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2022-08-29KVM: s390: pci: Hook to access KVM lowlevel from VFIOPierre Morel1-11/+6
We have a cross dependency between KVM and VFIO when using s390 vfio_pci_zdev extensions for PCI passthrough To be able to keep both subsystem modular we add a registering hook inside the S390 core code. This fixes a build problem when VFIO is built-in and KVM is built as a module. Reported-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Fixes: 09340b2fca007 ("KVM: s390: pci: add routines to start/stop interpretive execution") Cc: <stable@vger.kernel.org> Acked-by: Janosch Frank <frankja@linux.ibm.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Link: https://lore.kernel.org/r/20220819122945.9309-1-pmorel@linux.ibm.com Message-Id: <20220819122945.9309-1-pmorel@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2022-07-20KVM: s390: guest support for topology functionPierre Morel1-3/+15
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>
2022-07-19KVM: s390: pv: add mmu_notifierClaudio Imbrenda1-0/+2
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>
2022-07-11Merge tag 'kvm-s390-pci-5.20' into kernelorgnextChristian Borntraeger1-0/+23
KVM: s390/pci: enable zPCI for interpretive execution Add the necessary code in s390 base, pci and KVM to enable interpretion of PCI pasthru.
2022-07-11KVM: s390: pci: add routines to start/stop interpretive executionMatthew Rosato1-0/+18
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>
2022-07-11KVM: s390: mechanism to enable guest zPCI InterpretationMatthew Rosato1-0/+4
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>
2022-07-11KVM: s390: pci: enable host forwarding of Adapter Event NotificationsMatthew Rosato1-0/+1
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>
2022-06-01KVM: s390: Add configuration dump functionalityJanosch Frank1-0/+1
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>
2022-03-01KVM: s390: Replace KVM_REQ_MMU_RELOAD usage with arch specific requestSean Christopherson1-0/+2
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>
2021-12-08KVM: Drop obsolete kvm_arch_vcpu_block_finish()Sean Christopherson1-2/+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>
2021-09-07Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-0/+2
Pull KVM updates from Paolo Bonzini: "ARM: - Page ownership tracking between host EL1 and EL2 - Rely on userspace page tables to create large stage-2 mappings - Fix incompatibility between pKVM and kmemleak - Fix the PMU reset state, and improve the performance of the virtual PMU - Move over to the generic KVM entry code - Address PSCI reset issues w.r.t. save/restore - Preliminary rework for the upcoming pKVM fixed feature - A bunch of MM cleanups - a vGIC fix for timer spurious interrupts - Various cleanups s390: - enable interpretation of specification exceptions - fix a vcpu_idx vs vcpu_id mixup x86: - fast (lockless) page fault support for the new MMU - new MMU now the default - increased maximum allowed VCPU count - allow inhibit IRQs on KVM_RUN while debugging guests - let Hyper-V-enabled guests run with virtualized LAPIC as long as they do not enable the Hyper-V "AutoEOI" feature - fixes and optimizations for the toggling of AMD AVIC (virtualized LAPIC) - tuning for the case when two-dimensional paging (EPT/NPT) is disabled - bugfixes and cleanups, especially with respect to vCPU reset and choosing a paging mode based on CR0/CR4/EFER - support for 5-level page table on AMD processors Generic: - MMU notifier invalidation callbacks do not take mmu_lock unless necessary - improved caching of LRU kvm_memory_slot - support for histogram statistics - add statistics for halt polling and remote TLB flush requests" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (210 commits) KVM: Drop unused kvm_dirty_gfn_invalid() KVM: x86: Update vCPU's hv_clock before back to guest when tsc_offset is adjusted KVM: MMU: mark role_regs and role accessors as maybe unused KVM: MIPS: Remove a "set but not used" variable x86/kvm: Don't enable IRQ when IRQ enabled in kvm_wait KVM: stats: Add VM stat for remote tlb flush requests KVM: Remove unnecessary export of kvm_{inc,dec}_notifier_count() KVM: x86/mmu: Move lpage_disallowed_link further "down" in kvm_mmu_page KVM: x86/mmu: Relocate kvm_mmu_page.tdp_mmu_page for better cache locality Revert "KVM: x86: mmu: Add guest physical address check in translate_gpa()" KVM: x86/mmu: Remove unused field mmio_cached in struct kvm_mmu_page kvm: x86: Increase KVM_SOFT_MAX_VCPUS to 710 kvm: x86: Increase MAX_VCPUS to 1024 kvm: x86: Set KVM_MAX_VCPU_ID to 4*KVM_MAX_VCPUS KVM: VMX: avoid running vmx_handle_exit_irqoff in case of emulation KVM: x86/mmu: Don't freak out if pml5_root is NULL on 4-level host KVM: s390: index kvm->arch.idle_mask by vcpu_idx KVM: s390: Enable specification exception interpretation KVM: arm64: Trim guest debug exception handling KVM: SVM: Add 5-level page table support for SVM ...
2021-09-06Merge tag 'kvm-s390-next-5.15-1' of ↵Paolo Bonzini1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Fix and feature for 5.15 - enable interpretion of specification exceptions - fix a vcpu_idx vs vcpu_id mixup
2021-08-27KVM: s390: index kvm->arch.idle_mask by vcpu_idxHalil Pasic1-0/+1
While in practice vcpu->vcpu_idx == vcpu->vcp_id is often true, it may not always be, and we must not rely on this. Reason is that KVM decides the vcpu_idx, userspace decides the vcpu_id, thus the two might not match. Currently kvm->arch.idle_mask is indexed by vcpu_id, which implies that code like for_each_set_bit(vcpu_id, kvm->arch.idle_mask, online_vcpus) { vcpu = kvm_get_vcpu(kvm, vcpu_id); do_stuff(vcpu); } is not legit. Reason is that kvm_get_vcpu expects an vcpu_idx, not an vcpu_id. The trouble is, we do actually use kvm->arch.idle_mask like this. To fix this problem we have two options. Either use kvm_get_vcpu_by_id(vcpu_id), which would loop to find the right vcpu_id, or switch to indexing via vcpu_idx. The latter is preferable for obvious reasons. Let us make switch from indexing kvm->arch.idle_mask by vcpu_id to indexing it by vcpu_idx. To keep gisa_int.kicked_mask indexed by the same index as idle_mask lets make the same change for it as well. Fixes: 1ee0bc559dc3 ("KVM: s390: get rid of local_int array") Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Christian Bornträger <borntraeger@de.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: <stable@vger.kernel.org> # 3.15+ Link: https://lore.kernel.org/r/20210827125429.1912577-1-pasic@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-08-27KVM: s390: Enable specification exception interpretationJanis Schoetterl-Glausch1-0/+1
When this feature is enabled the hardware is free to interpret specification exceptions generated by the guest, instead of causing program interruption interceptions. This benefits (test) programs that generate a lot of specification exceptions (roughly 4x increase in exceptions/sec). Interceptions will occur as before if ICTL_PINT is set, i.e. if guest debug is enabled. There is no indication if this feature is available or not and the hardware is free to interpret or not. So we can simply set this bit and if the hardware ignores it we fall back to intercept 8 handling. Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Link: https://lore.kernel.org/linux-s390/20210706114714.3936825-1-scgl@linux.ibm.com/ Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-08-24s390/vfio-ap: r/w lock for PQAP interception handler function pointerTony Krowiak1-5/+3
The function pointer to the interception handler for the PQAP instruction can get changed during the interception process. Let's add a semaphore to struct kvm_s390_crypto to control read/write access to the function pointer contained therein. The semaphore must be locked for write access by the vfio_ap device driver when notified that the KVM pointer has been set or cleared. It must be locked for read access by the interception framework when the PQAP instruction is intercepted. Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Link: https://lore.kernel.org/r/20210823212047.1476436-2-akrowiak@linux.ibm.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-07-27KVM: s390: restore old debugfs namesChristian Borntraeger1-9/+9
commit bc9e9e672df9 ("KVM: debugfs: Reuse binary stats descriptors") did replace the old definitions with the binary ones. While doing that it missed that some files are names different than the counters. This is especially important for kvm_stat which does have special handling for counters named instruction_*. Fixes: commit bc9e9e672df9 ("KVM: debugfs: Reuse binary stats descriptors") CC: Jing Zhang <jingzhangos@google.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Message-Id: <20210726150108.5603-1-borntraeger@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24KVM: stats: Separate generic stats from architecture specific onesJing Zhang1-7/+2
Generic KVM stats are those collected in architecture independent code or those supported by all architectures; put all generic statistics in a separate structure. This ensures that they are defined the same way in the statistics API which is being added, removing duplication among different architectures in the declaration of the descriptors. No functional change intended. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-2-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-17KVM: s390x: implement KVM_CAP_SET_GUEST_DEBUG2Maxim Levitsky1-0/+4
Define KVM_GUESTDBG_VALID_MASK and use it to implement this capabiity. Compile tested only. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210401135451.1004564-6-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-09KVM: s390: diag9c (directed yield) forwardingPierre Morel1-0/+1
When we intercept a DIAG_9C from the guest we verify that the target real CPU associated with the virtual CPU designated by the guest is running and if not we forward the DIAG_9C to the target real CPU. To avoid a diag9c storm we allow a maximal rate of diag9c forwarding. The rate is calculated as a count per second defined as a new parameter of the s390 kvm module: diag9c_forwarding_hz . The default value of 0 is to not forward diag9c. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Link: https://lore.kernel.org/r/1613997661-22525-2-git-send-email-pmorel@linux.ibm.com Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-02-09KVM: Raise the maximum number of user memslotsVitaly Kuznetsov1-1/+0
Current KVM_USER_MEM_SLOTS limits are arch specific (512 on Power, 509 on x86, 32 on s390, 16 on MIPS) but they don't really need to be. Memory slots are allocated dynamically in KVM when added so the only real limitation is 'id_to_index' array which is 'short'. We don't have any other KVM_MEM_SLOTS_NUM/KVM_USER_MEM_SLOTS-sized statically defined structures. Low KVM_USER_MEM_SLOTS can be a limiting factor for some configurations. In particular, when QEMU tries to start a Windows guest with Hyper-V SynIC enabled and e.g. 256 vCPUs the limit is hit as SynIC requires two pages per vCPU and the guest is free to pick any GFN for each of them, this fragments memslots as QEMU wants to have a separate memslot for each of these pages (which are supposed to act as 'overlay' pages). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210127175731.2020089-3-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-10KVM: s390: track synchronous pfault events in kvm_statChristian Borntraeger1-0/+1
Right now we do count pfault (pseudo page faults aka async page faults start and completion events). What we do not count is, if an async page fault would have been possible by the host, but it was disabled by the guest (e.g. interrupts off, pfault disabled, secure execution....). Let us count those as well in the pfault_sync counter. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/r/20201125090658.38463-1-borntraeger@de.ibm.com
2020-08-03Merge tag 'kvm-s390-next-5.9-1' of ↵Paolo Bonzini1-1/+3
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-next-5.6 KVM: s390: Enhancement for 5.9 - implement diagnose 318
2020-06-23s390/kvm: diagnose 0x318 sync and resetCollin Walling1-1/+3
DIAGNOSE 0x318 (diag318) sets information regarding the environment the VM is running in (Linux, z/VM, etc) and is observed via firmware/service events. This is a privileged s390x instruction that must be intercepted by SIE. Userspace handles the instruction as well as migration. Data is communicated via VCPU register synchronization. The Control Program Name Code (CPNC) is stored in the SIE block. The CPNC along with the Control Program Version Code (CPVC) are stored in the kvm_vcpu_arch struct. This data is reset on load normal and clear resets. Signed-off-by: Collin Walling <walling@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Acked-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200622154636.5499-3-walling@linux.ibm.com [borntraeger@de.ibm.com: fix sync_reg position] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-06-18KVM: s390: reduce number of IO pins to 1Christian Borntraeger1-4/+4
The current number of KVM_IRQCHIP_NUM_PINS results in an order 3 allocation (32kb) for each guest start/restart. This can result in OOM killer activity even with free swap when the memory is fragmented enough: kernel: qemu-system-s39 invoked oom-killer: gfp_mask=0x440dc0(GFP_KERNEL_ACCOUNT|__GFP_COMP|__GFP_ZERO), order=3, oom_score_adj=0 kernel: CPU: 1 PID: 357274 Comm: qemu-system-s39 Kdump: loaded Not tainted 5.4.0-29-generic #33-Ubuntu kernel: Hardware name: IBM 8562 T02 Z06 (LPAR) kernel: Call Trace: kernel: ([<00000001f848fe2a>] show_stack+0x7a/0xc0) kernel: [<00000001f8d3437a>] dump_stack+0x8a/0xc0 kernel: [<00000001f8687032>] dump_header+0x62/0x258 kernel: [<00000001f8686122>] oom_kill_process+0x172/0x180 kernel: [<00000001f8686abe>] out_of_memory+0xee/0x580 kernel: [<00000001f86e66b8>] __alloc_pages_slowpath+0xd18/0xe90 kernel: [<00000001f86e6ad4>] __alloc_pages_nodemask+0x2a4/0x320 kernel: [<00000001f86b1ab4>] kmalloc_order+0x34/0xb0 kernel: [<00000001f86b1b62>] kmalloc_order_trace+0x32/0xe0 kernel: [<00000001f84bb806>] kvm_set_irq_routing+0xa6/0x2e0 kernel: [<00000001f84c99a4>] kvm_arch_vm_ioctl+0x544/0x9e0 kernel: [<00000001f84b8936>] kvm_vm_ioctl+0x396/0x760 kernel: [<00000001f875df66>] do_vfs_ioctl+0x376/0x690 kernel: [<00000001f875e304>] ksys_ioctl+0x84/0xb0 kernel: [<00000001f875e39a>] __s390x_sys_ioctl+0x2a/0x40 kernel: [<00000001f8d55424>] system_call+0xd8/0x2c8 As far as I can tell s390x does not use the iopins as we bail our for anything other than KVM_IRQ_ROUTING_S390_ADAPTER and the chip/pin is only used for KVM_IRQ_ROUTING_IRQCHIP. So let us use a small number to reduce the memory footprint. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200617083620.5409-1-borntraeger@de.ibm.com
2020-06-11KVM: async_pf: Inject 'page ready' event only if 'page not present' was ↵Vitaly Kuznetsov1-1/+1
previously injected 'Page not present' event may or may not get injected depending on guest's state. If the event wasn't injected, there is no need to inject the corresponding 'page ready' event as the guest may get confused. E.g. Linux thinks that the corresponding 'page not present' event wasn't delivered *yet* and allocates a 'dummy entry' for it. This entry is never freed. Note, 'wakeup all' events have no corresponding 'page not present' event and always get injected. s390 seems to always be able to inject 'page not present', the change is effectively a nop. Suggested-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200610175532.779793-2-vkuznets@redhat.com> Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=208081 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: x86: acknowledgment mechanism for async pf page ready notificationsVitaly Kuznetsov1-0/+2
If two page ready notifications happen back to back the second one is not delivered and the only mechanism we currently have is kvm_check_async_pf_completion() check in vcpu_run() loop. The check will only be performed with the next vmexit when it happens and in some cases it may take a while. With interrupt based page ready notification delivery the situation is even worse: unlike exceptions, interrupts are not handled immediately so we must check if the slot is empty. This is slow and unnecessary. Introduce dedicated MSR_KVM_ASYNC_PF_ACK MSR to communicate the fact that the slot is free and host should check its notification queue. Mandate using it for interrupt based 'page ready' APF event delivery. As kvm_check_async_pf_completion() is going away from vcpu_run() we need a way to communicate the fact that vcpu->async_pf.done queue has transitioned from empty to non-empty state. Introduce kvm_arch_async_page_present_queued() and KVM_REQ_APF_READY to do the job. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200525144125.143875-7-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: rename kvm_arch_can_inject_async_page_present() to ↵Vitaly Kuznetsov1-1/+1
kvm_arch_can_dequeue_async_page_present() An innocent reader of the following x86 KVM code: bool kvm_arch_can_inject_async_page_present(struct kvm_vcpu *vcpu) { if (!(vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED)) return true; ... may get very confused: if APF mechanism is not enabled, why do we report that we 'can inject async page present'? In reality, upon injection kvm_arch_async_page_present() will check the same condition again and, in case APF is disabled, will just drop the item. This is fine as the guest which deliberately disabled APF doesn't expect to get any APF notifications. Rename kvm_arch_can_inject_async_page_present() to kvm_arch_can_dequeue_async_page_present() to make it clear what we are checking: if the item can be dequeued (meaning either injected or just dropped). On s390 kvm_arch_can_inject_async_page_present() always returns 'true' so the rename doesn't matter much. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200525144125.143875-4-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-15kvm: add halt-polling cpu usage statsDavid Matlack1-0/+2
Two new stats for exposing halt-polling cpu usage: halt_poll_success_ns halt_poll_fail_ns Thus sum of these 2 stats is the total cpu time spent polling. "success" means the VCPU polled until a virtual interrupt was delivered. "fail" means the VCPU had to schedule out (either because the maximum poll time was reached or it needed to yield the CPU). To avoid touching every arch's kvm_vcpu_stat struct, only update and export halt-polling cpu usage stats if we're on x86. Exporting cpu usage as a u64 and in nanoseconds means we will overflow at ~500 years, which seems reasonably large. Signed-off-by: David Matlack <dmatlack@google.com> Signed-off-by: Jon Cargille <jcargill@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <20200508182240.68440-1-jcargill@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-26Merge tag 'kvm-s390-next-5.7-2' of ↵Paolo Bonzini1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: cleanups for 5.7 - mark sie control block as 512 byte aligned - use fallthrough;
2020-03-23KVM: s390: mark sie block as 512 byte alignedChristian Borntraeger1-1/+1
The sie block must be aligned to 512 bytes. Mark it as such. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2020-03-16Merge tag 'kvm-s390-next-5.7-1' of ↵Paolo Bonzini1-19/+94
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Features and Enhancements for 5.7 part1 1. Allow to disable gisa 2. protected virtual machines Protected VMs (PVM) are KVM VMs, where KVM can't access the VM's state like guest memory and guest registers anymore. Instead the PVMs are mostly managed by a new entity called Ultravisor (UV), which provides an API, so KVM and the PV can request management actions. PVMs are encrypted at rest and protected from hypervisor access while running. They switch from a normal operation into protected mode, so we can still use the standard boot process to load a encrypted blob and then move it into protected mode. Rebooting is only possible by passing through the unprotected/normal mode and switching to protected again. One mm related patch will go via Andrews mm tree ( mm/gup/writeback: add callbacks for inaccessible pages)
2020-03-16KVM: Simplify kvm_free_memslot() and all its descendentsSean Christopherson1-1/+1
Now that all callers of kvm_free_memslot() pass NULL for @dont, remove the param from the top-level routine and all arch's implementations. No functional change intended. Tested-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-27KVM: s390: protvirt: handle secure guest prefix pagesJanosch Frank1-0/+1
The SPX instruction is handled by the ultravisor. We do get a notification intercept, though. Let us update our internal view. In addition to that, when the guest prefix page is not secure, an intercept 112 (0x70) is indicated. Let us make the prefix pages secure again. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: S390: protvirt: Introduce instruction data area bounce bufferJanosch Frank1-1/+10
Now that we can't access guest memory anymore, we have a dedicated satellite block that's a bounce buffer for instruction data. We re-use the memop interface to copy the instruction data to / from userspace. This lets us re-use a lot of QEMU code which used that interface to make logical guest memory accesses which are not possible anymore in protected mode anyway. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390: protvirt: Add new gprs location handlingJanosch Frank1-1/+3
Guest registers for protected guests are stored at offset 0x380. We will copy those to the usual places. Long term we could refactor this or use register access functions. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390: protvirt: Add SCLP interrupt handlingChristian Borntraeger1-1/+5
The sclp interrupt is kind of special. The ultravisor polices that we do not inject an sclp interrupt with payload if no sccb is outstanding. On the other hand we have "asynchronous" event interrupts, e.g. for console input. We separate both variants into sclp interrupt and sclp event interrupt. The sclp interrupt is masked until a previous servc instruction has finished (sie exit 108). [frankja@linux.ibm.com: factoring out write_sclp] Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390: protvirt: Implement interrupt injectionMichael Mueller1-12/+50
This defines the necessary data structures in the SIE control block to inject machine checks,external and I/O interrupts. We first define the the interrupt injection control, which defines the next interrupt to inject. Then we define the fields that contain the payload for machine checks,external and I/O interrupts. This is then used to implement interruption injection for the following list of interruption types: - I/O (uses inject io interruption) __deliver_io - External (uses inject external interruption) __deliver_cpu_timer __deliver_ckc __deliver_emergency_signal __deliver_external_call - cpu restart (uses inject restart interruption) __deliver_restart - machine checks (uses mcic, failing address and external damage) __write_machine_check Please note that posted interrupts (GISA) are not used for protected guests as of today. The service interrupt is handled in a followup patch. Signed-off-by: Michael Mueller <mimu@linux.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390: protvirt: Instruction emulationJanosch Frank1-0/+2
We have two new SIE exit codes dealing with instructions. 104 (0x68) for a secure instruction interception, on which the SIE needs hypervisor action to complete the instruction. We can piggy-back on the existing instruction handlers. 108 which is merely a notification and provides data for tracking and management. For example this is used to tell the host about a new value for the prefix register. As there will be several special case handlers in later patches, we handle this in a separate function. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Thomas Huth <thuth@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390: protvirt: Handle SE notification interceptionsJanosch Frank1-0/+2
Since there is no interception for load control and load psw instruction in the protected mode, we need a new way to get notified whenever we can inject an IRQ right after the guest has just enabled the possibility for receiving them. The new interception codes solve that problem by providing a notification for changes to IRQ enablement relevant bits in CRs 0, 6 and 14, as well a the machine check mask bit in the PSW. No special handling is needed for these interception codes, the KVM pre-run code will consult all necessary CRs and PSW bits and inject IRQs the guest is enabled for. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390: protvirt: Add initial vm and cpu lifecycle handlingJanosch Frank1-2/+22
This contains 3 main changes: 1. changes in SIE control block handling for secure guests 2. helper functions for create/destroy/unpack secure guests 3. KVM_S390_PV_COMMAND ioctl to allow userspace dealing with secure machines Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390/interrupt: do not pin adapter interrupt pagesUlrich Weigand1-3/+0
The adapter interrupt page containing the indicator bits is currently pinned. That means that a guest with many devices can pin a lot of memory pages in the host. This also complicates the reference tracking which is needed for memory management handling of protected virtual machines. It might also have some strange side effects for madvise MADV_DONTNEED and other things. We can simply try to get the userspace page set the bits and free the page. By storing the userspace address in the irq routing entry instead of the guest address we can actually avoid many lookups and list walks so that this variant is very likely not slower. If userspace messes around with the memory slots the worst thing that can happen is that we write to some other memory within that process. As we get the the page with FOLL_WRITE this can also not be used to write to shared read-only pages. Signed-off-by: Ulrich Weigand <Ulrich.Weigand@de.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> [borntraeger@de.ibm.com: patch simplification] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-05Merge tag 'kvm-s390-next-5.6-1' of ↵Paolo Bonzini1-0/+5
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Fixes and cleanups for 5.6 - fix register corruption - ENOTSUPP/EOPNOTSUPP mixed - reset cleanups/fixes - selftests
2020-01-31KVM: s390: Cleanup initial cpu resetJanosch Frank1-0/+5
The code seems to be quite old and uses lots of unneeded spaces for alignment, which doesn't really help with readability. Let's: * Get rid of the extra spaces * Remove the ULs as they are not needed on 0s * Define constants for the CR 0 and 14 initial values * Use the sizeof of the gcr array to memset it to 0 Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Link: https://lore.kernel.org/r/20200131100205.74720-3-frankja@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-01-27KVM: Drop kvm_arch_vcpu_init() and kvm_arch_vcpu_uninit()Sean Christopherson1-1/+0
Remove kvm_arch_vcpu_init() and kvm_arch_vcpu_uninit() now that all arch specific implementations are nops. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-10KVM: s390: count invalid yieldsChristian Borntraeger1-0/+1
To analyze some performance issues with lock contention and scheduling it is nice to know when diag9c did not result in any action or when no action was tried. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
2019-07-13Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-1/+0
Pull KVM updates from Paolo Bonzini: "ARM: - support for chained PMU counters in guests - improved SError handling - handle Neoverse N1 erratum #1349291 - allow side-channel mitigation status to be migrated - standardise most AArch64 system register accesses to msr_s/mrs_s - fix host MPIDR corruption on 32bit - selftests ckleanups x86: - PMU event {white,black}listing - ability for the guest to disable host-side interrupt polling - fixes for enlightened VMCS (Hyper-V pv nested virtualization), - new hypercall to yield to IPI target - support for passing cstate MSRs through to the guest - lots of cleanups and optimizations Generic: - Some txt->rST conversions for the documentation" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (128 commits) Documentation: virtual: Add toctree hooks Documentation: kvm: Convert cpuid.txt to .rst Documentation: virtual: Convert paravirt_ops.txt to .rst KVM: x86: Unconditionally enable irqs in guest context KVM: x86: PMU Event Filter kvm: x86: Fix -Wmissing-prototypes warnings KVM: Properly check if "page" is valid in kvm_vcpu_unmap KVM: arm/arm64: Initialise host's MPIDRs by reading the actual register KVM: LAPIC: Retry tune per-vCPU timer_advance_ns if adaptive tuning goes insane kvm: LAPIC: write down valid APIC registers KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s KVM: doc: Add API documentation on the KVM_REG_ARM_WORKAROUNDS register KVM: arm/arm64: Add save/restore support for firmware workaround state arm64: KVM: Propagate full Spectre v2 workaround state to KVM guests KVM: arm/arm64: Support chained PMU counters KVM: arm/arm64: Remove pmc->bitmask KVM: arm/arm64: Re-create event when setting counter value KVM: arm/arm64: Extract duplicated code to own function KVM: arm/arm64: Rename kvm_pmu_{enable/disable}_counter functions KVM: LAPIC: ARBPRI is a reserved register for x2APIC ...
2019-07-02s390: ap: kvm: add PQAP interception for AQICPierre Morel1-0/+7
We prepare the interception of the PQAP/AQIC instruction for the case the AQIC facility is enabled in the guest. First of all we do not want to change existing behavior when intercepting AP instructions without the SIE allowing the guest to use AP instructions. In this patch we only handle the AQIC interception allowed by facility 65 which will be enabled when the complete interception infrastructure will be present. We add a callback inside the KVM arch structure for s390 for a VFIO driver to handle a specific response to the PQAP instruction with the AQIC command and only this command. But we want to be able to return a correct answer to the guest even there is no VFIO AP driver in the kernel. Therefor, we inject the correct exceptions from inside KVM for the case the callback is not initialized, which happens when the vfio_ap driver is not loaded. We do consider the responsibility of the driver to always initialize the PQAP callback if it defines queues by initializing the CRYCB for a guest. If the callback has been setup we call it. If not we setup an answer considering that no queue is available for the guest when no callback has been setup. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com> Acked-by: Harald Freudenberger <freude@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-06-04KVM: Directly return result from kvm_arch_check_processor_compat()Sean Christopherson1-1/+0
Add a wrapper to invoke kvm_arch_check_processor_compat() so that the boilerplate ugliness of checking virtualization support on all CPUs is hidden from the arch specific code. x86's implementation in particular is quite heinous, as it unnecessarily propagates the out-param pattern into kvm_x86_ops. While the x86 specific issue could be resolved solely by changing kvm_x86_ops, make the change for all architectures as returning a value directly is prettier and technically more robust, e.g. s390 doesn't set the out param, which could lead to subtle breakage in the (highly unlikely) scenario where the out-param was not pre-initialized by the caller. Opportunistically annotate svm_check_processor_compat() with __init. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-05-20KVM: s390: change default halt poll time to 50usChristian Borntraeger1-1/+1
Recent measurements indicate that using 50us results in a reduced CPU consumption, while still providing the benefit of halt polling. Let's use 50us instead. Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> Acked-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2019-04-26KVM: s390: provide kvm_arch_no_poll functionChristian Borntraeger1-0/+1
We do track the current steal time of the host CPUs. Let us use this value to disable halt polling if the steal time goes beyond a configured value. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>