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2019-09-20Merge tag 'powerpc-5.4-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "This is a bit late, partly due to me travelling, and partly due to a power outage knocking out some of my test systems *while* I was travelling. - Initial support for running on a system with an Ultravisor, which is software that runs below the hypervisor and protects guests against some attacks by the hypervisor. - Support for building the kernel to run as a "Secure Virtual Machine", ie. as a guest capable of running on a system with an Ultravisor. - Some changes to our DMA code on bare metal, to allow devices with medium sized DMA masks (> 32 && < 59 bits) to use more than 2GB of DMA space. - Support for firmware assisted crash dumps on bare metal (powernv). - Two series fixing bugs in and refactoring our PCI EEH code. - A large series refactoring our exception entry code to use gas macros, both to make it more readable and also enable some future optimisations. As well as many cleanups and other minor features & fixups. Thanks to: Adam Zerella, Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anshuman Khandual, Balbir Singh, Benjamin Herrenschmidt, Cédric Le Goater, Christophe JAILLET, Christophe Leroy, Christopher M. Riedl, Christoph Hellwig, Claudio Carvalho, Daniel Axtens, David Gibson, David Hildenbrand, Desnes A. Nunes do Rosario, Ganesh Goudar, Gautham R. Shenoy, Greg Kurz, Guerney Hunt, Gustavo Romero, Halil Pasic, Hari Bathini, Joakim Tjernlund, Jonathan Neuschafer, Jordan Niethe, Leonardo Bras, Lianbo Jiang, Madhavan Srinivasan, Mahesh Salgaonkar, Mahesh Salgaonkar, Masahiro Yamada, Maxiwell S. Garcia, Michael Anderson, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Qian Cai, Ram Pai, Ravi Bangoria, Reza Arbab, Ryan Grimm, Sam Bobroff, Santosh Sivaraj, Segher Boessenkool, Sukadev Bhattiprolu, Thiago Bauermann, Thiago Jung Bauermann, Thomas Gleixner, Tom Lendacky, Vasant Hegde" * tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (264 commits) powerpc/mm/mce: Keep irqs disabled during lockless page table walk powerpc: Use ftrace_graph_ret_addr() when unwinding powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR ftrace: Look up the address of return_to_handler() using helpers powerpc: dump kernel log before carrying out fadump or kdump docs: powerpc: Add missing documentation reference powerpc/xmon: Fix output of XIVE IPI powerpc/xmon: Improve output of XIVE interrupts powerpc/mm/radix: remove useless kernel messages powerpc/fadump: support holes in kernel boot memory area powerpc/fadump: remove RMA_START and RMA_END macros powerpc/fadump: update documentation about option to release opalcore powerpc/fadump: consider f/w load area powerpc/opalcore: provide an option to invalidate /sys/firmware/opal/core file powerpc/opalcore: export /sys/firmware/opal/core for analysing opal crashes powerpc/fadump: update documentation about CONFIG_PRESERVE_FA_DUMP powerpc/fadump: add support to preserve crash data on FADUMP disabled kernel powerpc/fadump: improve how crashed kernel's memory is reserved powerpc/fadump: consider reserved ranges while releasing memory powerpc/fadump: make crash memory ranges array allocation generic ...
2019-08-30powerpc/kvm: Use UV_RETURN ucall to return to ultravisorSukadev Bhattiprolu
When an SVM makes an hypercall or incurs some other exception, the Ultravisor usually forwards (a.k.a. reflects) the exceptions to the Hypervisor. After processing the exception, Hypervisor uses the UV_RETURN ultracall to return control back to the SVM. The expected register state on entry to this ultracall is: * Non-volatile registers are restored to their original values. * If returning from an hypercall, register R0 contains the return value (unlike other ultracalls) and, registers R4 through R12 contain any output values of the hypercall. * R3 contains the ultracall number, i.e UV_RETURN. * If returning with a synthesized interrupt, R2 contains the synthesized interrupt number. Thanks to input from Paul Mackerras, Ram Pai and Mike Anderson. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com> Acked-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190822034838.27876-8-cclaudio@linux.ibm.com
2019-08-23KVM: PPC: Book3S HV: Define usage types for rmap array in guest memslotSuraj Jitindar Singh
The rmap array in the guest memslot is an array of size number of guest pages, allocated at memslot creation time. Each rmap entry in this array is used to store information about the guest page to which it corresponds. For example for a hpt guest it is used to store a lock bit, rc bits, a present bit and the index of a hpt entry in the guest hpt which maps this page. For a radix guest which is running nested guests it is used to store a pointer to a linked list of nested rmap entries which store the nested guest physical address which maps this guest address and for which there is a pte in the shadow page table. As there are currently two uses for the rmap array, and the potential for this to expand to more in the future, define a type field (being the top 8 bits of the rmap entry) to be used to define the type of the rmap entry which is currently present and define two values for this field for the two current uses of the rmap array. Since the nested case uses the rmap entry to store a pointer, define this type as having the two high bits set as is expected for a pointer. Define the hpt entry type as having bit 56 set (bit 7 IBM bit ordering). Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation 51 franklin street fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 67 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141333.953658117@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-29KVM: PPC: Book3S: Use new mutex to synchronize access to rtas token listPaul Mackerras
Currently the Book 3S KVM code uses kvm->lock to synchronize access to the kvm->arch.rtas_tokens list. Because this list is scanned inside kvmppc_rtas_hcall(), which is called with the vcpu mutex held, taking kvm->lock cause a lock inversion problem, which could lead to a deadlock. To fix this, we add a new mutex, kvm->arch.rtas_token_lock, which nests inside the vcpu mutexes, and use that instead of kvm->lock when accessing the rtas token list. This removes the lockdep_assert_held() in kvmppc_rtas_tokens_free(). At this point we don't hold the new mutex, but that is OK because kvmppc_rtas_tokens_free() is only called when the whole VM is being destroyed, and at that point nothing can be looking up a token in the list. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-05-29KVM: PPC: Book3S HV: Use new mutex to synchronize MMU setupPaul Mackerras
Currently the HV KVM code uses kvm->lock in conjunction with a flag, kvm->arch.mmu_ready, to synchronize MMU setup and hold off vcpu execution until the MMU-related data structures are ready. However, this means that kvm->lock is being taken inside vcpu->mutex, which is contrary to Documentation/virtual/kvm/locking.txt and results in lockdep warnings. To fix this, we add a new mutex, kvm->arch.mmu_setup_lock, which nests inside the vcpu mutexes, and is taken in the places where kvm->lock was taken that are related to MMU setup. Additionally we take the new mutex in the vcpu creation code at the point where we are creating a new vcore, in order to provide mutual exclusion with kvmppc_update_lpcr() and ensure that an update to kvm->arch.lpcr doesn't get missed, which could otherwise lead to a stale vcore->lpcr value. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30KVM: PPC: Book3S HV: XIVE: Replace the 'destroy' method by a 'release' methodCédric Le Goater
When a P9 sPAPR VM boots, the CAS negotiation process determines which interrupt mode to use (XICS legacy or XIVE native) and invokes a machine reset to activate the chosen mode. We introduce 'release' methods for the XICS-on-XIVE and the XIVE native KVM devices which are called when the file descriptor of the device is closed after the TIMA and ESB pages have been unmapped. They perform the necessary cleanups : clear the vCPU interrupt presenters that could be attached and then destroy the device. The 'release' methods replace the 'destroy' methods as 'destroy' is not called anymore once 'release' is. Compatibility with older QEMU is nevertheless maintained. This is not considered as a safe operation as the vCPUs are still running and could be referencing the KVM device through their presenters. To protect the system from any breakage, the kvmppc_xive objects representing both KVM devices are now stored in an array under the VM. Allocation is performed on first usage and memory is freed only when the VM exits. [paulus@ozlabs.org - Moved freeing of xive structures to book3s.c, put it under #ifdef CONFIG_KVM_XICS.] Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30KVM: PPC: Book3S HV: XIVE: Introduce a new capability KVM_CAP_PPC_IRQ_XIVECédric Le Goater
The user interface exposes a new capability KVM_CAP_PPC_IRQ_XIVE to let QEMU connect the vCPU presenters to the XIVE KVM device if required. The capability is not advertised for now as the full support for the XIVE native exploitation mode is not yet available. When this is case, the capability will be advertised on PowerNV Hypervisors only. Nested guests (pseries KVM Hypervisor) are not supported. Internally, the interface to the new KVM device is protected with a new interrupt mode: KVMPPC_IRQ_XIVE. Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30KVM: PPC: Book3S HV: Add a new KVM device for the XIVE native exploitation modeCédric Le Goater
This is the basic framework for the new KVM device supporting the XIVE native exploitation mode. The user interface exposes a new KVM device to be created by QEMU, only available when running on a L0 hypervisor. Support for nested guests is not available yet. The XIVE device reuses the device structure of the XICS-on-XIVE device as they have a lot in common. That could possibly change in the future if the need arise. Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30KVM: PPC: Book3S: Allocate guest TCEs on demand tooAlexey Kardashevskiy
We already allocate hardware TCE tables in multiple levels and skip intermediate levels when we can, now it is a turn of the KVM TCE tables. Thankfully these are allocated already in 2 levels. This moves the table's last level allocation from the creating helper to kvmppc_tce_put() and kvm_spapr_tce_fault(). Since such allocation cannot be done in real mode, this creates a virtual mode version of kvmppc_tce_put() which handles allocations. This adds kvmppc_rm_ioba_validate() to do an additional test if the consequent kvmppc_tce_put() needs a page which has not been allocated; if this is the case, we bail out to virtual mode handlers. The allocations are protected by a new mutex as kvm->lock is not suitable for the task because the fault handler is called with the mmap_sem held but kvmhv_setup_mmu() locks kvm->lock and mmap_sem in the reverse order. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-02-22Merge tag 'kvm-ppc-next-5.1-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-next PPC KVM update for 5.1 There are no major new features this time, just a collection of bug fixes and improvements in various areas, including machine check handling and context switching of protection-key-related registers.
2019-02-20KVM: Call kvm_arch_memslots_updated() before updating memslotsSean Christopherson
kvm_arch_memslots_updated() is at this point in time an x86-specific hook for handling MMIO generation wraparound. x86 stashes 19 bits of the memslots generation number in its MMIO sptes in order to avoid full page fault walks for repeat faults on emulated MMIO addresses. Because only 19 bits are used, wrapping the MMIO generation number is possible, if unlikely. kvm_arch_memslots_updated() alerts x86 that the generation has changed so that it can invalidate all MMIO sptes in case the effective MMIO generation has wrapped so as to avoid using a stale spte, e.g. a (very) old spte that was created with generation==0. Given that the purpose of kvm_arch_memslots_updated() is to prevent consuming stale entries, it needs to be called before the new generation is propagated to memslots. Invalidating the MMIO sptes after updating memslots means that there is a window where a vCPU could dereference the new memslots generation, e.g. 0, and incorrectly reuse an old MMIO spte that was created with (pre-wrap) generation==0. Fixes: e59dbe09f8e6 ("KVM: Introduce kvm_arch_memslots_updated()") Cc: <stable@vger.kernel.org> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-19KVM: PPC: Book3S HV: Add KVM stat largepages_[2M/1G]Suraj Jitindar Singh
This adds an entry to the kvm_stats_debugfs directory which provides the number of large (2M or 1G) pages which have been used to setup the guest mappings, for radix guests. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-02-19KVM: PPC: Book3S PR: Add emulation for slbfee. instructionPaul Mackerras
Recent kernels, since commit e15a4fea4dee ("powerpc/64s/hash: Add some SLB debugging tests", 2018-10-03) use the slbfee. instruction, which PR KVM currently does not have code to emulate. Consequently recent kernels fail to boot under PR KVM. This adds emulation of slbfee., enabling these kernels to boot successfully. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-21KVM: Make kvm_set_spte_hva() return intLan Tianyu
The patch is to make kvm_set_spte_hva() return int and caller can check return value to determine flush tlb or not. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Acked-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-17KVM: PPC: Book3S HV: Allow passthrough of an emulated device to an L2 guestSuraj Jitindar Singh
Allow for a device which is being emulated at L0 (the host) for an L1 guest to be passed through to a nested (L2) guest. The existing kvmppc_hv_emulate_mmio function can be used here. The main challenge is that for a load the result must be stored into the L2 gpr, not an L1 gpr as would normally be the case after going out to qemu to complete the operation. This presents a challenge as at this point the L2 gpr state has been written back into L1 memory. To work around this we store the address in L1 memory of the L2 gpr where the result of the load is to be stored and use the new io_gpr value KVM_MMIO_REG_NESTED_GPR to indicate that this is a nested load for which completion must be done when returning back into the kernel. Then in kvmppc_complete_mmio_load() the resultant value is written into L1 memory at the location of the indicated L2 gpr. Note that we don't currently let an L1 guest emulate a device for an L2 guest which is then passed through to an L3 guest. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-10-09KVM: PPC: Book3S HV: Handle page fault for a nested guestSuraj Jitindar Singh
Consider a normal (L1) guest running under the main hypervisor (L0), and then a nested guest (L2) running under the L1 guest which is acting as a nested hypervisor. L0 has page tables to map the address space for L1 providing the translation from L1 real address -> L0 real address; L1 | | (L1 -> L0) | ----> L0 There are also page tables in L1 used to map the address space for L2 providing the translation from L2 real address -> L1 read address. Since the hardware can only walk a single level of page table, we need to maintain in L0 a "shadow_pgtable" for L2 which provides the translation from L2 real address -> L0 real address. Which looks like; L2 L2 | | | (L2 -> L1) | | | ----> L1 | (L2 -> L0) | | | (L1 -> L0) | | | ----> L0 --------> L0 When a page fault occurs while running a nested (L2) guest we need to insert a pte into this "shadow_pgtable" for the L2 -> L0 mapping. To do this we need to: 1. Walk the pgtable in L1 memory to find the L2 -> L1 mapping, and provide a page fault to L1 if this mapping doesn't exist. 2. Use our L1 -> L0 pgtable to convert this L1 address to an L0 address, or try to insert a pte for that mapping if it doesn't exist. 3. Now we have a L2 -> L0 mapping, insert this into our shadow_pgtable Once this mapping exists we can take rc faults when hardware is unable to automatically set the reference and change bits in the pte. On these we need to: 1. Check the rc bits on the L2 -> L1 pte match, and otherwise reflect the fault down to L1. 2. Set the rc bits in the L1 -> L0 pte which corresponds to the same host page. 3. Set the rc bits in the L2 -> L0 pte. As we reuse a large number of functions in book3s_64_mmu_radix.c for this we also needed to refactor a number of these functions to take an lpid parameter so that the correct lpid is used for tlb invalidations. The functionality however has remained the same. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-09KVM: PPC: Book3S HV: Nested guest entry via hypercallPaul Mackerras
This adds a new hypercall, H_ENTER_NESTED, which is used by a nested hypervisor to enter one of its nested guests. The hypercall supplies register values in two structs. Those values are copied by the level 0 (L0) hypervisor (the one which is running in hypervisor mode) into the vcpu struct of the L1 guest, and then the guest is run until an interrupt or error occurs which needs to be reported to L1 via the hypercall return value. Currently this assumes that the L0 and L1 hypervisors are the same endianness, and the structs passed as arguments are in native endianness. If they are of different endianness, the version number check will fail and the hcall will be rejected. Nested hypervisors do not support indep_threads_mode=N, so this adds code to print a warning message if the administrator has set indep_threads_mode=N, and treat it as Y. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-09KVM: PPC: Book3S HV: Framework and hcall stubs for nested virtualizationPaul Mackerras
This starts the process of adding the code to support nested HV-style virtualization. It defines a new H_SET_PARTITION_TABLE hypercall which a nested hypervisor can use to set the base address and size of a partition table in its memory (analogous to the PTCR register). On the host (level 0 hypervisor) side, the H_SET_PARTITION_TABLE hypercall from the guest is handled by code that saves the virtual PTCR value for the guest. This also adds code for creating and destroying nested guests and for reading the partition table entry for a nested guest from L1 memory. Each nested guest has its own shadow LPID value, different in general from the LPID value used by the nested hypervisor to refer to it. The shadow LPID value is allocated at nested guest creation time. Nested hypervisor functionality is only available for a radix guest, which therefore means a radix host on a POWER9 (or later) processor. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-09KVM: PPC: Use ccr field in pt_regs struct embedded in vcpu structPaul Mackerras
When the 'regs' field was added to struct kvm_vcpu_arch, the code was changed to use several of the fields inside regs (e.g., gpr, lr, etc.) but not the ccr field, because the ccr field in struct pt_regs is 64 bits on 64-bit platforms, but the cr field in kvm_vcpu_arch is only 32 bits. This changes the code to use the regs.ccr field instead of cr, and changes the assembly code on 64-bit platforms to use 64-bit loads and stores instead of 32-bit ones. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-09KVM: PPC: Book3S HV: Add a debugfs file to dump radix mappingsPaul Mackerras
This adds a file called 'radix' in the debugfs directory for the guest, which when read gives all of the valid leaf PTEs in the partition-scoped radix tree for a radix guest, in human-readable format. It is analogous to the existing 'htab' file which dumps the HPT entries for a HPT guest. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-09KVM: PPC: Book3S: Simplify external interrupt handlingPaul Mackerras
Currently we use two bits in the vcpu pending_exceptions bitmap to indicate that an external interrupt is pending for the guest, one for "one-shot" interrupts that are cleared when delivered, and one for interrupts that persist until cleared by an explicit action of the OS (e.g. an acknowledge to an interrupt controller). The BOOK3S_IRQPRIO_EXTERNAL bit is used for one-shot interrupt requests and BOOK3S_IRQPRIO_EXTERNAL_LEVEL is used for persisting interrupts. In practice BOOK3S_IRQPRIO_EXTERNAL never gets used, because our Book3S platforms generally, and pseries in particular, expect external interrupt requests to persist until they are acknowledged at the interrupt controller. That combined with the confusion introduced by having two bits for what is essentially the same thing makes it attractive to simplify things by only using one bit. This patch does that. With this patch there is only BOOK3S_IRQPRIO_EXTERNAL, and by default it has the semantics of a persisting interrupt. In order to avoid breaking the ABI, we introduce a new "external_oneshot" flag which preserves the behaviour of the KVM_INTERRUPT ioctl with the KVM_INTERRUPT_SET argument. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-26KVM: PPC: Book3S HV: Allow creating max number of VCPUs on POWER9Paul Mackerras
Commit 1e175d2 ("KVM: PPC: Book3S HV: Pack VCORE IDs to access full VCPU ID space", 2018-07-25) allowed use of VCPU IDs up to KVM_MAX_VCPU_ID on POWER9 in all guest SMT modes and guest emulated hardware SMT modes. However, with the current definition of KVM_MAX_VCPU_ID, a guest SMT mode of 1 and an emulated SMT mode of 8, it is only possible to create KVM_MAX_VCPUS / 2 VCPUS, because threads_per_subcore is 4 on POWER9 CPUs. (Using an emulated SMT mode of 8 is useful when migrating VMs to or from POWER8 hosts.) This increases KVM_MAX_VCPU_ID to 8 * KVM_MAX_VCPUS when HV KVM is configured in, so that a full complement of KVM_MAX_VCPUS VCPUs can be created on POWER9 in all guest SMT modes and emulated hardware SMT modes. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-07-18KVM: PPC: Remove mmio_vsx_tx_sx_enabled in KVM MMIO emulationSimon Guo
Originally PPC KVM MMIO emulation uses only 0~31#(5 bits) for VSR reg number, and use mmio_vsx_tx_sx_enabled field together for 0~63# VSR regs. Currently PPC KVM MMIO emulation is reimplemented with analyse_instr() assistance. analyse_instr() returns 0~63 for VSR register number, so it is not necessary to use additional mmio_vsx_tx_sx_enabled field any more. This patch extends related reg bits (expand io_gpr to u16 from u8 and use 6 bits for VSR reg#), so that mmio_vsx_tx_sx_enabled can be removed. Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-06-01KVM: PPC: Book3S PR: Add transaction memory save/restore skeletonSimon Guo
The transaction memory checkpoint area save/restore behavior is triggered when VCPU qemu process is switching out/into CPU, i.e. at kvmppc_core_vcpu_put_pr() and kvmppc_core_vcpu_load_pr(). MSR TM active state is determined by TS bits: active: 10(transactional) or 01 (suspended) inactive: 00 (non-transactional) We don't "fake" TM functionality for guest. We "sync" guest virtual MSR TM active state(10 or 01) with shadow MSR. That is to say, we don't emulate a transactional guest with a TM inactive MSR. TM SPR support(TFIAR/TFAR/TEXASR) has already been supported by commit 9916d57e64a4 ("KVM: PPC: Book3S PR: Expose TM registers"). Math register support (FPR/VMX/VSX) will be done at subsequent patch. Whether TM context need to be saved/restored can be determined by kvmppc_get_msr() TM active state: * TM active - save/restore TM context * TM inactive - no need to do so and only save/restore TM SPRs. Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Suggested-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-22KVM: PPC: Reimplement LOAD_VMX/STORE_VMX instruction mmio emulation with ↵Simon Guo
analyse_instr() input This patch reimplements LOAD_VMX/STORE_VMX MMIO emulation with analyse_instr() input. When emulating the store, the VMX reg will need to be flushed so that the right reg val can be retrieved before writing to IO MEM. This patch also adds support for lvebx/lvehx/lvewx/stvebx/stvehx/stvewx MMIO emulation. To meet the requirement of handling different element sizes, kvmppc_handle_load128_by2x64()/kvmppc_handle_store128_by2x64() were replaced with kvmppc_handle_vmx_load()/kvmppc_handle_vmx_store(). The framework used is similar to VSX instruction MMIO emulation. Suggested-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-22KVM: PPC: Expand mmio_vsx_copy_type to cover VMX load/store element typesSimon Guo
VSX MMIO emulation uses mmio_vsx_copy_type to represent VSX emulated element size/type, such as KVMPPC_VSX_COPY_DWORD_LOAD, etc. This patch expands mmio_vsx_copy_type to cover VMX copy type, such as KVMPPC_VMX_COPY_BYTE(stvebx/lvebx), etc. As a result, mmio_vsx_copy_type is also renamed to mmio_copy_type. It is a preparation for reimplementing VMX MMIO emulation. Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-22KVM: PPC: Add KVMPPC_VSX_COPY_WORD_LOAD_DUMP type support for mmio emulationSimon Guo
Some VSX instructions like lxvwsx will splat word into VSR. This patch adds a new VSX copy type KVMPPC_VSX_COPY_WORD_LOAD_DUMP to support this. Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18KVM: PPC: Book3S HV: Lockless tlbie for HPT hcallsNicholas Piggin
tlbies to an LPAR do not have to be serialised since POWER4/PPC970, after which the MMU_FTR_LOCKLESS_TLBIE feature was introduced to avoid tlbie locking. Since commit c17b98cf6028 ("KVM: PPC: Book3S HV: Remove code for PPC970 processors"), KVM no longer supports processors that do not have this feature, so the tlbie locking can be removed completely. A sanity check for the feature is put in kvmppc_mmu_hv_init. Testing was done on a POWER9 system in HPT mode, with a -smp 32 guest in HPT mode. 32 instances of the powerpc fork benchmark from selftests were run with --fork, and the results measured. Without this patch, total throughput was about 13.5K/sec, and this is the top of the host profile: 74.52% [k] do_tlbies 2.95% [k] kvmppc_book3s_hv_page_fault 1.80% [k] calc_checksum 1.80% [k] kvmppc_vcpu_run_hv 1.49% [k] kvmppc_run_core After this patch, throughput was about 51K/sec, with this profile: 21.28% [k] do_tlbies 5.26% [k] kvmppc_run_core 4.88% [k] kvmppc_book3s_hv_page_fault 3.30% [k] _raw_spin_lock_irqsave 3.25% [k] gup_pgd_range Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18KVM: PPC: Move nip/ctr/lr/xer registers to pt_regs in kvm_vcpu_archSimon Guo
This patch moves nip/ctr/lr/xer registers from scattered places in kvm_vcpu_arch to pt_regs structure. cr register is "unsigned long" in pt_regs and u32 in vcpu->arch. It will need more consideration and may move in later patches. Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18KVM: PPC: Add pt_regs into kvm_vcpu_arch and move vcpu->arch.gpr[] into itSimon Guo
Current regs are scattered at kvm_vcpu_arch structure and it will be more neat to organize them into pt_regs structure. Also it will enable reimplementation of MMIO emulation code with analyse_instr() later. Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-17KVM: PPC: Book3S HV: Add 'online' register to ONE_REG interfacePaul Mackerras
This adds a new KVM_REG_PPC_ONLINE register which userspace can set to 0 or 1 via the GET/SET_ONE_REG interface to indicate whether it considers the VCPU to be offline (0), that is, not currently running, or online (1). This will be used in a later patch to configure the register which controls PURR and SPURR accumulation. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-04-09Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM: - VHE optimizations - EL2 address space randomization - speculative execution mitigations ("variant 3a", aka execution past invalid privilege register access) - bugfixes and cleanups PPC: - improvements for the radix page fault handler for HV KVM on POWER9 s390: - more kvm stat counters - virtio gpu plumbing - documentation - facilities improvements x86: - support for VMware magic I/O port and pseudo-PMCs - AMD pause loop exiting - support for AMD core performance extensions - support for synchronous register access - expose nVMX capabilities to userspace - support for Hyper-V signaling via eventfd - use Enlightened VMCS when running on Hyper-V - allow userspace to disable MWAIT/HLT/PAUSE vmexits - usual roundup of optimizations and nested virtualization bugfixes Generic: - API selftest infrastructure (though the only tests are for x86 as of now)" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (174 commits) kvm: x86: fix a prototype warning kvm: selftests: add sync_regs_test kvm: selftests: add API testing infrastructure kvm: x86: fix a compile warning KVM: X86: Add Force Emulation Prefix for "emulate the next instruction" KVM: X86: Introduce handle_ud() KVM: vmx: unify adjacent #ifdefs x86: kvm: hide the unused 'cpu' variable KVM: VMX: remove bogus WARN_ON in handle_ept_misconfig Revert "KVM: X86: Fix SMRAM accessing even if VM is shutdown" kvm: Add emulation for movups/movupd KVM: VMX: raise internal error for exception during invalid protected mode state KVM: nVMX: Optimization: Dont set KVM_REQ_EVENT when VMExit with nested_run_pending KVM: nVMX: Require immediate-exit when event reinjected to L2 and L1 event pending KVM: x86: Fix misleading comments on handling pending exceptions KVM: x86: Rename interrupt.pending to interrupt.injected KVM: VMX: No need to clear pending NMI/interrupt on inject realmode interrupt x86/kvm: use Enlightened VMCS when running on Hyper-V x86/hyper-v: detect nested features x86/hyper-v: define struct hv_enlightened_vmcs and clean field bits ...
2018-03-24KVM: PPC: Book3S HV: Work around transactional memory bugs in POWER9Paul Mackerras
POWER9 has hardware bugs relating to transactional memory and thread reconfiguration (changes to hardware SMT mode). Specifically, the core does not have enough storage to store a complete checkpoint of all the architected state for all four threads. The DD2.2 version of POWER9 includes hardware modifications designed to allow hypervisor software to implement workarounds for these problems. This patch implements those workarounds in KVM code so that KVM guests see a full, working transactional memory implementation. The problems center around the use of TM suspended state, where the CPU has a checkpointed state but execution is not transactional. The workaround is to implement a "fake suspend" state, which looks to the guest like suspended state but the CPU does not store a checkpoint. In this state, any instruction that would cause a transition to transactional state (rfid, rfebb, mtmsrd, tresume) or would use the checkpointed state (treclaim) causes a "soft patch" interrupt (vector 0x1500) to the hypervisor so that it can be emulated. The trechkpt instruction also causes a soft patch interrupt. On POWER9 DD2.2, we avoid returning to the guest in any state which would require a checkpoint to be present. The trechkpt in the guest entry path which would normally create that checkpoint is replaced by either a transition to fake suspend state, if the guest is in suspend state, or a rollback to the pre-transactional state if the guest is in transactional state. Fake suspend state is indicated by a flag in the PACA plus a new bit in the PSSCR. The new PSSCR bit is write-only and reads back as 0. On exit from the guest, if the guest is in fake suspend state, we still do the treclaim instruction as we would in real suspend state, in order to get into non-transactional state, but we do not save the resulting register state since there was no checkpoint. Emulation of the instructions that cause a softpatch interrupt is handled in two paths. If the guest is in real suspend mode, we call kvmhv_p9_tm_emulation_early() to handle the cases where the guest is transitioning to transactional state. This is called before we do the treclaim in the guest exit path; because we haven't done treclaim, we can get back to the guest with the transaction still active. If the instruction is a case that kvmhv_p9_tm_emulation_early() doesn't handle, or if the guest is in fake suspend state, then we proceed to do the complete guest exit path and subsequently call kvmhv_p9_tm_emulation() in host context with the MMU on. This handles all the cases including the cases that generate program interrupts (illegal instruction or TM Bad Thing) and facility unavailable interrupts. The emulation is reasonably straightforward and is mostly concerned with checking for exception conditions and updating the state of registers such as MSR and CR0. The treclaim emulation takes care to ensure that the TEXASR register gets updated as if it were the guest treclaim instruction that had done failure recording, not the treclaim done in hypervisor state in the guest exit path. With this, the KVM_CAP_PPC_HTM capability returns true (1) even if transactional memory is not available to host userspace. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-19KVM: PPC: Remove unused kvm_unmap_hva callbackPaul Mackerras
Since commit fb1522e099f0 ("KVM: update to new mmu_notifier semantic v2", 2017-08-31), the MMU notifier code in KVM no longer calls the kvm_unmap_hva callback. This removes the PPC implementations of kvm_unmap_hva(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-02-09KVM: PPC: Book3S: Add MMIO emulation for VMX instructionsJose Ricardo Ziviani
This patch provides the MMIO load/store vector indexed X-Form emulation. Instructions implemented: lvx: the quadword in storage addressed by the result of EA & 0xffff_ffff_ffff_fff0 is loaded into VRT. stvx: the contents of VRS are stored into the quadword in storage addressed by the result of EA & 0xffff_ffff_ffff_fff0. Reported-by: Gopesh Kumar Chaudhary <gopchaud@in.ibm.com> Reported-by: Balamuruhan S <bala24@linux.vnet.ibm.com> Signed-off-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-19KVM: PPC: Book3S HV: Keep XIVE escalation interrupt masked unless cededBenjamin Herrenschmidt
This works on top of the single escalation support. When in single escalation, with this change, we will keep the escalation interrupt disabled unless the VCPU is in H_CEDE (idle). In any other case, we know the VCPU will be rescheduled and thus there is no need to take escalation interrupts in the host whenever a guest interrupt fires. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-19KVM: PPC: Book3S HV: Make xive_pushed a byte, not a wordBenjamin Herrenschmidt
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-19KVM: PPC: Book3S HV: Don't use existing "prodded" flag for XIVE escalationsBenjamin Herrenschmidt
The prodded flag is only cleared at the beginning of H_CEDE, so every time we have an escalation, we will cause the *next* H_CEDE to return immediately. Instead use a dedicated "irq_pending" flag to indicate that a guest interrupt is pending for the VCPU. We don't reuse the existing exception bitmap so as to avoid expensive atomic ops. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-11-01KVM: PPC: Book3S HV: Allow for running POWER9 host in single-threaded modePaul Mackerras
This patch allows for a mode on POWER9 hosts where we control all the threads of a core, much as we do on POWER8. The mode is controlled by a module parameter on the kvm_hv module, called "indep_threads_mode". The normal mode on POWER9 is the "independent threads" mode, with indep_threads_mode=Y, where the host is in SMT4 mode (or in fact any desired SMT mode) and each thread independently enters and exits from KVM guests without reference to what other threads in the core are doing. If indep_threads_mode is set to N at the point when a VM is started, KVM will expect every core that the guest runs on to be in single threaded mode (that is, threads 1, 2 and 3 offline), and will set the flag that prevents secondary threads from coming online. We can still use all four threads; the code that implements dynamic micro-threading on POWER8 will become active in over-commit situations and will allow up to three other VCPUs to be run on the secondary threads of the core whenever a VCPU is run. The reason for wanting this mode is that this will allow us to run HPT guests on a radix host on a POWER9 machine that does not support "mixed mode", that is, having some threads in a core be in HPT mode while other threads are in radix mode. It will also make it possible to implement a "strict threads" mode in future, if desired. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-11-01KVM: PPC: Book3S HV: Unify dirty page map between HPT and radixPaul Mackerras
Currently, the HPT code in HV KVM maintains a dirty bit per guest page in the rmap array, whether or not dirty page tracking has been enabled for the memory slot. In contrast, the radix code maintains a dirty bit per guest page in memslot->dirty_bitmap, and only does so when dirty page tracking has been enabled. This changes the HPT code to maintain the dirty bits in the memslot dirty_bitmap like radix does. This results in slightly less code overall, and will mean that we do not lose the dirty bits when transitioning between HPT and radix mode in future. There is one minor change to behaviour as a result. With HPT, when dirty tracking was enabled for a memslot, we would previously clear all the dirty bits at that point (both in the HPT entries and in the rmap arrays), meaning that a KVM_GET_DIRTY_LOG ioctl immediately following would show no pages as dirty (assuming no vcpus have run in the meantime). With this change, the dirty bits on HPT entries are not cleared at the point where dirty tracking is enabled, so KVM_GET_DIRTY_LOG would show as dirty any guest pages that are resident in the HPT and dirty. This is consistent with what happens on radix. This also fixes a bug in the mark_pages_dirty() function for radix (in the sense that the function no longer exists). In the case where a large page of 64 normal pages or more is marked dirty, the addressing of the dirty bitmap was incorrect and could write past the end of the bitmap. Fortunately this case was never hit in practice because a 2MB large page is only 32 x 64kB pages, and we don't support backing the guest with 1GB huge pages at this point. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-11-01KVM: PPC: Book3S HV: Rename hpte_setup_done to mmu_readyPaul Mackerras
This renames the kvm->arch.hpte_setup_done field to mmu_ready because we will want to use it for radix guests too -- both for setting things up before vcpu execution, and for excluding vcpus from executing while MMU-related things get changed, such as in future switching the MMU from radix to HPT mode or vice-versa. This also moves the call to kvmppc_setup_partition_table() that was done in kvmppc_hv_setup_htab_rma() for HPT guests, and the setting of mmu_ready, into the caller in kvmppc_vcpu_run_hv(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-31KVM: update to new mmu_notifier semantic v2Jérôme Glisse
Calls to mmu_notifier_invalidate_page() were replaced by calls to mmu_notifier_invalidate_range() and are now bracketed by calls to mmu_notifier_invalidate_range_start()/end() Remove now useless invalidate_page callback. Changed since v1 (Linus Torvalds) - remove now useless kvm_arch_mmu_notifier_invalidate_page() Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Tested-by: Mike Galbraith <efault@gmx.de> Tested-by: Adam Borowski <kilobyte@angband.pl> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: kvm@vger.kernel.org Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-03Merge branch 'kvm-ppc-next' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD - Better machine check handling for HV KVM - Ability to support guests with threads=2, 4 or 8 on POWER9 - Fix for a race that could cause delayed recognition of signals - Fix for a bug where POWER9 guests could sleep with interrupts pending.
2017-06-22KVM: PPC: Book3S HV: Exit guest upon MCE when FWNMI capability is enabledAravinda Prasad
Enhance KVM to cause a guest exit with KVM_EXIT_NMI exit reason upon a machine check exception (MCE) in the guest address space if the KVM_CAP_PPC_FWNMI capability is enabled (instead of delivering a 0x200 interrupt to guest). This enables QEMU to build error log and deliver machine check exception to guest via guest registered machine check handler. This approach simplifies the delivery of machine check exception to guest OS compared to the earlier approach of KVM directly invoking 0x200 guest interrupt vector. This design/approach is based on the feedback for the QEMU patches to handle machine check exception. Details of earlier approach of handling machine check exception in QEMU and related discussions can be found at: https://lists.nongnu.org/archive/html/qemu-devel/2014-11/msg00813.html Note: This patch now directly invokes machine_check_print_event_info() from kvmppc_handle_exit_hv() to print the event to host console at the time of guest exit before the exception is passed on to the guest. Hence, the host-side handling which was performed earlier via machine_check_fwnmi is removed. The reasons for this approach is (i) it is not possible to distinguish whether the exception occurred in the guest or the host from the pt_regs passed on the machine_check_exception(). Hence machine_check_exception() calls panic, instead of passing on the exception to the guest, if the machine check exception is not recoverable. (ii) the approach introduced in this patch gives opportunity to the host kernel to perform actions in virtual mode before passing on the exception to the guest. This approach does not require complex tweaks to machine_check_fwnmi and friends. Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-21KVM: PPC: Book3S HV: Add new capability to control MCE behaviourAravinda Prasad
This introduces a new KVM capability to control how KVM behaves on machine check exception (MCE) in HV KVM guests. If this capability has not been enabled, KVM redirects machine check exceptions to guest's 0x200 vector, if the address in error belongs to the guest. With this capability enabled, KVM will cause a guest exit with the exit reason indicating an NMI. The new capability is required to avoid problems if a new kernel/KVM is used with an old QEMU, running a guest that doesn't issue "ibm,nmi-register". As old QEMU does not understand the NMI exit type, it treats it as a fatal error. However, the guest could have handled the machine check error if the exception was delivered to guest's 0x200 interrupt vector instead of NMI exit in case of old QEMU. [paulus@ozlabs.org - Reworded the commit message to be clearer, enable only on HV KVM.] Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-19KVM: PPC: Book3S HV: Virtualize doorbell facility on POWER9Paul Mackerras
On POWER9, we no longer have the restriction that we had on POWER8 where all threads in a core have to be in the same partition, so the CPU threads are now independent. However, we still want to be able to run guests with a virtual SMT topology, if only to allow migration of guests from POWER8 systems to POWER9. A guest that has a virtual SMT mode greater than 1 will expect to be able to use the doorbell facility; it will expect the msgsndp and msgclrp instructions to work appropriately and to be able to read sensible values from the TIR (thread identification register) and DPDES (directed privileged doorbell exception status) special-purpose registers. However, since each CPU thread is a separate sub-processor in POWER9, these instructions and registers can only be used within a single CPU thread. In order for these instructions to appear to act correctly according to the guest's virtual SMT mode, we have to trap and emulate them. We cause them to trap by clearing the HFSCR_MSGP bit in the HFSCR register. The emulation is triggered by the hypervisor facility unavailable interrupt that occurs when the guest uses them. To cause a doorbell interrupt to occur within the guest, we set the DPDES register to 1. If the guest has interrupts enabled, the CPU will generate a doorbell interrupt and clear the DPDES register in hardware. The DPDES hardware register for the guest is saved in the vcpu->arch.vcore->dpdes field. Since this gets written by the guest exit code, other VCPUs wishing to cause a doorbell interrupt don't write that field directly, but instead set a vcpu->arch.doorbell_request flag. This is consumed and set to 0 by the guest entry code, which then sets DPDES to 1. Emulating reads of the DPDES register is somewhat involved, because it requires reading the doorbell pending interrupt status of all of the VCPU threads in the virtual core, and if any of those VCPUs are running, their doorbell status is only up-to-date in the hardware DPDES registers of the CPUs where they are running. In order to get a reasonable approximation of the current doorbell status, we send those CPUs an IPI, causing an exit from the guest which will update the vcpu->arch.vcore->dpdes field. We then use that value in constructing the emulated DPDES register value. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-19KVM: PPC: Book3S HV: Allow userspace to set the desired SMT modePaul Mackerras
This allows userspace to set the desired virtual SMT (simultaneous multithreading) mode for a VM, that is, the number of VCPUs that get assigned to each virtual core. Previously, the virtual SMT mode was fixed to the number of threads per subcore, and if userspace wanted to have fewer vcpus per vcore, then it would achieve that by using a sparse CPU numbering. This had the disadvantage that the vcpu numbers can get quite large, particularly for SMT1 guests on a POWER8 with 8 threads per core. With this patch, userspace can set its desired virtual SMT mode and then use contiguous vcpu numbering. On POWER8, where the threading mode is "strict", the virtual SMT mode must be less than or equal to the number of threads per subcore. On POWER9, which implements a "loose" threading mode, the virtual SMT mode can be any power of 2 between 1 and 8, even though there is effectively one thread per subcore, since the threads are independent and can all be in different partitions. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-19KVM: PPC: Book3S HV: Context-switch HFSCR between host and guest on POWER9Paul Mackerras
This adds code to allow us to use a different value for the HFSCR (Hypervisor Facilities Status and Control Register) when running the guest from that which applies in the host. The reason for doing this is to allow us to trap the msgsndp instruction and related operations in future so that they can be virtualized. We also save the value of HFSCR when a hypervisor facility unavailable interrupt occurs, because the high byte of HFSCR indicates which facility the guest attempted to access. We save and restore the host value on guest entry/exit because some bits of it affect host userspace execution. We only do all this on POWER9, not on POWER8, because we are not intending to virtualize any of the facilities controlled by HFSCR on POWER8. In particular, the HFSCR bit that controls execution of msgsndp and related operations does not exist on POWER8. The HFSCR doesn't exist at all on POWER7. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-19KVM: PPC: Book3S HV: Enable guests to use large decrementer mode on POWER9Paul Mackerras
This allows userspace (e.g. QEMU) to enable large decrementer mode for the guest when running on a POWER9 host, by setting the LPCR_LD bit in the guest LPCR value. With this, the guest exit code saves 64 bits of the guest DEC value on exit. Other places that use the guest DEC value check the LPCR_LD bit in the guest LPCR value, and if it is set, omit the 32-bit sign extension that would otherwise be done. This doesn't change the DEC emulation used by PR KVM because PR KVM is not supported on POWER9 yet. This is partly based on an earlier patch by Oliver O'Halloran. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>