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path: root/arch/x86/kvm/mmu/page_track.c
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2022-03-08KVM: use __vcalloc for very large allocationsPaolo Bonzini1-3/+4
Allocations whose size is related to the memslot size can be arbitrarily large. Do not use kvzalloc/kvcalloc, as those are limited to "not crazy" sizes that fit in 32 bits. Cc: stable@vger.kernel.org Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls") Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: x86/mmu: Propagate memslot const qualifierBen Gardon1-2/+2
In preparation for implementing in-place hugepage promotion, various functions will need to be called from zap_collapsible_spte_range, which has the const qualifier on its memslot argument. Propagate the const qualifier to the various functions which will be needed. This just serves to simplify the following patch. No functional change intended. Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20211115234603.2908381-11-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: x86/mmu: Remove need for a vcpu from kvm_slot_page_track_is_activeBen Gardon1-2/+2
kvm_slot_page_track_is_active only uses its vCPU argument to get a pointer to the assoicated struct kvm, so just pass in the struct KVM to remove the need for a vCPU pointer. No functional change intended. Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20211115234603.2908381-6-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-22KVM: cleanup allocation of rmaps and page tracking dataDavid Stevens1-42/+15
Unify the flags for rmaps and page tracking data, using a single flag in struct kvm_arch and a single loop to go over all the address spaces and memslots. This avoids code duplication between alloc_all_memslots_rmaps and kvm_page_track_enable_mmu_write_tracking. Signed-off-by: David Stevens <stevensd@chromium.org> [This patch is the delta between David's v2 and v3, with conflicts fixed and my own commit message. - Paolo] Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-01KVM: x86: only allocate gfn_track when necessaryDavid Stevens1-3/+69
Avoid allocating the gfn_track arrays if nothing needs them. If there are no external to KVM users of the API (i.e. no GVT-g), then page tracking is only needed for shadow page tables. This means that when tdp is enabled and there are no external users, then the gfn_track arrays can be lazily allocated when the shadow MMU is actually used. This avoid allocations equal to .05% of guest memory when nested virtualization is not used, if the kernel is compiled without GVT-g. Signed-off-by: David Stevens <stevensd@chromium.org> Message-Id: <20210922045859.2011227-3-stevensd@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-01KVM: x86/mmu: Avoid memslot lookup in make_spte and mmu_try_to_unsync_pagesDavid Matlack1-11/+3
mmu_try_to_unsync_pages checks if page tracking is active for the given gfn, which requires knowing the memslot. We can pass down the memslot via make_spte to avoid this lookup. The memslot is also handy for make_spte's marking of the gfn as dirty: we can test whether dirty page tracking is enabled, and if so ensure that pages are mapped as writable with 4K granularity. Apart from the warning, no functional change is intended. Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20210813203504.2742757-7-dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-01KVM: x86/mmu: Avoid memslot lookup in page_fault_handle_page_trackDavid Matlack1-7/+13
Now that kvm_page_fault has a pointer to the memslot it can be passed down to the page tracking code to avoid a redundant slot lookup. No functional change intended. Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20210813203504.2742757-5-dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: x86: Handle SRCU initialization failure during page track initHaimin Zhang1-2/+2
Check the return of init_srcu_struct(), which can fail due to OOM, when initializing the page track mechanism. Lack of checking leads to a NULL pointer deref found by a modified syzkaller. Reported-by: TCS Robot <tcs_robot@tencent.com> Signed-off-by: Haimin Zhang <tcs_kernel@tencent.com> Message-Id: <1630636626-12262-1-git-send-email-tcs_kernel@tencent.com> [Move the call towards the beginning of kvm_arch_init_vm. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-20KVM: X86: Introduce kvm_mmu_slot_lpages() helpersPeter Xu1-0/+1
Introduce kvm_mmu_slot_lpages() to calculcate lpage_info and rmap array size. The other __kvm_mmu_slot_lpages() can take an extra parameter of npages rather than fetching from the memslot pointer. Start to use the latter one in kvm_alloc_memslot_metadata(). Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20210730220455.26054-4-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17KVM: x86: Support write protecting only large pagesKeqian Zhu1-1/+1
Prepare for write protecting large page lazily during dirty log tracking, for which we will only need to write protect gfns at large page granularity. No functional or performance change expected. Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com> Message-Id: <20210429034115.35560-2-zhukeqian1@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04KVM: x86/mmu: Use an rwlock for the x86 MMUBen Gardon1-4/+4
Add a read / write lock to be used in place of the MMU spinlock on x86. The rwlock will enable the TDP MMU to handle page faults, and other operations in parallel in future commits. Reviewed-by: Peter Feiner <pfeiner@google.com> Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20210202185734.1680553-19-bgardon@google.com> [Introduce virt/kvm/mmu_lock.h - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-25kvm: mmu: page_track: Fix RCU list API usageMadhuparna Bhowmik1-2/+4
Use hlist_for_each_entry_srcu() instead of hlist_for_each_entry_rcu() as it also checkes if the right lock is held. Using hlist_for_each_entry_rcu() with a condition argument will not report the cases where a SRCU protected list is traversed using rcu_read_lock(). Hence, use hlist_for_each_entry_srcu(). Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: <kvm@vger.kernel.org>
2020-07-08KVM: x86/mmu: Add MMU-internal headerSean Christopherson1-1/+1
Add mmu/mmu_internal.h to hold declarations and definitions that need to be shared between various mmu/ files, but should not be used by anything outside of the MMU. Begin populating mmu_internal.h with declarations of the helpers used by page_track.c. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200622202034.15093-4-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-15KVM: x86/mmu: Drop KVM's hugepage enums in favor of the kernel's enumsSean Christopherson1-2/+2
Replace KVM's PT_PAGE_TABLE_LEVEL, PT_DIRECTORY_LEVEL and PT_PDPE_LEVEL with the kernel's PG_LEVEL_4K, PG_LEVEL_2M and PG_LEVEL_1G. KVM's enums are borderline impossible to remember and result in code that is visually difficult to audit, e.g. if (!enable_ept) ept_lpage_level = 0; else if (cpu_has_vmx_ept_1g_page()) ept_lpage_level = PT_PDPE_LEVEL; else if (cpu_has_vmx_ept_2m_page()) ept_lpage_level = PT_DIRECTORY_LEVEL; else ept_lpage_level = PT_PAGE_TABLE_LEVEL; versus if (!enable_ept) ept_lpage_level = 0; else if (cpu_has_vmx_ept_1g_page()) ept_lpage_level = PG_LEVEL_1G; else if (cpu_has_vmx_ept_2m_page()) ept_lpage_level = PG_LEVEL_2M; else ept_lpage_level = PG_LEVEL_4K; No functional change intended. Suggested-by: Barret Rhoden <brho@google.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200428005422.4235-4-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: Remove unnecessary asm/kvm_host.h includesPeter Xu1-1/+0
Remove includes of asm/kvm_host.h from files that already include linux/kvm_host.h to make it more obvious that there is no ordering issue between the two headers. linux/kvm_host.h includes asm/kvm_host.h to pick up architecture specific settings, and this will never change, i.e. including asm/kvm_host.h after linux/kvm_host.h may seem problematic, but in practice is simply redundant. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: Simplify kvm_free_memslot() and all its descendentsSean Christopherson1-9/+6
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>
2019-11-21KVM: x86: create mmu/ subdirectoryPaolo Bonzini1-0/+265
Preparatory work for shattering mmu.c into multiple files. Besides making it easier to follow, this will also make it possible to write unit tests for various parts. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>