host from kvm_vcpu_arch KVM: arm64: Exclude host_debug_data from vcpu_arch KVM: arm64: Add accessor for per-CPU state Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-03KVM: arm64: Move management of __hyp_running_vcpu to load/put on VHEMarc Zyngier
The per-CPU host context structure contains a __hyp_running_vcpu that serves as a replacement for kvm_get_current_vcpu() in contexts where we cannot make direct use of it (such as in the nVHE hypervisor). Since there is a lot of common code between nVHE and VHE, the latter also populates this field even if kvm_get_running_vcpu() always works. We currently pretty inconsistent when populating __hyp_running_vcpu to point to the currently running vcpu: - on {n,h}VHE, we set __hyp_running_vcpu on entry to __kvm_vcpu_run and clear it on exit. - on VHE, we set __hyp_running_vcpu on entry to __kvm_vcpu_run_vhe and never clear it, effectively leaving a dangling pointer... VHE is obviously the odd one here. Although we could make it behave just like nVHE, this wouldn't match the behaviour of KVM with VHE, where the load phase is where most of the context-switch gets done. So move all the __hyp_running_vcpu management to the VHE-specific load/put phases, giving us a bit more sanity and matching the behaviour of kvm_get_running_vcpu(). Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240502154030.3011995-1-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: selftests: Add stress test for LPI injectionOliver Upton
Now that all the infrastructure is in place, add a test to stress KVM's LPI injection. Keep a 1:1 mapping of device IDs to signalling threads, allowing the user to scale up/down the sender side of an LPI. Make use of the new VM stats for the translation cache to estimate the translation hit rate. Since the primary focus of the test is on performance, you'll notice that the guest code is not pedantic about the LPIs it receives. Counting the number of LPIs would require synchronization between the device and vCPU threads to avoid coalescing and would get in the way of performance numbers. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-20-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: selftests: Use MPIDR_HWID_BITMASK from cputype.hOliver Upton
No need for a home-rolled definition, just rely on the common header. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-19-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: selftests: Add helper for enabling LPIs on a redistributorOliver Upton
The selftests GIC library presently does not support LPIs. Add a userspace helper for configuring a redistributor for LPIs, installing an LPI configuration table and LPI pending table. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-18-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: selftests: Add a minimal library for interacting with an ITSOliver Upton
A prerequisite of testing LPI injection performance is of course instantiating an ITS for the guest. Add a small library for creating an ITS and interacting with it from the guest. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-17-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: selftests: Add quadword MMIO accessorsOliver Upton
The base registers in the GIC ITS and redistributor for LPIs are 64 bits wide. Add quadword accessors to poke at them. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-16-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: selftests: Standardise layout of GIC framesOliver Upton
It would appear that all of the selftests are using the same exact layout for the GIC frames. Fold this back into the library implementation to avoid defining magic values all over the selftests. This is an extension of Colton's change, ripping out parameterization of from the library internals in addition to the public interfaces. Co-developed-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-15-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: selftests: Align with kernel's GIC definitionsOliver Upton
There are a few subtle incongruencies between the GIC definitions used by the kernel and selftests. Furthermore, the selftests header blends implementation detail (e.g. default priority) with the architectural definitions. This is all rather annoying, since bulk imports of the kernel header is not possible. Move selftests-specific definitions out of the offending header and realign tests on the canonical definitions for things like sysregs. Finally, haul in a fresh copy of the gicv3 header to enable a forthcoming ITS selftest. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-14-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: arm64: vgic-its: Get rid of the lpi_list_lockOliver Upton
The last genuine use case for the lpi_list_lock was the global LPI translation cache, which has been removed in favor of a per-ITS xarray. Remove a layer from the locking puzzle by getting rid of it. vgic_add_lpi() still has a critical section that needs to protect against the insertion of other LPIs; change it to take the LPI xarray's xa_lock to retain this property. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-13-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: arm64: vgic-its: Rip out the global translation cacheOliver Upton
The MSI injection fast path has been transitioned away from the global translation cache. Rip it out. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-12-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: arm64: vgic-its: Use the per-ITS translation cache for injectionOliver Upton
Everything is in place to switch to per-ITS translation caches. Start using the per-ITS cache to avoid the lock serialization related to the global translation cache. Explicitly check for out-of-range device and event IDs as the cache index is packed based on the range the ITS actually supports. Take the RCU read lock to protect against the returned descriptor being freed while trying to take a reference on it, as it is no longer necessary to acquire the lpi_list_lock. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-11-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: arm64: vgic-its: Spin off helper for finding ITS by doorbell addrOliver Upton
The fast path will soon need to find an ITS by doorbell address, as the translation caches will become local to an ITS. Spin off a helper to do just that. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-10-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: arm64: vgic-its: Maintain a translation cache per ITSOliver Upton
Within the context of a single ITS, it is possible to use an xarray to cache the device ID & event ID translation to a particular irq descriptor. Take advantage of this to build a translation cache capable of fitting all valid translations for a given ITS. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-9-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: arm64: vgic-its: Scope translation cache invalidations to an ITSOliver Upton
As the current LPI translation cache is global, the corresponding invalidation helpers are also globally-scoped. In anticipation of constructing a translation cache per ITS, add a helper for scoped cache invalidations. We still need to support global invalidations when LPIs are toggled on a redistributor, as a property of the translation cache is that all stored LPIs are known to be delieverable. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-8-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: arm64: vgic-its: Get rid of vgic_copy_lpi_list()Oliver Upton
The last user has been transitioned to walking the LPI xarray directly. Cut the wart off, and get rid of the now unneeded lpi_count while doing so. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-7-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: arm64: vgic-debug: Use an xarray mark for debug iteratorOliver Upton
The vgic debug iterator is the final user of vgic_copy_lpi_list(), but is a bit more complicated to transition to something else. Use a mark in the LPI xarray to record the indices 'known' to the debug iterator. Protect against the LPIs from being freed by associating an additional reference with the xarray mark. Rework iter_next() to let the xarray walk 'drive' the iteration after visiting all of the SGIs, PPIs, and SPIs. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-6-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: arm64: vgic-its: Walk LPI xarray in vgic_its_cmd_handle_movall()Oliver Upton
The new LPI xarray makes it possible to walk the VM's LPIs without holding a lock, meaning that vgic_copy_lpi_list() is no longer necessary. Prepare for the deletion by walking the LPI xarray directly in vgic_its_cmd_handle_movall(). Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-5-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: arm64: vgic-its: Walk LPI xarray in vgic_its_invall()Oliver Upton
The new LPI xarray makes it possible to walk the VM's LPIs without holding a lock, meaning that vgic_copy_lpi_list() is no longer necessary. Prepare for the deletion by walking the LPI xarray directly in vgic_its_invall(). Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-4-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: arm64: vgic-its: Walk LPI xarray in its_sync_lpi_pending_table()Oliver Upton
The new LPI xarray makes it possible to walk the VM's LPIs without holding a lock, meaning that vgic_copy_lpi_list() is no longer necessary. Prepare for the deletion by walking the LPI xarray directly in its_sync_lpi_pending_table(). Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240422200158.2606761-3-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-25KVM: Treat the device list as an rculistOliver Upton
A subsequent change to KVM/arm64 will necessitate walking the device list outside of the kvm->lock. Prepare by converting to an rculist. This has zero effect on the VM destruction path, as it is expected every reader is backed by a reference on the kvm struct. On the other hand, ensure a given device is completely destroyed before dropping the kvm->lock in the release() path, as certain devices expect to be a singleton (e.g. the vfio-kvm device). Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20240422200158.2606761-2-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-23KVM: arm64: nv: Work around lack of pauth support in old toolchainsMarc Zyngier
We still support GCC 8.x, and it appears that this toolchain usually comes with an assembler that does not understand "pauth" as a valid architectural extension. This results in the NV ERETAx code breaking the build, as it relies on this extention to make use of the PACGA instruction (required by assemblers such as LLVM's). Work around it by hand-assembling the instruction, which removes the requirement for any assembler directive. Fixes: 6ccc971ee2c6 ("KVM: arm64: nv: Add emulation for ERETAx instructions") Reported-by: Linaro Kernel Functional Testing <lkft@linaro.org> Suggested-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: Drop trapping of PAuth instructions/keysMarc Zyngier
We currently insist on disabling PAuth on vcpu_load(), and get to enable it on first guest use of an instruction or a key (ignoring the NV case for now). It isn't clear at all what this is trying to achieve: guests tend to use PAuth when available, and nothing forces you to expose it to the guest if you don't want to. This also isn't totally free: we take a full GPR save/restore between host and guest, only to write ten 64bit registers. The "value proposition" escapes me. So let's forget this stuff and enable PAuth eagerly if exposed to the guest. This results in much simpler code. Performance wise, that's not bad either (tested on M2 Pro running a fully automated Debian installer as the workload): - On a non-NV guest, I can see reduction of 0.24% in the number of cycles (measured with perf over 10 consecutive runs) - On a NV guest (L2), I see a 2% reduction in wall-clock time (measured with 'time', as M2 doesn't have a PMUv3 and NV doesn't support it either) So overall, a much reduced complexity and a (small) performance improvement. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-16-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: nv: Advertise support for PAuthMarc Zyngier
Now that we (hopefully) correctly handle ERETAx, drop the masking of the PAuth feature (something that was not even complete, as APA3 and AGA3 were still exposed). Reviewed-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-15-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: nv: Handle ERETA[AB] instructionsMarc Zyngier
Now that we have some emulation in place for ERETA[AB], we can plug it into the exception handling machinery. As for a bare ERET, an "easy" ERETAx instruction is processed as a fixup, while something that requires a translation regime transition or an exception delivery is left to the slow path. Reviewed-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-14-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: nv: Add emulation for ERETAx instructionsMarc Zyngier
FEAT_NV has the interesting property of relying on ERET being trapped. An added complexity is that it also traps ERETAA and ERETAB, meaning that the Pointer Authentication aspect of these instruction must be emulated. Add an emulation of Pointer Authentication, limited to ERETAx (always using SP_EL2 as the modifier and ELR_EL2 as the pointer), using the Generic Authentication instructions. The emulation, however small, is placed in its own compilation unit so that it can be avoided if the configuration doesn't include it (or the toolchan in not up to the task). Reviewed-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-13-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: nv: Add kvm_has_pauth() helperMarc Zyngier
Pointer Authentication comes in many flavors, and a faithful emulation relies on correctly handling the flavour implemented by the HW. For this, provide a new kvm_has_pauth() that checks whether we expose to the guest a particular level of support. This checks across all 3 possible authentication algorithms (Q5, Q3 and IMPDEF). Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-12-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0Marc Zyngier
In order for a L1 hypervisor to correctly handle PAuth instructions, it must observe traps caused by a L1 PAuth instruction when HCR_EL2.API==0. Since we already handle the case for API==1 as a fixup, only the exception injection case needs to be handled. Rework the kvm_handle_ptrauth() callback to reinject the trap in this case. Note that APK==0 is already handled by the exising triage_sysreg_trap() helper. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-11-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: nv: Handle HCR_EL2.{API,APK} independentlyMarc Zyngier
Although KVM couples API and APK for simplicity, the architecture makes no such requirement, and the two can be independently set or cleared. Check for which of the two possible reasons we have trapped here, and if the corresponding L1 control bit isn't set, delegate the handling for forwarding. Otherwise, set this exact bit in HCR_EL2 and resume the guest. Of course, in the non-NV case, we keep setting both bits and be done with it. Note that the entry core already saves/restores the keys should any of the two control bits be set. This results in a bit of rework, and the removal of the (trivial) vcpu_ptrauth_enable() helper. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-10-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: nv: Honor HFGITR_EL2.ERET being setMarc Zyngier
If the L1 hypervisor decides to trap ERETs while running L2, make sure we don't try to emulate it, just like we wouldn't if it had its NV bit set. The exception will be reinjected from the core handler. Reviewed-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-9-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: nv: Fast-track 'InHost' exception returnsMarc Zyngier
A significant part of the FEAT_NV extension is to trap ERET instructions so that the hypervisor gets a chance to switch from a vEL2 L1 guest to an EL1 L2 guest. But this also has the unfortunate consequence of trapping ERET in unsuspecting circumstances, such as staying at vEL2 (interrupt handling while being in the guest hypervisor), or returning to host userspace in the case of a VHE guest. Although we already make some effort to handle these ERET quicker by not doing the put/load dance, it is still way too far down the line for it to be efficient enough. For these cases, it would ideal to ERET directly, no question asked. Of course, we can't do that. But the next best thing is to do it as early as possible, in fixup_guest_exit(), much as we would handle FPSIMD exceptions. Reviewed-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-8-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: nv: Add trap forwarding for ERET and SMCMarc Zyngier
Honor the trap forwarding bits for both ERET and SMC, using a new helper that checks for common conditions. Reviewed-by: Joey Gouly <joey.gouly@arm.com> Co-developed-by: Jintack Lim <jintack.lim@linaro.org> Signed-off-by: Jintack Lim <jintack.lim@linaro.org> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-7-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: nv: Configure HCR_EL2 for FEAT_NV2Marc Zyngier
Add the HCR_EL2 configuration for FEAT_NV2, adding the required bits for running a guest hypervisor, and overall merging the allowed bits provided by the guest. This heavily replies on unavaliable features being sanitised when the HCR_EL2 shadow register is accessed, and only a couple of bits must be explicitly disabled. Non-NV guests are completely unaffected by any of this. Reviewed-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-6-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: nv: Drop VCPU_HYP_CONTEXT flagMarc Zyngier
It has become obvious that HCR_EL2.NV serves the exact same use as VCPU_HYP_CONTEXT, only in an architectural way. So just drop the flag for good. Reviewed-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-5-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: Constraint PAuth support to consistent implementationsMarc Zyngier
PAuth comes it two parts: address authentication, and generic authentication. So far, KVM mandates that both are implemented. PAuth also comes in three flavours: Q5, Q3, and IMPDEF. Only one can be implemented for any of address and generic authentication. Crucially, the architecture doesn't mandate that address and generic authentication implement the *same* flavour. This would make implementing ERETAx very difficult for NV, something we are not terribly keen on. So only allow PAuth support for KVM on systems that are not totally insane. Which is so far 100% of the known HW. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-4-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: Add helpers for ESR_ELx_ERET_ISS_ERET*Marc Zyngier
The ESR_ELx_ERET_ISS_ERET* macros are a bit confusing: - ESR_ELx_ERET_ISS_ERET really indicates that we have trapped an ERETA* instruction, as opposed to an ERET - ESR_ELx_ERET_ISS_ERETA really indicates that we have trapped an ERETAB instruction, as opposed to an ERETAA. We could repaint those to make more sense, but these are the names that are present in the ARM ARM, and we are sentimentally attached to those. Instead, add two new helpers: - esr_iss_is_eretax() being true tells you that you need to authenticate the ERET - esr_iss_is_eretab() tells you that you need to use the B key instead of the A key Following patches will make use of these primitives. Suggested-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-3-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: Harden __ctxt_sys_reg() against out-of-range valuesMarc Zyngier
The unsuspecting kernel tinkerer can be easily confused into writing something that looks like this: ikey.lo = __vcpu_sys_reg(vcpu, SYS_APIAKEYLO_EL1); which seems vaguely sensible, until you realise that the second parameter is the encoding of a sysreg, and not the index into the vcpu sysreg file... Debugging what happens in this case is an interesting exercise in head<->wall interactions. As they often say: "Any resemblance to actual persons, living or dead, or actual events is purely coincidental". In order to save people's time, add some compile-time hardening that will at least weed out the "stupidly out of range" values. This will *not* catch anything that isn't a compile-time constant. Reviewed-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-2-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-12KVM: arm64: Exclude FP ownership from kvm_vcpu_archMarc Zyngier
In retrospect, it is fairly obvious that the FP state ownership is only meaningful for a given CPU, and that locating this information in the vcpu was just a mistake. Move the ownership tracking into the host data structure, and rename it from fp_state to fp_owner, which is a better description (name suggested by Mark Brown). Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-12KVM: arm64: Exclude host_fpsimd_state pointer from kvm_vcpu_archMarc Zyngier
As the name of the field indicates, host_fpsimd_state is strictly a host piece of data, and we reset this pointer on each PID change. So let's move it where it belongs, and set it at load-time. Although this is slightly more often, it is a well defined life-cycle which matches other pieces of data. Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-12KVM: arm64: Exclude mdcr_el2_host from kvm_vcpu_archMarc Zyngier
As for the rest of the host debug state, the host copy of mdcr_el2 has little to do in the vcpu, and is better placed in the host_data structure. Reviewed-by : Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-12KVM: arm64: Exclude host_debug_data from vcpu_archMarc Zyngier
Keeping host_debug_state on a per-vcpu basis is completely pointless. The lifetime of this data is only that of the inner run-loop, which means it is never accessed outside of the core EL2 code. Move the structure into kvm_host_data, and save over 500 bytes per vcpu. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-12KVM: arm64: Add accessor for per-CPU stateMarc Zyngier
In order to facilitate the introduction of new per-CPU state, add a new host_data_ptr() helped that hides some of the per-CPU verbosity, and make it easier to move that state around in the future. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-07Linux 6.9-rc3v6.9-rc3Linus Torvalds
2024-04-07Merge tag 'x86-urgent-2024-04-07' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: - Fix MCE timer reinit locking - Fix/improve CoCo guest random entropy pool init - Fix SEV-SNP late disable bugs - Fix false positive objtool build warning - Fix header dependency bug - Fix resctrl CPU offlining bug * tag 'x86-urgent-2024-04-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/retpoline: Add NOENDBR annotation to the SRSO dummy return thunk x86/mce: Make sure to grab mce_sysfs_mutex in set_bank() x86/CPU/AMD: Track SNP host status with cc_platform_*() x86/cc: Add cc_platform_set/_clear() helpers x86/kvm/Kconfig: Have KVM_AMD_SEV select ARCH_HAS_CC_PLATFORM x86/coco: Require seeding RNG with RDRAND on CoCo systems x86/numa/32: Include missing <asm/pgtable_areas.h> x86/resctrl: Fix uninitialized memory read when last CPU of domain goes offline
2024-04-07Merge tag 'timers-urgent-2024-04-07' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Ingo Molnar: "Fix various timer bugs: - Fix a timer migration bug that may result in missed events - Fix timer migration group hierarchy event updates - Fix a PowerPC64 build warning - Fix a handful of DocBook annotation bugs" * tag 'timers-urgent-2024-04-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers/migration: Return early on deactivation timers/migration: Fix ignored event due to missing CPU update vdso: Use CONFIG_PAGE_SHIFT in vdso/datapage.h timers: Fix text inconsistencies and spelling tick/sched: Fix struct tick_sched doc warnings tick/sched: Fix various kernel-doc warnings timers: Fix kernel-doc format and add Return values time/timekeeping: Fix kernel-doc warnings and typos time/timecounter: Fix inline documentation
2024-04-07Merge tag 'perf-urgent-2024-04-07' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 perf fix from Ingo Molnar: "Fix a combined PEBS events bug on x86 Intel CPUs" * tag 'perf-urgent-2024-04-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel/ds: Don't clear ->pebs_data_cfg for the last PEBS event
2024-04-06Merge tag 'nfsd-6.9-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull nfsd fixes from Chuck Lever: - Address a slow memory leak with RPC-over-TCP - Prevent another NFS4ERR_DELAY loop during CREATE_SESSION * tag 'nfsd-6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: nfsd: hold a lighter-weight client reference over CB_RECALL_ANY SUNRPC: Fix a slow server-side memory leak with RPC-over-TCP
2024-04-06Merge tag 'i2c-for-6.9-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c fix from Wolfram Sang: "A host driver build fix" * tag 'i2c-for-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: pxa: hide unused icr_bits[] variable