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2020-06-16KVM: Replace zero-length array with flexible-arrayGustavo A. R. Silva1-1/+1
There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://github.com/KSPP/linux/issues/21 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-06-11KVM: async_pf: Inject 'page ready' event only if 'page not present' was ↵Vitaly Kuznetsov1-0/+1
previously injected 'Page not present' event may or may not get injected depending on guest's state. If the event wasn't injected, there is no need to inject the corresponding 'page ready' event as the guest may get confused. E.g. Linux thinks that the corresponding 'page not present' event wasn't delivered *yet* and allocates a 'dummy entry' for it. This entry is never freed. Note, 'wakeup all' events have no corresponding 'page not present' event and always get injected. s390 seems to always be able to inject 'page not present', the change is effectively a nop. Suggested-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200610175532.779793-2-vkuznets@redhat.com> Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=208081 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-08KVM: x86: Fix APIC page invalidation raceEiichi Tsukata1-2/+2
Commit b1394e745b94 ("KVM: x86: fix APIC page invalidation") tried to fix inappropriate APIC page invalidation by re-introducing arch specific kvm_arch_mmu_notifier_invalidate_range() and calling it from kvm_mmu_notifier_invalidate_range_start. However, the patch left a possible race where the VMCS APIC address cache is updated *before* it is unmapped: (Invalidator) kvm_mmu_notifier_invalidate_range_start() (Invalidator) kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD) (KVM VCPU) vcpu_enter_guest() (KVM VCPU) kvm_vcpu_reload_apic_access_page() (Invalidator) actually unmap page Because of the above race, there can be a mismatch between the host physical address stored in the APIC_ACCESS_PAGE VMCS field and the host physical address stored in the EPT entry for the APIC GPA (0xfee0000). When this happens, the processor will not trap APIC accesses, and will instead show the raw contents of the APIC-access page. Because Windows OS periodically checks for unexpected modifications to the LAPIC register, this will show up as a BSOD crash with BugCheck CRITICAL_STRUCTURE_CORRUPTION (109) we are currently seeing in https://bugzilla.redhat.com/show_bug.cgi?id=1751017. The root cause of the issue is that kvm_arch_mmu_notifier_invalidate_range() cannot guarantee that no additional references are taken to the pages in the range before kvm_mmu_notifier_invalidate_range_end(). Fortunately, this case is supported by the MMU notifier API, as documented in include/linux/mmu_notifier.h: * If the subsystem * can't guarantee that no additional references are taken to * the pages in the range, it has to implement the * invalidate_range() notifier to remove any references taken * after invalidate_range_start(). The fix therefore is to reload the APIC-access page field in the VMCS from kvm_mmu_notifier_invalidate_range() instead of ..._range_start(). Cc: stable@vger.kernel.org Fixes: b1394e745b94 ("KVM: x86: fix APIC page invalidation") Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=197951 Signed-off-by: Eiichi Tsukata <eiichi.tsukata@nutanix.com> Message-Id: <20200606042627.61070-1-eiichi.tsukata@nutanix.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-04KVM: let kvm_destroy_vm_debugfs clean up vCPU debugfs directoriesPaolo Bonzini1-2/+1
After commit 63d0434 ("KVM: x86: move kvm_create_vcpu_debugfs after last failure point") we are creating the pre-vCPU debugfs files after the creation of the vCPU file descriptor. This makes it possible for userspace to reach kvm_vcpu_release before kvm_create_vcpu_debugfs has finished. The vcpu->debugfs_dentry then does not have any associated inode anymore, and this causes a NULL-pointer dereference in debugfs_create_file. The solution is simply to avoid removing the files; they are cleaned up when the VM file descriptor is closed (and that must be after KVM_CREATE_VCPU returns). We can stop storing the dentry in struct kvm_vcpu too, because it is not needed anywhere after kvm_create_vcpu_debugfs returns. Reported-by: syzbot+705f4401d5a93a59b87d@syzkaller.appspotmail.com Fixes: 63d04348371b ("KVM: x86: move kvm_create_vcpu_debugfs after last failure point") Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: introduce kvm_read_guest_offset_cached()Vitaly Kuznetsov1-0/+3
We already have kvm_write_guest_offset_cached(), introduce read analogue. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200525144125.143875-5-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-13kvm: Replace vcpu->swait with rcuwaitDavidlohr Bueso1-5/+5
The use of any sort of waitqueue (simple or regular) for wait/waking vcpus has always been an overkill and semantically wrong. Because this is per-vcpu (which is blocked) there is only ever a single waiting vcpu, thus no need for any sort of queue. As such, make use of the rcuwait primitive, with the following considerations: - rcuwait already provides the proper barriers that serialize concurrent waiter and waker. - Task wakeup is done in rcu read critical region, with a stable task pointer. - Because there is no concurrency among waiters, we need not worry about rcuwait_wait_event() calls corrupting the wait->task. As a consequence, this saves the locking done in swait when modifying the queue. This also applies to per-vcore wait for powerpc kvm-hv. The x86 tscdeadline_latency test mentioned in 8577370fb0cb ("KVM: Use simple waitqueue for vcpu->wq") shows that, on avg, latency is reduced by around 15-20% with this change. Cc: Paul Mackerras <paulus@ozlabs.org> Cc: kvmarm@lists.cs.columbia.edu Cc: linux-mips@vger.kernel.org Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Message-Id: <20200424054837.5138-6-dave@stgolabs.net> [Avoid extra logic changes. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-13Merge branch 'kvm-amd-fixes' into HEADPaolo Bonzini1-0/+3
2020-05-08KVM: Introduce kvm_make_all_cpus_request_except()Suravee Suthikulpanit1-0/+3
This allows making request to all other vcpus except the one specified in the parameter. Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Message-Id: <1588771076-73790-2-git-send-email-suravee.suthikulpanit@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-24kvm: add capability for halt pollingDavid Matlack1-0/+1
KVM_CAP_HALT_POLL is a per-VM capability that lets userspace control the halt-polling time, allowing halt-polling to be tuned or disabled on particular VMs. With dynamic halt-polling, a VM's VCPUs can poll from anywhere from [0, halt_poll_ns] on each halt. KVM_CAP_HALT_POLL sets the upper limit on the poll time. Signed-off-by: David Matlack <dmatlack@google.com> Signed-off-by: Jon Cargille <jcargill@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <20200417221446.108733-1-jcargill@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-21KVM: Remove redundant argument to kvm_arch_vcpu_ioctl_runTianjia Zhang1-1/+1
In earlier versions of kvm, 'kvm_run' was an independent structure and was not included in the vcpu structure. At present, 'kvm_run' is already included in the vcpu structure, so the parameter 'kvm_run' is redundant. This patch simplifies the function definition, removes the extra 'kvm_run' parameter, and extracts it from the 'kvm_vcpu' structure if necessary. Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com> Message-Id: <20200416051057.26526-1-tianjia.zhang@linux.alibaba.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-21KVM: x86/mmu: Avoid an extra memslot lookup in try_async_pf() for L2Paolo Bonzini1-0/+6
Create a new function kvm_is_visible_memslot() and use it from kvm_is_visible_gfn(); use the new function in try_async_pf() too, to avoid an extra memslot lookup. Opportunistically squish a multi-line comment into a single-line comment. Note, the end result, KVM_PFN_NOSLOT, is unchanged. Cc: Jim Mattson <jmattson@google.com> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-21kvm_host: unify VM_STAT and VCPU_STAT definitions in a single placeEmanuele Giuseppe Esposito1-0/+5
The macros VM_STAT and VCPU_STAT are redundantly implemented in multiple files, each used by a different architecure to initialize the debugfs entries for statistics. Since they all have the same purpose, they can be unified in a single common definition in include/linux/kvm_host.h Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20200414155625.20559-1-eesposit@redhat.com> Acked-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-14KVM: Check validity of resolved slot when searching memslotsSean Christopherson1-1/+1
Check that the resolved slot (somewhat confusingly named 'start') is a valid/allocated slot before doing the final comparison to see if the specified gfn resides in the associated slot. The resolved slot can be invalid if the binary search loop terminated because the search index was incremented beyond the number of used slots. This bug has existed since the binary search algorithm was introduced, but went unnoticed because KVM statically allocated memory for the max number of slots, i.e. the access would only be truly out-of-bounds if all possible slots were allocated and the specified gfn was less than the base of the lowest memslot. Commit 36947254e5f98 ("KVM: Dynamically size memslot array based on number of used slots") eliminated the "all possible slots allocated" condition and made the bug embarrasingly easy to hit. Fixes: 9c1a5d38780e6 ("kvm: optimize GFN to memslot lookup with large slots amount") Reported-by: syzbot+d889b59b2bb87d4047a2@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200408064059.8957-2-sean.j.christopherson@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-31KVM: Pass kvm_init()'s opaque param to additional arch funcsSean Christopherson1-2/+2
Pass @opaque to kvm_arch_hardware_setup() and kvm_arch_check_processor_compat() to allow architecture specific code to reference @opaque without having to stash it away in a temporary global variable. This will enable x86 to separate its vendor specific callback ops, which are passed via @opaque, into "init" and "runtime" ops without having to stash away the "init" ops. No functional change intended. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Tested-by: Cornelia Huck <cohuck@redhat.com> #s390 Acked-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200321202603.19355-2-sean.j.christopherson@intel.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-31Merge tag 'kvmarm-5.7' of ↵Paolo Bonzini1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm updates for Linux 5.7 - GICv4.1 support - 32bit host removal
2020-03-26KVM: Fix out of range accesses to memslotsSean Christopherson1-0/+3
Reset the LRU slot if it becomes invalid when deleting a memslot to fix an out-of-bounds/use-after-free access when searching through memslots. Explicitly check for there being no used slots in search_memslots(), and in the caller of s390's approximation variant. Fixes: 36947254e5f9 ("KVM: Dynamically size memslot array based on number of used slots") Reported-by: Qian Cai <cai@lca.pw> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320205546.2396-2-sean.j.christopherson@intel.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: Drop largepages_enabled and its accessor/mutatorSean Christopherson1-2/+0
Drop largepages_enabled, kvm_largepages_enabled() and kvm_disable_largepages() now that all users are gone. Note, largepages_enabled was an x86-only flag that got left in common KVM code when KVM gained support for multiple architectures. No functional change intended. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: Drop gfn_to_pfn_atomic()Peter Xu1-1/+0
It's never used anywhere now. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: x86: enable dirty log gradually in small chunksJay Zhou1-1/+10
It could take kvm->mmu_lock for an extended period of time when enabling dirty log for the first time. The main cost is to clear all the D-bits of last level SPTEs. This situation can benefit from manual dirty log protect as well, which can reduce the mmu_lock time taken. The sequence is like this: 1. Initialize all the bits of the dirty bitmap to 1 when enabling dirty log for the first time 2. Only write protect the huge pages 3. KVM_GET_DIRTY_LOG returns the dirty bitmap info 4. KVM_CLEAR_DIRTY_LOG will clear D-bit for each of the leaf level SPTEs gradually in small chunks Under the Intel(R) Xeon(R) Gold 6152 CPU @ 2.10GHz environment, I did some tests with a 128G windows VM and counted the time taken of memory_global_dirty_log_start, here is the numbers: VM Size Before After optimization 128G 460ms 10ms Signed-off-by: Jay Zhou <jianjay.zhou@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: Dynamically size memslot array based on number of used slotsSean Christopherson1-1/+1
Now that the memslot logic doesn't assume memslots are always non-NULL, dynamically size the array of memslots instead of unconditionally allocating memory for the maximum number of memslots. Note, because a to-be-deleted memslot must first be invalidated, the array size cannot be immediately reduced when deleting a memslot. However, consecutive deletions will realize the memory savings, i.e. a second deletion will trim the entry. Tested-by: Christoffer Dall <christoffer.dall@arm.com> Tested-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: Terminate memslot walks via used_slotsSean Christopherson1-6/+12
Refactor memslot handling to treat the number of used slots as the de facto size of the memslot array, e.g. return NULL from id_to_memslot() when an invalid index is provided instead of relying on npages==0 to detect an invalid memslot. Rework the sorting and walking of memslots in advance of dynamically sizing memslots to aid bisection and debug, e.g. with luck, a bug in the refactoring will bisect here and/or hit a WARN instead of randomly corrupting memory. Alternatively, a global null/invalid memslot could be returned, i.e. so callers of id_to_memslot() don't have to explicitly check for a NULL memslot, but that approach runs the risk of introducing difficult-to- debug issues, e.g. if the global null slot is modified. Constifying the return from id_to_memslot() to combat such issues is possible, but would require a massive refactoring of arch specific code and would still be susceptible to casting shenanigans. Add function comments to update_memslots() and search_memslots() to explicitly (and loudly) state how memslots are sorted. Opportunistically stuff @hva with a non-canonical value when deleting a private memslot on x86 to detect bogus usage of the freed slot. No functional change intended. Tested-by: Christoffer Dall <christoffer.dall@arm.com> Tested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: Ensure validity of memslot with respect to kvm_get_dirty_log()Sean Christopherson1-1/+1
Rework kvm_get_dirty_log() so that it "returns" the associated memslot on success. A future patch will rework memslot handling such that id_to_memslot() can return NULL, returning the memslot makes it more obvious that the validity of the memslot has been verified, i.e. precludes the need to add validity checks in the arch code that are technically unnecessary. To maintain ordering in s390, move the call to kvm_arch_sync_dirty_log() from s390's kvm_vm_ioctl_get_dirty_log() to the new kvm_get_dirty_log(). This is a nop for PPC, the only other arch that doesn't select KVM_GENERIC_DIRTYLOG_READ_PROTECT, as its sync_dirty_log() is empty. Ideally, moving the sync_dirty_log() call would be done in a separate patch, but it can't be done in a follow-on patch because that would temporarily break s390's ordering. Making the move in a preparatory patch would be functionally correct, but would create an odd scenario where the moved sync_dirty_log() would operate on a "different" memslot due to consuming the result of a different id_to_memslot(). The memslot couldn't actually be different as slots_lock is held, but the code is confusing enough as it is, i.e. moving sync_dirty_log() in this patch is the lesser of all evils. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: Provide common implementation for generic dirty log functionsSean Christopherson1-13/+10
Move the implementations of KVM_GET_DIRTY_LOG and KVM_CLEAR_DIRTY_LOG for CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT into common KVM code. The arch specific implemenations are extremely similar, differing only in whether the dirty log needs to be sync'd from hardware (x86) and how the TLBs are flushed. Add new arch hooks to handle sync and TLB flush; the sync will also be used for non-generic dirty log support in a future patch (s390). The ulterior motive for providing a common implementation is to eliminate the dependency between arch and common code with respect to the memslot referenced by the dirty log, i.e. to make it obvious in the code that the validity of the memslot is guaranteed, as a future patch will rework memslot handling such that id_to_memslot() can return NULL. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: Simplify kvm_free_memslot() and all its descendentsSean Christopherson1-2/+1
Now that all callers of kvm_free_memslot() pass NULL for @dont, remove the param from the top-level routine and all arch's implementations. No functional change intended. Tested-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: Drop "const" attribute from old memslot in commit_memory_region()Sean Christopherson1-1/+1
Drop the "const" attribute from @old in kvm_arch_commit_memory_region() to allow arch specific code to free arch specific resources in the old memslot without having to cast away the attribute. Freeing resources in kvm_arch_commit_memory_region() paves the way for simplifying kvm_free_memslot() by eliminating the last usage of its @dont param. Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: Drop kvm_arch_create_memslot()Sean Christopherson1-2/+0
Remove kvm_arch_create_memslot() now that all arch implementations are effectively nops. Removing kvm_arch_create_memslot() eliminates the possibility for arch specific code to allocate memory prior to setting a memslot, which sets the stage for simplifying kvm_free_memslot(). Cc: Janosch Frank <frankja@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-28KVM: let declaration of kvm_get_running_vcpus match implementationChristian Borntraeger1-1/+1
Sparse notices that declaration and implementation do not match: arch/s390/kvm/../../../virt/kvm/kvm_main.c:4435:17: warning: incorrect type in return expression (different address spaces) arch/s390/kvm/../../../virt/kvm/kvm_main.c:4435:17: expected struct kvm_vcpu [noderef] <asn:3> ** arch/s390/kvm/../../../virt/kvm/kvm_main.c:4435:17: got struct kvm_vcpu *[noderef] <asn:3> * Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-17KVM: x86: fix missing prototypesPaolo Bonzini1-0/+2
Reported with "make W=1" due to -Wmissing-prototypes. Reported-by: Qian Cai <cai@lca.pw> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-30Merge branch 'cve-2019-3016' into kvm-next-5.6Paolo Bonzini1-0/+5
From Boris Ostrovsky: The KVM hypervisor may provide a guest with ability to defer remote TLB flush when the remote VCPU is not running. When this feature is used, the TLB flush will happen only when the remote VPCU is scheduled to run again. This will avoid unnecessary (and expensive) IPIs. Under certain circumstances, when a guest initiates such deferred action, the hypervisor may miss the request. It is also possible that the guest may mistakenly assume that it has already marked remote VCPU as needing a flush when in fact that request had already been processed by the hypervisor. In both cases this will result in an invalid translation being present in a vCPU, potentially allowing accesses to memory locations in that guest's address space that should not be accessible. Note that only intra-guest memory is vulnerable. The five patches address both of these problems: 1. The first patch makes sure the hypervisor doesn't accidentally clear a guest's remote flush request 2. The rest of the patches prevent the race between hypervisor acknowledging a remote flush request and guest issuing a new one. Conflicts: arch/x86/kvm/x86.c [move from kvm_arch_vcpu_free to kvm_arch_vcpu_destroy]
2020-01-30x86/kvm: Cache gfn to pfn translationBoris Ostrovsky1-2/+5
__kvm_map_gfn()'s call to gfn_to_pfn_memslot() is * relatively expensive * in certain cases (such as when done from atomic context) cannot be called Stashing gfn-to-pfn mapping should help with both cases. This is part of CVE-2019-3016. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-30x86/kvm: Introduce kvm_(un)map_gfn()Boris Ostrovsky1-0/+2
kvm_vcpu_(un)map operates on gfns from any current address space. In certain cases we want to make sure we are not mapping SMRAM and for that we can use kvm_(un)map_gfn() that we are introducing in this patch. This is part of CVE-2019-3016. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-27KVM: Use vcpu-specific gva->hva translation when querying host page sizeSean Christopherson1-1/+1
Use kvm_vcpu_gfn_to_hva() when retrieving the host page size so that the correct set of memslots is used when handling x86 page faults in SMM. Fixes: 54bf36aac520 ("KVM: x86: use vcpu-specific functions to read/write/translate GFNs") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-27mm: thp: KVM: Explicitly check for THP when populating secondary MMUSean Christopherson1-0/+1
Add a helper, is_transparent_hugepage(), to explicitly check whether a compound page is a THP and use it when populating KVM's secondary MMU. The explicit check fixes a bug where a remapped compound page, e.g. for an XDP Rx socket, is mapped into a KVM guest and is mistaken for a THP, which results in KVM incorrectly creating a huge page in its secondary MMU. Fixes: 936a5fe6e6148 ("thp: kvm mmu transparent hugepage support") Reported-by: syzbot+c9d1fb51ac9d0d10c39d@syzkaller.appspotmail.com Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-27KVM: Move running VCPU from ARM to common codePaolo Bonzini1-0/+3
For ring-based dirty log tracking, it will be more efficient to account writes during schedule-out or schedule-in to the currently running VCPU. We would like to do it even if the write doesn't use the current VCPU's address space, as is the case for cached writes (see commit 4e335d9e7ddb, "Revert "KVM: Support vCPU-based gfn->hva cache"", 2017-05-02). Therefore, add a mechanism to track the currently-loaded kvm_vcpu struct. There is already something similar in KVM/ARM; one important difference is that kvm_arch_vcpu_{load,put} have two callers in virt/kvm/kvm_main.c: we have to update both the architecture-independent vcpu_{load,put} and the preempt notifiers. Another change made in the process is to allow using kvm_get_running_vcpu() in preemptible code. This is allowed because preempt notifiers ensure that the value does not change even after the VCPU thread is migrated. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-27KVM: Remove kvm_read_guest_atomic()Peter Xu1-2/+0
Remove kvm_read_guest_atomic() because it's not used anywhere. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-27KVM: Drop kvm_arch_vcpu_init() and kvm_arch_vcpu_uninit()Sean Christopherson1-3/+0
Remove kvm_arch_vcpu_init() and kvm_arch_vcpu_uninit() now that all arch specific implementations are nops. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-27KVM: Drop kvm_arch_vcpu_setup()Sean Christopherson1-1/+0
Remove kvm_arch_vcpu_setup() now that all arch specific implementations are nops. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-27KVM: Unexport kvm_vcpu_cache and kvm_vcpu_{un}init()Sean Christopherson1-4/+0
Unexport kvm_vcpu_cache and kvm_vcpu_{un}init() and make them static now that they are referenced only in kvm_main.c. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-27KVM: Move vcpu alloc and init invocation to common codeSean Christopherson1-1/+1
Now that all architectures tightly couple vcpu allocation/free with the mandatory calls to kvm_{un}init_vcpu(), move the sequences verbatim to common KVM code. Move both allocation and initialization in a single patch to eliminate thrash in arch specific code. The bisection benefits of moving the two pieces in separate patches is marginal at best, whereas the odds of introducing a transient arch specific bug are non-zero. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24KVM: Introduce kvm_vcpu_destroy()Sean Christopherson1-0/+1
Add kvm_vcpu_destroy() and wire up all architectures to call the common function instead of their arch specific implementation. The common destruction function will be used by future patches to move allocation and initialization of vCPUs to common KVM code, i.e. to free resources that are allocated by arch agnostic code. No functional change intended. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24KVM: Add kvm_arch_vcpu_precreate() to handle pre-allocation issuesSean Christopherson1-0/+1
Add a pre-allocation arch hook to handle checks that are currently done by arch specific code prior to allocating the vCPU object. This paves the way for moving the allocation to common KVM code. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24KVM: Remove kvm_arch_vcpu_free() declarationSean Christopherson1-1/+0
Remove KVM's declaration of kvm_arch_vcpu_free() now that the function is gone from all architectures (several architectures were relying on the forward declaration). Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-21kvm: Refactor handling of VM debugfs filesMilan Pandurov1-2/+5
We can store reference to kvm_stats_debugfs_item instead of copying its values to kvm_stat_data. This allows us to remove duplicated code and usage of temporary kvm_stat_data inside vm_stat_get et al. Signed-off-by: Milan Pandurov <milanpa@amazon.de> Reviewed-by: Alexander Graf <graf@amazon.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: x86: Use gpa_t for cr2/gpa to fix TDP support on 32-bit KVMSean Christopherson1-3/+3
Convert a plethora of parameters and variables in the MMU and page fault flows from type gva_t to gpa_t to properly handle TDP on 32-bit KVM. Thanks to PSE and PAE paging, 32-bit kernels can access 64-bit physical addresses. When TDP is enabled, the fault address is a guest physical address and thus can be a 64-bit value, even when both KVM and its guest are using 32-bit virtual addressing, e.g. VMX's VMCS.GUEST_PHYSICAL is a 64-bit field, not a natural width field. Using a gva_t for the fault address means KVM will incorrectly drop the upper 32-bits of the GPA. Ditto for gva_to_gpa() when it is used to translate L2 GPAs to L1 GPAs. Opportunistically rename variables and parameters to better reflect the dual address modes, e.g. use "cr2_or_gpa" for fault addresses and plain "addr" instead of "vaddr" when the address may be either a GVA or an L2 GPA. Similarly, use "gpa" in the nonpaging_page_fault() flows to avoid a confusing "gpa_t gva" declaration; this also sets the stage for a future patch to combing nonpaging_page_fault() and tdp_page_fault() with minimal churn. Sprinkle in a few comments to document flows where an address is known to be a GVA and thus can be safely truncated to a 32-bit value. Add WARNs in kvm_handle_page_fault() and FNAME(gva_to_gpa_nested)() to help document such cases and detect bugs. Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: Remove duplicated declaration of kvm_vcpu_kickZenghui Yu1-1/+0
There are two declarations of kvm_vcpu_kick() in kvm_host.h where one of them is redundant. Remove to keep the git grep a bit cleaner. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-12-09treewide: Use sizeof_field() macroPankaj Bharadiya1-1/+1
Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except at places where these are defined. Later patches will remove the unused definition of FIELD_SIZEOF(). This patch is generated using following script: EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h" git grep -l -e "\bFIELD_SIZEOF\b" | while read file; do if [[ "$file" =~ $EXCLUDE_FILES ]]; then continue fi sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file; done Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com> Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: David Miller <davem@davemloft.net> # for net
2019-11-21Merge branch 'kvm-tsx-ctrl' into HEADPaolo Bonzini1-0/+7
Conflicts: arch/x86/kvm/vmx/vmx.c
2019-11-21Merge tag 'kvmarm-5.5' of ↵Paolo Bonzini1-2/+24
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm updates for Linux 5.5: - Allow non-ISV data aborts to be reported to userspace - Allow injection of data aborts from userspace - Expose stolen time to guests - GICv4 performance improvements - vgic ITS emulation fixes - Simplify FWB handling - Enable halt pool counters - Make the emulated timer PREEMPT_RT compliant Conflicts: include/uapi/linux/kvm.h
2019-11-15KVM: x86: deliver KVM IOAPIC scan request to target vCPUsNitesh Narayan Lal1-0/+2
In IOAPIC fixed delivery mode instead of flushing the scan requests to all vCPUs, we should only send the requests to vCPUs specified within the destination field. This patch introduces kvm_get_dest_vcpus_mask() API which retrieves an array of target vCPUs by using kvm_apic_map_get_dest_lapic() and then based on the vcpus_idx, it sets the bit in a bitmap. However, if the above fails kvm_get_dest_vcpus_mask() finds the target vCPUs by traversing all available vCPUs. Followed by setting the bits in the bitmap. If we had different vCPUs in the previous request for the same redirection table entry then bits corresponding to these vCPUs are also set. This to done to keep ioapic_handled_vectors synchronized. This bitmap is then eventually passed on to kvm_make_vcpus_request_mask() to generate a masked request only for the target vCPUs. This would enable us to reduce the latency overhead on isolated vCPUs caused by the IPI to process due to KVM_REQ_IOAPIC_SCAN. Suggested-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-15KVM: remember position in kvm->vcpus arrayRadim Krčmář1-8/+3
Fetching an index for any vcpu in kvm->vcpus array by traversing the entire array everytime is costly. This patch remembers the position of each vcpu in kvm->vcpus array by storing it in vcpus_idx under kvm_vcpu structure. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>