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* KVM: s390: pv: don't allow userspace to set the clock under PVNico Boehr2022-11-071-9/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When running under PV, the guest's TOD clock is under control of the ultravisor and the hypervisor isn't allowed to change it. Hence, don't allow userspace to change the guest's TOD clock by returning -EOPNOTSUPP. When userspace changes the guest's TOD clock, KVM updates its kvm.arch.epoch field and, in addition, the epoch field in all state descriptions of all VCPUs. But, under PV, the ultravisor will ignore the epoch field in the state description and simply overwrite it on next SIE exit with the actual guest epoch. This leads to KVM having an incorrect view of the guest's TOD clock: it has updated its internal kvm.arch.epoch field, but the ultravisor ignores the field in the state description. Whenever a guest is now waiting for a clock comparator, KVM will incorrectly calculate the time when the guest should wake up, possibly causing the guest to sleep for much longer than expected. With this change, kvm_s390_set_tod() will now take the kvm->lock to be able to call kvm_s390_pv_is_protected(). Since kvm_s390_set_tod_clock() also takes kvm->lock, use __kvm_s390_set_tod_clock() instead. The function kvm_s390_set_tod_clock is now unused, hence remove it. Update the documentation to indicate the TOD clock attr calls can now return -EOPNOTSUPP. Fixes: 0f3035047140 ("KVM: s390: protvirt: Do only reset registers that are accessible") Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com> Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20221011160712.928239-2-nrb@linux.ibm.com Message-Id: <20221011160712.928239-2-nrb@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
* Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2022-10-091-2/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull kvm updates from Paolo Bonzini: "The first batch of KVM patches, mostly covering x86. ARM: - Account stage2 page table allocations in memory stats x86: - Account EPT/NPT arm64 page table allocations in memory stats - Tracepoint cleanups/fixes for nested VM-Enter and emulated MSR accesses - Drop eVMCS controls filtering for KVM on Hyper-V, all known versions of Hyper-V now support eVMCS fields associated with features that are enumerated to the guest - Use KVM's sanitized VMCS config as the basis for the values of nested VMX capabilities MSRs - A myriad event/exception fixes and cleanups. Most notably, pending exceptions morph into VM-Exits earlier, as soon as the exception is queued, instead of waiting until the next vmentry. This fixed a longstanding issue where the exceptions would incorrecly become double-faults instead of triggering a vmexit; the common case of page-fault vmexits had a special workaround, but now it's fixed for good - A handful of fixes for memory leaks in error paths - Cleanups for VMREAD trampoline and VMX's VM-Exit assembly flow - Never write to memory from non-sleepable kvm_vcpu_check_block() - Selftests refinements and cleanups - Misc typo cleanups Generic: - remove KVM_REQ_UNHALT" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (94 commits) KVM: remove KVM_REQ_UNHALT KVM: mips, x86: do not rely on KVM_REQ_UNHALT KVM: x86: never write to memory from kvm_vcpu_check_block() KVM: x86: Don't snapshot pending INIT/SIPI prior to checking nested events KVM: nVMX: Make event request on VMXOFF iff INIT/SIPI is pending KVM: nVMX: Make an event request if INIT or SIPI is pending on VM-Enter KVM: SVM: Make an event request if INIT or SIPI is pending when GIF is set KVM: x86: lapic does not have to process INIT if it is blocked KVM: x86: Rename kvm_apic_has_events() to make it INIT/SIPI specific KVM: x86: Rename and expose helper to detect if INIT/SIPI are allowed KVM: nVMX: Make an event request when pending an MTF nested VM-Exit KVM: x86: make vendor code check for all nested events mailmap: Update Oliver's email address KVM: x86: Allow force_emulation_prefix to be written without a reload KVM: selftests: Add an x86-only test to verify nested exception queueing KVM: selftests: Use uapi header to get VMX and SVM exit reasons/codes KVM: x86: Rename inject_pending_events() to kvm_check_and_inject_events() KVM: VMX: Update MTF and ICEBP comments to document KVM's subtle behavior KVM: x86: Treat pending TRIPLE_FAULT requests as pending exceptions KVM: x86: Morph pending exceptions to pending VM-Exits at queue time ...
| * KVM: remove KVM_REQ_UNHALTPaolo Bonzini2022-09-261-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | KVM_REQ_UNHALT is now unnecessary because it is replaced by the return value of kvm_vcpu_block/kvm_vcpu_halt. Remove it. No functional change intended. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Acked-by: Marc Zyngier <maz@kernel.org> Message-Id: <20220921003201.1441511-13-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | KVM: s390: pci: register pci hooks without interpretationMatthew Rosato2022-09-211-2/+2
|/ | | | | | | | | | | | | | | | The kvm registration hooks must be registered even if the facilities necessary for zPCI interpretation are unavailable, as vfio-pci-zdev will expect to use the hooks regardless. This fixes an issue where vfio-pci-zdev will fail its open function because of a missing kvm_register when running on hardware that does not support zPCI interpretation. Fixes: ca922fecda6c ("KVM: s390: pci: Hook to access KVM lowlevel from VFIO") Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Link: https://lore.kernel.org/r/20220920193025.135655-1-mjrosato@linux.ibm.com Message-Id: <20220920193025.135655-1-mjrosato@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
* KVM: s390: resetting the Topology-Change-ReportPierre Morel2022-07-201-0/+51
| | | | | | | | | | | | | | | | | | | | | During a subsystem reset the Topology-Change-Report is cleared. Let's give userland the possibility to clear the MTCR in the case of a subsystem reset. To migrate the MTCR, we give userland the possibility to query the MTCR state. We indicate KVM support for the CPU topology facility with a new KVM capability: KVM_CAP_S390_CPU_TOPOLOGY. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Message-Id: <20220714194334.127812-1-pmorel@linux.ibm.com> Link: https://lore.kernel.org/all/20220714194334.127812-1-pmorel@linux.ibm.com/ [frankja@linux.ibm.com: Simple conflict resolution in Documentation/virt/kvm/api.rst] Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
* KVM: s390: guest support for topology functionPierre Morel2022-07-201-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | We report a topology change to the guest for any CPU hotplug. The reporting to the guest is done using the Multiprocessor Topology-Change-Report (MTCR) bit of the utility entry in the guest's SCA which will be cleared during the interpretation of PTF. On every vCPU creation we set the MCTR bit to let the guest know the next time it uses the PTF with command 2 instruction that the topology changed and that it should use the STSI(15.1.x) instruction to get the topology details. STSI(15.1.x) gives information on the CPU configuration topology. Let's accept the interception of STSI with the function code 15 and let the userland part of the hypervisor handle it when userland supports the CPU Topology facility. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Nico Boehr <nrb@linux.ibm.com> Reviewed-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20220714101824.101601-2-pmorel@linux.ibm.com Message-Id: <20220714101824.101601-2-pmorel@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
* KVM: s390: pv: add mmu_notifierClaudio Imbrenda2022-07-191-0/+10
| | | | | | | | | | | | | | | | | | Add an mmu_notifier for protected VMs. The callback function is triggered when the mm is torn down, and will attempt to convert all protected vCPUs to non-protected. This allows the mm teardown to use the destroy page UVC instead of export. Also make KVM select CONFIG_MMU_NOTIFIER, needed to use mmu_notifiers. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Nico Boehr <nrb@linux.ibm.com> Link: https://lore.kernel.org/r/20220628135619.32410-10-imbrenda@linux.ibm.com Message-Id: <20220628135619.32410-10-imbrenda@linux.ibm.com> [frankja@linux.ibm.com: Conflict resolution for mmu_notifier.h include and struct kvm_s390_pv] Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
* KVM: s390: pv: Add kvm_s390_cpus_from_pv to kvm-s390.h and add documentationClaudio Imbrenda2022-07-131-6/+30
| | | | | | | | | | | | | Future changes make it necessary to call this function from pv.c. While we are at it, let's properly document kvm_s390_cpus_from_pv() and kvm_s390_cpus_to_pv(). Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20220628135619.32410-9-imbrenda@linux.ibm.com Message-Id: <20220628135619.32410-9-imbrenda@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
* Merge tag 'kvm-s390-pci-5.20' into kernelorgnextChristian Borntraeger2022-07-111-1/+82
|\ | | | | | | | | | | | | KVM: s390/pci: enable zPCI for interpretive execution Add the necessary code in s390 base, pci and KVM to enable interpretion of PCI pasthru.
| * KVM: s390: add KVM_S390_ZPCI_OP to manage guest zPCI devicesMatthew Rosato2022-07-111-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | The KVM_S390_ZPCI_OP ioctl provides a mechanism for managing hardware-assisted virtualization features for s390x zPCI passthrough. Add the first 2 operations, which can be used to enable/disable the specified device for Adapter Event Notification interpretation. Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com> Acked-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Link: https://lore.kernel.org/r/20220606203325.110625-21-mjrosato@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
| * KVM: s390: pci: add routines to start/stop interpretive executionMatthew Rosato2022-07-111-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | These routines will be invoked at the time an s390x vfio-pci device is associated with a KVM (or when the association is removed), allowing the zPCI device to enable or disable load/store intepretation mode; this requires the host zPCI device to inform firmware of the unique token (GISA designation) that is associated with the owning KVM. Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com> Acked-by: Pierre Morel <pmorel@linux.ibm.com> Link: https://lore.kernel.org/r/20220606203325.110625-17-mjrosato@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
| * KVM: s390: mechanism to enable guest zPCI InterpretationMatthew Rosato2022-07-111-0/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The guest must have access to certain facilities in order to allow interpretive execution of zPCI instructions and adapter event notifications. However, there are some cases where a guest might disable interpretation -- provide a mechanism via which we can defer enabling the associated zPCI interpretation facilities until the guest indicates it wishes to use them. Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/20220606203325.110625-15-mjrosato@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
| * KVM: s390: pci: enable host forwarding of Adapter Event NotificationsMatthew Rosato2022-07-111-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | In cases where interrupts are not forwarded to the guest via firmware, KVM is responsible for ensuring delivery. When an interrupt presents with the forwarding bit, we must process the forwarding tables until all interrupts are delivered. Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/20220606203325.110625-14-mjrosato@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
| * KVM: s390: pci: do initial setup for AEN interpretationMatthew Rosato2022-07-111-0/+11
| | | | | | | | | | | | | | | | | | | | | | Initial setup for Adapter Event Notification Interpretation for zPCI passthrough devices. Specifically, allocate a structure for forwarding of adapter events and pass the address of this structure to firmware. Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/20220606203325.110625-13-mjrosato@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
* | KVM: Move kvm_arch_vcpu_precreate() under kvm->lockZeng Guang2022-06-081-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kvm_arch_vcpu_precreate() targets to handle arch specific VM resource to be prepared prior to the actual creation of vCPU. For example, x86 platform may need do per-VM allocation based on max_vcpu_ids at the first vCPU creation. It probably leads to concurrency control on this allocation as multiple vCPU creation could happen simultaneously. From the architectual point of view, it's necessary to execute kvm_arch_vcpu_precreate() under protect of kvm->lock. Currently only arm64, x86 and s390 have non-nop implementations at the stage of vCPU pre-creation. Remove the lock acquiring in s390's design and make sure all architecture can run kvm_arch_vcpu_precreate() safely under kvm->lock without recrusive lock issue. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com> Message-Id: <20220419154409.11842-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | Merge tag 'kvm-s390-next-5.19-2' of ↵Paolo Bonzini2022-06-071-0/+269
|\ \ | |/ |/| | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: pvdump and selftest improvements - add an interface to provide a hypervisor dump for secure guests - improve selftests to show tests
| * KVM: s390: Add KVM_CAP_S390_PROTECTED_DUMPJanosch Frank2022-06-011-0/+20
| | | | | | | | | | | | | | | | | | | | The capability indicates dump support for protected VMs. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20220517163629.3443-9-frankja@linux.ibm.com Message-Id: <20220517163629.3443-9-frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
| * KVM: s390: Add CPU dump functionalityJanosch Frank2022-06-011-0/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | The previous patch introduced the per-VM dump functions now let's focus on dumping the VCPU state via the newly introduced KVM_S390_PV_CPU_COMMAND ioctl which mirrors the VM UV ioctl and can be extended with new commands later. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20220517163629.3443-8-frankja@linux.ibm.com Message-Id: <20220517163629.3443-8-frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
| * KVM: s390: Add configuration dump functionalityJanosch Frank2022-06-011-0/+93
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sometimes dumping inside of a VM fails, is unavailable or doesn't yield the required data. For these occasions we dump the VM from the outside, writing memory and cpu data to a file. Up to now PV guests only supported dumping from the inside of the guest through dumpers like KDUMP. A PV guest can be dumped from the hypervisor but the data will be stale and / or encrypted. To get the actual state of the PV VM we need the help of the Ultravisor who safeguards the VM state. New UV calls have been added to initialize the dump, dump storage state data, dump cpu data and complete the dump process. We expose these calls in this patch via a new UV ioctl command. The sensitive parts of the dump data are encrypted, the dump key is derived from the Customer Communication Key (CCK). This ensures that only the owner of the VM who has the CCK can decrypt the dump data. The memory is dumped / read via a normal export call and a re-import after the dump initialization is not needed (no re-encryption with a dump key). Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20220517163629.3443-7-frankja@linux.ibm.com Message-Id: <20220517163629.3443-7-frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
| * KVM: s390: pv: Add query dump informationJanosch Frank2022-06-011-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | The dump API requires userspace to provide buffers into which we will store data. The dump information added in this patch tells userspace how big those buffers need to be. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Link: https://lore.kernel.org/r/20220517163629.3443-6-frankja@linux.ibm.com Message-Id: <20220517163629.3443-6-frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
| * KVM: s390: pv: Add query interfaceJanosch Frank2022-06-011-0/+76
| | | | | | | | | | | | | | | | | | | | | | | | Some of the query information is already available via sysfs but having a IOCTL makes the information easier to retrieve. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Link: https://lore.kernel.org/r/20220517163629.3443-4-frankja@linux.ibm.com Message-Id: <20220517163629.3443-4-frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
* | Merge tag 'bitmap-for-5.19-rc1' of https://github.com/norov/linuxLinus Torvalds2022-06-041-7/+3
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull bitmap updates from Yury Norov: - bitmap: optimize bitmap_weight() usage, from me - lib/bitmap.c make bitmap_print_bitmask_to_buf parseable, from Mauro Carvalho Chehab - include/linux/find: Fix documentation, from Anna-Maria Behnsen - bitmap: fix conversion from/to fix-sized arrays, from me - bitmap: Fix return values to be unsigned, from Kees Cook It has been in linux-next for at least a week with no problems. * tag 'bitmap-for-5.19-rc1' of https://github.com/norov/linux: (31 commits) nodemask: Fix return values to be unsigned bitmap: Fix return values to be unsigned KVM: x86: hyper-v: replace bitmap_weight() with hweight64() KVM: x86: hyper-v: fix type of valid_bank_mask ia64: cleanup remove_siblinginfo() drm/amd/pm: use bitmap_{from,to}_arr32 where appropriate KVM: s390: replace bitmap_copy with bitmap_{from,to}_arr64 where appropriate lib/bitmap: add test for bitmap_{from,to}_arr64 lib: add bitmap_{from,to}_arr64 lib/bitmap: extend comment for bitmap_(from,to)_arr32() include/linux/find: Fix documentation lib/bitmap.c make bitmap_print_bitmask_to_buf parseable MAINTAINERS: add cpumask and nodemask files to BITMAP_API arch/x86: replace nodes_weight with nodes_empty where appropriate mm/vmstat: replace cpumask_weight with cpumask_empty where appropriate clocksource: replace cpumask_weight with cpumask_empty in clocksource.c genirq/affinity: replace cpumask_weight with cpumask_empty where appropriate irq: mips: replace cpumask_weight with cpumask_empty where appropriate drm/i915/pmu: replace cpumask_weight with cpumask_empty where appropriate arch/x86: replace cpumask_weight with cpumask_empty where appropriate ...
| * KVM: s390: replace bitmap_copy with bitmap_{from,to}_arr64 where appropriateYury Norov2022-06-031-7/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Copying bitmaps from/to 64-bit arrays with bitmap_copy is not safe on 32-bit BE machines. Use designated functions instead. CC: Alexander Gordeev <agordeev@linux.ibm.com> CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com> CC: Christian Borntraeger <borntraeger@linux.ibm.com> CC: Claudio Imbrenda <imbrenda@linux.ibm.com> CC: David Hildenbrand <david@redhat.com> CC: Heiko Carstens <hca@linux.ibm.com> CC: Janosch Frank <frankja@linux.ibm.com> CC: Rasmus Villemoes <linux@rasmusvillemoes.dk> CC: Sven Schnelle <svens@linux.ibm.com> CC: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com>
* | KVM: s390: Fix lockdep issue in vm memopJanis Schoetterl-Glausch2022-05-021-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Issuing a memop on a protected vm does not make sense, neither is the memory readable/writable, nor does it make sense to check storage keys. This is why the ioctl will return -EINVAL when it detects the vm to be protected. However, in order to ensure that the vm cannot become protected during the memop, the kvm->lock would need to be taken for the duration of the ioctl. This is also required because kvm_s390_pv_is_protected asserts that the lock must be held. Instead, don't try to prevent this. If user space enables secure execution concurrently with a memop it must accecpt the possibility of the memop failing. Still check if the vm is currently protected, but without locking and consider it a heuristic. Fixes: ef11c9463ae0 ("KVM: s390: Add vm IOCTL for key checked guest absolute memory access") Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20220322153204.2637400-1-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* | KVM: Add helpers to wrap vcpu->srcu_idx and yell if it's abusedSean Christopherson2022-04-211-4/+4
|/ | | | | | | | | | | | | | | | | Add wrappers to acquire/release KVM's SRCU lock when stashing the index in vcpu->src_idx, along with rudimentary detection of illegal usage, e.g. re-acquiring SRCU and thus overwriting vcpu->src_idx. Because the SRCU index is (currently) either 0 or 1, illegal nesting bugs can go unnoticed for quite some time and only cause problems when the nested lock happens to get a different index. Wrap the WARNs in PROVE_RCU=y, and make them ONCE, otherwise KVM will likely yell so loudly that it will bring the kernel to its knees. Signed-off-by: Sean Christopherson <seanjc@google.com> Tested-by: Fabiano Rosas <farosas@linux.ibm.com> Message-Id: <20220415004343.2203171-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2022-04-021-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull kvm fixes from Paolo Bonzini: - Only do MSR filtering for MSRs accessed by rdmsr/wrmsr - Documentation improvements - Prevent module exit until all VMs are freed - PMU Virtualization fixes - Fix for kvm_irq_delivery_to_apic_fast() NULL-pointer dereferences - Other miscellaneous bugfixes * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (42 commits) KVM: x86: fix sending PV IPI KVM: x86/mmu: do compare-and-exchange of gPTE via the user address KVM: x86: Remove redundant vm_entry_controls_clearbit() call KVM: x86: cleanup enter_rmode() KVM: x86: SVM: fix tsc scaling when the host doesn't support it kvm: x86: SVM: remove unused defines KVM: x86: SVM: move tsc ratio definitions to svm.h KVM: x86: SVM: fix avic spec based definitions again KVM: MIPS: remove reference to trap&emulate virtualization KVM: x86: document limitations of MSR filtering KVM: x86: Only do MSR filtering when access MSR by rdmsr/wrmsr KVM: x86/emulator: Emulate RDPID only if it is enabled in guest KVM: x86/pmu: Fix and isolate TSX-specific performance event logic KVM: x86: mmu: trace kvm_mmu_set_spte after the new SPTE was set KVM: x86/svm: Clear reserved bits written to PerfEvtSeln MSRs KVM: x86: Trace all APICv inhibit changes and capture overall status KVM: x86: Add wrappers for setting/clearing APICv inhibits KVM: x86: Make APICv inhibit reasons an enum and cleanup naming KVM: X86: Handle implicit supervisor access with SMAP KVM: X86: Rename variable smap to not_smap in permission_fault() ...
| * KVM: Don't actually set a request when evicting vCPUs for GFN cache invdSean Christopherson2022-04-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't actually set a request bit in vcpu->requests when making a request purely to force a vCPU to exit the guest. Logging a request but not actually consuming it would cause the vCPU to get stuck in an infinite loop during KVM_RUN because KVM would see the pending request and bail from VM-Enter to service the request. Note, it's currently impossible for KVM to set KVM_REQ_GPC_INVALIDATE as nothing in KVM is wired up to set guest_uses_pa=true. But, it'd be all too easy for arch code to introduce use of kvm_gfn_to_pfn_cache_init() without implementing handling of the request, especially since getting test coverage of MMU notifier interaction with specific KVM features usually requires a directed test. Opportunistically rename gfn_to_pfn_cache_invalidate_start()'s wake_vcpus to evict_vcpus. The purpose of the request is to get vCPUs out of guest mode, it's supposed to _avoid_ waking vCPUs that are blocking. Opportunistically rename KVM_REQ_GPC_INVALIDATE to be more specific as to what it wants to accomplish, and to genericize the name so that it can used for similar but unrelated scenarios, should they arise in the future. Add a comment and documentation to explain why the "no action" request exists. Add compile-time assertions to help detect improper usage. Use the inner assertless helper in the one s390 path that makes requests without a hardcoded request. Cc: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220223165302.3205276-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | Merge tag 's390-5.18-1' of ↵Linus Torvalds2022-03-251-1/+0
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Raise minimum supported machine generation to z10, which comes with various cleanups and code simplifications (usercopy/spectre mitigation/etc). - Rework extables and get rid of anonymous out-of-line fixups. - Page table helpers cleanup. Add set_pXd()/set_pte() helper functions. Covert pte_val()/pXd_val() macros to functions. - Optimize kretprobe handling by avoiding extra kprobe on __kretprobe_trampoline. - Add support for CEX8 crypto cards. - Allow to trigger AP bus rescan via writing to /sys/bus/ap/scans. - Add CONFIG_EXPOLINE_EXTERN option to build the kernel without COMDAT group sections which simplifies kpatch support. - Always use the packed stack layout and extend kernel unwinder tests. - Add sanity checks for ftrace code patching. - Add s390dbf debug log for the vfio_ap device driver. - Various virtual vs physical address confusion fixes. - Various small fixes and improvements all over the code. * tag 's390-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (69 commits) s390/test_unwind: add kretprobe tests s390/kprobes: Avoid additional kprobe in kretprobe handling s390: convert ".insn" encoding to instruction names s390: assume stckf is always present s390/nospec: move to single register thunks s390: raise minimum supported machine generation to z10 s390/uaccess: Add copy_from/to_user_key functions s390/nospec: align and size extern thunks s390/nospec: add an option to use thunk-extern s390/nospec: generate single register thunks if possible s390/pci: make zpci_set_irq()/zpci_clear_irq() static s390: remove unused expoline to BC instructions s390/irq: use assignment instead of cast s390/traps: get rid of magic cast for per code s390/traps: get rid of magic cast for program interruption code s390/signal: fix typo in comments s390/asm-offsets: remove unused defines s390/test_unwind: avoid build warning with W=1 s390: remove .fixup section s390/bpf: encode register within extable entry ...
| * s390: remove invalid email address of Heiko CarstensHeiko Carstens2022-02-061-1/+0
| | | | | | | | | | | | | | | | | | | | | | Remove my old invalid email address which can be found in a couple of files. Instead of updating it, just remove my contact data completely from source files. We have git and other tools which allow to figure out who is responsible for what with recent contact data. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* | Merge tag 'kvm-s390-next-5.18-2' of ↵Paolo Bonzini2022-03-151-6/+24
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Fix, test and feature for 5.18 part 2 - memop selftest - fix SCK locking - adapter interruptions virtualization for secure guests
| * | KVM: s390x: fix SCK lockingClaudio Imbrenda2022-03-141-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When handling the SCK instruction, the kvm lock is taken, even though the vcpu lock is already being held. The normal locking order is kvm lock first and then vcpu lock. This is can (and in some circumstances does) lead to deadlocks. The function kvm_s390_set_tod_clock is called both by the SCK handler and by some IOCTLs to set the clock. The IOCTLs will not hold the vcpu lock, so they can safely take the kvm lock. The SCK handler holds the vcpu lock, but will also somehow need to acquire the kvm lock without relinquishing the vcpu lock. The solution is to factor out the code to set the clock, and provide two wrappers. One is called like the original function and does the locking, the other is called kvm_s390_try_set_tod_clock and uses trylock to try to acquire the kvm lock. This new wrapper is then used in the SCK handler. If locking fails, -EAGAIN is returned, which is eventually propagated to userspace, thus also freeing the vcpu lock and allowing for forward progress. This is not the most efficient or elegant way to solve this issue, but the SCK instruction is deprecated and its performance is not critical. The goal of this patch is just to provide a simple but correct way to fix the bug. Fixes: 6a3f95a6b04c ("KVM: s390: Intercept SCK instruction") Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Link: https://lore.kernel.org/r/20220301143340.111129-1-imbrenda@linux.ibm.com Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
| * | KVM: s390: pv: make use of ultravisor AIV supportMichael Mueller2022-02-251-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch enables the ultravisor adapter interruption vitualization support indicated by UV feature BIT_UV_FEAT_AIV. This allows ISC interruption injection directly into the GISA IPM for PV kvm guests. Hardware that does not support this feature will continue to use the UV interruption interception method to deliver ISC interruptions to PV kvm guests. For this purpose, the ECA_AIV bit for all guest cpus will be cleared and the GISA will be disabled during PV CPU setup. In addition a check in __inject_io() has been removed. That reduces the required instructions for interruption handling for PV and traditional kvm guests. Signed-off-by: Michael Mueller <mimu@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20220209152217.1793281-2-mimu@linux.ibm.com Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
* | | KVM: s390: Replace KVM_REQ_MMU_RELOAD usage with arch specific requestSean Christopherson2022-03-011-4/+4
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add an arch request, KVM_REQ_REFRESH_GUEST_PREFIX, to deal with guest prefix changes instead of piggybacking KVM_REQ_MMU_RELOAD. This will allow for the removal of the generic KVM_REQ_MMU_RELOAD, which isn't actually used by generic KVM. No functional change intended. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220225182248.3812651-6-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | KVM: s390: Add missing vm MEM_OP size checkJanis Schoetterl-Glausch2022-02-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Check that size is not zero, preventing the following warning: WARNING: CPU: 0 PID: 9692 at mm/vmalloc.c:3059 __vmalloc_node_range+0x528/0x648 Modules linked in: CPU: 0 PID: 9692 Comm: memop Not tainted 5.17.0-rc3-e4+ #80 Hardware name: IBM 8561 T01 701 (LPAR) Krnl PSW : 0704c00180000000 0000000082dc584c (__vmalloc_node_range+0x52c/0x648) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 Krnl GPRS: 0000000000000083 ffffffffffffffff 0000000000000000 0000000000000001 0000038000000000 000003ff80000000 0000000000000cc0 000000008ebb8000 0000000087a8a700 000000004040aeb1 000003ffd9f7dec8 000000008ebb8000 000000009d9b8000 000000000102a1b4 00000380035afb68 00000380035afaa8 Krnl Code: 0000000082dc583e: d028a7f4ff80 trtr 2036(41,%r10),3968(%r15) 0000000082dc5844: af000000 mc 0,0 #0000000082dc5848: af000000 mc 0,0 >0000000082dc584c: a7d90000 lghi %r13,0 0000000082dc5850: b904002d lgr %r2,%r13 0000000082dc5854: eb6ff1080004 lmg %r6,%r15,264(%r15) 0000000082dc585a: 07fe bcr 15,%r14 0000000082dc585c: 47000700 bc 0,1792 Call Trace: [<0000000082dc584c>] __vmalloc_node_range+0x52c/0x648 [<0000000082dc5b62>] vmalloc+0x5a/0x68 [<000003ff8067f4ca>] kvm_arch_vm_ioctl+0x2da/0x2a30 [kvm] [<000003ff806705bc>] kvm_vm_ioctl+0x4ec/0x978 [kvm] [<0000000082e562fe>] __s390x_sys_ioctl+0xbe/0x100 [<000000008360a9bc>] __do_syscall+0x1d4/0x200 [<0000000083618bd2>] system_call+0x82/0xb0 Last Breaking-Event-Address: [<0000000082dc5348>] __vmalloc_node_range+0x28/0x648 Other than the warning, there is no ill effect from the missing check, the condition is detected by subsequent code and causes a return with ENOMEM. Fixes: ef11c9463ae0 (KVM: s390: Add vm IOCTL for key checked guest absolute memory access) Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Link: https://lore.kernel.org/r/20220221163237.4122868-1-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
* | KVM: s390: Add capability for storage key extension of MEM_OP IOCTLJanis Schoetterl-Glausch2022-02-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | Availability of the KVM_CAP_S390_MEM_OP_EXTENSION capability signals that: * The vcpu MEM_OP IOCTL supports storage key checking. * The vm MEM_OP IOCTL exists. Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20220211182215.2730017-9-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
* | KVM: s390: Rename existing vcpu memop functionsJanis Schoetterl-Glausch2022-02-141-9/+10
| | | | | | | | | | | | | | | | | | | | Makes the naming consistent, now that we also have a vm ioctl. Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20220211182215.2730017-8-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
* | KVM: s390: Add vm IOCTL for key checked guest absolute memory accessJanis Schoetterl-Glausch2022-02-141-0/+81
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Channel I/O honors storage keys and is performed on absolute memory. For I/O emulation user space therefore needs to be able to do key checked accesses. The vm IOCTL supports read/write accesses, as well as checking if an access would succeed. Unlike relying on KVM_S390_GET_SKEYS for key checking would, the vm IOCTL performs the check in lockstep with the read or write, by, ultimately, mapping the access to move instructions that support key protection checking with a supplied key. Fetch and storage protection override are not applicable to absolute accesses and so are not applied as they are when using the vcpu memop. Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20220211182215.2730017-7-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
* | KVM: s390: Add optional storage key checking to MEMOP IOCTLJanis Schoetterl-Glausch2022-02-141-10/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | User space needs a mechanism to perform key checked accesses when emulating instructions. The key can be passed as an additional argument. Having an additional argument is flexible, as user space can pass the guest PSW's key, in order to make an access the same way the CPU would, or pass another key if necessary. Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20220211182215.2730017-6-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
* | KVM: s390: Honor storage keys when accessing guest memoryJanis Schoetterl-Glausch2022-02-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Storage key checking had not been implemented for instructions emulated by KVM. Implement it by enhancing the functions used for guest access, in particular those making use of access_guest which has been renamed to access_guest_with_key. Accesses via access_guest_real should not be key checked. For actual accesses, key checking is done by copy_from/to_user_key (which internally uses MVCOS/MVCP/MVCS). In cases where accessibility is checked without an actual access, this is performed by getting the storage key and checking if the access key matches. In both cases, if applicable, storage and fetch protection override are honored. Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20220211182215.2730017-3-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
* | KVM: s390: Return error on SIDA memop on normal guestJanis Schoetterl-Glausch2022-02-021-0/+2
|/ | | | | | | | | | | Refuse SIDA memops on guests which are not protected. For normal guests, the secure instruction data address designation, which determines the location we access, is not under control of KVM. Fixes: 19e122776886 (KVM: S390: protvirt: Introduce instruction data area bounce buffer) Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
* Merge tag 'bitmap-5.17-rc1' of git://github.com/norov/linuxLinus Torvalds2022-01-231-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull bitmap updates from Yury Norov: - introduce for_each_set_bitrange() - use find_first_*_bit() instead of find_next_*_bit() where possible - unify for_each_bit() macros * tag 'bitmap-5.17-rc1' of git://github.com/norov/linux: vsprintf: rework bitmap_list_string lib: bitmap: add performance test for bitmap_print_to_pagebuf bitmap: unify find_bit operations mm/percpu: micro-optimize pcpu_is_populated() Replace for_each_*_bit_from() with for_each_*_bit() where appropriate find: micro-optimize for_each_{set,clear}_bit() include/linux: move for_each_bit() macros from bitops.h to find.h cpumask: replace cpumask_next_* with cpumask_first_* where appropriate tools: sync tools/bitmap with mother linux all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate cpumask: use find_first_and_bit() lib: add find_first_and_bit() arch: remove GENERIC_FIND_FIRST_BIT entirely include: move find.h from asm_generic to linux bitops: move find_bit_*_le functions from le.h to find.h bitops: protect find_first_{,zero}_bit properly
| * all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriateYury Norov2022-01-151-1/+1
| | | | | | | | | | | | | | | | | | find_first{,_zero}_bit is a more effective analogue of 'next' version if start == 0. This patch replaces 'next' with 'first' where things look trivial. Signed-off-by: Yury Norov <yury.norov@gmail.com> Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
* | Merge tag 'kvm-s390-next-5.17-1' of ↵Paolo Bonzini2021-12-211-2/+7
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Fix and cleanup - fix sigp sense/start/stop/inconsistency - cleanups
| * | KVM: s390: Clarify SIGP orders versus STOP/RESTARTEric Farman2021-12-171-2/+7
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With KVM_CAP_S390_USER_SIGP, there are only five Signal Processor orders (CONDITIONAL EMERGENCY SIGNAL, EMERGENCY SIGNAL, EXTERNAL CALL, SENSE, and SENSE RUNNING STATUS) which are intended for frequent use and thus are processed in-kernel. The remainder are sent to userspace with the KVM_CAP_S390_USER_SIGP capability. Of those, three orders (RESTART, STOP, and STOP AND STORE STATUS) have the potential to inject work back into the kernel, and thus are asynchronous. Let's look for those pending IRQs when processing one of the in-kernel SIGP orders, and return BUSY (CC2) if one is in process. This is in agreement with the Principles of Operation, which states that only one order can be "active" on a CPU at a time. Cc: stable@vger.kernel.org Suggested-by: David Hildenbrand <david@redhat.com> Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20211213210550.856213-2-farman@linux.ibm.com [borntraeger@linux.ibm.com: add stable tag] Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
* | KVM: Drop obsolete kvm_arch_vcpu_block_finish()Sean Christopherson2021-12-081-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | Drop kvm_arch_vcpu_block_finish() now that all arch implementations are nops. No functional change intended. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: David Matlack <dmatlack@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211009021236.4122790-10-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | KVM: s390: Clear valid_wakeup in kvm_s390_handle_wait(), not in arch hookSean Christopherson2021-12-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the clearing of valid_wakeup from kvm_arch_vcpu_block_finish() so that a future patch can drop said arch hook. Unlike the other blocking- related arch hooks, vcpu_blocking/unblocking(), vcpu_block_finish() needs to be called even if the KVM doesn't actually block the vCPU. This will allow future patches to differentiate between truly blocking the vCPU and emulating a halt condition without introducing a contradiction. Alternatively, the hook could be renamed to kvm_arch_vcpu_halt_finish(), but there's literally one call site in s390, and future cleanup can also be done to handle valid_wakeup fully within kvm_s390_handle_wait() and allow generic KVM to drop vcpu_valid_wakeup(). No functional change intended. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211009021236.4122790-9-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | KVM: s390: Ensure kvm_arch_no_poll() is read once when blocking vCPUSean Christopherson2021-12-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Wrap s390's halt_poll_max_steal with READ_ONCE and snapshot the result of kvm_arch_no_poll() in kvm_vcpu_block() to avoid a mostly-theoretical, largely benign bug on s390 where the result of kvm_arch_no_poll() could change due to userspace modifying halt_poll_max_steal while the vCPU is blocking. The bug is largely benign as it will either cause KVM to skip updating halt-polling times (no_poll toggles false=>true) or to update halt-polling times with a slightly flawed block_ns. Note, READ_ONCE is unnecessary in the current code, add it in case the arch hook is ever inlined, and to provide a hint that userspace can change the param at will. Fixes: 8b905d28ee17 ("KVM: s390: provide kvm_arch_no_poll function") Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211009021236.4122790-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | KVM: Keep memslots in tree-based structures instead of array-based onesMaciej S. Szmigiero2021-12-081-13/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
* | KVM: s390: Introduce kvm_s390_get_gfn_end()Maciej S. Szmigiero2021-12-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | And use it where s390 code would just access the memslot with the highest gfn directly. No functional change intended. Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-Id: <42496041d6af1c23b1cbba2636b344ca8d5fc3af.1638817641.git.maciej.szmigiero@oracle.com>
* | KVM: Integrate gfn_to_memslot_approx() into search_memslots()Maciej S. Szmigiero2021-12-081-37/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | s390 arch has gfn_to_memslot_approx() which is almost identical to search_memslots(), differing only in that in case the gfn falls in a hole one of the memslots bordering the hole is returned. Add this lookup mode as an option to search_memslots() so we don't have two almost identical functions for looking up a memslot by its gfn. Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> [sean: tweaked helper names to keep gfn_to_memslot_approx() in s390] Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <171cd89b52c718dbe180ecd909b4437a64a7e2ec.1638817640.git.maciej.szmigiero@oracle.com>
generated by cgit (git 2.34.1) at 2025-02-23 22:45:55 +0000