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2020-07-21KVM: PPC: Book3S HV: Increase KVMPPC_NR_LPIDS on POWER8 and POWER9Cédric Le Goater1-2/+6
POWER8 and POWER9 have 12-bit LPIDs. Change LPID_RSVD to support up to (4096 - 2) guests on these processors. POWER7 is kept the same with a limitation of (1024 - 2), but it might be time to drop KVM support for POWER7. Tested with 2048 guests * 4 vCPUs on a witherspoon system with 512G RAM and a bit of swap. Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2020-06-12Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-6/+6
Pull more KVM updates from Paolo Bonzini: "The guest side of the asynchronous page fault work has been delayed to 5.9 in order to sync with Thomas's interrupt entry rework, but here's the rest of the KVM updates for this merge window. MIPS: - Loongson port PPC: - Fixes ARM: - Fixes x86: - KVM_SET_USER_MEMORY_REGION optimizations - Fixes - Selftest fixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (62 commits) KVM: x86: do not pass poisoned hva to __kvm_set_memory_region KVM: selftests: fix sync_with_host() in smm_test KVM: async_pf: Inject 'page ready' event only if 'page not present' was previously injected KVM: async_pf: Cleanup kvm_setup_async_pf() kvm: i8254: remove redundant assignment to pointer s KVM: x86: respect singlestep when emulating instruction KVM: selftests: Don't probe KVM_CAP_HYPERV_ENLIGHTENED_VMCS when nested VMX is unsupported KVM: selftests: do not substitute SVM/VMX check with KVM_CAP_NESTED_STATE check KVM: nVMX: Consult only the "basic" exit reason when routing nested exit KVM: arm64: Move hyp_symbol_addr() to kvm_asm.h KVM: arm64: Synchronize sysreg state on injecting an AArch32 exception KVM: arm64: Make vcpu_cp1x() work on Big Endian hosts KVM: arm64: Remove host_cpu_context member from vcpu structure KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptr KVM: arm64: Handle PtrAuth traps early KVM: x86: Unexport x86_fpu_cache and make it static KVM: selftests: Ignore KVM 5-level paging support for VM_MODE_PXXV48_4K KVM: arm64: Save the host's PtrAuth keys in non-preemptible context KVM: arm64: Stop save/restoring ACTLR_EL1 KVM: arm64: Add emulation for 32bit guests accessing ACTLR2 ...
2020-06-08mm/gup.c: convert to use get_user_{page|pages}_fast_only()Souptick Joarder1-1/+1
API __get_user_pages_fast() renamed to get_user_pages_fast_only() to align with pin_user_pages_fast_only(). As part of this we will get rid of write parameter. Instead caller will pass FOLL_WRITE to get_user_pages_fast_only(). This will not change any existing functionality of the API. All the callers are changed to pass FOLL_WRITE. Also introduce get_user_page_fast_only(), and use it in a few places that hard-code nr_pages to 1. Updated the documentation of the API. Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> [arch/powerpc/kvm] Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Michal Suchanek <msuchanek@suse.de> Link: http://lkml.kernel.org/r/1590396812-31277-1-git-send-email-jrdr.linux@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-27KVM: PPC: Clean up redundant 'kvm_run' parametersTianjia Zhang1-6/+6
In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu' structure. For historical reasons, many kvm-related function parameters retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time. This patch does a unified cleanup of these remaining redundant parameters. Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2020-05-05powerpc/kvm/book3s: Use find_kvm_host_pte in h_enterAneesh Kumar K.V1-3/+2
Since kvmppc_do_h_enter can get called in realmode use low level arch_spin_lock which is safe to be called in realmode. 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/20200505071729.54912-15-aneesh.kumar@linux.ibm.com
2020-05-05powerpc/kvm/book3s: Use find_kvm_host_pte in page fault handlerAneesh Kumar K.V1-4/+4
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/20200505071729.54912-14-aneesh.kumar@linux.ibm.com
2020-05-05Merge tag 'kvm-ppc-fixes-5.7-1' into topic/ppc-kvmMichael Ellerman1-4/+5
This brings in a fix from the kvm-ppc tree that was merged to mainline after rc2, and so isn't in the base of our topic branch. We'd like it in the topic branch because it interacts with patches we plan to carry in this branch.
2020-04-21Merge tag 'kvm-ppc-fixes-5.7-1' of ↵Paolo Bonzini1-4/+5
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-master PPC KVM fix for 5.7 - Fix a regression introduced in the last merge window, which results in guests in HPT mode dying randomly.
2020-04-21KVM: PPC: Book3S HV: Handle non-present PTEs in page fault functionsPaul Mackerras1-4/+5
Since cd758a9b57ee "KVM: PPC: Book3S HV: Use __gfn_to_pfn_memslot in HPT page fault handler", it's been possible in fairly rare circumstances to load a non-present PTE in kvmppc_book3s_hv_page_fault() when running a guest on a POWER8 host. Because that case wasn't checked for, we could misinterpret the non-present PTE as being a cache-inhibited PTE. That could mismatch with the corresponding hash PTE, which would cause the function to fail with -EFAULT a little further down. That would propagate up to the KVM_RUN ioctl() generally causing the KVM userspace (usually qemu) to fall over. This addresses the problem by catching that case and returning to the guest instead. For completeness, this fixes the radix page fault handler in the same way. For radix this didn't cause any obvious misbehaviour, because we ended up putting the non-present PTE into the guest's partition-scoped page tables, leading immediately to another hypervisor data/instruction storage interrupt, which would go through the page fault path again and fix things up. Fixes: cd758a9b57ee "KVM: PPC: Book3S HV: Use __gfn_to_pfn_memslot in HPT page fault handler" Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1820402 Reported-by: David Gibson <david@gibson.dropbear.id.au> Tested-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2020-04-05Merge tag 'powerpc-5.7-1' of ↵Linus Torvalds1-3/+2
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Slightly late as I had to rebase mid-week to insert a bug fix: - A large series from Nick for 64-bit to further rework our exception vectors, and rewrite portions of the syscall entry/exit and interrupt return in C. The result is much easier to follow code that is also faster in general. - Cleanup of our ptrace code to split various parts out that had become badly intertwined with #ifdefs over the years. - Changes to our NUMA setup under the PowerVM hypervisor which should hopefully avoid non-sensical topologies which can lead to warnings from the workqueue code and other problems. - MAINTAINERS updates to remove some of our old orphan entries and update the status of others. - Quite a few other small changes and fixes all over the map. Thanks to: Abdul Haleem, afzal mohammed, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Balamuruhan S, Cédric Le Goater, Chen Zhou, Christophe JAILLET, Christophe Leroy, Christoph Hellwig, Clement Courbet, Daniel Axtens, David Gibson, Douglas Miller, Fabiano Rosas, Fangrui Song, Ganesh Goudar, Gautham R. Shenoy, Greg Kroah-Hartman, Greg Kurz, Gustavo Luiz Duarte, Hari Bathini, Ilie Halip, Jan Kara, Joe Lawrence, Joe Perches, Kajol Jain, Larry Finger, Laurentiu Tudor, Leonardo Bras, Libor Pechacek, Madhavan Srinivasan, Mahesh Salgaonkar, Masahiro Yamada, Masami Hiramatsu, Mauricio Faria de Oliveira, Michael Neuling, Michal Suchanek, Mike Rapoport, Nageswara R Sastry, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Po-Hsu Lin, Pratik Rajesh Sampat, Rasmus Villemoes, Ravi Bangoria, Roman Bolshakov, Sam Bobroff, Sandipan Das, Santosh S, Sedat Dilek, Segher Boessenkool, Shilpasri G Bhat, Sourabh Jain, Srikar Dronamraju, Stephen Rothwell, Tyrel Datwyler, Vaibhav Jain, YueHaibing" * tag 'powerpc-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (158 commits) powerpc: Make setjmp/longjmp signature standard powerpc/cputable: Remove unnecessary copy of cpu_spec->oprofile_type powerpc: Suppress .eh_frame generation powerpc: Drop -fno-dwarf2-cfi-asm powerpc/32: drop unused ISA_DMA_THRESHOLD powerpc/powernv: Add documentation for the opal sensor_groups sysfs interfaces selftests/powerpc: Fix try-run when source tree is not writable powerpc/vmlinux.lds: Explicitly retain .gnu.hash powerpc/ptrace: move ptrace_triggered() into hw_breakpoint.c powerpc/ptrace: create ppc_gethwdinfo() powerpc/ptrace: create ptrace_get_debugreg() powerpc/ptrace: split out ADV_DEBUG_REGS related functions. powerpc/ptrace: move register viewing functions out of ptrace.c powerpc/ptrace: split out TRANSACTIONAL_MEM related functions. powerpc/ptrace: split out SPE related functions. powerpc/ptrace: split out ALTIVEC related functions. powerpc/ptrace: split out VSX related functions. powerpc/ptrace: drop PARAMETER_SAVE_AREA_OFFSET powerpc/ptrace: drop unnecessary #ifdefs CONFIG_PPC64 powerpc/ptrace: remove unused header includes ...
2020-03-19KVM: PPC: Book3S HV: Use __gfn_to_pfn_memslot in HPT page fault handlerPaul Mackerras1-62/+57
This makes the same changes in the page fault handler for HPT guests that commits 31c8b0d0694a ("KVM: PPC: Book3S HV: Use __gfn_to_pfn_memslot() in page fault handler", 2018-03-01), 71d29f43b633 ("KVM: PPC: Book3S HV: Don't use compound_order to determine host mapping size", 2018-09-11) and 6579804c4317 ("KVM: PPC: Book3S HV: Avoid crash from THP collapse during radix page fault", 2018-10-04) made for the page fault handler for radix guests. In summary, where we used to call get_user_pages_fast() and then do special handling for VM_PFNMAP vmas, we now call __get_user_pages_fast() and then __gfn_to_pfn_memslot() if that fails, followed by reading the Linux PTE to get the host PFN, host page size and mapping attributes. This also brings in the change from SetPageDirty() to set_page_dirty_lock() which was done for the radix page fault handler in commit c3856aeb2940 ("KVM: PPC: Book3S HV: Fix handling of large pages in radix page fault handler", 2018-02-23). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2020-03-04powerpc/kvm: no need to check return value of debugfs_create functionsGreg Kroah-Hartman1-3/+2
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Because of this cleanup, we get to remove a few fields in struct kvm_arch that are now unused. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [mpe: Fix build error in kvm/timing.c, adapt kvmppc_remove_cpu_debugfs()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200209105901.1620958-2-gregkh@linuxfoundation.org
2020-01-17KVM: PPC: Book3S: Replace current->mm by kvm->mmLeonardo Bras1-2/+2
Given that in kvm_create_vm() there is: kvm->mm = current->mm; And that on every kvm_*_ioctl we have: if (kvm->mm != current->mm) return -EIO; I see no reason to keep using current->mm instead of kvm->mm. By doing so, we would reduce the use of 'global' variables on code, relying more in the contents of kvm struct. Signed-off-by: Leonardo Bras <leonardo@linux.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-11-01Merge tag 'kvm-ppc-next-5.5-1' of ↵Paolo Bonzini1-18/+6
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD KVM PPC update for 5.5 * Add capability to tell userspace whether we can single-step the guest. * Improve the allocation of XIVE virtual processor IDs, to reduce the risk of running out of IDs when running many VMs on POWER9. * Rewrite interrupt synthesis code to deliver interrupts in virtual mode when appropriate. * Minor cleanups and improvements.
2019-10-22KVM: Add separate helper for putting borrowed reference to kvmSean Christopherson1-1/+1
Add a new helper, kvm_put_kvm_no_destroy(), to handle putting a borrowed reference[*] to the VM when installing a new file descriptor fails. KVM expects the refcount to remain valid in this case, as the in-progress ioctl() has an explicit reference to the VM. The primary motiviation for the helper is to document that the 'kvm' pointer is still valid after putting the borrowed reference, e.g. to document that doing mutex(&kvm->lock) immediately after putting a ref to kvm isn't broken. [*] When exposing a new object to userspace via a file descriptor, e.g. a new vcpu, KVM grabs a reference to itself (the VM) prior to making the object visible to userspace to avoid prematurely freeing the VM in the scenario where userspace immediately closes file descriptor. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-22KVM: PPC: Book3S: Replace reset_msr mmu op with inject_interrupt arch opNicholas Piggin1-13/+0
reset_msr sets the MSR for interrupt injection, but it's cleaner and more flexible to provide a single op to set both MSR and PC for the interrupt. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22KVM: PPC: Reduce calls to get current->mm by storing the value locallyLeonardo Bras1-5/+6
Reduces the number of calls to get_current() in order to get the value of current->mm by doing it once and storing the value, since it is not supposed to change inside the same process). Signed-off-by: Leonardo Bras <leonardo@linux.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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>
2019-05-29KVM: PPC: Book3S HV: Use new mutex to synchronize MMU setupPaul Mackerras1-18/+18
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>
2019-05-14mm/gup: change GUP fast to use flags rather than a write 'bool'Ira Weiny1-2/+2
To facilitate additional options to get_user_pages_fast() change the singular write parameter to be gup_flags. This patch does not change any functionality. New functionality will follow in subsequent patches. Some of the get_user_pages_fast() call sites were unchanged because they already passed FOLL_WRITE or 0 for the write parameter. NOTE: It was suggested to change the ordering of the get_user_pages_fast() arguments to ensure that callers were converted. This breaks the current GUP call site convention of having the returned pages be the final parameter. So the suggestion was rejected. Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Mike Marshall <hubcap@omnibond.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-19KVM: PPC: Book3S HV: Optimise mmio emulation for devices on FAST_MMIO_BUSSuraj Jitindar Singh1-0/+18
Devices on the KVM_FAST_MMIO_BUS by definition have length zero and are thus used for notification purposes rather than data transfer. For example eventfd for virtio devices. This means that when emulating mmio instructions which target devices on this bus we can immediately handle them and return without needing to load the instruction from guest memory. For now we restrict this to stores as this is the only use case at present. For a normal guest the effect is negligible, however for a nested guest we save on the order of 5us per access. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-01-03Remove 'type' argument from access_ok() functionLinus Torvalds1-2/+2
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-17KVM: PPC: Book3S HV: Flush guest mappings when turning dirty tracking on/offPaul Mackerras1-4/+5
This adds code to flush the partition-scoped page tables for a radix guest when dirty tracking is turned on or off for a memslot. Only the guest real addresses covered by the memslot are flushed. The reason for this is to get rid of any 2M PTEs in the partition-scoped page tables that correspond to host transparent huge pages, so that page dirtiness is tracked at a system page (4k or 64k) granularity rather than a 2M granularity. The page tables are also flushed when turning dirty tracking off so that the memslot's address space can be repopulated with THPs if possible. To do this, we add a new function kvmppc_radix_flush_memslot(). Since this does what's needed for kvmppc_core_flush_memslot_hv() on a radix guest, we now make kvmppc_core_flush_memslot_hv() call the new kvmppc_radix_flush_memslot() rather than calling kvm_unmap_radix() for each page in the memslot. This has the effect of fixing a bug in that kvmppc_core_flush_memslot_hv() was previously calling kvm_unmap_radix() without holding the kvm->mmu_lock spinlock, which is required to be held. 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>
2018-12-14KVM: PPC: Book3S HV: Fix race between kvm_unmap_hva_range and MMU mode switchPaul Mackerras1-0/+3
Testing has revealed an occasional crash which appears to be caused by a race between kvmppc_switch_mmu_to_hpt and kvm_unmap_hva_range_hv. The symptom is a NULL pointer dereference in __find_linux_pte() called from kvm_unmap_radix() with kvm->arch.pgtable == NULL. Looking at kvmppc_switch_mmu_to_hpt(), it does indeed clear kvm->arch.pgtable (via kvmppc_free_radix()) before setting kvm->arch.radix to NULL, and there is nothing to prevent kvm_unmap_hva_range_hv() or the other MMU callback functions from being called concurrently with kvmppc_switch_mmu_to_hpt() or kvmppc_switch_mmu_to_radix(). This patch therefore adds calls to spin_lock/unlock on the kvm->mmu_lock around the assignments to kvm->arch.radix, and makes sure that the partition-scoped radix tree or HPT is only freed after changing kvm->arch.radix. This also takes the kvm->mmu_lock in kvmppc_rmap_reset() to make sure that the clearing of each rmap array (one per memslot) doesn't happen concurrently with use of the array in the kvm_unmap_hva_range_hv() or the other MMU callbacks. Fixes: 18c3640cefc7 ("KVM: PPC: Book3S HV: Add infrastructure for running HPT guests on radix host") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-10-09KVM: PPC: Book3S HV: Don't access HFSCR, LPIDR or LPCR when running nestedPaul Mackerras1-4/+3
When running as a nested hypervisor, this avoids reading hypervisor privileged registers (specifically HFSCR, LPIDR and LPCR) at startup; instead reasonable default values are used. This also avoids writing LPIDR in the single-vcpu entry/exit path. Also, this removes the check for CPU_FTR_HVMODE in kvmppc_mmu_hv_init() since its only caller already checks this. 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>
2018-09-04Merge tag 'kvm-ppc-fixes-4.19-1' of ↵Radim Krčmář1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc PPC KVM fixes for 4.19 Two small fixes for KVM on POWER machines; one fixes a bug where pages might not get marked dirty, causing guest memory corruption on migration, and the other fixes a bug causing reads from guest memory to use the wrong guest real address for very large HPT guests (>256G of memory), leading to failures in instruction emulation.
2018-08-20KVM: PPC: Book3S HV: Don't truncate HPTE index in xlate functionPaul Mackerras1-1/+1
This fixes a bug which causes guest virtual addresses to get translated to guest real addresses incorrectly when the guest is using the HPT MMU and has more than 256GB of RAM, or more specifically has a HPT larger than 2GB. This has showed up in testing as a failure of the host to emulate doorbell instructions correctly on POWER9 for HPT guests with more than 256GB of RAM. The bug is that the HPTE index in kvmppc_mmu_book3s_64_hv_xlate() is stored as an int, and in forming the HPTE address, the index gets shifted left 4 bits as an int before being signed-extended to 64 bits. The simple fix is to make the variable a long int, matching the return type of kvmppc_hv_find_lock_hpte(), which is what calculates the index. Fixes: 697d3899dcb4 ("KVM: PPC: Implement MMIO emulation support for Book3S HV guests") Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-07-30powerpc: remove unnecessary inclusion of asm/tlbflush.hChristophe Leroy1-1/+0
asm/tlbflush.h is only needed for: - using functions xxx_flush_tlb_xxx() - using MMU_NO_CONTEXT - including asm-generic/pgtable.h Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-14Merge tag 'kvm-ppc-next-4.18-2' of ↵Paolo Bonzini1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD
2018-06-12treewide: Use array_size() in vmalloc()Kees Cook1-1/+1
The vmalloc() function has no 2-factor argument form, so multiplication factors need to be wrapped in array_size(). This patch replaces cases of: vmalloc(a * b) with: vmalloc(array_size(a, b)) as well as handling cases of: vmalloc(a * b * c) with: vmalloc(array3_size(a, b, c)) This does, however, attempt to ignore constant size factors like: vmalloc(4 * 1024) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( vmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | vmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( vmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(u8) * COUNT + COUNT , ...) | vmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | vmalloc( - sizeof(char) * COUNT + COUNT , ...) | vmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( vmalloc( - sizeof(TYPE) * (COUNT_ID) + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT_ID + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT_CONST + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vmalloc( - sizeof(THING) * (COUNT_ID) + array_size(COUNT_ID, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT_ID + array_size(COUNT_ID, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT_CONST + array_size(COUNT_CONST, sizeof(THING)) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ vmalloc( - SIZE * COUNT + array_size(COUNT, SIZE) , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( vmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( vmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( vmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( vmalloc(C1 * C2 * C3, ...) | vmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants. @@ expression E1, E2; constant C1, C2; @@ ( vmalloc(C1 * C2, ...) | vmalloc( - E1 * E2 + array_size(E1, E2) , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-05-18KVM: PPC: Book3S HV: Lockless tlbie for HPT hcallsNicholas Piggin1-0/+3
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>
2018-03-19KVM: PPC: Remove unused kvm_unmap_hva callbackPaul Mackerras1-9/+0
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>
2018-02-09Merge tag 'kvm-ppc-next-4.16-2' of ↵Radim Krčmář1-13/+25
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc Second PPC KVM update for 4.16 Seven fixes that are either trivial or that address bugs that people are actually hitting. The main ones are: - Drop spinlocks before reading guest memory - Fix a bug causing corruption of VCPU state in PR KVM with preemption enabled - Make HPT resizing work on POWER9 - Add MMIO emulation for vector loads and stores, because guests now use these instructions in memcpy and similar routines.
2018-02-09KVM: PPC: Book3S HV: Make HPT resizing work on POWER9David Gibson1-7/+23
This adds code to enable the HPT resizing code to work on POWER9, which uses a slightly modified HPT entry format compared to POWER8. On POWER9, we convert HPTEs read from the HPT from the new format to the old format so that the rest of the HPT resizing code can work as before. HPTEs written to the new HPT are converted to the new format as the last step before writing them into the new HPT. This takes out the checks added by commit bcd3bb63dbc8 ("KVM: PPC: Book3S HV: Disable HPT resizing on POWER9 for now", 2017-02-18), now that HPT resizing works on POWER9. On POWER9, when we pivot to the new HPT, we now call kvmppc_setup_partition_table() to update the partition table in order to make the hardware use the new HPT. [paulus@ozlabs.org - added kvmppc_setup_partition_table() call, wrote commit message.] Tested-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-02-09KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing codePaul Mackerras1-6/+2
This fixes the computation of the HPTE index to use when the HPT resizing code encounters a bolted HPTE which is stored in its secondary HPTE group. The code inverts the HPTE group number, which is correct, but doesn't then mask it with new_hash_mask. As a result, new_pteg will be effectively negative, resulting in new_hptep pointing before the new HPT, which will corrupt memory. In addition, this removes two BUG_ON statements. The condition that the BUG_ONs were testing -- that we have computed the hash value incorrectly -- has never been observed in testing, and if it did occur, would only affect the guest, not the host. Given that BUG_ON should only be used in conditions where the kernel (i.e. the host kernel, in this case) can't possibly continue execution, it is not appropriate here. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-10KVM: PPC: Book3S HV: Always flush TLB in kvmppc_alloc_reset_hpt()David Gibson1-2/+4
The KVM_PPC_ALLOCATE_HTAB ioctl(), implemented by kvmppc_alloc_reset_hpt() is supposed to completely clear and reset a guest's Hashed Page Table (HPT) allocating or re-allocating it if necessary. In the case where an HPT of the right size already exists and it just zeroes it, it forces a TLB flush on all guest CPUs, to remove any stale TLB entries loaded from the old HPT. However, that situation can arise when the HPT is resizing as well - or even when switching from an RPT to HPT - so those cases need a TLB flush as well. So, move the TLB flush to trigger in all cases except for errors. Cc: stable@vger.kernel.org # v4.10+ Fixes: f98a8bf9ee20 ("KVM: PPC: Book3S HV: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size") Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-12-06KVM: PPC: Book3S HV: Fix use after free in case of multiple resize requestsSerhii Popovych1-15/+35
When serving multiple resize requests following could happen: CPU0 CPU1 ---- ---- kvm_vm_ioctl_resize_hpt_prepare(1); -> schedule_work() /* system_rq might be busy: delay */ kvm_vm_ioctl_resize_hpt_prepare(2); mutex_lock(); if (resize) { ... release_hpt_resize(); } ... resize_hpt_prepare_work() -> schedule_work() { mutex_unlock() /* resize->kvm could be wrong */ struct kvm *kvm = resize->kvm; mutex_lock(&kvm->lock); <<<< UAF ... } i.e. a second resize request with different order could be started by kvm_vm_ioctl_resize_hpt_prepare(), causing the previous request to be free()d when there's still an active worker thread which will try to access it. This leads to a use after free in point marked with UAF on the diagram above. To prevent this from happening, instead of unconditionally releasing a pre-existing resize structure from the prepare ioctl(), we check if the existing structure has an in-progress worker. We do that by checking if the resize->error == -EBUSY, which is safe because the resize->error field is protected by the kvm->lock. If there is an active worker, instead of releasing, we mark the structure as stale by unlinking it from kvm_struct. In the worker thread we check for a stale structure (with kvm->lock held), and in that case abort, releasing the stale structure ourself. We make the check both before and the actual allocation. Strictly, only the check afterwards is needed, the check before is an optimization: if the structure happens to become stale before the worker thread is dispatched, rather than during the allocation, it means we can avoid allocating then immediately freeing a potentially substantial amount of memory. This fixes following or similar host kernel crash message: [ 635.277361] Unable to handle kernel paging request for data at address 0x00000000 [ 635.277438] Faulting instruction address: 0xc00000000052f568 [ 635.277446] Oops: Kernel access of bad area, sig: 11 [#1] [ 635.277451] SMP NR_CPUS=2048 NUMA PowerNV [ 635.277470] Modules linked in: xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter nfsv3 nfs_acl nfs lockd grace fscache kvm_hv kvm rpcrdma sunrpc ib_isert iscsi_target_mod ib_iser libiscsi scsi_transport_iscsi ib_srpt target_core_mod ext4 ib_srp scsi_transport_srp ib_ipoib mbcache jbd2 rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm ocrdma(T) ib_core ses enclosure scsi_transport_sas sg shpchp leds_powernv ibmpowernv i2c_opal i2c_core powernv_rng ipmi_powernv ipmi_devintf ipmi_msghandler ip_tables xfs libcrc32c sr_mod sd_mod cdrom lpfc nvme_fc(T) nvme_fabrics nvme_core ipr nvmet_fc(T) tg3 nvmet libata be2net crc_t10dif crct10dif_generic scsi_transport_fc ptp scsi_tgt pps_core crct10dif_common dm_mirror dm_region_hash dm_log dm_mod [ 635.278687] CPU: 40 PID: 749 Comm: kworker/40:1 Tainted: G ------------ T 3.10.0.bz1510771+ #1 [ 635.278782] Workqueue: events resize_hpt_prepare_work [kvm_hv] [ 635.278851] task: c0000007e6840000 ti: c0000007e9180000 task.ti: c0000007e9180000 [ 635.278919] NIP: c00000000052f568 LR: c0000000009ea310 CTR: c0000000009ea4f0 [ 635.278988] REGS: c0000007e91837f0 TRAP: 0300 Tainted: G ------------ T (3.10.0.bz1510771+) [ 635.279077] MSR: 9000000100009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 24002022 XER: 00000000 [ 635.279248] CFAR: c000000000009368 DAR: 0000000000000000 DSISR: 40000000 SOFTE: 1 GPR00: c0000000009ea310 c0000007e9183a70 c000000001250b00 c0000007e9183b10 GPR04: 0000000000000000 0000000000000000 c0000007e9183650 0000000000000000 GPR08: c0000007ffff7b80 00000000ffffffff 0000000080000028 d00000000d2529a0 GPR12: 0000000000002200 c000000007b56800 c000000000120028 c0000007f135bb40 GPR16: 0000000000000000 c000000005c1e018 c000000005c1e018 0000000000000000 GPR20: 0000000000000001 c0000000011bf778 0000000000000001 fffffffffffffef7 GPR24: 0000000000000000 c000000f1e262e50 0000000000000002 c0000007e9180000 GPR28: c000000f1e262e4c c000000f1e262e50 0000000000000000 c0000007e9183b10 [ 635.280149] NIP [c00000000052f568] __list_add+0x38/0x110 [ 635.280197] LR [c0000000009ea310] __mutex_lock_slowpath+0xe0/0x2c0 [ 635.280253] Call Trace: [ 635.280277] [c0000007e9183af0] [c0000000009ea310] __mutex_lock_slowpath+0xe0/0x2c0 [ 635.280356] [c0000007e9183b70] [c0000000009ea554] mutex_lock+0x64/0x70 [ 635.280426] [c0000007e9183ba0] [d00000000d24da04] resize_hpt_prepare_work+0xe4/0x1c0 [kvm_hv] [ 635.280507] [c0000007e9183c40] [c000000000113c0c] process_one_work+0x1dc/0x680 [ 635.280587] [c0000007e9183ce0] [c000000000114250] worker_thread+0x1a0/0x520 [ 635.280655] [c0000007e9183d80] [c00000000012010c] kthread+0xec/0x100 [ 635.280724] [c0000007e9183e30] [c00000000000a4b8] ret_from_kernel_thread+0x5c/0xa4 [ 635.280814] Instruction dump: [ 635.280880] 7c0802a6 fba1ffe8 fbc1fff0 7cbd2b78 fbe1fff8 7c9e2378 7c7f1b78 f8010010 [ 635.281099] f821ff81 e8a50008 7fa52040 40de00b8 <e8be0000> 7fbd2840 40de008c 7fbff040 [ 635.281324] ---[ end trace b628b73449719b9d ]--- Cc: stable@vger.kernel.org # v4.10+ Fixes: b5baa6877315 ("KVM: PPC: Book3S HV: KVM-HV HPT resizing implementation") Signed-off-by: Serhii Popovych <spopovyc@redhat.com> [dwg: Replaced BUG_ON()s with WARN_ONs() and reworded commit message for clarity] Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-12-06KVM: PPC: Book3S HV: Drop prepare_done from struct kvm_resize_hptSerhii Popovych1-17/+27
Currently the kvm_resize_hpt structure has two fields relevant to the state of an ongoing resize: 'prepare_done', which indicates whether the worker thread has completed or not, and 'error' which indicates whether it was successful or not. Since the success/failure isn't known until completion, this is confusingly redundant. This patch consolidates the information into just the 'error' value: -EBUSY indicates the worked is still in progress, other negative values indicate (completed) failure, 0 indicates successful completion. As a bonus this reduces size of struct kvm_resize_hpt by __alignof__(struct kvm_hpt_info) and saves few bytes of code. While there correct comment in struct kvm_resize_hpt which references a non-existent semaphore (leftover from an early draft). Assert with WARN_ON() in case of HPT allocation thread work runs more than once for resize request or resize_hpt_allocate() returns -EBUSY that is treated specially. Change comparison against zero to make checkpatch.pl happy. Cc: stable@vger.kernel.org # v4.10+ Signed-off-by: Serhii Popovych <spopovyc@redhat.com> [dwg: Changed BUG_ON()s to WARN_ON()s and altered commit message for clarity] Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-11-23KVM: PPC: Book3S HV: Fix migration and HPT resizing of HPT guests on radix hostsPaul Mackerras1-14/+23
This fixes two errors that prevent a guest using the HPT MMU from successfully migrating to a POWER9 host in radix MMU mode, or resizing its HPT when running on a radix host. The first bug was that commit 8dc6cca556e4 ("KVM: PPC: Book3S HV: Don't rely on host's page size information", 2017-09-11) missed two uses of hpte_base_page_size(), one in the HPT rehashing code and one in kvm_htab_write() (which is used on the destination side in migrating a HPT guest). Instead we use kvmppc_hpte_base_page_shift(). Having the shift count means that we can use left and right shifts instead of multiplication and division in a few places. Along the way, this adds a check in kvm_htab_write() to ensure that the page size encoding in the incoming HPTEs is recognized, and if not return an EINVAL error to userspace. The second bug was that kvm_htab_write was performing some but not all of the functions of kvmhv_setup_mmu(), resulting in the destination VM being left in radix mode as far as the hardware is concerned. The simplest fix for now is make kvm_htab_write() call kvmppc_setup_partition_table() like kvmppc_hv_setup_htab_rma() does. In future it would be better to refactor the code more extensively to remove the duplication. Fixes: 8dc6cca556e4 ("KVM: PPC: Book3S HV: Don't rely on host's page size information") Fixes: 7a84084c6054 ("KVM: PPC: Book3S HV: Set partition table rather than SDR1 on POWER9") Reported-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Tested-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-11-09Merge branch 'kvm-ppc-fixes' into kvm-ppc-nextPaul Mackerras1-0/+10
This merges in a couple of fixes from the kvm-ppc-fixes branch that modify the same areas of code as some commits from the kvm-ppc-next branch, in order to resolve the conflicts. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-11-08KVM: PPC: Book3S HV: Fix exclusion between HPT resizing and other HPT updatesPaul Mackerras1-0/+10
Commit 5e9859699aba ("KVM: PPC: Book3S HV: Outline of KVM-HV HPT resizing implementation", 2016-12-20) added code that tries to exclude any use or update of the hashed page table (HPT) while the HPT resizing code is iterating through all the entries in the HPT. It does this by taking the kvm->lock mutex, clearing the kvm->arch.hpte_setup_done flag and then sending an IPI to all CPUs in the host. The idea is that any VCPU task that tries to enter the guest will see that the hpte_setup_done flag is clear and therefore call kvmppc_hv_setup_htab_rma, which also takes the kvm->lock mutex and will therefore block until we release kvm->lock. However, any VCPU that is already in the guest, or is handling a hypervisor page fault or hypercall, can re-enter the guest without rechecking the hpte_setup_done flag. The IPI will cause a guest exit of any VCPUs that are currently in the guest, but does not prevent those VCPU tasks from immediately re-entering the guest. The result is that after resize_hpt_rehash_hpte() has made a HPTE absent, a hypervisor page fault can occur and make that HPTE present again. This includes updating the rmap array for the guest real page, meaning that we now have a pointer in the rmap array which connects with pointers in the old rev array but not the new rev array. In fact, if the HPT is being reduced in size, the pointer in the rmap array could point outside the bounds of the new rev array. If that happens, we can get a host crash later on such as this one: [91652.628516] Unable to handle kernel paging request for data at address 0xd0000000157fb10c [91652.628668] Faulting instruction address: 0xc0000000000e2640 [91652.628736] Oops: Kernel access of bad area, sig: 11 [#1] [91652.628789] LE SMP NR_CPUS=1024 NUMA PowerNV [91652.628847] Modules linked in: binfmt_misc vhost_net vhost tap xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_mangle ip6table_security ip6table_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack libcrc32c iptable_mangle iptable_security iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables ses enclosure scsi_transport_sas i2c_opal ipmi_powernv ipmi_devintf i2c_core ipmi_msghandler powernv_op_panel nfsd auth_rpcgss oid_registry nfs_acl lockd grace sunrpc kvm_hv kvm_pr kvm scsi_dh_alua dm_service_time dm_multipath tg3 ptp pps_core [last unloaded: stap_552b612747aec2da355051e464fa72a1_14259] [91652.629566] CPU: 136 PID: 41315 Comm: CPU 21/KVM Tainted: G O 4.14.0-1.rc4.dev.gitb27fc5c.el7.centos.ppc64le #1 [91652.629684] task: c0000007a419e400 task.stack: c0000000028d8000 [91652.629750] NIP: c0000000000e2640 LR: d00000000c36e498 CTR: c0000000000e25f0 [91652.629829] REGS: c0000000028db5d0 TRAP: 0300 Tainted: G O (4.14.0-1.rc4.dev.gitb27fc5c.el7.centos.ppc64le) [91652.629932] MSR: 900000010280b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]> CR: 44022422 XER: 00000000 [91652.630034] CFAR: d00000000c373f84 DAR: d0000000157fb10c DSISR: 40000000 SOFTE: 1 [91652.630034] GPR00: d00000000c36e498 c0000000028db850 c000000001403900 c0000007b7960000 [91652.630034] GPR04: d0000000117fb100 d000000007ab00d8 000000000033bb10 0000000000000000 [91652.630034] GPR08: fffffffffffffe7f 801001810073bb10 d00000000e440000 d00000000c373f70 [91652.630034] GPR12: c0000000000e25f0 c00000000fdb9400 f000000003b24680 0000000000000000 [91652.630034] GPR16: 00000000000004fb 00007ff7081a0000 00000000000ec91a 000000000033bb10 [91652.630034] GPR20: 0000000000010000 00000000001b1190 0000000000000001 0000000000010000 [91652.630034] GPR24: c0000007b7ab8038 d0000000117fb100 0000000ec91a1190 c000001e6a000000 [91652.630034] GPR28: 00000000033bb100 000000000073bb10 c0000007b7960000 d0000000157fb100 [91652.630735] NIP [c0000000000e2640] kvmppc_add_revmap_chain+0x50/0x120 [91652.630806] LR [d00000000c36e498] kvmppc_book3s_hv_page_fault+0xbb8/0xc40 [kvm_hv] [91652.630884] Call Trace: [91652.630913] [c0000000028db850] [c0000000028db8b0] 0xc0000000028db8b0 (unreliable) [91652.630996] [c0000000028db8b0] [d00000000c36e498] kvmppc_book3s_hv_page_fault+0xbb8/0xc40 [kvm_hv] [91652.631091] [c0000000028db9e0] [d00000000c36a078] kvmppc_vcpu_run_hv+0xdf8/0x1300 [kvm_hv] [91652.631179] [c0000000028dbb30] [d00000000c2248c4] kvmppc_vcpu_run+0x34/0x50 [kvm] [91652.631266] [c0000000028dbb50] [d00000000c220d54] kvm_arch_vcpu_ioctl_run+0x114/0x2a0 [kvm] [91652.631351] [c0000000028dbbd0] [d00000000c2139d8] kvm_vcpu_ioctl+0x598/0x7a0 [kvm] [91652.631433] [c0000000028dbd40] [c0000000003832e0] do_vfs_ioctl+0xd0/0x8c0 [91652.631501] [c0000000028dbde0] [c000000000383ba4] SyS_ioctl+0xd4/0x130 [91652.631569] [c0000000028dbe30] [c00000000000b8e0] system_call+0x58/0x6c [91652.631635] Instruction dump: [91652.631676] fba1ffe8 fbc1fff0 fbe1fff8 f8010010 f821ffa1 2fa70000 793d0020 e9432110 [91652.631814] 7bbf26e4 7c7e1b78 7feafa14 409e0094 <807f000c> 786326e4 7c6a1a14 93a40008 [91652.631959] ---[ end trace ac85ba6db72e5b2e ]--- To fix this, we tighten up the way that the hpte_setup_done flag is checked to ensure that it does provide the guarantee that the resizing code needs. In kvmppc_run_core(), we check the hpte_setup_done flag after disabling interrupts and refuse to enter the guest if it is clear (for a HPT guest). The code that checks hpte_setup_done and calls kvmppc_hv_setup_htab_rma() is moved from kvmppc_vcpu_run_hv() to a point inside the main loop in kvmppc_run_vcpu(), ensuring that we don't just spin endlessly calling kvmppc_run_core() while hpte_setup_done is clear, but instead have a chance to block on the kvm->lock mutex. Finally we also check hpte_setup_done inside the region in kvmppc_book3s_hv_page_fault() where the HPTE is locked and we are about to update the HPTE, and bail out if it is clear. If another CPU is inside kvm_vm_ioctl_resize_hpt_commit) and has cleared hpte_setup_done, then we know that either we are looking at a HPTE that resize_hpt_rehash_hpte() has not yet processed, which is OK, or else we will see hpte_setup_done clear and refuse to update it, because of the full barrier formed by the unlock of the HPTE in resize_hpt_rehash_hpte() combined with the locking of the HPTE in kvmppc_book3s_hv_page_fault(). Fixes: 5e9859699aba ("KVM: PPC: Book3S HV: Outline of KVM-HV HPT resizing implementation") Cc: stable@vger.kernel.org # v4.10+ Reported-by: Satheesh Rajendran <satheera@in.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-11-01KVM: PPC: Book3S HV: Add infrastructure for running HPT guests on radix hostPaul Mackerras1-10/+12
This sets up the machinery for switching a guest between HPT (hashed page table) and radix MMU modes, so that in future we can run a HPT guest on a radix host on POWER9 machines. * The KVM_PPC_CONFIGURE_V3_MMU ioctl can now specify either HPT or radix mode, on a radix host. * The KVM_CAP_PPC_MMU_HASH_V3 capability now returns 1 on POWER9 with HV KVM on a radix host. * The KVM_PPC_GET_SMMU_INFO returns information about the HPT MMU on a radix host. * The KVM_PPC_ALLOCATE_HTAB ioctl on a radix host will switch the guest to HPT mode and allocate a HPT. * For simplicity, we now allocate the rmap array for each memslot, even on a radix host, since it will be needed if the guest switches to HPT mode. * Since we cannot yet run a HPT guest on a radix host, the KVM_RUN ioctl will return an EINVAL error in that case. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-11-01KVM: PPC: Book3S HV: Unify dirty page map between HPT and radixPaul Mackerras1-28/+11
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 Mackerras1-18/+18
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>
2017-11-01KVM: PPC: Book3S HV: Don't rely on host's page size informationPaul Mackerras1-6/+7
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>
2017-10-16KVM: PPC: Book3S HV: Explicitly disable HPT operations on radix guestsPaul Mackerras1-3/+10
This adds code to make sure that we don't try to access the non-existent HPT for a radix guest using the htab file for the VM in debugfs, a file descriptor obtained using the KVM_PPC_GET_HTAB_FD ioctl, or via the KVM_PPC_RESIZE_HPT_{PREPARE,COMMIT} ioctls. At present nothing bad happens if userspace does access these interfaces on a radix guest, mostly because kvmppc_hpt_npte() gives 0 for a radix guest, which in turn is because 1 << -4 comes out as 0 on POWER processors. However, that relies on undefined behaviour, so it is better to be explicit about not accessing the HPT for a radix guest. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-10-14KVM: PPC: Book3S HV: Delete an error message for a failed memory allocation ↵Markus Elfring1-1/+0
in kvmppc_allocate_hpt() Omit an extra message for a memory allocation failure in this function. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-09-01KVM: PPC: Book3S HV: Fix memory leak in kvm_vm_ioctl_get_htab_fdnixiaoming1-0/+1
We do ctx = kzalloc(sizeof(*ctx), GFP_KERNEL) and then later on call anon_inode_getfd(), but if that fails we don't free ctx, so that memory gets leaked. To fix it, this adds kfree(ctx) in the failure path. Signed-off-by: nixiaoming <nixiaoming@huawei.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-31Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-nextPaul Mackerras1-2/+3
This merges in the 'ppc-kvm' topic branch from the powerpc tree in order to bring in some fixes which touch both powerpc and KVM code. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-17powerpc/mm: Rename find_linux_pte_or_hugepte()Aneesh Kumar K.V1-2/+3
Add newer helpers to make the function usage simpler. It is always recommended to use find_current_mm_pte() for walking the page table. If we cannot use find_current_mm_pte(), it should be documented why the said usage of __find_linux_pte() is safe against a parallel THP split. For now we have KVM code using __find_linux_pte(). This is because kvm code ends up calling __find_linux_pte() in real mode with MSR_EE=0 but with PACA soft_enabled = 1. We may want to fix that later and make sure we keep the MSR_EE and PACA soft_enabled in sync. When we do that we can switch kvm to use find_linux_pte(). Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-05 08:47:39 +0000