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2025-03-19Merge branch 'kvm-arm64/pv-cpuid' into kvmarm/nextOliver Upton
* kvm-arm64/pv-cpuid: : Paravirtualized implementation ID, courtesy of Shameer Kolothum : : Big-little has historically been a pain in the ass to virtualize. The : implementation ID (MIDR, REVIDR, AIDR) of a vCPU can change at the whim : of vCPU scheduling. This can be particularly annoying when the guest : needs to know the underlying implementation to mitigate errata. : : "Hyperscalers" face a similar scheduling problem, where VMs may freely : migrate between hosts in a pool of heterogenous hardware. And yes, our : server-class friends are equally riddled with errata too. : : In absence of an architected solution to this wart on the ecosystem, : introduce support for paravirtualizing the implementation exposed : to a VM, allowing the VMM to describe the pool of implementations that a : VM may be exposed to due to scheduling/migration. : : Userspace is expected to intercept and handle these hypercalls using the : SMCCC filter UAPI, should it choose to do so. smccc: kvm_guest: Fix kernel builds for 32 bit arm KVM: selftests: Add test for KVM_REG_ARM_VENDOR_HYP_BMAP_2 smccc/kvm_guest: Enable errata based on implementation CPUs arm64: Make  _midr_in_range_list() an exported function KVM: arm64: Introduce KVM_REG_ARM_VENDOR_HYP_BMAP_2 KVM: arm64: Specify hypercall ABI for retrieving target implementations arm64: Modify _midr_range() functions to read MIDR/REVIDR internally Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-03KVM: arm64: nv: Nested GICv3 emulationMarc Zyngier
When entering a nested VM, we set up the hypervisor control interface based on what the guest hypervisor has set. Especially, we investigate each list register written by the guest hypervisor whether HW bit is set. If so, we translate hw irq number from the guest's point of view to the real hardware irq number if there is a mapping. Co-developed-by: Jintack Lim <jintack@cs.columbia.edu> Signed-off-by: Jintack Lim <jintack@cs.columbia.edu> [Christoffer: Redesigned execution flow around vcpu load/put] Co-developed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> [maz: Rewritten to support GICv3 instead of GICv2, NV2 support] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250225172930.1850838-9-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-03arm64: sysreg: Add layout for ICH_VTR_EL2Marc Zyngier
The ICH_VTR_EL2-related macros are missing a number of config bits that we are about to handle. Take this opportunity to fully describe the layout of that register as part of the automatic generation infrastructure. This results in a bit of churn to repaint constants that are now generated with a different format. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250225172930.1850838-3-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-03arm64: sysreg: Add layout for ICH_HCR_EL2Marc Zyngier
The ICH_HCR_EL2-related macros are missing a number of control bits that we are about to handle. Take this opportunity to fully describe the layout of that register as part of the automatic generation infrastructure. This results in a bit of churn, unfortunately. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250225172930.1850838-2-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-26arm64: Modify _midr_range() functions to read MIDR/REVIDR internallyShameer Kolothum
These changes lay the groundwork for adding support for guest kernels, allowing them to leverage target CPU implementations provided by the VMM. No functional changes intended. Suggested-by: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Sebastian Ott <sebott@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20250221140229.12588-2-shameerali.kolothum.thodi@huawei.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-01-17Merge branch kvm-arm64/misc-6.14 into kvmarm-master/nextMarc Zyngier
* kvm-arm64/misc-6.14: : . : Misc KVM/arm64 changes for 6.14 : : - Don't expose AArch32 EL0 capability when NV is enabled : : - Update documentation to reflect the full gamut of kvm-arm.mode : behaviours : : - Use the hypervisor VA bit width when dumping stacktraces : : - Decouple the hypervisor stack size from PAGE_SIZE, at least : on the surface... : : - Make use of str_enabled_disabled() when advertising GICv4.1 support : : - Explicitly handle BRBE traps as UNDEFINED : . KVM: arm64: Explicitly handle BRBE traps as UNDEFINED KVM: arm64: vgic: Use str_enabled_disabled() in vgic_v3_probe() arm64: kvm: Introduce nvhe stack size constants KVM: arm64: Fix nVHE stacktrace VA bits mask Documentation: Update the behaviour of "kvm-arm.mode" KVM: arm64: nv: Advertise the lack of AArch32 EL0 support Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-11KVM: arm64: vgic: Use str_enabled_disabled() in vgic_v3_probe()Thorsten Blum
Remove hard-coded strings by using the str_enabled_disabled() helper function. Suggested-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20250110225310.369980-2-thorsten.blum@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-12-20KVM: arm64: Introduce __pkvm_vcpu_{load,put}()Marc Zyngier
Rather than look-up the hyp vCPU on every run hypercall at EL2, introduce a per-CPU 'loaded_hyp_vcpu' tracking variable which is updated by a pair of load/put hypercalls called directly from kvm_arch_vcpu_{load,put}() when pKVM is enabled. Tested-by: Fuad Tabba <tabba@google.com> Reviewed-by: Fuad Tabba <tabba@google.com> Signed-off-by: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20241218194059.3670226-10-qperret@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-11-20KVM: arm64: vgic: Make vgic_get_irq() more robustMarc Zyngier
vgic_get_irq() has an awkward signature, as it takes both a kvm *and* a vcpu, where the vcpu is allowed to be NULL if the INTID being looked up is a global interrupt (SPI or LPI). This leads to potentially problematic situations where the INTID passed is a private interrupt, but that there is no vcpu. In order to make things less ambiguous, let have *two* helpers instead: - vgic_get_irq(struct kvm *kvm, u32 intid), which is only concerned with *global* interrupts, as indicated by the lack of vcpu. - vgic_get_vcpu_irq(struct kvm_vcpu *vcpu, u32 intid), which can return *any* interrupt class, but must have of course a non-NULL vcpu. Most of the code nicely falls under one or the other situations, except for a couple of cases (close to the UABI or in the debug code) where we have to distinguish between the two cases. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20241117165757.247686-3-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-08-27KVM: arm64: Force SRE traps when SRE access is not enabledMarc Zyngier
We so far only write the ICH_HCR_EL2 config in two situations: - when we need to emulate the GICv3 CPU interface due to HW bugs - when we do direct injection, as the virtual CPU interface needs to be enabled This is all good. But it also means that we don't do anything special when we emulate a GICv2, or that there is no GIC at all. What happens in this case when the guest uses the GICv3 system registers? The *guest* gets a trap for a sysreg access (EC=0x18) while we'd really like it to get an UNDEF. Fixing this is a bit involved: - we need to set all the required trap bits (TC, TALL0, TALL1, TDIR) - for these traps to take effect, we need to (counter-intuitively) set ICC_SRE_EL1.SRE to 1 so that the above traps take priority. Note that doesn't fully work when GICv2 emulation is enabled, as we cannot set ICC_SRE_EL1.SRE to 1 (it breaks Group0 delivery as IRQ). Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240827152517.3909653-3-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-08-27KVM: arm64: Move GICv3 trap configuration to kvm_calculate_traps()Marc Zyngier
Follow the pattern introduced with vcpu_set_hcr(), and introduce vcpu_set_ich_hcr(), which configures the GICv3 traps at the same point. This will allow future changes to introduce trap configuration on a per-VM basis. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240827152517.3909653-2-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-08-02KVM: arm64: fix kdoc warnings in W=1 buildsSebastian Ott
Fix kdoc warnings by adding missing function parameter descriptions or by conversion to a normal comment. Signed-off-by: Sebastian Ott <sebott@redhat.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240723101204.7356-3-sebott@redhat.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-05-01KVM: arm64: Simplify vgic-v3 hypercallsMarc Zyngier
Consolidate the GICv3 VMCR accessor hypercalls into the APR save/restore hypercalls so that all of the EL2 GICv3 state is covered by a single pair of hypercalls. Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240423150538.2103045-17-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-02-23KVM: arm64: vgic-v3: Iterate the xarray to find pending LPIsOliver Upton
Start walking the LPI xarray to find pending LPIs in preparation for the removal of the LPI linked-list. Note that the 'basic' iterator is chosen here as each iteration needs to drop the xarray read lock (RCU) as reads/writes to guest memory can potentially block. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240221054253.3848076-4-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-16arm64: kvm: Use cpus_have_final_cap() explicitlyMark Rutland
Much of the arm64 KVM code uses cpus_have_const_cap() to check for cpucaps, but this is unnecessary and it would be preferable to use cpus_have_final_cap(). For historical reasons, cpus_have_const_cap() is more complicated than it needs to be. Before cpucaps are finalized, it will perform a bitmap test of the system_cpucaps bitmap, and once cpucaps are finalized it will use an alternative branch. This used to be necessary to handle some race conditions in the window between cpucap detection and the subsequent patching of alternatives and static branches, where different branches could be out-of-sync with one another (or w.r.t. alternative sequences). Now that we use alternative branches instead of static branches, these are all patched atomically w.r.t. one another, and there are only a handful of cases that need special care in the window between cpucap detection and alternative patching. Due to the above, it would be nice to remove cpus_have_const_cap(), and migrate callers over to alternative_has_cap_*(), cpus_have_final_cap(), or cpus_have_cap() depending on when their requirements. This will remove redundant instructions and improve code generation, and will make it easier to determine how each callsite will behave before, during, and after alternative patching. KVM is initialized after cpucaps have been finalized and alternatives have been patched. Since commit: d86de40decaa14e6 ("arm64: cpufeature: upgrade hyp caps to final") ... use of cpus_have_const_cap() in hyp code is automatically converted to use cpus_have_final_cap(): | static __always_inline bool cpus_have_const_cap(int num) | { | if (is_hyp_code()) | return cpus_have_final_cap(num); | else if (system_capabilities_finalized()) | return __cpus_have_const_cap(num); | else | return cpus_have_cap(num); | } Thus, converting hyp code to use cpus_have_final_cap() directly will not result in any functional change. Non-hyp KVM code is also not executed until cpucaps have been finalized, and it would be preferable to extent the same treatment to this code and use cpus_have_final_cap() directly. This patch converts instances of cpus_have_const_cap() in KVM-only code over to cpus_have_final_cap(). As all of this code runs after cpucaps have been finalized, there should be no functional change as a result of this patch, but the redundant instructions generated by cpus_have_const_cap() will be removed from the non-hyp KVM code. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-07-13KVM: arm64: vgic-v4: Make the doorbell request robust w.r.t preemptionMarc Zyngier
Xiang reports that VMs occasionally fail to boot on GICv4.1 systems when running a preemptible kernel, as it is possible that a vCPU is blocked without requesting a doorbell interrupt. The issue is that any preemption that occurs between vgic_v4_put() and schedule() on the block path will mark the vPE as nonresident and *not* request a doorbell irq. This occurs because when the vcpu thread is resumed on its way to block, vcpu_load() will make the vPE resident again. Once the vcpu actually blocks, we don't request a doorbell anymore, and the vcpu won't be woken up on interrupt delivery. Fix it by tracking that we're entering WFI, and key the doorbell request on that flag. This allows us not to make the vPE resident when going through a preempt/schedule cycle, meaning we don't lose any state. Cc: stable@vger.kernel.org Fixes: 8e01d9a396e6 ("KVM: arm64: vgic-v4: Move the GICv4 residency flow to be driven by vcpu_load/put") Reported-by: Xiang Chen <chenxiang66@hisilicon.com> Suggested-by: Zenghui Yu <yuzenghui@huawei.com> Tested-by: Xiang Chen <chenxiang66@hisilicon.com> Co-developed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Zenghui Yu <yuzenghui@huawei.com> Link: https://lore.kernel.org/r/20230713070657.3873244-1-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-05-19KVM: arm64: vgic: Fix a circular locking issueJean-Philippe Brucker
Lockdep reports a circular lock dependency between the srcu and the config_lock: [ 262.179917] -> #1 (&kvm->srcu){.+.+}-{0:0}: [ 262.182010] __synchronize_srcu+0xb0/0x224 [ 262.183422] synchronize_srcu_expedited+0x24/0x34 [ 262.184554] kvm_io_bus_register_dev+0x324/0x50c [ 262.185650] vgic_register_redist_iodev+0x254/0x398 [ 262.186740] vgic_v3_set_redist_base+0x3b0/0x724 [ 262.188087] kvm_vgic_addr+0x364/0x600 [ 262.189189] vgic_set_common_attr+0x90/0x544 [ 262.190278] vgic_v3_set_attr+0x74/0x9c [ 262.191432] kvm_device_ioctl+0x2a0/0x4e4 [ 262.192515] __arm64_sys_ioctl+0x7ac/0x1ba8 [ 262.193612] invoke_syscall.constprop.0+0x70/0x1e0 [ 262.195006] do_el0_svc+0xe4/0x2d4 [ 262.195929] el0_svc+0x44/0x8c [ 262.196917] el0t_64_sync_handler+0xf4/0x120 [ 262.198238] el0t_64_sync+0x190/0x194 [ 262.199224] [ 262.199224] -> #0 (&kvm->arch.config_lock){+.+.}-{3:3}: [ 262.201094] __lock_acquire+0x2b70/0x626c [ 262.202245] lock_acquire+0x454/0x778 [ 262.203132] __mutex_lock+0x190/0x8b4 [ 262.204023] mutex_lock_nested+0x24/0x30 [ 262.205100] vgic_mmio_write_v3_misc+0x5c/0x2a0 [ 262.206178] dispatch_mmio_write+0xd8/0x258 [ 262.207498] __kvm_io_bus_write+0x1e0/0x350 [ 262.208582] kvm_io_bus_write+0xe0/0x1cc [ 262.209653] io_mem_abort+0x2ac/0x6d8 [ 262.210569] kvm_handle_guest_abort+0x9b8/0x1f88 [ 262.211937] handle_exit+0xc4/0x39c [ 262.212971] kvm_arch_vcpu_ioctl_run+0x90c/0x1c04 [ 262.214154] kvm_vcpu_ioctl+0x450/0x12f8 [ 262.215233] __arm64_sys_ioctl+0x7ac/0x1ba8 [ 262.216402] invoke_syscall.constprop.0+0x70/0x1e0 [ 262.217774] do_el0_svc+0xe4/0x2d4 [ 262.218758] el0_svc+0x44/0x8c [ 262.219941] el0t_64_sync_handler+0xf4/0x120 [ 262.221110] el0t_64_sync+0x190/0x194 Note that the current report, which can be triggered by the vgic_irq kselftest, is a triple chain that includes slots_lock, but after inverting the slots_lock/config_lock dependency, the actual problem reported above remains. In several places, the vgic code calls kvm_io_bus_register_dev(), which synchronizes the srcu, while holding config_lock (#1). And the MMIO handler takes the config_lock while holding the srcu read lock (#0). Break dependency #1, by registering the distributor and redistributors without holding config_lock. The ITS also uses kvm_io_bus_register_dev() but already relies on slots_lock to serialize calls. The distributor iodev is created on the first KVM_RUN call. Multiple threads will race for vgic initialization, and only the first one will see !vgic_ready() under the lock. To serialize those threads, rely on slots_lock rather than config_lock. Redistributors are created earlier, through KVM_DEV_ARM_VGIC_GRP_ADDR ioctls and vCPU creation. Similarly, serialize the iodev creation with slots_lock, and the rest with config_lock. Fixes: f00327731131 ("KVM: arm64: Use config_lock to protect vgic state") Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230518100914.2837292-2-jean-philippe@linaro.org
2023-05-11KVM: arm64: vgic: Add Apple M2 PRO/MAX cpus to the list of broken SEIS ↵Marc Zyngier
implementations Unsurprisingly, the M2 PRO is also affected by the SEIS bug, so add it to the naughty list. And since M2 MAX is likely to be of the same ilk, flag it as well. Tested on a M2 PRO mini machine. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Link: https://lore.kernel.org/r/20230501182141.39770-1-maz@kernel.org
2023-02-20Merge tag 'kvmarm-6.3' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 6.3 - Provide a virtual cache topology to the guest to avoid inconsistencies with migration on heterogenous systems. Non secure software has no practical need to traverse the caches by set/way in the first place. - Add support for taking stage-2 access faults in parallel. This was an accidental omission in the original parallel faults implementation, but should provide a marginal improvement to machines w/o FEAT_HAFDBS (such as hardware from the fruit company). - A preamble to adding support for nested virtualization to KVM, including vEL2 register state, rudimentary nested exception handling and masking unsupported features for nested guests. - Fixes to the PSCI relay that avoid an unexpected host SVE trap when resuming a CPU when running pKVM. - VGIC maintenance interrupt support for the AIC - Improvements to the arch timer emulation, primarily aimed at reducing the trap overhead of running nested. - Add CONFIG_USERFAULTFD to the KVM selftests config fragment in the interest of CI systems. - Avoid VM-wide stop-the-world operations when a vCPU accesses its own redistributor. - Serialize when toggling CPACR_EL1.SMEN to avoid unexpected exceptions in the host. - Aesthetic and comment/kerneldoc fixes - Drop the vestiges of the old Columbia mailing list and add [Oliver] as co-maintainer This also drags in arm64's 'for-next/sme2' branch, because both it and the PSCI relay changes touch the EL2 initialization code.
2023-02-13Merge branch kvm-arm64/misc into kvmarm/nextOliver Upton
* kvm-arm64/misc: : Miscellaneous updates : : - Convert CPACR_EL1_TTA to the new, generated system register : definitions. : : - Serialize toggling CPACR_EL1.SMEN to avoid unexpected exceptions when : accessing SVCR in the host. : : - Avoid quiescing the guest if a vCPU accesses its own redistributor's : SGIs/PPIs, eliminating the need to IPI. Largely an optimization for : nested virtualization, as the L1 accesses the affected registers : rather often. : : - Conversion to kstrtobool() : : - Common definition of INVALID_GPA across architectures : : - Enable CONFIG_USERFAULTFD for CI runs of KVM selftests KVM: arm64: Fix non-kerneldoc comments KVM: selftests: Enable USERFAULTFD KVM: selftests: Remove redundant setbuf() arm64/sysreg: clean up some inconsistent indenting KVM: MMU: Make the definition of 'INVALID_GPA' common KVM: arm64: vgic-v3: Use kstrtobool() instead of strtobool() KVM: arm64: vgic-v3: Limit IPI-ing when accessing GICR_{C,S}ACTIVER0 KVM: arm64: Synchronize SMEN on vcpu schedule out KVM: arm64: Kill CPACR_EL1_TTA definition Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-01-29KVM: arm64: Allow no running vcpu on saving vgic3 pending tableGavin Shan
We don't have a running VCPU context to save vgic3 pending table due to KVM_DEV_ARM_VGIC_{GRP_CTRL, SAVE_PENDING_TABLES} command on KVM device "kvm-arm-vgic-v3". The unknown case is caught by kvm-unit-tests. # ./kvm-unit-tests/tests/its-pending-migration WARNING: CPU: 120 PID: 7973 at arch/arm64/kvm/../../../virt/kvm/kvm_main.c:3325 \ mark_page_dirty_in_slot+0x60/0xe0 : mark_page_dirty_in_slot+0x60/0xe0 __kvm_write_guest_page+0xcc/0x100 kvm_write_guest+0x7c/0xb0 vgic_v3_save_pending_tables+0x148/0x2a0 vgic_set_common_attr+0x158/0x240 vgic_v3_set_attr+0x4c/0x5c kvm_device_ioctl+0x100/0x160 __arm64_sys_ioctl+0xa8/0xf0 invoke_syscall.constprop.0+0x7c/0xd0 el0_svc_common.constprop.0+0x144/0x160 do_el0_svc+0x34/0x60 el0_svc+0x3c/0x1a0 el0t_64_sync_handler+0xb4/0x130 el0t_64_sync+0x178/0x17c Use vgic_write_guest_lock() to save vgic3 pending table. Reported-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230126235451.469087-5-gshan@redhat.com
2023-01-29KVM: arm64: Allow no running vcpu on restoring vgic3 LPI pending statusGavin Shan
We don't have a running VCPU context to restore vgic3 LPI pending status due to command KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_RESTORE_TABLES} on KVM device "kvm-arm-vgic-its". Use vgic_write_guest_lock() to restore vgic3 LPI pending status. Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230126235451.469087-4-gshan@redhat.com
2023-01-21KVM: arm64: GICv4.1: Fix race with doorbell on VPE activation/deactivationMarc Zyngier
To save the vgic LPI pending state with GICv4.1, the VPEs must all be unmapped from the ITSs so that the sGIC caches can be flushed. The opposite is done once the state is saved. This is all done by using the activate/deactivate irqdomain callbacks directly from the vgic code. Crutially, this is done without holding the irqdesc lock for the interrupts that represent the VPE. And these callbacks are changing the state of the irqdesc. What could possibly go wrong? If a doorbell fires while we are messing with the irqdesc state, it will acquire the lock and change the interrupt state concurrently. Since we don't hole the lock, curruption occurs in on the interrupt state. Oh well. While acquiring the lock would fix this (and this was Shanker's initial approach), this is still a layering violation we could do without. A better approach is actually to free the VPE interrupt, do what we have to do, and re-request it. It is more work, but this usually happens only once in the lifetime of the VM and we don't really care about this sort of overhead. Fixes: f66b7b151e00 ("KVM: arm64: GICv4.1: Try to save VLPI state in save_pending_tables") Reported-by: Shanker Donthineni <sdonthineni@nvidia.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230118022348.4137094-1-sdonthineni@nvidia.com
2023-01-17KVM: arm64: vgic-v3: Use kstrtobool() instead of strtobool()Christophe JAILLET
strtobool() is the same as kstrtobool(). However, the latter is more used within the kernel. In order to remove strtobool() and slightly simplify kstrtox.h, switch to the other function name. While at it, include the corresponding header file (<linux/kstrtox.h>) Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Link: https://lore.kernel.org/r/f546e636c6d2bbcc0d8c4191ab98ce892fce4584.1673702763.git.christophe.jaillet@wanadoo.fr Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-01-05KVM: arm64: vgic: Add Apple M2 cpus to the list of broken SEIS implementationsMarc Zyngier
I really hoped that Apple had fixed their not-quite-a-vgic implementation when moving from M1 to M2. Alas, it seems they didn't, and running a buggy EFI version results in the vgic generating SErrors outside of the guest and taking the host down. Apply the same workaround as for M1. Yes, this is all a bit crap. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230103095022.3230946-2-maz@kernel.org
2022-05-15KVM: arm64: vgic-v3: List M1 Pro/Max as requiring the SEIS workaroundMarc Zyngier
Unsusprisingly, Apple M1 Pro/Max have the exact same defect as the original M1 and generate random SErrors in the host when a guest tickles the GICv3 CPU interface the wrong way. Add the part numbers for both the CPU types found in these two new implementations, and add them to the hall of shame. This also applies to the Ultra version, as it is composed of 2 Max SoCs. Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20220514102524.3188730-1-maz@kernel.org
2022-01-28Merge tag 'kvmarm-fixes-5.17-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 5.17, take #1 - Correctly update the shadow register on exception injection when running in nVHE mode - Correctly use the mm_ops indirection when performing cache invalidation from the page-table walker - Restrict the vgic-v3 workaround for SEIS to the two known broken implementations
2022-01-22KVM: arm64: vgic-v3: Restrict SEIS workaround to known broken systemsMarc Zyngier
Contrary to what df652bcf1136 ("KVM: arm64: vgic-v3: Work around GICv3 locally generated SErrors") was asserting, there is at least one other system out there (Cavium ThunderX2) implementing SEIS, and not in an obviously broken way. So instead of imposing the M1 workaround on an innocent bystander, let's limit it to the two known broken Apple implementations. Fixes: df652bcf1136 ("KVM: arm64: vgic-v3: Work around GICv3 locally generated SErrors") Reported-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220122103912.795026-1-maz@kernel.org
2022-01-07Merge tag 'kvmarm-5.17' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for Linux 5.16 - Simplification of the 'vcpu first run' by integrating it into KVM's 'pid change' flow - Refactoring of the FP and SVE state tracking, also leading to a simpler state and less shared data between EL1 and EL2 in the nVHE case - Tidy up the header file usage for the nvhe hyp object - New HYP unsharing mechanism, finally allowing pages to be unmapped from the Stage-1 EL2 page-tables - Various pKVM cleanups around refcounting and sharing - A couple of vgic fixes for bugs that would trigger once the vcpu xarray rework is merged, but not sooner - Add minimal support for ARMv8.7's PMU extension - Rework kvm_pgtable initialisation ahead of the NV work - New selftest for IRQ injection - Teach selftests about the lack of default IPA space and page sizes - Expand sysreg selftest to deal with Pointer Authentication - The usual bunch of cleanups and doc update
2021-12-16Merge branch kvm-arm64/vgic-fixes-5.17 into kvmarm-master/nextMarc Zyngier
* kvm-arm64/vgic-fixes-5.17: : . : A few vgic fixes: : - Harden vgic-v3 error handling paths against signed vs unsigned : comparison that will happen once the xarray-based vcpus are in : - Demote userspace-triggered console output to kvm_debug() : . KVM: arm64: vgic: Demote userspace-triggered console prints to kvm_debug() KVM: arm64: vgic-v3: Fix vcpu index comparison Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-12-16KVM: arm64: vgic: Demote userspace-triggered console prints to kvm_debug()Marc Zyngier
Running the KVM selftests results in these messages being dumped in the kernel console: [ 188.051073] kvm [469]: VGIC redist and dist frames overlap [ 188.056820] kvm [469]: VGIC redist and dist frames overlap [ 188.076199] kvm [469]: VGIC redist and dist frames overlap Being amle to trigger this from userspace is definitely not on, so demote these warnings to kvm_debug(). Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211216104507.1482017-1-maz@kernel.org
2021-12-15KVM: arm64: pkvm: Disable GICv2 supportQuentin Perret
GICv2 requires having device mappings in guests and the hypervisor, which is incompatible with the current pKVM EL2 page ownership model which only covers memory. While it would be desirable to support pKVM with GICv2, this will require a lot more work, so let's make the current assumption clear until then. Co-developed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20211208152300.2478542-3-qperret@google.com
2021-12-08KVM: Use 'unsigned long' as kvm_for_each_vcpu()'s indexMarc Zyngier
Everywhere we use kvm_for_each_vpcu(), we use an int as the vcpu index. Unfortunately, we're about to move rework the iterator, which requires this to be upgrade to an unsigned long. Let's bite the bullet and repaint all of it in one go. Signed-off-by: Marc Zyngier <maz@kernel.org> Message-Id: <20211116160403.4074052-7-maz@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-17Merge branch kvm-arm64/vgic-fixes-5.16 into kvmarm-master/nextMarc Zyngier
* kvm-arm64/vgic-fixes-5.16: : . : Multiple updates to the GICv3 emulation in order to better support : the dreadful Apple M1 that only implements half of it, and in a : broken way... : . KVM: arm64: vgic-v3: Align emulated cpuif LPI state machine with the pseudocode KVM: arm64: vgic-v3: Don't advertise ICC_CTLR_EL1.SEIS KVM: arm64: vgic-v3: Reduce common group trapping to ICV_DIR_EL1 when possible KVM: arm64: vgic-v3: Work around GICv3 locally generated SErrors KVM: arm64: Force ID_AA64PFR0_EL1.GIC=1 when exposing a virtual GICv3 Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-10-17KVM: arm64: vgic-v3: Reduce common group trapping to ICV_DIR_EL1 when possibleMarc Zyngier
On systems that advertise ICH_VTR_EL2.SEIS, we trap all GICv3 sysreg accesses from the guest. From a performance perspective, this is OK as long as the guest doesn't hammer the GICv3 CPU interface. In most cases, this is fine, unless the guest actively uses priorities and switches PMR_EL1 very often. Which is exactly what happens when a Linux guest runs with irqchip.gicv3_pseudo_nmi=1. In these condition, the performance plumets as we hit PMR each time we mask/unmask interrupts. Not good. There is however an opportunity for improvement. Careful reading of the architecture specification indicates that the only GICv3 sysreg belonging to the common group (which contains the SGI registers, PMR, DIR, CTLR and RPR) that is allowed to generate a SError is DIR. Everything else is safe. It is thus possible to substitute the trapping of all the common group with just that of DIR if it supported by the implementation. Yes, that's yet another optional bit of the architecture. So let's just do that, as it leads to some impressive result on the M1: Without this change: bash-5.1# /host/home/maz/hackbench 100 process 1000 Running with 100*40 (== 4000) tasks. Time: 56.596 With this change: bash-5.1# /host/home/maz/hackbench 100 process 1000 Running with 100*40 (== 4000) tasks. Time: 8.649 which is a pretty convincing result. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Link: https://lore.kernel.org/r/20211010150910.2911495-4-maz@kernel.org
2021-10-17KVM: arm64: vgic-v3: Work around GICv3 locally generated SErrorsMarc Zyngier
The infamous M1 has a feature nobody else ever implemented, in the form of the "GIC locally generated SError interrupts", also known as SEIS for short. These SErrors are generated when a guest does something that violates the GIC state machine. It would have been simpler to just *ignore* the damned thing, but that's not what this HW does. Oh well. This part of of the architecture is also amazingly under-specified. There is a whole 10 lines that describe the feature in a spec that is 930 pages long, and some of these lines are factually wrong. Oh, and it is deprecated, so the insentive to clarify it is low. Now, the spec says that this should be a *virtual* SError when HCR_EL2.AMO is set. As it turns out, that's not always the case on this CPU, and the SError sometimes fires on the host as a physical SError. Goodbye, cruel world. This clearly is a HW bug, and it means that a guest can easily take the host down, on demand. Thankfully, we have seen systems that were just as broken in the past, and we have the perfect vaccine for it. Apple M1, please meet the Cavium ThunderX workaround. All your GIC accesses will be trapped, sanitised, and emulated. Only the signalling aspect of the HW will be used. It won't be super speedy, but it will at least be safe. You're most welcome. Given that this has only ever been seen on this single implementation, that the spec is unclear at best and that we cannot trust it to ever be implemented correctly, gate the workaround solely on ICH_VTR_EL2.SEIS being set. Tested-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211010150910.2911495-3-maz@kernel.org
2021-10-11KVM: arm64: vgic-v3: Check redist region is not above the VM IPA sizeRicardo Koller
Verify that the redistributor regions do not extend beyond the VM-specified IPA range (phys_size). This can happen when using KVM_VGIC_V3_ADDR_TYPE_REDIST or KVM_VGIC_V3_ADDR_TYPE_REDIST_REGIONS with: base + size > phys_size AND base < phys_size Add the missing check into vgic_v3_alloc_redist_region() which is called when setting the regions, and into vgic_v3_check_base() which is called when attempting the first vcpu-run. The vcpu-run check does not apply to KVM_VGIC_V3_ADDR_TYPE_REDIST_REGIONS because the regions size is known before the first vcpu-run. Note that using the REDIST_REGIONS API results in a different check, which already exists, at first vcpu run: that the number of redist regions is enough for all vcpus. Finally, this patch also enables some extra tests in vgic_v3_alloc_redist_region() by calculating "size" early for the legacy redist api: like checking that the REDIST region can fit all the already created vcpus. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211005011921.437353-3-ricarkol@google.com
2021-08-20KVM: arm64: vgic: Resample HW pending state on deactivationMarc Zyngier
When a mapped level interrupt (a timer, for example) is deactivated by the guest, the corresponding host interrupt is equally deactivated. However, the fate of the pending state still needs to be dealt with in SW. This is specially true when the interrupt was in the active+pending state in the virtual distributor at the point where the guest was entered. On exit, the pending state is potentially stale (the guest may have put the interrupt in a non-pending state). If we don't do anything, the interrupt will be spuriously injected in the guest. Although this shouldn't have any ill effect (spurious interrupts are always possible), we can improve the emulation by detecting the deactivation-while-pending case and resample the interrupt. While we're at it, move the logic into a common helper that can be shared between the two GIC implementations. Fixes: e40cc57bac79 ("KVM: arm/arm64: vgic: Support level-triggered mapped interrupts") Reported-by: Raghavendra Rao Ananta <rananta@google.com> Tested-by: Raghavendra Rao Ananta <rananta@google.com> Reviewed-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210819180305.1670525-1-maz@kernel.org
2021-06-01KVM: arm64: vgic: Implement SW-driven deactivationMarc Zyngier
In order to deal with these systems that do not offer HW-based deactivation of interrupts, let implement a SW-based approach: - When the irq is queued into a LR, treat it as a pure virtual interrupt and set the EOI flag in the LR. - When the interrupt state is read back from the LR, force a deactivation when the state is invalid (neither active nor pending) Interrupts requiring such treatment get the VGIC_SW_RESAMPLE flag. Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-03-24KVM: arm64: GICv4.1: Try to save VLPI state in save_pending_tablesShenming Lu
After pausing all vCPUs and devices capable of interrupting, in order to save the states of all interrupts, besides flushing the states in kvm’s vgic, we also try to flush the states of VLPIs in the virtual pending tables into guest RAM, but we need to have GICv4.1 and safely unmap the vPEs first. As for the saving of VSGIs, which needs the vPEs to be mapped and might conflict with the saving of VLPIs, but since we will map the vPEs back at the end of save_pending_tables and both savings require the kvm->lock to be held (thus only happen serially), it will work fine. Signed-off-by: Shenming Lu <lushenming@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210322060158.1584-5-lushenming@huawei.com
2021-03-06KVM: arm64: Workaround firmware wrongly advertising GICv2-on-v3 compatibilityMarc Zyngier
It looks like we have broken firmware out there that wrongly advertises a GICv2 compatibility interface, despite the CPUs not being able to deal with it. To work around this, check that the CPU initialising KVM is actually able to switch to MMIO instead of system registers, and use that as a precondition to enable GICv2 compatibility in KVM. Note that the detection happens on a single CPU. If the firmware is lying *and* that the CPUs are asymetric, all hope is lost anyway. Reported-by: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Message-Id: <20210305185254.3730990-8-maz@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-06KVM: arm64: Rename __vgic_v3_get_ich_vtr_el2() to __vgic_v3_get_gic_config()Marc Zyngier
As we are about to report a bit more information to the rest of the kernel, rename __vgic_v3_get_ich_vtr_el2() to the more explicit __vgic_v3_get_gic_config(). No functional change. Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Message-Id: <20210305185254.3730990-7-maz@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-27KVM: arm64: Consolidate dist->ready setting into kvm_vgic_map_resources()Marc Zyngier
dist->ready setting is pointlessly spread across the two vgic backends, while it could be consolidated in kvm_vgic_map_resources(). Move it there, and slightly simplify the flows in both backends. Suggested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-12-23KVM: arm64: Move double-checked lock to kvm_vgic_map_resources()Alexandru Elisei
kvm_vgic_map_resources() is called when a VCPU if first run and it maps all the VGIC MMIO regions. To prevent double-initialization, the VGIC uses the ready variable to keep track of the state of resources and the global KVM mutex to protect against concurrent accesses. After the lock is taken, the variable is checked again in case another VCPU took the lock between the current VCPU reading ready equals false and taking the lock. The double-checked lock pattern is spread across four different functions: in kvm_vcpu_first_run_init(), in kvm_vgic_map_resource() and in vgic_{v2,v3}_map_resources(), which makes it hard to reason about and introduces minor code duplication. Consolidate the checks in kvm_vgic_map_resources(), where the lock is taken. No functional change intended. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201201150157.223625-4-alexandru.elisei@arm.com
2020-09-15KVM: arm64: nVHE: Fix pointers during SMCCC convertionAndrew Scull
The host need not concern itself with the pointer differences for the hyp interfaces that are shared between VHE and nVHE so leave it to the hyp to handle. As the SMCCC function IDs are converted into function calls, it is a suitable place to also convert any pointer arguments into hyp pointers. This, additionally, eases the reuse of the handlers in different contexts. Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200915104643.2543892-20-ascull@google.com
2020-05-28KVM: arm64: vgic-v3: Take cpu_if pointer directly instead of vcpuChristoffer Dall
If we move the used_lrs field to the version-specific cpu interface structure, the following functions only operate on the struct vgic_v3_cpu_if and not the full vcpu: __vgic_v3_save_state __vgic_v3_restore_state __vgic_v3_activate_traps __vgic_v3_deactivate_traps __vgic_v3_save_aprs __vgic_v3_restore_aprs This is going to be very useful for nested virt, so move the used_lrs field and change the prototypes and implementations of these functions to take the cpu_if parameter directly. No functional change. Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-05-16KVM: Fix spelling in code commentsFuad Tabba
Fix spelling and typos (e.g., repeated words) in comments. Signed-off-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200401140310.29701-1-tabba@google.com
2020-05-16KVM: arm64: Move virt/kvm/arm to arch/arm64Marc Zyngier
Now that the 32bit KVM/arm host is a distant memory, let's move the whole of the KVM/arm64 code into the arm64 tree. As they said in the song: Welcome Home (Sanitarium). Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200513104034.74741-1-maz@kernel.org