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2019-02-13Merge tag 'kvm-arm-fixes-for-5.0' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master KVM/ARM fixes for 5.0: - Fix the way we reset vcpus, plugging the race that could happen on VHE - Fix potentially inconsistent group setting for private interrupts - Don't generate UNDEF when LORegion feature is present - Relax the restriction on using stage2 PUD huge mapping - Turn some spinlocks into raw_spinlocks to help RT compliance
2019-02-07kvm: fix kvm_ioctl_create_device() reference counting (CVE-2019-6974)Jann Horn
kvm_ioctl_create_device() does the following: 1. creates a device that holds a reference to the VM object (with a borrowed reference, the VM's refcount has not been bumped yet) 2. initializes the device 3. transfers the reference to the device to the caller's file descriptor table 4. calls kvm_get_kvm() to turn the borrowed reference to the VM into a real reference The ownership transfer in step 3 must not happen before the reference to the VM becomes a proper, non-borrowed reference, which only happens in step 4. After step 3, an attacker can close the file descriptor and drop the borrowed reference, which can cause the refcount of the kvm object to drop to zero. This means that we need to grab a reference for the device before anon_inode_getfd(), otherwise the VM can disappear from under us. Fixes: 852b6d57dc7f ("kvm: add device control API") Cc: stable@kernel.org Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-07KVM: arm64: Relax the restriction on using stage2 PUD huge mappingSuzuki K Poulose
We restrict mapping the PUD huge pages in stage2 to only when the stage2 has 4 level page table, leaving the feature unused with the default IPA size. But we could use it even with a 3 level page table, i.e, when the PUD level is folded into PGD, just like the stage1. Relax the condition to allow using the PUD huge page mappings at stage2 when it is possible. Cc: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-07KVM: arm/arm64: vgic: Always initialize the group of private IRQsChristoffer Dall
We currently initialize the group of private IRQs during kvm_vgic_vcpu_init, and the value of the group depends on the GIC model we are emulating. However, CPUs created before creating (and initializing) the VGIC might end up with the wrong group if the VGIC is created as GICv3 later. Since we have no enforced ordering of creating the VGIC and creating VCPUs, we can end up with part the VCPUs being properly intialized and the remaining incorrectly initialized. That also means that we have no single place to do the per-cpu data structure initialization which depends on knowing the emulated GIC model (which is only the group field). This patch removes the incorrect comment from kvm_vgic_vcpu_init and initializes the group of all previously created VCPUs's private interrupts in vgic_init in addition to the existing initialization in kvm_vgic_vcpu_init. Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-07arm/arm64: KVM: Allow a VCPU to fully reset itselfMarc Zyngier
The current kvm_psci_vcpu_on implementation will directly try to manipulate the state of the VCPU to reset it. However, since this is not done on the thread that runs the VCPU, we can end up in a strangely corrupted state when the source and target VCPUs are running at the same time. Fix this by factoring out all reset logic from the PSCI implementation and forwarding the required information along with a request to the target VCPU. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2019-01-24KVM: arm/arm64: vgic: Make vgic_cpu->ap_list_lock a raw_spinlockJulien Thierry
vgic_cpu->ap_list_lock must always be taken with interrupts disabled as it is used in interrupt context. For configurations such as PREEMPT_RT_FULL, this means that it should be a raw_spinlock since RT spinlocks are interruptible. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2019-01-24KVM: arm/arm64: vgic: Make vgic_dist->lpi_list_lock a raw_spinlockJulien Thierry
vgic_dist->lpi_list_lock must always be taken with interrupts disabled as it is used in interrupt context. For configurations such as PREEMPT_RT_FULL, this means that it should be a raw_spinlock since RT spinlocks are interruptible. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2019-01-24KVM: arm/arm64: vgic: Make vgic_irq->irq_lock a raw_spinlockJulien Thierry
vgic_irq->irq_lock must always be taken with interrupts disabled as it is used in interrupt context. For configurations such as PREEMPT_RT_FULL, this means that it should be a raw_spinlock since RT spinlocks are interruptible. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2019-01-11KVM: validate userspace input in kvm_clear_dirty_log_protect()Tomas Bortoli
The function at issue does not fully validate the content of the structure pointed by the log parameter, though its content has just been copied from userspace and lacks validation. Fix that. Moreover, change the type of n to unsigned long as that is the type returned by kvm_dirty_bitmap_bytes(). Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com> Reported-by: syzbot+028366e52c9ace67deb3@syzkaller.appspotmail.com [Squashed the fix from Paolo. - Radim.] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2019-01-05Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: - procfs updates - various misc bits - lib/ updates - epoll updates - autofs - fatfs - a few more MM bits * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (58 commits) mm/page_io.c: fix polled swap page in checkpatch: add Co-developed-by to signature tags docs: fix Co-Developed-by docs drivers/base/platform.c: kmemleak ignore a known leak fs: don't open code lru_to_page() fs/: remove caller signal_pending branch predictions mm/: remove caller signal_pending branch predictions arch/arc/mm/fault.c: remove caller signal_pending_branch predictions kernel/sched/: remove caller signal_pending branch predictions kernel/locking/mutex.c: remove caller signal_pending branch predictions mm: select HAVE_MOVE_PMD on x86 for faster mremap mm: speed up mremap by 20x on large regions mm: treewide: remove unused address argument from pte_alloc functions initramfs: cleanup incomplete rootfs scripts/gdb: fix lx-version string output kernel/kcov.c: mark write_comp_data() as notrace kernel/sysctl: add panic_print into sysctl panic: add options to print system info when panic happens bfs: extra sanity checking and static inode bitmap exec: separate MM_ANONPAGES and RLIMIT_STACK accounting ...
2019-01-04mm: treewide: remove unused address argument from pte_alloc functionsJoel Fernandes (Google)
Patch series "Add support for fast mremap". This series speeds up the mremap(2) syscall by copying page tables at the PMD level even for non-THP systems. There is concern that the extra 'address' argument that mremap passes to pte_alloc may do something subtle architecture related in the future that may make the scheme not work. Also we find that there is no point in passing the 'address' to pte_alloc since its unused. This patch therefore removes this argument tree-wide resulting in a nice negative diff as well. Also ensuring along the way that the enabled architectures do not do anything funky with the 'address' argument that goes unnoticed by the optimization. Build and boot tested on x86-64. Build tested on arm64. The config enablement patch for arm64 will be posted in the future after more testing. The changes were obtained by applying the following Coccinelle script. (thanks Julia for answering all Coccinelle questions!). Following fix ups were done manually: * Removal of address argument from pte_fragment_alloc * Removal of pte_alloc_one_fast definitions from m68k and microblaze. // Options: --include-headers --no-includes // Note: I split the 'identifier fn' line, so if you are manually // running it, please unsplit it so it runs for you. virtual patch @pte_alloc_func_def depends on patch exists@ identifier E2; identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; type T2; @@ fn(... - , T2 E2 ) { ... } @pte_alloc_func_proto_noarg depends on patch exists@ type T1, T2, T3, T4; identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; @@ ( - T3 fn(T1, T2); + T3 fn(T1); | - T3 fn(T1, T2, T4); + T3 fn(T1, T2); ) @pte_alloc_func_proto depends on patch exists@ identifier E1, E2, E4; type T1, T2, T3, T4; identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; @@ ( - T3 fn(T1 E1, T2 E2); + T3 fn(T1 E1); | - T3 fn(T1 E1, T2 E2, T4 E4); + T3 fn(T1 E1, T2 E2); ) @pte_alloc_func_call depends on patch exists@ expression E2; identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; @@ fn(... -, E2 ) @pte_alloc_macro depends on patch exists@ identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; identifier a, b, c; expression e; position p; @@ ( - #define fn(a, b, c) e + #define fn(a, b) e | - #define fn(a, b) e + #define fn(a) e ) Link: http://lkml.kernel.org/r/20181108181201.88826-2-joelaf@google.com Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Suggested-by: Kirill A. Shutemov <kirill@shutemov.name> Acked-by: Kirill A. Shutemov <kirill@shutemov.name> Cc: Michal Hocko <mhocko@kernel.org> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: William Kucharski <william.kucharski@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-03Remove 'type' argument from access_ok() functionLinus Torvalds
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>
2018-12-28mm/mmu_notifier: use structure for invalidate_range_start/end callbackJérôme Glisse
Patch series "mmu notifier contextual informations", v2. This patchset adds contextual information, why an invalidation is happening, to mmu notifier callback. This is necessary for user of mmu notifier that wish to maintains their own data structure without having to add new fields to struct vm_area_struct (vma). For instance device can have they own page table that mirror the process address space. When a vma is unmap (munmap() syscall) the device driver can free the device page table for the range. Today we do not have any information on why a mmu notifier call back is happening and thus device driver have to assume that it is always an munmap(). This is inefficient at it means that it needs to re-allocate device page table on next page fault and rebuild the whole device driver data structure for the range. Other use case beside munmap() also exist, for instance it is pointless for device driver to invalidate the device page table when the invalidation is for the soft dirtyness tracking. Or device driver can optimize away mprotect() that change the page table permission access for the range. This patchset enables all this optimizations for device drivers. I do not include any of those in this series but another patchset I am posting will leverage this. The patchset is pretty simple from a code point of view. The first two patches consolidate all mmu notifier arguments into a struct so that it is easier to add/change arguments. The last patch adds the contextual information (munmap, protection, soft dirty, clear, ...). This patch (of 3): To avoid having to change many callback definition everytime we want to add a parameter use a structure to group all parameters for the mmu_notifier invalidate_range_start/end callback. No functional changes with this patch. [akpm@linux-foundation.org: fix drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c kerneldoc] Link: http://lkml.kernel.org/r/20181205053628.3210-2-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Acked-by: Jan Kara <jack@suse.cz> Acked-by: Jason Gunthorpe <jgg@mellanox.com> [infiniband] Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: Felix Kuehling <felix.kuehling@amd.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-26Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The biggest RCU changes in this cycle were: - Convert RCU's BUG_ON() and similar calls to WARN_ON() and similar. - Replace calls of RCU-bh and RCU-sched update-side functions to their vanilla RCU counterparts. This series is a step towards complete removal of the RCU-bh and RCU-sched update-side functions. ( Note that some of these conversions are going upstream via their respective maintainers. ) - Documentation updates, including a number of flavor-consolidation updates from Joel Fernandes. - Miscellaneous fixes. - Automate generation of the initrd filesystem used for rcutorture testing. - Convert spin_is_locked() assertions to instead use lockdep. ( Note that some of these conversions are going upstream via their respective maintainers. ) - SRCU updates, especially including a fix from Dennis Krein for a bag-on-head-class bug. - RCU torture-test updates" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (112 commits) rcutorture: Don't do busted forward-progress testing rcutorture: Use 100ms buckets for forward-progress callback histograms rcutorture: Recover from OOM during forward-progress tests rcutorture: Print forward-progress test age upon failure rcutorture: Print time since GP end upon forward-progress failure rcutorture: Print histogram of CB invocation at OOM time rcutorture: Print GP age upon forward-progress failure rcu: Print per-CPU callback counts for forward-progress failures rcu: Account for nocb-CPU callback counts in RCU CPU stall warnings rcutorture: Dump grace-period diagnostics upon forward-progress OOM rcutorture: Prepare for asynchronous access to rcu_fwd_startat torture: Remove unnecessary "ret" variables rcutorture: Affinity forward-progress test to avoid housekeeping CPUs rcutorture: Break up too-long rcu_torture_fwd_prog() function rcutorture: Remove cbflood facility torture: Bring any extra CPUs online during kernel startup rcutorture: Add call_rcu() flooding forward-progress tests rcutorture/formal: Replace synchronize_sched() with synchronize_rcu() tools/kernel.h: Replace synchronize_sched() with synchronize_rcu() net/decnet: Replace rcu_barrier_bh() with rcu_barrier() ...
2018-12-26Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "ARM: - selftests improvements - large PUD support for HugeTLB - single-stepping fixes - improved tracing - various timer and vGIC fixes x86: - Processor Tracing virtualization - STIBP support - some correctness fixes - refactorings and splitting of vmx.c - use the Hyper-V range TLB flush hypercall - reduce order of vcpu struct - WBNOINVD support - do not use -ftrace for __noclone functions - nested guest support for PAUSE filtering on AMD - more Hyper-V enlightenments (direct mode for synthetic timers) PPC: - nested VFIO s390: - bugfixes only this time" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (171 commits) KVM: x86: Add CPUID support for new instruction WBNOINVD kvm: selftests: ucall: fix exit mmio address guessing Revert "compiler-gcc: disable -ftracer for __noclone functions" KVM: VMX: Move VM-Enter + VM-Exit handling to non-inline sub-routines KVM: VMX: Explicitly reference RCX as the vmx_vcpu pointer in asm blobs KVM: x86: Use jmp to invoke kvm_spurious_fault() from .fixup MAINTAINERS: Add arch/x86/kvm sub-directories to existing KVM/x86 entry KVM/x86: Use SVM assembly instruction mnemonics instead of .byte streams KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range() KVM/MMU: Flush tlb directly in kvm_set_pte_rmapp() KVM/MMU: Move tlb flush in kvm_set_pte_rmapp() to kvm_mmu_notifier_change_pte() KVM: Make kvm_set_spte_hva() return int KVM: Replace old tlb flush function with new one to flush a specified range. KVM/MMU: Add tlb flush with range helper function KVM/VMX: Add hv tlb range flush support x86/hyper-v: Add HvFlushGuestAddressList hypercall support KVM: Add tlb_remote_flush_with_range callback in kvm_x86_ops KVM: x86: Disable Intel PT when VMXON in L1 guest KVM: x86: Set intercept for Intel PT MSRs read/write KVM: x86: Implement Intel PT MSRs read/write emulation ...
2018-12-25Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 festive updates from Will Deacon: "In the end, we ended up with quite a lot more than I expected: - Support for ARMv8.3 Pointer Authentication in userspace (CRIU and kernel-side support to come later) - Support for per-thread stack canaries, pending an update to GCC that is currently undergoing review - Support for kexec_file_load(), which permits secure boot of a kexec payload but also happens to improve the performance of kexec dramatically because we can avoid the sucky purgatory code from userspace. Kdump will come later (requires updates to libfdt). - Optimisation of our dynamic CPU feature framework, so that all detected features are enabled via a single stop_machine() invocation - KPTI whitelisting of Cortex-A CPUs unaffected by Meltdown, so that they can benefit from global TLB entries when KASLR is not in use - 52-bit virtual addressing for userspace (kernel remains 48-bit) - Patch in LSE atomics for per-cpu atomic operations - Custom preempt.h implementation to avoid unconditional calls to preempt_schedule() from preempt_enable() - Support for the new 'SB' Speculation Barrier instruction - Vectorised implementation of XOR checksumming and CRC32 optimisations - Workaround for Cortex-A76 erratum #1165522 - Improved compatibility with Clang/LLD - Support for TX2 system PMUS for profiling the L3 cache and DMC - Reflect read-only permissions in the linear map by default - Ensure MMIO reads are ordered with subsequent calls to Xdelay() - Initial support for memory hotplug - Tweak the threshold when we invalidate the TLB by-ASID, so that mremap() performance is improved for ranges spanning multiple PMDs. - Minor refactoring and cleanups" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (125 commits) arm64: kaslr: print PHYS_OFFSET in dump_kernel_offset() arm64: sysreg: Use _BITUL() when defining register bits arm64: cpufeature: Rework ptr auth hwcaps using multi_entry_cap_matches arm64: cpufeature: Reduce number of pointer auth CPU caps from 6 to 4 arm64: docs: document pointer authentication arm64: ptr auth: Move per-thread keys from thread_info to thread_struct arm64: enable pointer authentication arm64: add prctl control for resetting ptrauth keys arm64: perf: strip PAC when unwinding userspace arm64: expose user PAC bit positions via ptrace arm64: add basic pointer authentication support arm64/cpufeature: detect pointer authentication arm64: Don't trap host pointer auth use to EL2 arm64/kvm: hide ptrauth from guests arm64/kvm: consistently handle host HCR_EL2 flags arm64: add pointer authentication register bits arm64: add comments about EC exception levels arm64: perf: Treat EXCLUDE_EL* bit definitions as unsigned arm64: kpti: Whitelist Cortex-A CPUs that don't implement the CSV3 field arm64: enable per-task stack canaries ...
2018-12-21KVM/MMU: Move tlb flush in kvm_set_pte_rmapp() to kvm_mmu_notifier_change_pte()Lan Tianyu
This patch is to move tlb flush in kvm_set_pte_rmapp() to kvm_mmu_notifier_change_pte() in order to avoid redundant tlb flush. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: Make kvm_set_spte_hva() return intLan Tianyu
The patch is to make kvm_set_spte_hva() return int and caller can check return value to determine flush tlb or not. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Acked-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: fix some typosWei Yang
Signed-off-by: Wei Yang <richard.weiyang@gmail.com> [Preserved the iff and a probably intentional weird bracket notation. Also dropped the style change to make a single-purpose patch. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-12-21kvm: Change offset in kvm_write_guest_offset_cached to unsignedJim Mattson
Since the offset is added directly to the hva from the gfn_to_hva_cache, a negative offset could result in an out of bounds write. The existing BUG_ON only checks for addresses beyond the end of the gfn_to_hva_cache, not for addresses before the start of the gfn_to_hva_cache. Note that all current call sites have non-negative offsets. Fixes: 4ec6e8636256 ("kvm: Introduce kvm_write_guest_offset_cached()") Reported-by: Cfir Cohen <cfir@google.com> Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Cfir Cohen <cfir@google.com> Reviewed-by: Peter Shier <pshier@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-12-21kvm: Disallow wraparound in kvm_gfn_to_hva_cache_initJim Mattson
Previously, in the case where (gpa + len) wrapped around, the entire region was not validated, as the comment claimed. It doesn't actually seem that wraparound should be allowed here at all. Furthermore, since some callers don't check the return code from this function, it seems prudent to clear ghc->memslot in the event of an error. Fixes: 8f964525a121f ("KVM: Allow cross page reads and writes from cached translations.") Reported-by: Cfir Cohen <cfir@google.com> Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Cfir Cohen <cfir@google.com> Reviewed-by: Marc Orr <marcorr@google.com> Cc: Andrew Honig <ahonig@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-12-19Merge tag 'kvmarm-for-v4.21' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm updates for 4.21 - Large PUD support for HugeTLB - Single-stepping fixes - Improved tracing - Various timer and vgic fixups
2018-12-19arm/arm64: KVM: Add ARM_EXCEPTION_IS_TRAP macroMarc Zyngier
32 and 64bit use different symbols to identify the traps. 32bit has a fine grained approach (prefetch abort, data abort and HVC), while 64bit is pretty happy with just "trap". This has been fine so far, except that we now need to decode some of that in tracepoints that are common to both architectures. Introduce ARM_EXCEPTION_IS_TRAP which abstracts the trap symbols and make the tracepoint use it. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19KVM: arm/arm64: Fix unintended stage 2 PMD mappingsChristoffer Dall
There are two things we need to take care of when we create block mappings in the stage 2 page tables: (1) The alignment within a PMD between the host address range and the guest IPA range must be the same, since otherwise we end up mapping pages with the wrong offset. (2) The head and tail of a memory slot may not cover a full block size, and we have to take care to not map those with block descriptors, since we could expose memory to the guest that the host did not intend to expose. So far, we have been taking care of (1), but not (2), and our commentary describing (1) was somewhat confusing. This commit attempts to factor out the checks of both into a common function, and if we don't pass the check, we won't attempt any PMD mappings for neither hugetlbfs nor THP. Note that we used to only check the alignment for THP, not for hugetlbfs, but as far as I can tell the check needs to be applied to both scenarios. Cc: Ralph Palutke <ralph.palutke@fau.de> Cc: Lukas Braun <koomi@moshbit.net> Reported-by: Lukas Braun <koomi@moshbit.net> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19arm/arm64: KVM: vgic: Force VM halt when changing the active state of GICv3 ↵Marc Zyngier
PPIs/SGIs We currently only halt the guest when a vCPU messes with the active state of an SPI. This is perfectly fine for GICv2, but isn't enough for GICv3, where all vCPUs can access the state of any other vCPU. Let's broaden the condition to include any GICv3 interrupt that has an active state (i.e. all but LPIs). Cc: stable@vger.kernel.org Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19KVM: arm/arm64: arch_timer: Simplify kvm_timer_vcpu_terminateChristoffer Dall
kvm_timer_vcpu_terminate can only be called in two scenarios: 1. As part of cleanup during a failed VCPU create 2. As part of freeing the whole VM (struct kvm refcount == 0) In the first case, we cannot have programmed any timers or mapped any IRQs, and therefore we do not have to cancel anything or unmap anything. In the second case, the VCPU will have gone through kvm_timer_vcpu_put, which will have canceled the emulated physical timer's hrtimer, and we do not need to that here as well. We also do not care if the irq is recorded as mapped or not in the VGIC data structure, because the whole VM is going away. That leaves us only with having to ensure that we cancel the bg_timer if we were blocking the last time we called kvm_timer_vcpu_put(). Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19KVM: arm/arm64: Remove arch timer workqueueChristoffer Dall
The use of a work queue in the hrtimer expire function for the bg_timer is a leftover from the time when we would inject interrupts when the bg_timer expired. Since we are no longer doing that, we can instead call kvm_vcpu_wake_up() directly from the hrtimer function and remove all workqueue functionality from the arch timer code. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19KVM: arm/arm64: Fixup the kvm_exit tracepointChristoffer Dall
The kvm_exit tracepoint strangely always reported exits as being IRQs. This seems to be because either the __print_symbolic or the tracepoint macros use a variable named idx. Take this chance to update the fields in the tracepoint to reflect the concepts in the arm64 architecture that we pass to the tracepoint and move the exception type table to the same location and header files as the exits code. We also clear out the exception code to 0 for IRQ exits (which translates to UNKNOWN in text) to make it slighyly less confusing to parse the trace output. Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19KVM: arm/arm64: vgic: Consider priority and active state for pending irqChristoffer Dall
When checking if there are any pending IRQs for the VM, consider the active state and priority of the IRQs as well. Otherwise we could be continuously scheduling a guest hypervisor without it seeing an IRQ. Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19KVM: arm/arm64: vgic: Fix off-by-one bug in vgic_get_irq()Gustavo A. R. Silva
When using the nospec API, it should be taken into account that: "...if the CPU speculates past the bounds check then * array_index_nospec() will clamp the index within the range of [0, * size)." The above is part of the header for macro array_index_nospec() in linux/nospec.h Now, in this particular case, if intid evaluates to exactly VGIC_MAX_SPI or to exaclty VGIC_MAX_PRIVATE, the array_index_nospec() macro ends up returning VGIC_MAX_SPI - 1 or VGIC_MAX_PRIVATE - 1 respectively, instead of VGIC_MAX_SPI or VGIC_MAX_PRIVATE, which, based on the original logic: /* SGIs and PPIs */ if (intid <= VGIC_MAX_PRIVATE) return &vcpu->arch.vgic_cpu.private_irqs[intid]; /* SPIs */ if (intid <= VGIC_MAX_SPI) return &kvm->arch.vgic.spis[intid - VGIC_NR_PRIVATE_IRQS]; are valid values for intid. Fix this by calling array_index_nospec() macro with VGIC_MAX_PRIVATE + 1 and VGIC_MAX_SPI + 1 as arguments for its parameter size. Fixes: 41b87599c743 ("KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_get_irq()") Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> [dropped the SPI part which was fixed separately] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18KVM: fix unregistering coalesced mmio zone from wrong busEric Biggers
If you register a kvm_coalesced_mmio_zone with '.pio = 0' but then unregister it with '.pio = 1', KVM_UNREGISTER_COALESCED_MMIO will try to unregister it from KVM_PIO_BUS rather than KVM_MMIO_BUS, which is a no-op. But it frees the kvm_coalesced_mmio_dev anyway, causing a use-after-free. Fix it by only unregistering and freeing the zone if the correct value of 'pio' is provided. Reported-by: syzbot+f87f60bb6f13f39b54e3@syzkaller.appspotmail.com Fixes: 0804c849f1df ("kvm/x86 : add coalesced pio support") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-18KVM: arm/arm64: vgic: Cap SPIs to the VM-defined maximumMarc Zyngier
SPIs should be checked against the VMs specific configuration, and not the architectural maximum. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18KVM: arm64: Clarify explanation of STAGE2_PGTABLE_LEVELSChristoffer Dall
In attempting to re-construct the logic for our stage 2 page table layout I found the reasoning in the comment explaining how we calculate the number of levels used for stage 2 page tables a bit backwards. This commit attempts to clarify the comment, to make it slightly easier to read without having the Arm ARM open on the right page. While we're at it, fixup a typo in a comment that was recently changed. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18KVM: arm/arm64: vgic: Do not cond_resched_lock() with IRQs disabledJulien Thierry
To change the active state of an MMIO, halt is requested for all vcpus of the affected guest before modifying the IRQ state. This is done by calling cond_resched_lock() in vgic_mmio_change_active(). However interrupts are disabled at this point and we cannot reschedule a vcpu. We actually don't need any of this, as kvm_arm_halt_guest ensures that all the other vcpus are out of the guest. Let's just drop that useless code. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Suggested-by: Christoffer Dall <christoffer.dall@arm.com> Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18KVM: arm64: Add support for creating PUD hugepages at stage 2Punit Agrawal
KVM only supports PMD hugepages at stage 2. Now that the various page handling routines are updated, extend the stage 2 fault handling to map in PUD hugepages. Addition of PUD hugepage support enables additional page sizes (e.g., 1G with 4K granule) which can be useful on cores that support mapping larger block sizes in the TLB entries. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> [ Replace BUG() => WARN_ON(1) for arm32 PUD helpers ] Signed-off-by: Suzuki Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18KVM: arm64: Update age handlers to support PUD hugepagesPunit Agrawal
In preparation for creating larger hugepages at Stage 2, add support to the age handling notifiers for PUD hugepages when encountered. Provide trivial helpers for arm32 to allow sharing code. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> [ Replaced BUG() => WARN_ON(1) for arm32 PUD helpers ] Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18KVM: arm64: Support handling access faults for PUD hugepagesPunit Agrawal
In preparation for creating larger hugepages at Stage 2, extend the access fault handling at Stage 2 to support PUD hugepages when encountered. Provide trivial helpers for arm32 to allow sharing of code. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> [ Replaced BUG() => WARN_ON(1) in PUD helpers ] Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18KVM: arm64: Support PUD hugepage in stage2_is_exec()Punit Agrawal
In preparation for creating PUD hugepages at stage 2, add support for detecting execute permissions on PUD page table entries. Faults due to lack of execute permissions on page table entries is used to perform i-cache invalidation on first execute. Provide trivial implementations of arm32 helpers to allow sharing of code. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> [ Replaced BUG() => WARN_ON(1) in arm32 PUD helpers ] Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18KVM: arm64: Support dirty page tracking for PUD hugepagesPunit Agrawal
In preparation for creating PUD hugepages at stage 2, add support for write protecting PUD hugepages when they are encountered. Write protecting guest tables is used to track dirty pages when migrating VMs. Also, provide trivial implementations of required kvm_s2pud_* helpers to allow sharing of code with arm32. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> [ Replaced BUG() => WARN_ON() in arm32 pud helpers ] Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18KVM: arm/arm64: Introduce helpers to manipulate page table entriesPunit Agrawal
Introduce helpers to abstract architectural handling of the conversion of pfn to page table entries and marking a PMD page table entry as a block entry. The helpers are introduced in preparation for supporting PUD hugepages at stage 2 - which are supported on arm64 but do not exist on arm. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18KVM: arm/arm64: Re-factor setting the Stage 2 entry to exec on faultPunit Agrawal
Stage 2 fault handler marks a page as executable if it is handling an execution fault or if it was a permission fault in which case the executable bit needs to be preserved. The logic to decide if the page should be marked executable is duplicated for PMD and PTE entries. To avoid creating another copy when support for PUD hugepages is introduced refactor the code to share the checks needed to mark a page table entry as executable. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18KVM: arm/arm64: Share common code in user_mem_abort()Punit Agrawal
The code for operations such as marking the pfn as dirty, and dcache/icache maintenance during stage 2 fault handling is duplicated between normal pages and PMD hugepages. Instead of creating another copy of the operations when we introduce PUD hugepages, let's share them across the different pagesizes. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18KVM: arm/arm64: vgic-v2: Set active_source to 0 when restoring stateChristoffer Dall
When restoring the active state from userspace, we don't know which CPU was the source for the active state, and this is not architecturally exposed in any of the register state. Set the active_source to 0 in this case. In the future, we can expand on this and exposse the information as additional information to userspace for GICv2 if anyone cares. Cc: stable@vger.kernel.org Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18KVM: arm/arm64: Fix VMID alloc race by reverting to lock-lessChristoffer Dall
We recently addressed a VMID generation race by introducing a read/write lock around accesses and updates to the vmid generation values. However, kvm_arch_vcpu_ioctl_run() also calls need_new_vmid_gen() but does so without taking the read lock. As far as I can tell, this can lead to the same kind of race: VM 0, VCPU 0 VM 0, VCPU 1 ------------ ------------ update_vttbr (vmid 254) update_vttbr (vmid 1) // roll over read_lock(kvm_vmid_lock); force_vm_exit() local_irq_disable need_new_vmid_gen == false //because vmid gen matches enter_guest (vmid 254) kvm_arch.vttbr = <PGD>:<VMID 1> read_unlock(kvm_vmid_lock); enter_guest (vmid 1) Which results in running two VCPUs in the same VM with different VMIDs and (even worse) other VCPUs from other VMs could now allocate clashing VMID 254 from the new generation as long as VCPU 0 is not exiting. Attempt to solve this by making sure vttbr is updated before another CPU can observe the updated VMID generation. Cc: stable@vger.kernel.org Fixes: f0cf47d939d0 "KVM: arm/arm64: Close VMID generation race" Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18arm64: KVM: Consistently advance singlestep when emulating instructionsMark Rutland
When we emulate a guest instruction, we don't advance the hardware singlestep state machine, and thus the guest will receive a software step exception after a next instruction which is not emulated by the host. We bodge around this in an ad-hoc fashion. Sometimes we explicitly check whether userspace requested a single step, and fake a debug exception from within the kernel. Other times, we advance the HW singlestep state rely on the HW to generate the exception for us. Thus, the observed step behaviour differs for host and guest. Let's make this simpler and consistent by always advancing the HW singlestep state machine when we skip an instruction. Thus we can rely on the hardware to generate the singlestep exception for us, and never need to explicitly check for an active-pending step, nor do we need to fake a debug exception from the guest. Cc: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18arm64: KVM: Skip MMIO insn after emulationMark Rutland
When we emulate an MMIO instruction, we advance the CPU state within decode_hsr(), before emulating the instruction effects. Having this logic in decode_hsr() is opaque, and advancing the state before emulation is problematic. It gets in the way of applying consistent single-step logic, and it prevents us from being able to fail an MMIO instruction with a synchronous exception. Clean this up by only advancing the CPU state *after* the effects of the instruction are emulated. Cc: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-14kvm: introduce manual dirty log reprotectPaolo Bonzini
There are two problems with KVM_GET_DIRTY_LOG. First, and less important, it can take kvm->mmu_lock for an extended period of time. Second, its user can actually see many false positives in some cases. The latter is due to a benign race like this: 1. KVM_GET_DIRTY_LOG returns a set of dirty pages and write protects them. 2. The guest modifies the pages, causing them to be marked ditry. 3. Userspace actually copies the pages. 4. KVM_GET_DIRTY_LOG returns those pages as dirty again, even though they were not written to since (3). This is especially a problem for large guests, where the time between (1) and (3) can be substantial. This patch introduces a new capability which, when enabled, makes KVM_GET_DIRTY_LOG not write-protect the pages it returns. Instead, userspace has to explicitly clear the dirty log bits just before using the content of the page. The new KVM_CLEAR_DIRTY_LOG ioctl can also operate on a 64-page granularity rather than requiring to sync a full memslot; this way, the mmu_lock is taken for small amounts of time, and only a small amount of time will pass between write protection of pages and the sending of their content. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14kvm: rename last argument to kvm_get_dirty_log_protectPaolo Bonzini
When manual dirty log reprotect will be enabled, kvm_get_dirty_log_protect's pointer argument will always be false on exit, because no TLB flush is needed until the manual re-protection operation. Rename it from "is_dirty" to "flush", which more accurately tells the caller what they have to do with it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14kvm: make KVM_CAP_ENABLE_CAP_VM architecture agnosticPaolo Bonzini
The first such capability to be handled in virt/kvm/ will be manual dirty page reprotection. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-10KVM: arm64: Rework detection of SVE, !VHE systemsMarc Zyngier
An SVE system is so far the only case where we mandate VHE. As we're starting to grow this requirements, let's slightly rework the way we deal with that situation, allowing for easy extension of this check. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>