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2016-08-12KVM: s390: reset KVM_REQ_MMU_RELOAD if mapping the prefix failedJulius Niedworok1-1/+3
When triggering KVM_RUN without a user memory region being mapped (KVM_SET_USER_MEMORY_REGION) a validity intercept occurs. This could happen, if the user memory region was not mapped initially or if it was unmapped after the vcpu is initialized. The function kvm_s390_handle_requests checks for the KVM_REQ_MMU_RELOAD bit. The check function always clears this bit. If gmap_mprotect_notify returns an error code, the mapping failed, but the KVM_REQ_MMU_RELOAD was not set anymore. So the next time kvm_s390_handle_requests is called, the execution would fall trough the check for KVM_REQ_MMU_RELOAD. The bit needs to be resetted, if gmap_mprotect_notify returns an error code. Resetting the bit with kvm_make_request(KVM_REQ_MMU_RELOAD, vcpu) fixes the bug. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Julius Niedworok <jniedwor@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-08-12KVM: s390: set the prefix initially properlyJulius Niedworok1-0/+1
When KVM_RUN is triggered on a VCPU without an initial reset, a validity intercept occurs. Setting the prefix will set the KVM_REQ_MMU_RELOAD bit initially, thus preventing the bug. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Julius Niedworok <jniedwor@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-08-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-58/+346
Pull KVM updates from Paolo Bonzini: - ARM: GICv3 ITS emulation and various fixes. Removal of the old VGIC implementation. - s390: support for trapping software breakpoints, nested virtualization (vSIE), the STHYI opcode, initial extensions for CPU model support. - MIPS: support for MIPS64 hosts (32-bit guests only) and lots of cleanups, preliminary to this and the upcoming support for hardware virtualization extensions. - x86: support for execute-only mappings in nested EPT; reduced vmexit latency for TSC deadline timer (by about 30%) on Intel hosts; support for more than 255 vCPUs. - PPC: bugfixes. * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (302 commits) KVM: PPC: Introduce KVM_CAP_PPC_HTM MIPS: Select HAVE_KVM for MIPS64_R{2,6} MIPS: KVM: Reset CP0_PageMask during host TLB flush MIPS: KVM: Fix ptr->int cast via KVM_GUEST_KSEGX() MIPS: KVM: Sign extend MFC0/RDHWR results MIPS: KVM: Fix 64-bit big endian dynamic translation MIPS: KVM: Fail if ebase doesn't fit in CP0_EBase MIPS: KVM: Use 64-bit CP0_EBase when appropriate MIPS: KVM: Set CP0_Status.KX on MIPS64 MIPS: KVM: Make entry code MIPS64 friendly MIPS: KVM: Use kmap instead of CKSEG0ADDR() MIPS: KVM: Use virt_to_phys() to get commpage PFN MIPS: Fix definition of KSEGX() for 64-bit KVM: VMX: Add VMCS to CPU's loaded VMCSs before VMPTRLD kvm: x86: nVMX: maintain internal copy of current VMCS KVM: PPC: Book3S HV: Save/restore TM state in H_CEDE KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures KVM: arm64: vgic-its: Simplify MAPI error handling KVM: arm64: vgic-its: Make vgic_its_cmd_handle_mapi similar to other handlers KVM: arm64: vgic-its: Turn device_id validation into generic ID validation ...
2016-07-26Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "There are a couple of new things for s390 with this merge request: - a new scheduling domain "drawer" is added to reflect the unusual topology found on z13 machines. Performance tests showed up to 8 percent gain with the additional domain. - the new crc-32 checksum crypto module uses the vector-galois-field multiply and sum SIMD instruction to speed up crc-32 and crc-32c. - proper __ro_after_init support, this requires RO_AFTER_INIT_DATA in the generic vmlinux.lds linker script definitions. - kcov instrumentation support. A prerequisite for that is the inline assembly basic block cleanup, which is the reason for the net/iucv/iucv.c change. - support for 2GB pages is added to the hugetlbfs backend. Then there are two removals: - the oprofile hardware sampling support is dead code and is removed. The oprofile user space uses the perf interface nowadays. - the ETR clock synchronization is removed, this has been superseeded be the STP clock synchronization. And it always has been "interesting" code.. And the usual bug fixes and cleanups" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (82 commits) s390/pci: Delete an unnecessary check before the function call "pci_dev_put" s390/smp: clean up a condition s390/cio/chp : Remove deprecated create_singlethread_workqueue s390/chsc: improve channel path descriptor determination s390/chsc: sanitize fmt check for chp_desc determination s390/cio: make fmt1 channel path descriptor optional s390/chsc: fix ioctl CHSC_INFO_CU command s390/cio/device_ops: fix kernel doc s390/cio: allow to reset channel measurement block s390/console: Make preferred console handling more consistent s390/mm: fix gmap tlb flush issues s390/mm: add support for 2GB hugepages s390: have unique symbol for __switch_to address s390/cpuinfo: show maximum thread id s390/ptrace: clarify bits in the per_struct s390: stack address vs thread_info s390: remove pointless load within __switch_to s390: enable kcov support s390/cpumf: use basic block for ecctr inline assembly s390/hypfs: use basic block for diag inline assembly ...
2016-07-18KVM: s390: allow user space to handle instr 0x0000David Hildenbrand1-2/+24
We will use illegal instruction 0x0000 for handling 2 byte sw breakpoints from user space. As it can be enabled dynamically via a capability, let's move setting of ICTL_OPEREXC to the post creation step, so we avoid any races when enabling that capability just while adding new cpus. Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-07-01KVM: remove kvm_guest_enter/exit wrappersPaolo Bonzini1-2/+2
Use the functions from context_tracking.h directly. Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-21KVM: s390: vsie: add module parameter "nested"David Hildenbrand1-1/+6
Let's be careful first and allow nested virtualization only if enabled by the system administrator. In addition, user space still has to explicitly enable it via SCLP features for it to work. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: add indication for future featuresDavid Hildenbrand1-0/+18
We have certain SIE features that we cannot support for now. Let's add these features, so user space can directly prepare to enable them, so we don't have to update yet another component. In addition, add a comment block, telling why it is for now not possible to forward/enable these features. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: correctly set and handle guest TODDavid Hildenbrand1-0/+2
Guest 2 sets up the epoch of guest 3 from his point of view. Therefore, we have to add the guest 2 epoch to the guest 3 epoch. We also have to take care of guest 2 epoch changes on STP syncs. This will work just fine by also updating the guest 3 epoch when a vsie_block has been set for a VCPU. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support IBS interpretationDavid Hildenbrand1-0/+2
We can easily enable ibs for guest 2, so he can use it for guest 3. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support conditional-external-interceptionDavid Hildenbrand1-0/+2
We can easily enable cei for guest 2, so he can use it for guest 3. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support intervention-bypassDavid Hildenbrand1-0/+2
We can easily enable intervention bypass for guest 2, so it can use it for guest 3. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support guest-storage-limit-suppressionDavid Hildenbrand1-0/+2
We can easily forward guest-storage-limit-suppression if available. One thing to care about is keeping the prefix properly mapped when gsls in toggled on/off or the mso changes in between. Therefore we better remap the prefix on any mso changes just like we already do with the prefix. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support guest-PER-enhancementDavid Hildenbrand1-0/+2
We can easily forward the guest-PER-enhancement facility to guest 2 if available. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support shared IPTE-interlock facilityDavid Hildenbrand1-0/+2
As we forward the whole SCA provided by guest 2, we can directly forward SIIF if available. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support 64-bit-SCAODavid Hildenbrand1-0/+2
Let's provide the 64-bit-SCAO facility to guest 2, so he can set up a SCA for guest 3 that has a 64 bit address. Please note that we already require the 64 bit SCAO for our vsie implementation, in order to forward the SCA directly (by pinning the page). Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: initial support for nested virtualizationDavid Hildenbrand1-0/+15
This patch adds basic support for nested virtualization on s390x, called VSIE (virtual SIE) and allows it to be used by the guest if the necessary facilities are supported by the hardware and enabled for the guest. In order to make this work, we have to shadow the sie control block provided by guest 2. In order to gain some performance, we have to reuse the same shadow blocks as good as possible. For now, we allow as many shadow blocks as we have VCPUs (that way, every VCPU can run the VSIE concurrently). We have to watch out for the prefix getting unmapped out of our shadow gmap and properly get the VCPU out of VSIE in that case, to fault the prefix pages back in. We use the PROG_REQUEST bit for that purpose. This patch is based on an initial prototype by Tobias Elpelt. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20KVM: s390: backup the currently enabled gmap when scheduled outDavid Hildenbrand1-3/+5
Nested virtualization will have to enable own gmaps. Current code would enable the wrong gmap whenever scheduled out and back in, therefore resulting in the wrong gmap being enabled. This patch reenables the last enabled gmap, therefore avoiding having to touch vcpu->arch.gmap when enabling a different gmap. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20KVM: s390: fast path for shadow gmaps in gmap notifierDavid Hildenbrand1-0/+2
The default kvm gmap notifier doesn't have to handle shadow gmaps. So let's just directly exit in case we get notified about one. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: add reference counter to gmap structureMartin Schwidefsky1-8/+8
Let's use a reference counter mechanism to control the lifetime of gmap structures. This will be needed for further changes related to gmap shadows. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: extended gmap pte notifierMartin Schwidefsky1-6/+7
The current gmap pte notifier forces a pte into to a read-write state. If the pte is invalidated the gmap notifier is called to inform KVM that the mapping will go away. Extend this approach to allow read-write, read-only and no-access as possible target states and call the pte notifier for any change to the pte. This mechanism is used to temporarily set specific access rights for a pte without doing the heavy work of a true mprotect call. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/kvm: page table invalidation notifierMartin Schwidefsky1-5/+13
Pass an address range to the page table invalidation notifier for KVM. This allows to notify changes that affect a larger virtual memory area, e.g. for 1MB pages. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-16KVM: s390: use kvm->created_vcpusPaolo Bonzini1-5/+5
The new created_vcpus field avoids possible races between enabling capabilities and creating VCPUs. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-13s390/time: remove ETR supportMartin Schwidefsky1-1/+1
The External-Time-Reference (ETR) clock synchronization interface has been superseded by Server-Time-Protocol (STP). Remove the outdated ETR interface. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-10KVM: s390: storage keys fit into a charDavid Hildenbrand1-2/+1
No need to convert the storage key into an unsigned long, the target function expects a char as argument. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10s390/mm: return key via pointer in get_guest_storage_keyDavid Hildenbrand1-6/+2
Let's just split returning the key and reporting errors. This makes calling code easier and avoids bugs as happened already. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10s390/mm: set and get guest storage key mmap lockingMartin Schwidefsky1-10/+16
Move the mmap semaphore locking out of set_guest_storage_key and get_guest_storage_key. This makes the two functions more like the other ptep_xxx operations and allows to avoid repeated semaphore operations if multiple keys are read or written. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: turn on tx even without ctxDavid Hildenbrand1-1/+1
Constrained transactional execution is an addon of transactional execution. Let's enable the assist also if only TX is enabled for the guest. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: enable host-protection-interruption only with ESOPDavid Hildenbrand1-1/+3
host-protection-interruption control was introduced with ESOP. So let's enable it only if we have ESOP and add an explanatory comment why we can live without it. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: enable ibs only if availableDavid Hildenbrand1-0/+2
Let's enable interlock-and-broadcast suppression only if the facility is actually available. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: enable PFMFI only if availableDavid Hildenbrand1-1/+1
Let's enable interpretation of PFMFI only if the facility is actually available. Emulation code still works in case the guest is offered EDAT-1. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: enable cei only if availableDavid Hildenbrand1-1/+3
Let's only enable conditional-external-interruption if the facility is actually available. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: enable ib only if availableDavid Hildenbrand1-1/+3
Let's enable intervention bypass only if the facility is acutally available. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: handle missing guest-storage-limit-suppressionDavid Hildenbrand1-0/+4
If guest-storage-limit-suppression is not available, we would for now have a valid guest address space with size 0. So let's simply set the origin to 0 and the limit to hamax. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: provide CMMA attributes only if availableDavid Hildenbrand1-1/+6
Let's not provide the device attribute for cmma enabling and clearing if the hardware doesn't support it. This also helps getting rid of the undocumented return value "-EINVAL" in case CMMA is not available when trying to enable it. Also properly document the meaning of -EINVAL for CMMA clearing. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: enable CMMA if the interpration is availableDavid Hildenbrand1-2/+1
Now that we can detect if collaborative-memory-management interpretation is available, replace the heuristic by a real hardware detection. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: guestdbg: signal missing hardware supportDavid Hildenbrand1-0/+2
Without guest-PER enhancement, we can't provide any debugging support. Therefore act like kernel support is missing. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: handle missing 64-bit-SCAO facilityDavid Hildenbrand1-4/+8
Without that facility, we may only use scaol. So fallback to DMA allocation in that case, so we won't overwrite random memory via the SIE. Also disallow ESCA, so we don't have to handle that allocation case. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: interface to query and configure cpu subfunctionsDavid Hildenbrand1-0/+89
We have certain instructions that indicate available subfunctions via a query subfunction (crypto functions and ptff), or via a test bit function (plo). By exposing these "subfunction blocks" to user space, we allow user space to 1) query available subfunctions and make sure subfunctions won't get lost during migration - e.g. properly indicate them via a CPU model 2) change the subfunctions to be reported to the guest (even adding unavailable ones) This mechanism works just like the way we indicate the stfl(e) list to user space. This way, user space could even emulate some subfunctions in QEMU in the future. If this is ever applicable, we have to make sure later on, that unsupported subfunctions result in an intercept to QEMU. Please note that support to indicate them to the guest is still missing and requires hardware support. Usually, the IBC takes already care of these subfunctions for migration safety. QEMU should make sure to always set these bits properly according to the machine generation to be emulated. Available subfunctions are only valid in combination with STFLE bits retrieved via KVM_S390_VM_CPU_MACHINE and enabled via KVM_S390_VM_CPU_PROCESSOR. If the applicable bits are available, the indicated subfunctions are guaranteed to be correct. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: forward ESOP if availableDavid Hildenbrand1-0/+13
ESOP guarantees that during a protection exception, bit 61 of real location 168-175 will only be set to 1 if it was because of ALCP or DATP. If the exception is due to LAP or KCP, the bit will always be set to 0. The old SOP definition allowed bit 61 to be unpredictable in case of LAP or KCP in some conditions. So ESOP replaces this unpredictability by a guarantee. Therefore, we can directly forward ESOP if it is available on our machine. We don't have to do anything when ESOP is disabled - the guest will simply expect unpredictable values. Our guest access functions are already handling ESOP properly. Please note that future functionality in KVM will require knowledge about ESOP being enabled for a guest or not. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: interface to query and configure cpu featuresDavid Hildenbrand1-0/+63
For now, we only have an interface to query and configure facilities indicated via STFL(E). However, we also have features indicated via SCLP, that have to be indicated to the guest by user space and usually require KVM support. This patch allows user space to query and configure available cpu features for the guest. Please note that disabling a feature doesn't necessarily mean that it is completely disabled (e.g. ESOP is mostly handled by the SIE). We will try our best to disable it. Most features (e.g. SCLP) can't directly be forwarded, as most of them need in addition to hardware support, support in KVM. As we later on want to turn these features in KVM explicitly on/off (to simulate different behavior), we have to filter all features provided by the hardware and make them configurable. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: Limit sthyi executionJanosch Frank1-0/+2
Store hypervisor information is a valid instruction not only in supervisor state but also in problem state, i.e. the guest's userspace. Its execution is not only computational and memory intensive, but also has to get hold of the ipte lock to write to the guest's memory. This lock is not intended to be held often and long, especially not from the untrusted guest userspace. Therefore we apply rate limiting of sthyi executions per VM. Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Acked-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: Add sthyi emulationJanosch Frank1-0/+6
Store Hypervisor Information is an emulated z/VM instruction that provides a guest with basic information about the layers it is running on. This includes information about the cpu configuration of both the machine and the lpar, as well as their names, machine model and machine type. This information enables an application to determine the maximum capacity of CPs and IFLs available to software. The instruction is available whenever the facility bit 74 is set, otherwise executing it results in an operation exception. It is important to check the validity flags in the sections before using data from any structure member. It is not guaranteed that all members will be valid on all machines / machine configurations. Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: Add operation exception interception handlerJanosch Frank1-0/+1
This commit introduces code that handles operation exception interceptions. With this handler we can emulate instructions by using illegal opcodes. Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: Add stats for PEI eventsAlexander Yarygin1-0/+1
Add partial execution intercepted events in kvm_stats_debugfs. Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: ignore IBC if zeroDavid Hildenbrand1-1/+1
Looks like we forgot about the special IBC value of 0 meaning "no IBC". Let's fix that, otherwise it gets rounded up and suddenly an IBC is active with the lowest possible machine. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Fixes: commit 053dd2308d81 ("KVM: s390: force ibc into valid range") Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-05-13KVM: halt_polling: provide a way to qualify wakeups during pollChristian Borntraeger1-0/+6
Some wakeups should not be considered a sucessful poll. For example on s390 I/O interrupts are usually floating, which means that _ALL_ CPUs would be considered runnable - letting all vCPUs poll all the time for transactional like workload, even if one vCPU would be enough. This can result in huge CPU usage for large guests. This patch lets architectures provide a way to qualify wakeups if they should be considered a good/bad wakeups in regard to polls. For s390 the implementation will fence of halt polling for anything but known good, single vCPU events. The s390 implementation for floating interrupts does a wakeup for one vCPU, but the interrupt will be delivered by whatever CPU checks first for a pending interrupt. We prefer the woken up CPU by marking the poll of this CPU as "good" poll. This code will also mark several other wakeup reasons like IPI or expired timers as "good". This will of course also mark some events as not sucessful. As KVM on z runs always as a 2nd level hypervisor, we prefer to not poll, unless we are really sure, though. This patch successfully limits the CPU usage for cases like uperf 1byte transactional ping pong workload or wakeup heavy workload like OLTP while still providing a proper speedup. This also introduced a new vcpu stat "halt_poll_no_tuning" that marks wakeups that are considered not good for polling. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Radim Krčmář <rkrcmar@redhat.com> (for an earlier version) Cc: David Matlack <dmatlack@google.com> Cc: Wanpeng Li <kernellwp@gmail.com> [Rename config symbol. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-09KVM: s390: Populate mask of non-hypervisor managed facility bitsAlexander Yarygin1-3/+16
When a guest is initializing, KVM provides facility bits that can be successfully used by the guest. It's done by applying kvm_s390_fac_list_mask mask on host facility bits stored by the STFLE instruction. Facility bits can be one of two kinds: it's either a hypervisor managed bit or non-hypervisor managed. The hardware provides information which bits need special handling. Let's automatically passthrough to guests new facility bits, that don't require hypervisor support. Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Eric Farman <farman@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-05-09KVM: s390: Enable all facility bits that are known good for passthroughAlexander Yarygin1-2/+2
Some facility bits are in a range that is defined to be "ok for guests without any necessary hypervisor changes". Enable those bits. Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-05-09KVM: s390: force ibc into valid rangeDavid Hildenbrand1-1/+11
Some hardware variants will round the ibc value up/down themselves, others will report a validity intercept. Let's always round it up/down. This patch will also make sure that the ibc is set to 0 in case we don't have ibc support (lowest_ibc == 0). Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
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