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2020-04-21KVM: x86: make Hyper-V PV TLB flush use tlb_flush_guest()Vitaly Kuznetsov
Hyper-V PV TLB flush mechanism does TLB flush on behalf of the guest so doing tlb_flush_all() is an overkill, switch to using tlb_flush_guest() (just like KVM PV TLB flush mechanism) instead. Introduce KVM_REQ_HV_TLB_FLUSH to support the change. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-20KVM: x86: Move "flush guest's TLB" logic to separate kvm_x86_ops hookSean Christopherson
Add a dedicated hook to handle flushing TLB entries on behalf of the guest, i.e. for a paravirtualized TLB flush, and use it directly instead of bouncing through kvm_vcpu_flush_tlb(). For VMX, change the effective implementation implementation to never do INVEPT and flush only the current context, i.e. to always flush via INVVPID(SINGLE_CONTEXT). The INVEPT performed by __vmx_flush_tlb() when @invalidate_gpa=false and enable_vpid=0 is unnecessary, as it will only flush guest-physical mappings; linear and combined mappings are flushed by VM-Enter when VPID is disabled, and changes in the guest pages tables do not affect guest-physical mappings. When EPT and VPID are enabled, doing INVVPID is not required (by Intel's architecture) to invalidate guest-physical mappings, i.e. TLB entries that cache guest-physical mappings can live across INVVPID as the mappings are associated with an EPTP, not a VPID. The intent of @invalidate_gpa is to inform vmx_flush_tlb() that it must "invalidate gpa mappings", i.e. do INVEPT and not simply INVVPID. Other than nested VPID handling, which now calls vpid_sync_context() directly, the only scenario where KVM can safely do INVVPID instead of INVEPT (when EPT is enabled) is if KVM is flushing TLB entries from the guest's perspective, i.e. is only required to invalidate linear mappings. For SVM, flushing TLB entries from the guest's perspective can be done by flushing the current ASID, as changes to the guest's page tables are associated only with the current ASID. Adding a dedicated ->tlb_flush_guest() paves the way toward removing @invalidate_gpa, which is a potentially dangerous control flag as its meaning is not exactly crystal clear, even for those who are familiar with the subtleties of what mappings Intel CPUs are/aren't allowed to keep across various invalidation scenarios. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320212833.3507-15-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-20KVM: nVMX: Use vpid_sync_vcpu_addr() to emulate INVVPID with addressSean Christopherson
Use vpid_sync_vcpu_addr() to emulate the "individual address" variant of INVVPID now that said function handles the fallback case of the (host) CPU not supporting "individual address". Note, the "vpid == 0" checks in the vpid_sync_*() helpers aren't actually redundant with the "!operand.vpid" check in handle_invvpid(), as the vpid passed to vpid_sync_vcpu_addr() is a KVM (host) controlled value, i.e. vpid02 can be zero even if operand.vpid is non-zero. No functional change intended. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320212833.3507-14-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-20KVM: VMX: Drop redundant capability checks in low level INVVPID helpersSean Christopherson
Remove the INVVPID capabilities checks from vpid_sync_vcpu_single() and vpid_sync_vcpu_global() now that all callers ensure the INVVPID variant is supported. Note, in some cases the guarantee is provided in concert with hardware_setup(), which enables VPID if and only if at least of invvpid_single() or invvpid_global() is supported. Drop the WARN_ON_ONCE() from vmx_flush_tlb() as vpid_sync_vcpu_single() will trigger a WARN() on INVVPID failure, i.e. if SINGLE_CONTEXT isn't supported. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320212833.3507-13-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-20KVM: VMX: Handle INVVPID fallback logic in vpid_sync_vcpu_addr()Sean Christopherson
Directly invoke vpid_sync_context() to do a global INVVPID when the individual address variant is not supported instead of deferring such behavior to the caller. This allows for additional consolidation of code as the logic is basically identical to the emulation of the individual address variant in handle_invvpid(). No functional change intended. Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320212833.3507-12-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-20KVM: VMX: Move vpid_sync_vcpu_addr() down a few linesSean Christopherson
Move vpid_sync_vcpu_addr() below vpid_sync_context() so that it can be refactored in a future patch to call vpid_sync_context() directly when the "individual address" INVVPID variant isn't supported. No functional change intended. Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320212833.3507-11-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-20KVM: VMX: Use vpid_sync_context() directly when possibleSean Christopherson
Use vpid_sync_context() directly for flows that run if and only if enable_vpid=1, or more specifically, nested VMX flows that are gated by vmx->nested.msrs.secondary_ctls_high.SECONDARY_EXEC_ENABLE_VPID being set, which is allowed if and only if enable_vpid=1. Because these flows call __vmx_flush_tlb() with @invalidate_gpa=false, the if-statement that decides between INVEPT and INVVPID will always go down the INVVPID path, i.e. call vpid_sync_context() because "enable_ept && (invalidate_gpa || !enable_vpid)" always evaluates false. This helps pave the way toward removing @invalidate_gpa and @vpid from __vmx_flush_tlb() and its callers. Opportunstically drop unnecessary brackets in handle_invvpid() around an affected __vmx_flush_tlb()->vpid_sync_context() conversion. No functional change intended. Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320212833.3507-10-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-20KVM: VMX: Skip global INVVPID fallback if vpid==0 in vpid_sync_context()Sean Christopherson
Skip the global INVVPID in the unlikely scenario that vpid==0 and the SINGLE_CONTEXT variant of INVVPID is unsupported. If vpid==0, there's no need to INVVPID as it's impossible to do VM-Enter with VPID enabled and vmcs.VPID==0, i.e. there can't be any TLB entries for the vCPU with vpid==0. The fact that the SINGLE_CONTEXT variant isn't supported is irrelevant. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320212833.3507-9-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-20KVM: x86: Sync SPTEs when injecting page/EPT fault into L1Junaid Shahid
When injecting a page fault or EPT violation/misconfiguration, KVM is not syncing any shadow PTEs associated with the faulting address, including those in previous MMUs that are associated with L1's current EPTP (in a nested EPT scenario), nor is it flushing any hardware TLB entries. All this is done by kvm_mmu_invalidate_gva. Page faults that are either !PRESENT or RSVD are exempt from the flushing, as the CPU is not allowed to cache such translations. Signed-off-by: Junaid Shahid <junaids@google.com> Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320212833.3507-8-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-20KVM: x86: cleanup kvm_inject_emulated_page_faultPaolo Bonzini
To reconstruct the kvm_mmu to be used for page fault injection, we can simply use fault->nested_page_fault. This matches how fault->nested_page_fault is assigned in the first place by FNAME(walk_addr_generic). Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-20KVM: x86: introduce kvm_mmu_invalidate_gvaPaolo Bonzini
Wrap the combination of mmu->invlpg and kvm_x86_ops->tlb_flush_gva into a new function. This function also lets us specify the host PGD to invalidate and also the MMU, both of which will be useful in fixing and simplifying kvm_inject_emulated_page_fault. A nested guest's MMU however has g_context->invlpg == NULL. Instead of setting it to nonpaging_invlpg, make kvm_mmu_invalidate_gva the only entry point to mmu->invlpg and make a NULL invlpg pointer equivalent to nonpaging_invlpg, saving a retpoline. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: x86: Export kvm_propagate_fault() (as kvm_inject_emulated_page_fault)Sean Christopherson
Export the page fault propagation helper so that VMX can use it to correctly emulate TLB invalidation on page faults in an upcoming patch. In the (hopefully) not-too-distant future, SGX virtualization will also want access to the helper for injecting page faults to the correct level (L1 vs. L2) when emulating ENCLS instructions. Rename the function to kvm_inject_emulated_page_fault() to clarify that it is (a) injecting a fault and (b) only for page faults. WARN if it's invoked with an exception other than PF_VECTOR. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320212833.3507-6-sean.j.christopherson@intel.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: nVMX: Invalidate all roots when emulating INVVPID without EPTJunaid Shahid
Free all roots when emulating INVVPID for L1 and EPT is disabled, as outstanding changes to the page tables managed by L1 need to be recognized. Because L1 and L2 share an MMU when EPT is disabled, and because VPID is not tracked by the MMU role, all roots in the current MMU (root_mmu) need to be freed, otherwise a future nested VM-Enter or VM-Exit could do a fast CR3 switch (without a flush/sync) and consume stale SPTEs. Fixes: 5c614b3583e7b ("KVM: nVMX: nested VPID emulation") Signed-off-by: Junaid Shahid <junaids@google.com> [sean: ported to upstream KVM, reworded the comment and changelog] Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320212833.3507-5-sean.j.christopherson@intel.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: nVMX: Invalidate all EPTP contexts when emulating INVEPT for L1Sean Christopherson
Free all L2 (guest_mmu) roots when emulating INVEPT for L1. Outstanding changes to the EPT tables managed by L1 need to be recognized, and relying on KVM to always flush L2's EPTP context on nested VM-Enter is dangerous. Similar to handle_invpcid(), rely on kvm_mmu_free_roots() to do a remote TLB flush if necessary, e.g. if L1 has never entered L2 then there is nothing to be done. Nuking all L2 roots is overkill for the single-context variant, but it's the safe and easy bet. A more precise zap mechanism will be added in the future. Add a TODO to call out that KVM only needs to invalidate affected contexts. Fixes: 14c07ad89f4d ("x86/kvm/mmu: introduce guest_mmu") Reported-by: Jim Mattson <jmattson@google.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320212833.3507-4-sean.j.christopherson@intel.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: nVMX: Validate the EPTP when emulating INVEPT(EXTENT_CONTEXT)Sean Christopherson
Signal VM-Fail for the single-context variant of INVEPT if the specified EPTP is invalid. Per the INEVPT pseudocode in Intel's SDM, it's subject to the standard EPT checks: If VM entry with the "enable EPT" VM execution control set to 1 would fail due to the EPTP value then VMfail(Invalid operand to INVEPT/INVVPID); Fixes: bfd0a56b90005 ("nEPT: Nested INVEPT") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320212833.3507-3-sean.j.christopherson@intel.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: VMX: Flush all EPTP/VPID contexts on remote TLB flushSean Christopherson
Flush all EPTP/VPID contexts if a TLB flush _may_ have been triggered by a remote or deferred TLB flush, i.e. by KVM_REQ_TLB_FLUSH. Remote TLB flushes require all contexts to be invalidated, not just the active contexts, e.g. all mappings in all contexts for a given HVA need to be invalidated on a mmu_notifier invalidation. Similarly, the instigator of the deferred TLB flush may be expecting all contexts to be flushed, e.g. vmx_vcpu_load_vmcs(). Without nested VMX, flushing only the current EPTP/VPID context isn't problematic because KVM uses a constant VPID for each vCPU, and mmu_alloc_direct_roots() all but guarantees KVM will use a single EPTP for L1. In the rare case where a different EPTP is created or reused, KVM (currently) unconditionally flushes the new EPTP context prior to entering the guest. With nested VMX, KVM conditionally uses a different VPID for L2, and unconditionally uses a different EPTP for L2. Because KVM doesn't _intentionally_ guarantee L2's EPTP/VPID context is flushed on nested VM-Enter, it'd be possible for a malicious L1 to attack the host and/or different VMs by exploiting the lack of flushing for L2. 1) Launch nested guest from malicious L1. 2) Nested VM-Enter to L2. 3) Access target GPA 'g'. CPU inserts TLB entry tagged with L2's ASID mapping 'g' to host PFN 'x'. 2) Nested VM-Exit to L1. 3) L1 triggers kernel same-page merging (ksm) by duplicating/zeroing the page for PFN 'x'. 4) Host kernel merges PFN 'x' with PFN 'y', i.e. unmaps PFN 'x' and remaps the page to PFN 'y'. mmu_notifier sends invalidate command, KVM flushes TLB only for L1's ASID. 4) Host kernel reallocates PFN 'x' to some other task/guest. 5) Nested VM-Enter to L2. KVM does not invalidate L2's EPTP or VPID. 6) L2 accesses GPA 'g' and gains read/write access to PFN 'x' via its stale TLB entry. However, current KVM unconditionally flushes L1's EPTP/VPID context on nested VM-Exit. But, that behavior is mostly unintentional, KVM doesn't go out of its way to flush EPTP/VPID on nested VM-Enter/VM-Exit, rather a TLB flush is guaranteed to occur prior to re-entering L1 due to __kvm_mmu_new_cr3() always being called with skip_tlb_flush=false. On nested VM-Enter, this happens via kvm_init_shadow_ept_mmu() (nested EPT enabled) or in nested_vmx_load_cr3() (nested EPT disabled). On nested VM-Exit it occurs via nested_vmx_load_cr3(). This also fixes a bug where a deferred TLB flush in the context of L2, with EPT disabled, would flush L1's VPID instead of L2's VPID, as vmx_flush_tlb() flushes L1's VPID regardless of is_guest_mode(). Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Ben Gardon <bgardon@google.com> Cc: Jim Mattson <jmattson@google.com> Cc: Junaid Shahid <junaids@google.com> Cc: Liran Alon <liran.alon@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: John Haxby <john.haxby@oracle.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Fixes: efebf0aaec3d ("KVM: nVMX: Do not flush TLB on L1<->L2 transitions if L1 uses VPID and EPT") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320212833.3507-2-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15selftests: kvm: Add testcase for creating max number of memslotsWainer dos Santos Moschetta
This patch introduces test_add_max_memory_regions(), which checks that a VM can have added memory slots up to the limit defined in KVM_CAP_NR_MEMSLOTS. Then attempt to add one more slot to verify it fails as expected. Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200410231707.7128-11-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: selftests: Make set_memory_region_test common to all architecturesSean Christopherson
Make set_memory_region_test available on all architectures by wrapping the bits that are x86-specific in ifdefs. A future testcase to create the maximum number of memslots will be architecture agnostic. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200410231707.7128-10-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: selftests: Add "zero" testcase to set_memory_region_testSean Christopherson
Add a testcase for running a guest with no memslots to the memory region test. The expected result on x86_64 is that the guest will trigger an internal KVM error due to the initial code fetch encountering a non-existent memslot and resulting in an emulation failure. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200410231707.7128-9-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15selftests: kvm: Add vm_get_fd() in kvm_utilWainer dos Santos Moschetta
Introduces the vm_get_fd() function in kvm_util which returns the VM file descriptor. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200410231707.7128-8-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: selftests: Add "delete" testcase to set_memory_region_testSean Christopherson
Add a testcase for deleting memslots while the guest is running. Like the "move" testcase, this is x86_64-only as it relies on MMIO happening when a non-existent memslot is encountered. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200410231707.7128-7-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: sefltests: Add explicit synchronization to move mem region testSean Christopherson
Use sem_post() and sem_timedwait() to synchronize test stages between the vCPU thread and the main thread instead of using usleep() to wait for the vCPU thread and hoping for the best. Opportunistically refactor the code to make it suck less in general, and to prepare for adding more testcases. Suggested-by: Peter Xu <peterx@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200410231707.7128-6-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: selftests: Add GUEST_ASSERT variants to pass values to hostSean Christopherson
Add variants of GUEST_ASSERT to pass values back to the host, e.g. to help debug/understand a failure when the the cause of the assert isn't necessarily binary. It'd probably be possible to auto-calculate the number of arguments and just have a single GUEST_ASSERT, but there are a limited number of variants and silently eating arguments could lead to subtle code bugs. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200410231707.7128-5-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: selftests: Add util to delete memory regionSean Christopherson
Add a utility to delete a memory region, it will be used by x86's set_memory_region_test. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Message-Id: <20200410231707.7128-4-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: selftests: Use kernel's list instead of homebrewed replacementSean Christopherson
Replace the KVM selftests' homebrewed linked lists for vCPUs and memory regions with the kernel's 'struct list_head'. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Message-Id: <20200410231707.7128-3-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: selftests: Take vcpu pointer instead of id in vm_vcpu_rm()Sean Christopherson
The sole caller of vm_vcpu_rm() already has the vcpu pointer, take it directly instead of doing an extra lookup. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Message-Id: <20200410231707.7128-2-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: pass through CPUID(0x80000006)Eric Northup
Return the host's L2 cache and TLB information for CPUID.0x80000006 instead of zeroing out the entry as part of KVM_GET_SUPPORTED_CPUID. This allows a userspace VMM to feed KVM_GET_SUPPORTED_CPUID's output directly into KVM_SET_CPUID2 (without breaking the guest). Signed-off-by: Eric Northup (Google) <digitaleric@gmail.com> Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Jon Cargille <jcargill@google.com> Message-Id: <20200415012320.236065-1-jcargill@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: x86: Return updated timer current count register from KVM_GET_LAPICPeter Shier
kvm_vcpu_ioctl_get_lapic (implements KVM_GET_LAPIC ioctl) does a bulk copy of the LAPIC registers but must take into account that the one-shot and periodic timer current count register is computed upon reads and is not present in register state. When restoring LAPIC state (e.g. after migration), restart timers from their their current count values at time of save. Note: When a one-shot timer expires, the code in arch/x86/kvm/lapic.c does not zero the value of the LAPIC initial count register (emulating HW behavior). If no other timer is run and pending prior to a subsequent KVM_GET_LAPIC call, the returned register set will include the expired one-shot initial count. On a subsequent KVM_SET_LAPIC call the code will see a non-zero initial count and start a new one-shot timer using the expired timer's count. This is a prior existing bug and will be addressed in a separate patch. Thanks to jmattson@google.com for this find. Signed-off-by: Peter Shier <pshier@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Wanpeng Li <wanpengli@tencent.com> Message-Id: <20181010225653.238911-1-pshier@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: remove redundant assignment to variable rColin Ian King
The variable r is being assigned with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Message-Id: <20200410113526.13822-1-colin.king@canonical.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: SVM: Fix __svm_vcpu_run declaration.Uros Bizjak
The function returns no value. Cc: Paolo Bonzini <pbonzini@redhat.com> Fixes: 199cd1d7b534 ("KVM: SVM: Split svm_vcpu_run inline assembly to separate file") Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Message-Id: <20200409114926.1407442-1-ubizjak@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: SVM: Do not setup frame pointer in __svm_vcpu_runUros Bizjak
__svm_vcpu_run is a leaf function and does not need a frame pointer. %rbp is also destroyed a few instructions later when guest registers are loaded. Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Message-Id: <20200409120440.1427215-1-ubizjak@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: SVM: Fix build error due to missing release_pages() includeBorislav Petkov
Fix: arch/x86/kvm/svm/sev.c: In function ‘sev_pin_memory’: arch/x86/kvm/svm/sev.c:360:3: error: implicit declaration of function ‘release_pages’;\ did you mean ‘reclaim_pages’? [-Werror=implicit-function-declaration] 360 | release_pages(pages, npinned); | ^~~~~~~~~~~~~ | reclaim_pages because svm.c includes pagemap.h but the carved out sev.c needs it too. Triggered by a randconfig build. Fixes: eaf78265a4ab ("KVM: SVM: Move SEV code to separate file") Signed-off-by: Borislav Petkov <bp@suse.de> Message-Id: <20200411160927.27954-1-bp@alien8.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15KVM: SVM: Do not mark svm_vcpu_run with STACK_FRAME_NON_STANDARDUros Bizjak
svm_vcpu_run does not change stack or frame pointer anymore. Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Message-Id: <20200414113612.104501-1-ubizjak@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15kvm: nVMX: match comment with return type for nested_vmx_exit_reflectedOliver Upton
nested_vmx_exit_reflected() returns a bool, not int. As such, refer to the return values as true/false in the comment instead of 1/0. Signed-off-by: Oliver Upton <oupton@google.com> Message-Id: <20200414221241.134103-1-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-15kvm: nVMX: reflect MTF VM-exits if injected by L1Oliver Upton
According to SDM 26.6.2, it is possible to inject an MTF VM-exit via the VM-entry interruption-information field regardless of the 'monitor trap flag' VM-execution control. KVM appropriately copies the VM-entry interruption-information field from vmcs12 to vmcs02. However, if L1 has not set the 'monitor trap flag' VM-execution control, KVM fails to reflect the subsequent MTF VM-exit into L1. Fix this by consulting the VM-entry interruption-information field of vmcs12 to determine if L1 has injected the MTF VM-exit. If so, reflect the exit, regardless of the 'monitor trap flag' VM-execution control. Fixes: 5f3d45e7f282 ("kvm/x86: add support for MONITOR_TRAP_FLAG") Signed-off-by: Oliver Upton <oupton@google.com> Reviewed-by: Peter Shier <pshier@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <20200414224746.240324-1-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-14KVM: s390: Return last valid slot if approx index is out-of-boundsSean Christopherson
Return the index of the last valid slot from gfn_to_memslot_approx() if its binary search loop yielded an out-of-bounds index. The index can be out-of-bounds if the specified gfn is less than the base of the lowest memslot (which is also the last valid memslot). Note, the sole caller, kvm_s390_get_cmma(), ensures used_slots is non-zero. Fixes: afdad61615cc3 ("KVM: s390: Fix storage attributes migration with memory slots") Cc: stable@vger.kernel.org # 4.19.x: 0774a964ef56: KVM: Fix out of range accesses to memslots Cc: stable@vger.kernel.org # 4.19.x Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200408064059.8957-3-sean.j.christopherson@intel.com> Reviewed-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 Christopherson
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>
2020-04-14KVM: VMX: Enable machine check support for 32bit targetsUros Bizjak
There is no reason to limit the use of do_machine_check to 64bit targets. MCE handling works for both target familes. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: stable@vger.kernel.org Fixes: a0861c02a981 ("KVM: Add VT-x machine check support") Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Message-Id: <20200414071414.45636-1-ubizjak@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-14KVM: SVM: move more vmentry code to assemblyPaolo Bonzini
Manipulate IF around vmload/vmsave to remove the confusing usage of local_irq_enable where interrupts are actually disabled via GIF. And stuff the RSB immediately without waiting for a RET to avoid Spectre-v2 attacks. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-14KVM: SVM: fix compilation with modular PSP and non-modular KVMPaolo Bonzini
Use svm_sev_enabled() in order to cull all calls to PSP code. Otherwise, compilation fails with undefined symbols if the PSP device driver is compiled as a module and KVM is not. Reported-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-07KVM: VMX: fix crash cleanup when KVM wasn't usedVitaly Kuznetsov
If KVM wasn't used at all before we crash the cleanup procedure fails with BUG: unable to handle page fault for address: ffffffffffffffc8 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 23215067 P4D 23215067 PUD 23217067 PMD 0 Oops: 0000 [#8] SMP PTI CPU: 0 PID: 3542 Comm: bash Kdump: loaded Tainted: G D 5.6.0-rc2+ #823 RIP: 0010:crash_vmclear_local_loaded_vmcss.cold+0x19/0x51 [kvm_intel] The root cause is that loaded_vmcss_on_cpu list is not yet initialized, we initialize it in hardware_enable() but this only happens when we start a VM. Previously, we used to have a bitmap with enabled CPUs and that was preventing [masking] the issue. Initialized loaded_vmcss_on_cpu list earlier, right before we assign crash_vmclear_loaded_vmcss pointer. blocked_vcpu_on_cpu list and blocked_vcpu_on_cpu_lock are moved altogether for consistency. Fixes: 31603d4fc2bb ("KVM: VMX: Always VMCLEAR in-use VMCSes during crash with kexec support") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200401081348.1345307-1-vkuznets@redhat.com> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-07KVM: X86: Filter out the broadcast dest for IPI fastpathWanpeng Li
Except destination shorthand, a destination value 0xffffffff is used to broadcast interrupts, let's also filter out this for single target IPI fastpath. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Message-Id: <1585815626-28370-1-git-send-email-wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-07Merge tag 'kvm-s390-master-5.7-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Fixes for vsie (nested hypervisors) - Several fixes for corner cases of nesting. Still relevant as it might crash host or first level guest or temporarily leak memory.
2020-04-07KVM: s390: vsie: Fix possible race when shadowing region 3 tablesDavid Hildenbrand
We have to properly retry again by returning -EINVAL immediately in case somebody else instantiated the table concurrently. We missed to add the goto in this function only. The code now matches the other, similar shadowing functions. We are overwriting an existing region 2 table entry. All allocated pages are added to the crst_list to be freed later, so they are not lost forever. However, when unshadowing the region 2 table, we wouldn't trigger unshadowing of the original shadowed region 3 table that we replaced. It would get unshadowed when the original region 3 table is modified. As it's not connected to the page table hierarchy anymore, it's not going to get used anymore. However, for a limited time, this page table will stick around, so it's in some sense a temporary memory leak. Identified by manual code inspection. I don't think this classifies as stable material. Fixes: 998f637cc4b9 ("s390/mm: avoid races on region/segment/page table shadowing") Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200403153050.20569-4-david@redhat.com Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-04-07KVM: s390: vsie: Fix delivery of addressing exceptionsDavid Hildenbrand
Whenever we get an -EFAULT, we failed to read in guest 2 physical address space. Such addressing exceptions are reported via a program intercept to the nested hypervisor. We faked the intercept, we have to return to guest 2. Instead, right now we would be returning -EFAULT from the intercept handler, eventually crashing the VM. the correct thing to do is to return 1 as rc == 1 is the internal representation of "we have to go back into g2". Addressing exceptions can only happen if the g2->g3 page tables reference invalid g2 addresses (say, either a table or the final page is not accessible - so something that basically never happens in sane environments. Identified by manual code inspection. Fixes: a3508fbe9dc6 ("KVM: s390: vsie: initial support for nested virtualization") Cc: <stable@vger.kernel.org> # v4.8+ Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200403153050.20569-3-david@redhat.com Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [borntraeger@de.ibm.com: fix patch description] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-04-07KVM: s390: vsie: Fix region 1 ASCE sanity shadow address checksDavid Hildenbrand
In case we have a region 1 the following calculation (31 + ((gmap->asce & _ASCE_TYPE_MASK) >> 2)*11) results in 64. As shifts beyond the size are undefined the compiler is free to use instructions like sllg. sllg will only use 6 bits of the shift value (here 64) resulting in no shift at all. That means that ALL addresses will be rejected. The can result in endless loops, e.g. when prefix cannot get mapped. Fixes: 4be130a08420 ("s390/mm: add shadow gmap support") Tested-by: Janosch Frank <frankja@linux.ibm.com> Reported-by: Janosch Frank <frankja@linux.ibm.com> Cc: <stable@vger.kernel.org> # v4.8+ Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200403153050.20569-2-david@redhat.com Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [borntraeger@de.ibm.com: fix patch description, remove WARN_ON_ONCE] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-04-07KVM: nVMX: don't clear mtf_pending when nested events are blockedOliver Upton
If nested events are blocked, don't clear the mtf_pending flag to avoid missing later delivery of the MTF VM-exit. Fixes: 5ef8acbdd687c ("KVM: nVMX: Emulate MTF when performing instruction emulation") Signed-off-by: Oliver Upton <oupton@google.com> Message-Id: <20200406201237.178725-1-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-07KVM: VMX: Remove unnecessary exception trampoline in vmx_vmenterUros Bizjak
The exception trampoline in .fixup section is not needed, the exception handling code can jump directly to the label in the .text section. Changes since v1: - Fix commit message. Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Message-Id: <20200406202108.74300-1-ubizjak@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-03KVM: SVM: Split svm_vcpu_run inline assembly to separate fileUros Bizjak
The compiler (GCC) does not like the situation, where there is inline assembly block that clobbers all available machine registers in the middle of the function. This situation can be found in function svm_vcpu_run in file kvm/svm.c and results in many register spills and fills to/from stack frame. This patch fixes the issue with the same approach as was done for VMX some time ago. The big inline assembly is moved to a separate assembly .S file, taking into account all ABI requirements. There are two main benefits of the above approach: * elimination of several register spills and fills to/from stack frame, and consequently smaller function .text size. The binary size of svm_vcpu_run is lowered from 2019 to 1626 bytes. * more efficient access to a register save array. Currently, register save array is accessed as: 7b00: 48 8b 98 28 02 00 00 mov 0x228(%rax),%rbx 7b07: 48 8b 88 18 02 00 00 mov 0x218(%rax),%rcx 7b0e: 48 8b 90 20 02 00 00 mov 0x220(%rax),%rdx and passing ia pointer to a register array as an argument to a function one gets: 12: 48 8b 48 08 mov 0x8(%rax),%rcx 16: 48 8b 50 10 mov 0x10(%rax),%rdx 1a: 48 8b 58 18 mov 0x18(%rax),%rbx As a result, the total size, considering that the new function size is 229 bytes, gets lowered by 164 bytes. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-03KVM: SVM: Move SEV code to separate fileJoerg Roedel
Move the SEV specific parts of svm.c into the new sev.c file. Signed-off-by: Joerg Roedel <jroedel@suse.de> Message-Id: <20200324094154.32352-5-joro@8bytes.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>