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2020-05-29powerpc/book3s64/kvm: Fix secondary page table walk warning during migrationAneesh Kumar K.V1-0/+10
This patch fixes the below warning reported during migration: find_kvm_secondary_pte called with kvm mmu_lock not held CPU: 23 PID: 5341 Comm: qemu-system-ppc Tainted: G W 5.7.0-rc5-kvm-00211-g9ccf10d6d088 #432 NIP: c008000000fe848c LR: c008000000fe8488 CTR: 0000000000000000 REGS: c000001e19f077e0 TRAP: 0700 Tainted: G W (5.7.0-rc5-kvm-00211-g9ccf10d6d088) MSR: 9000000000029033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 42222422 XER: 20040000 CFAR: c00000000012f5ac IRQMASK: 0 GPR00: c008000000fe8488 c000001e19f07a70 c008000000ffe200 0000000000000039 GPR04: 0000000000000001 c000001ffc8b4900 0000000000018840 0000000000000007 GPR08: 0000000000000003 0000000000000001 0000000000000007 0000000000000001 GPR12: 0000000000002000 c000001fff6d9400 000000011f884678 00007fff70b70000 GPR16: 00007fff7137cb90 00007fff7dcb4410 0000000000000001 0000000000000000 GPR20: 000000000ffe0000 0000000000000000 0000000000000001 0000000000000000 GPR24: 8000000000000000 0000000000000001 c000001e1f67e600 c000001e1fd82410 GPR28: 0000000000001000 c000001e2e410000 0000000000000fff 0000000000000ffe NIP [c008000000fe848c] kvmppc_hv_get_dirty_log_radix+0x2e4/0x340 [kvm_hv] LR [c008000000fe8488] kvmppc_hv_get_dirty_log_radix+0x2e0/0x340 [kvm_hv] Call Trace: [c000001e19f07a70] [c008000000fe8488] kvmppc_hv_get_dirty_log_radix+0x2e0/0x340 [kvm_hv] (unreliable) [c000001e19f07b50] [c008000000fd42e4] kvm_vm_ioctl_get_dirty_log_hv+0x33c/0x3c0 [kvm_hv] [c000001e19f07be0] [c008000000eea878] kvm_vm_ioctl_get_dirty_log+0x30/0x50 [kvm] [c000001e19f07c00] [c008000000edc818] kvm_vm_ioctl+0x2b0/0xc00 [kvm] [c000001e19f07d50] [c00000000046e148] ksys_ioctl+0xf8/0x150 [c000001e19f07da0] [c00000000046e1c8] sys_ioctl+0x28/0x80 [c000001e19f07dc0] [c00000000003652c] system_call_exception+0x16c/0x240 [c000001e19f07e20] [c00000000000d070] system_call_common+0xf0/0x278 Instruction dump: 7d3a512a 4200ffd0 7ffefb78 4bfffdc4 60000000 3c820000 e8848468 3c620000 e86384a8 38840010 4800673d e8410018 <0fe00000> 4bfffdd4 60000000 60000000 Reported-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200528080456.87797-1-aneesh.kumar@linux.ibm.com
2020-05-05powerpc/kvm/book3s: Use pte_present instead of opencoding _PAGE_PRESENT checkAneesh Kumar K.V1-1/+1
This adds _PAGE_PTE check and makes sure we validate the pte value returned via find_kvm_host_pte. NOTE: this also considers _PAGE_INVALID to the software valid bit. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200505071729.54912-20-aneesh.kumar@linux.ibm.com
2020-05-05powerpc/kvm/book3s: Add helper for host page table walkAneesh Kumar K.V1-0/+16
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200505071729.54912-13-aneesh.kumar@linux.ibm.com
2020-05-05powerpc/kvm/book3s: Use kvm helpers to walk shadow or secondary tableAneesh Kumar K.V1-0/+3
update kvmppc_hv_handle_set_rc to use find_kvm_nested_guest_pte and find_kvm_secondary_pte Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200505071729.54912-12-aneesh.kumar@linux.ibm.com
2020-05-05powerpc/kvm/book3s: Add helper to walk partition scoped linux page table.Aneesh Kumar K.V1-0/+13
The locking rules for walking partition scoped table is different from process scoped table. Hence add a helper for secondary linux page table walk and also add check whether we are holding the right locks. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200505071729.54912-10-aneesh.kumar@linux.ibm.com
2019-08-01treewide: Rename rcu_dereference_raw_notrace() to _check()Joel Fernandes (Google)1-1/+1
The rcu_dereference_raw_notrace() API name is confusing. It is equivalent to rcu_dereference_raw() except that it also does sparse pointer checking. There are only a few users of rcu_dereference_raw_notrace(). This patches renames all of them to be rcu_dereference_raw_check() with the "_check()" indicating sparse checking. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> [ paulmck: Fix checkpatch warnings about parentheses. ] Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266Thomas Gleixner1-12/+1
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>
2018-12-21KVM: PPC: Book3S HV: Introduce kvmhv_update_nest_rmap_rc_list()Suraj Jitindar Singh1-0/+3
Introduce a function kvmhv_update_nest_rmap_rc_list() which for a given nest_rmap list will traverse it, find the corresponding pte in the shadow page tables, and if it still maps the same host page update the rc bits accordingly. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-17KVM: PPC: Book3S HV: Add function kvmhv_vcpu_is_radix()Suraj Jitindar Singh1-0/+13
There exists a function kvm_is_radix() which is used to determine if a kvm instance is using the radix mmu. However this only applies to the first level (L1) guest. Add a function kvmhv_vcpu_is_radix() which can be used to determine if the current execution context of the vcpu is radix, accounting for if the vcpu is running a nested guest. Currently all nested guests must be radix but this may change in the future. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-17KVM: PPC: Book3S HV: Cleanups - constify memslots, fix commentsPaul Mackerras1-1/+1
This adds 'const' to the declarations for the struct kvm_memory_slot pointer parameters of some functions, which will make it possible to call those functions from kvmppc_core_commit_memory_region_hv() in the next patch. This also fixes some comments about locking. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-10-09KVM: PPC: Book3S HV: Add nested shadow page tables to debugfsPaul Mackerras1-0/+1
This adds a list of valid shadow PTEs for each nested guest to the 'radix' file for the guest in debugfs. This can be useful for debugging. 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: Invalidate TLB when nested vcpu moves physical cpuSuraj Jitindar Singh1-0/+3
This is only done at level 0, since only level 0 knows which physical CPU a vcpu is running on. This does for nested guests what L0 already did for its own guests, which is to flush the TLB on a pCPU when it goes to run a vCPU there, and there is another vCPU in the same VM which previously ran on this pCPU and has now started to run on another pCPU. This is to handle the situation where the other vCPU touched a mapping, moved to another pCPU and did a tlbiel (local-only tlbie) on that new pCPU and thus left behind a stale TLB entry on this pCPU. This introduces a limit on the the vcpu_token values used in the H_ENTER_NESTED hcall -- they must now be less than NR_CPUS. [paulus@ozlabs.org - made prev_cpu array be short[] to reduce memory consumption.] 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: Use hypercalls for TLB invalidation when nestedPaul Mackerras1-0/+5
This adds code to call the H_TLB_INVALIDATE hypercall when running as a guest, in the cases where we need to invalidate TLBs (or other MMU caches) as part of managing the mappings for a nested guest. Calling H_TLB_INVALIDATE lets the nested hypervisor inform the parent hypervisor about changes to partition-scoped page tables or the partition table without needing to do hypervisor-privileged tlbie instructions. 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: Introduce rmap to track nested guest mappingsSuraj Jitindar Singh1-1/+68
When a host (L0) page which is mapped into a (L1) guest is in turn mapped through to a nested (L2) guest we keep a reverse mapping (rmap) so that these mappings can be retrieved later. Whenever we create an entry in a shadow_pgtable for a nested guest we create a corresponding rmap entry and add it to the list for the L1 guest memslot at the index of the L1 guest page it maps. This means at the L1 guest memslot we end up with lists of rmaps. When we are notified of a host page being invalidated which has been mapped through to a (L1) guest, we can then walk the rmap list for that guest page, and find and invalidate all of the corresponding shadow_pgtable entries. In order to reduce memory consumption, we compress the information for each rmap entry down to 52 bits -- 12 bits for the LPID and 40 bits for the guest real page frame number -- which will fit in a single unsigned long. To avoid a scenario where a guest can trigger unbounded memory allocations, we scan the list when adding an entry to see if there is already an entry with the contents we need. This can occur, because we don't ever remove entries from the middle of a list. A struct nested guest rmap is a list pointer and an rmap entry; ---------------- | next pointer | ---------------- | rmap entry | ---------------- Thus the rmap pointer for each guest frame number in the memslot can be either NULL, a single entry, or a pointer to a list of nested rmap entries. gfn memslot rmap array ------------------------- 0 | NULL | (no rmap entry) ------------------------- 1 | single rmap entry | (rmap entry with low bit set) ------------------------- 2 | list head pointer | (list of rmap entries) ------------------------- The final entry always has the lowest bit set and is stored in the next pointer of the last list entry, or as a single rmap entry. With a list of rmap entries looking like; ----------------- ----------------- ------------------------- | list head ptr | ----> | next pointer | ----> | single rmap entry | ----------------- ----------------- ------------------------- | rmap entry | | rmap entry | ----------------- ------------------------- Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> 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: Book3S HV: Handle page fault for a nested guestSuraj Jitindar Singh1-0/+4
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: Framework and hcall stubs for nested virtualizationPaul Mackerras1-0/+33
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 Mackerras1-2/+2
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 Mackerras1-0/+1
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>
2018-05-18KVM: PPC: Move nip/ctr/lr/xer registers to pt_regs in kvm_vcpu_archSimon Guo1-6/+6
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 Guo1-4/+4
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>
2018-03-24KVM: PPC: Book3S HV: Work around transactional memory bugs in POWER9Paul Mackerras1-0/+43
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>
2017-11-23KVM: PPC: Book3S HV: Avoid shifts by negative amountsPaul Mackerras1-5/+9
The kvmppc_hpte_page_shifts function decodes the actual and base page sizes for a HPTE, returning -1 if it doesn't recognize the page size encoding. This then gets used as a shift amount in various places, which is undefined behaviour. This was reported by Coverity. In fact this should never occur, since we should only get HPTEs in the HPT which have a recognized page size encoding. The only place where this might not be true is in the call to kvmppc_actual_pgsz() near the beginning of kvmppc_do_h_enter(), where we are validating the HPTE value passed in from the guest. So to fix this and eliminate the undefined behaviour, we make kvmppc_hpte_page_shifts return 0 for unrecognized page size encodings, and make kvmppc_actual_pgsz() detect that case and return 0 for the page size, which will then cause kvmppc_do_h_enter() to return an error and refuse to insert any HPTE with an unrecognized page size encoding. To ensure that we don't get undefined behaviour in compute_tlbie_rb(), we take the 4k page size path for any unrecognized page size encoding. This should never be hit in practice because it is only used on HPTE values which have previously been checked for having a recognized page size encoding. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-11-01KVM: PPC: Book3S HV: Unify dirty page map between HPT and radixPaul Mackerras1-0/+24
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: Don't rely on host's page size informationPaul Mackerras1-21/+95
This removes the dependence of KVM on the mmu_psize_defs array (which stores information about hardware support for various page sizes) and the things derived from it, chiefly hpte_page_sizes[], hpte_page_size(), hpte_actual_page_size() and get_sllp_encoding(). We also no longer rely on the mmu_slb_size variable or the MMU_FTR_1T_SEGMENTS feature bit. The reason for doing this is so we can support a HPT guest on a radix host. In a radix host, the mmu_psize_defs array contains information about page sizes supported by the MMU in radix mode rather than the page sizes supported by the MMU in HPT mode. Similarly, mmu_slb_size and the MMU_FTR_1T_SEGMENTS bit are not set. Instead we hard-code knowledge of the behaviour of the HPT MMU in the POWER7, POWER8 and POWER9 processors (which are the only processors supported by HV KVM) - specifically the encoding of the LP fields in the HPT and SLB entries, and the fact that they have 32 SLB entries and support 1TB segments. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-04-01powerpc/pseries: Skip using reserved virtual address rangeAneesh Kumar K.V1-2/+0
Now that we use all the available virtual address range, we need to make sure we don't generate VSID such that it overlaps with the reserved vsid range. Reserved vsid range include the virtual address range used by the adjunct partition and also the VRMA virtual segment. We find the context value that can result in generating such a VSID and reserve it early in boot. We don't look at the adjunct range, because for now we disable the adjunct usage in a Linux LPAR via CAS interface. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Rewrite hash__reserve_context_id(), move the rest into pseries] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-01-31KVM: PPC: Book3S HV: Split HPT allocation from activationDavid Gibson1-0/+4
Currently, kvmppc_alloc_hpt() both allocates a new hashed page table (HPT) and sets it up as the active page table for a VM. For the upcoming HPT resize implementation we're going to want to allocate HPTs separately from activating them. So, split the allocation itself out into kvmppc_allocate_hpt() and perform the activation with a new kvmppc_set_hpt() function. Likewise we split kvmppc_free_hpt(), which just frees the HPT, from kvmppc_release_hpt() which unsets it as an active HPT, then frees it. We also move the logic to fall back to smaller HPT sizes if the first try fails into the single caller which used that behaviour, kvmppc_hv_setup_htab_rma(). This introduces a slight semantic change, in that previously if the initial attempt at CMA allocation failed, we would fall back to attempting smaller sizes with the page allocator. Now, we try first CMA, then the page allocator at each size. As far as I can tell this change should be harmless. To match, we make kvmppc_free_hpt() just free the actual HPT itself. The call to kvmppc_free_lpid() that was there, we move to the single caller. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-01-31KVM: PPC: Book3S HV: Don't store values derivable from HPT orderDavid Gibson1-0/+12
Currently the kvm_hpt_info structure stores the hashed page table's order, and also the number of HPTEs it contains and a mask for its size. The last two can be easily derived from the order, so remove them and just calculate them as necessary with a couple of helper inlines. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-01-31KVM: PPC: Book3S HV: Add basic infrastructure for radix guestsPaul Mackerras1-0/+6
This adds a field in struct kvm_arch and an inline helper to indicate whether a guest is a radix guest or not, plus a new file to contain the radix MMU code, which currently contains just a translate function which knows how to traverse the guest page tables to translate an address. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-27KVM: PPC: Book3S: Remove duplicate setting of the B field in tlbieBalbir Singh1-2/+1
Remove duplicate setting of the the "B" field when doing a tlbie(l). In compute_tlbie_rb(), the "B" field is set again just before returning the rb value to be used for tlbie(l). Signed-off-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-09-09powerpc/mm: Speed up computation of base and actual page size for a HPTEPaul Mackerras1-80/+7
This replaces a 2-D search through an array with a simple 8-bit table lookup for determining the actual and/or base page size for a HPT entry. The encoding in the second doubleword of the HPTE is designed to encode the actual and base page sizes without using any more bits than would be needed for a 4k page number, by using between 1 and 8 low-order bits of the RPN (real page number) field to encode the page sizes. A single "large page" bit in the first doubleword indicates that these low-order bits are to be interpreted like this. We can determine the page sizes by using the low-order 8 bits of the RPN to look up a 256-entry table. For actual page sizes less than 1MB, some of the upper bits of these 8 bits are going to be real address bits, but we can cope with that by replicating the entries for those smaller page sizes. While we're at it, let's move the hpte_page_size() and hpte_base_page_size() functions from a KVM-specific header to a header for 64-bit HPT systems, since this computation doesn't have anything specifically to do with KVM. Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-08-01powerpc/mm/hash: Add helper for finding SLBE LLP encodingAneesh Kumar K.V1-2/+1
Replace opencoding of the same at multiple places with the helper. No functional change with this patch. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-01powerpc/mm/book3s: Rename hash specific PTE bits to carry H_ prefixAneesh Kumar K.V1-2/+2
This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-01powerpc/mm: Drop WIMG in favour of new constantsAneesh Kumar K.V1-17/+10
PowerISA 3.0 introduces two pte bits with the below meaning for radix: 00 -> Normal Memory 01 -> Strong Access Order (SAO) 10 -> Non idempotent I/O (Cache inhibited and guarded) 11 -> Tolerant I/O (Cache inhibited) We drop the existing WIMG bits in the Linux page table in favour of the above constants. We loose _PAGE_WRITETHRU with this conversion. We only use writethru via pgprot_cached_wthru() which is used by fbdev/controlfb.c which is Apple control display and also PPC32. With respect to _PAGE_COHERENCE, we have been marking hpte always coherent for some time now. htab_convert_pte_flags() always added HPTE_R_M. NOTE: KVM changes need closer review. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-01powerpc/mm: Add pte_xchg() helperMichael Ellerman1-4/+1
We have five locations in 64-bit hash MMU code that do a cmpxchg() of a PTE. Currently doing it inline OK, but in a future patch we will be converting the PTEs to __be64 in some configs. In that case we will need casts at every cmpxchg() site in order to keep sparse happy. So move the logic into a helper, this is a reasonably nice cleanup on its own. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-16KVM: PPC: Replace SPAPR_TCE_SHIFT with IOMMU_PAGE_SHIFT_4KAlexey Kardashevskiy1-2/+0
SPAPR_TCE_SHIFT is used in few places only and since IOMMU_PAGE_SHIFT_4K can be easily used instead, remove SPAPR_TCE_SHIFT. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2015-06-05KVM: implement multiple address spacesPaolo Bonzini1-1/+1
Only two ioctls have to be modified; the address space id is placed in the higher 16 bits of their slot id argument. As of this patch, no architecture defines more than one address space; x86 will be the first. Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-04-26Merge tag 'powerpc-4.1-2' of ↵Linus Torvalds1-11/+6
git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux Pull powerpc fixes from Michael Ellerman: - fix for mm_dec_nr_pmds() from Scott. - fixes for oopses seen with KVM + THP from Aneesh. - build fixes from Aneesh & Shreyas. * tag 'powerpc-4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: powerpc/mm: Fix build error with CONFIG_PPC_TRANSACTIONAL_MEM disabled powerpc/kvm: Fix ppc64_defconfig + PPC_POWERNV=n build error powerpc/mm/thp: Return pte address if we find trans_splitting. powerpc/mm/thp: Make page table walk safe against thp split/collapse KVM: PPC: Remove page table walk helpers KVM: PPC: Use READ_ONCE when dereferencing pte_t pointer powerpc/hugetlb: Call mm_dec_nr_pmds() in hugetlb_free_pmd_range()
2015-04-26Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-0/+18
Pull second batch of KVM changes from Paolo Bonzini: "This mostly includes the PPC changes for 4.1, which this time cover Book3S HV only (debugging aids, minor performance improvements and some cleanups). But there are also bug fixes and small cleanups for ARM, x86 and s390. The task_migration_notifier revert and real fix is still pending review, but I'll send it as soon as possible after -rc1" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (29 commits) KVM: arm/arm64: check IRQ number on userland injection KVM: arm: irqfd: fix value returned by kvm_irq_map_gsi KVM: VMX: Preserve host CR4.MCE value while in guest mode. KVM: PPC: Book3S HV: Use msgsnd for signalling threads on POWER8 KVM: PPC: Book3S HV: Translate kvmhv_commence_exit to C KVM: PPC: Book3S HV: Streamline guest entry and exit KVM: PPC: Book3S HV: Use bitmap of active threads rather than count KVM: PPC: Book3S HV: Use decrementer to wake napping threads KVM: PPC: Book3S HV: Don't wake thread with no vcpu on guest IPI KVM: PPC: Book3S HV: Get rid of vcore nap_count and n_woken KVM: PPC: Book3S HV: Move vcore preemption point up into kvmppc_run_vcpu KVM: PPC: Book3S HV: Minor cleanups KVM: PPC: Book3S HV: Simplify handling of VCPUs that need a VPA update KVM: PPC: Book3S HV: Accumulate timing information for real-mode code KVM: PPC: Book3S HV: Create debugfs file for each guest's HPT KVM: PPC: Book3S HV: Add ICP real mode counters KVM: PPC: Book3S HV: Move virtual mode ICP functions to real-mode KVM: PPC: Book3S HV: Convert ICS mutex lock to spin lock KVM: PPC: Book3S HV: Add guest->host real mode completion counters KVM: PPC: Book3S HV: Add helpers for lock/unlock hpte ...
2015-04-21KVM: PPC: Book3S HV: Translate kvmhv_commence_exit to CPaul Mackerras1-0/+2
This replaces the assembler code for kvmhv_commence_exit() with C code in book3s_hv_builtin.c. It also moves the IPI sending code that was in book3s_hv_rm_xics.c into a new kvmhv_rm_send_ipi() function so it can be used by kvmhv_commence_exit() as well as icp_rm_set_vcpu_irq(). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2015-04-21KVM: PPC: Book3S HV: Create debugfs file for each guest's HPTPaul Mackerras1-0/+2
This creates a debugfs directory for each HV guest (assuming debugfs is enabled in the kernel config), and within that directory, a file by which the contents of the guest's HPT (hashed page table) can be read. The directory is named vmnnnn, where nnnn is the PID of the process that created the guest. The file is named "htab". This is intended to help in debugging problems in the host's management of guest memory. The contents of the file consist of a series of lines like this: 3f48 4000d032bf003505 0000000bd7ff1196 00000003b5c71196 The first field is the index of the entry in the HPT, the second and third are the HPT entry, so the third entry contains the real page number that is mapped by the entry if the entry's valid bit is set. The fourth field is the guest's view of the second doubleword of the entry, so it contains the guest physical address. (The format of the second through fourth fields are described in the Power ISA and also in arch/powerpc/include/asm/mmu-hash64.h.) Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2015-04-21KVM: PPC: Book3S HV: Add helpers for lock/unlock hpteAneesh Kumar K.V1-0/+14
This adds helper routines for locking and unlocking HPTEs, and uses them in the rest of the code. We don't change any locking rules in this patch. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2015-04-17powerpc/mm/thp: Return pte address if we find trans_splitting.Aneesh Kumar K.V1-10/+2
For THP that is marked trans splitting, we return the pte. This require the callers to handle the pmd_trans_splitting scenario, if they care. All the current callers are either looking at pfn or write_ok, hence we don't need to update them. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-04-17KVM: PPC: Use READ_ONCE when dereferencing pte_t pointerAneesh Kumar K.V1-1/+4
pte can get updated from other CPUs as part of multiple activities like THP split, huge page collapse, unmap. We need to make sure we don't reload the pte value again and again for different checks. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-04-10powerpc: Fix compile errors with STRICT_MM_TYPECHECKS enabledMichael Ellerman1-5/+7
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Fix the 32-bit code also] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-31powerpc: Use bool function return values of true/false not 1/0Joe Perches1-2/+2
Use the normal return values for bool functions Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-12-17KVM: PPC: Book3S HV: Remove code for PPC970 processorsPaul Mackerras1-1/+0
This removes the code that was added to enable HV KVM to work on PPC970 processors. The PPC970 is an old CPU that doesn't support virtualizing guest memory. Removing PPC970 support also lets us remove the code for allocating and managing contiguous real-mode areas, the code for the !kvm->arch.using_mmu_notifiers case, the code for pinning pages of guest memory when first accessed and keeping track of which pages have been pinned, and the code for handling H_ENTER hypercalls in virtual mode. Book3S HV KVM is now supported only on POWER7 and POWER8 processors. The KVM_CAP_PPC_RMA capability now always returns 0. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-12-15KVM: PPC: Book3S HV: Fix computation of tlbie operandPaul Mackerras1-1/+1
The B (segment size) field in the RB operand for the tlbie instruction is two bits, which we get from the top two bits of the first doubleword of the HPT entry to be invalidated. These bits go in bits 8 and 9 of the RB operand (bits 54 and 55 in IBM bit numbering). The compute_tlbie_rb() function gets these bits as v >> (62 - 8), which is not correct as it will bring in the top 10 bits, not just the top two. These extra bits could corrupt the AP, AVAL and L fields in the RB value. To fix this we shift right 62 bits and then shift left 8 bits, so we only get the two bits of the B field. The first doubleword of the HPT entry is under the control of the guest kernel. In fact, Linux guests will always put zeroes in bits 54 -- 61 (IBM bits 2 -- 9), but we should not rely on guests doing this. Signed-off-by: Paul Mackerras <paulus@samba.org> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-08-05Merge tag 'signed-kvm-ppc-next' of git://github.com/agraf/linux-2.6 into kvmPaolo Bonzini1-11/+18
Patch queue for ppc - 2014-08-01 Highlights in this release include: - BookE: Rework instruction fetch, not racy anymore now - BookE HV: Fix ONE_REG accessors for some in-hardware registers - Book3S: Good number of LE host fixes, enable HV on LE - Book3S: Some misc bug fixes - Book3S HV: Add in-guest debug support - Book3S HV: Preload cache lines on context switch - Remove 440 support Alexander Graf (31): KVM: PPC: Book3s PR: Disable AIL mode with OPAL KVM: PPC: Book3s HV: Fix tlbie compile error KVM: PPC: Book3S PR: Handle hyp doorbell exits KVM: PPC: Book3S PR: Fix ABIv2 on LE KVM: PPC: Book3S PR: Fix sparse endian checks PPC: Add asm helpers for BE 32bit load/store KVM: PPC: Book3S HV: Make HTAB code LE host aware KVM: PPC: Book3S HV: Access guest VPA in BE KVM: PPC: Book3S HV: Access host lppaca and shadow slb in BE KVM: PPC: Book3S HV: Access XICS in BE KVM: PPC: Book3S HV: Fix ABIv2 on LE KVM: PPC: Book3S HV: Enable for little endian hosts KVM: PPC: Book3S: Move vcore definition to end of kvm_arch struct KVM: PPC: Deflect page write faults properly in kvmppc_st KVM: PPC: Book3S: Stop PTE lookup on write errors KVM: PPC: Book3S: Add hack for split real mode KVM: PPC: Book3S: Make magic page properly 4k mappable KVM: PPC: Remove 440 support KVM: Rename and add argument to check_extension KVM: Allow KVM_CHECK_EXTENSION on the vm fd KVM: PPC: Book3S: Provide different CAPs based on HV or PR mode KVM: PPC: Implement kvmppc_xlate for all targets KVM: PPC: Move kvmppc_ld/st to common code KVM: PPC: Remove kvmppc_bad_hva() KVM: PPC: Use kvm_read_guest in kvmppc_ld KVM: PPC: Handle magic page in kvmppc_ld/st KVM: PPC: Separate loadstore emulation from priv emulation KVM: PPC: Expose helper functions for data/inst faults KVM: PPC: Remove DCR handling KVM: PPC: HV: Remove generic instruction emulation KVM: PPC: PR: Handle FSCR feature deselects Alexey Kardashevskiy (1): KVM: PPC: Book3S: Fix LPCR one_reg interface Aneesh Kumar K.V (4): KVM: PPC: BOOK3S: PR: Fix PURR and SPURR emulation KVM: PPC: BOOK3S: PR: Emulate virtual timebase register KVM: PPC: BOOK3S: PR: Emulate instruction counter KVM: PPC: BOOK3S: HV: Update compute_tlbie_rb to handle 16MB base page Anton Blanchard (2): KVM: PPC: Book3S HV: Fix ABIv2 indirect branch issue KVM: PPC: Assembly functions exported to modules need _GLOBAL_TOC() Bharat Bhushan (10): kvm: ppc: bookehv: Added wrapper macros for shadow registers kvm: ppc: booke: Use the shared struct helpers of SRR0 and SRR1 kvm: ppc: booke: Use the shared struct helpers of SPRN_DEAR kvm: ppc: booke: Add shared struct helpers of SPRN_ESR kvm: ppc: booke: Use the shared struct helpers for SPRN_SPRG0-7 kvm: ppc: Add SPRN_EPR get helper function kvm: ppc: bookehv: Save restore SPRN_SPRG9 on guest entry exit KVM: PPC: Booke-hv: Add one reg interface for SPRG9 KVM: PPC: Remove comment saying SPRG1 is used for vcpu pointer KVM: PPC: BOOKEHV: rename e500hv_spr to bookehv_spr Michael Neuling (1): KVM: PPC: Book3S HV: Add H_SET_MODE hcall handling Mihai Caraman (8): KVM: PPC: e500mc: Enhance tlb invalidation condition on vcpu schedule KVM: PPC: e500: Fix default tlb for victim hint KVM: PPC: e500: Emulate power management control SPR KVM: PPC: e500mc: Revert "add load inst fixup" KVM: PPC: Book3e: Add TLBSEL/TSIZE defines for MAS0/1 KVM: PPC: Book3s: Remove kvmppc_read_inst() function KVM: PPC: Allow kvmppc_get_last_inst() to fail KVM: PPC: Bookehv: Get vcpu's last instruction for emulation Paul Mackerras (4): KVM: PPC: Book3S: Controls for in-kernel sPAPR hypercall handling KVM: PPC: Book3S: Allow only implemented hcalls to be enabled or disabled KVM: PPC: Book3S PR: Take SRCU read lock around RTAS kvm_read_guest() call KVM: PPC: Book3S: Make kvmppc_ld return a more accurate error indication Stewart Smith (2): Split out struct kvmppc_vcore creation to separate function Use the POWER8 Micro Partition Prefetch Engine in KVM HV on POWER8 Conflicts: Documentation/virtual/kvm/api.txt
2014-07-28KVM: PPC: BOOK3S: HV: Update compute_tlbie_rb to handle 16MB base pageAneesh Kumar K.V1-2/+4
When calculating the lower bits of AVA field, use the shift count based on the base page size. Also add the missing segment size and remove stale comment. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-07-28KVM: PPC: Book3S HV: Make HTAB code LE host awareAlexander Graf1-3/+12
When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>