summaryrefslogtreecommitdiff
AgeCommit message (Collapse)Author
2022-06-08KVM: x86: Allow userspace to set maximum VCPU id for VMZeng Guang
Introduce new max_vcpu_ids in KVM for x86 architecture. Userspace can assign maximum possible vcpu id for current VM session using KVM_CAP_MAX_VCPU_ID of KVM_ENABLE_CAP ioctl(). This is done for x86 only because the sole use case is to guide memory allocation for PID-pointer table, a structure needed to enable VMX IPI. By default, max_vcpu_ids set as KVM_MAX_VCPU_IDS. Suggested-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com> Message-Id: <20220419154444.11888-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: Move kvm_arch_vcpu_precreate() under kvm->lockZeng Guang
kvm_arch_vcpu_precreate() targets to handle arch specific VM resource to be prepared prior to the actual creation of vCPU. For example, x86 platform may need do per-VM allocation based on max_vcpu_ids at the first vCPU creation. It probably leads to concurrency control on this allocation as multiple vCPU creation could happen simultaneously. From the architectual point of view, it's necessary to execute kvm_arch_vcpu_precreate() under protect of kvm->lock. Currently only arm64, x86 and s390 have non-nop implementations at the stage of vCPU pre-creation. Remove the lock acquiring in s390's design and make sure all architecture can run kvm_arch_vcpu_precreate() safely under kvm->lock without recrusive lock issue. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com> Message-Id: <20220419154409.11842-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: VMX: Clean up vmx_refresh_apicv_exec_ctrl()Zeng Guang
Remove the condition check cpu_has_secondary_exec_ctrls(). Calling vmx_refresh_apicv_exec_ctrl() premises secondary controls activated and VMCS fields related to APICv valid as well. If it's invoked in wrong circumstance at the worst case, VMX operation will report VMfailValid error without further harmful impact and just functions as if all the secondary controls were 0. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com> Message-Id: <20220419153604.11786-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: x86: Add support for vICR APIC-write VM-Exits in x2APIC modeZeng Guang
Upcoming Intel CPUs will support virtual x2APIC MSR writes to the vICR, i.e. will trap and generate an APIC-write VM-Exit instead of intercepting the WRMSR. Add support for handling "nodecode" x2APIC writes, which were previously impossible. Note, x2APIC MSR writes are 64 bits wide. Signed-off-by: Zeng Guang <guang.zeng@intel.com> Message-Id: <20220419153516.11739-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: VMX: Report tertiary_exec_control field in dump_vmcs()Robert Hoo
Add tertiary_exec_control field report in dump_vmcs(). Meanwhile, reorganize the dump output of VMCS category as follows. Before change: *** Control State *** PinBased=0x000000ff CPUBased=0xb5a26dfa SecondaryExec=0x061037eb EntryControls=0000d1ff ExitControls=002befff After change: *** Control State *** CPUBased=0xb5a26dfa SecondaryExec=0x061037eb TertiaryExec=0x0000000000000010 PinBased=0x000000ff EntryControls=0000d1ff ExitControls=002befff Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com> Message-Id: <20220419153441.11687-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: VMX: Detect Tertiary VM-Execution control when setup VMCS configRobert Hoo
Check VMX features on tertiary execution control in VMCS config setup. Sub-features in tertiary execution control to be enabled are adjusted according to hardware capabilities although no sub-feature is enabled in this patch. EVMCSv1 doesn't support tertiary VM-execution control, so disable it when EVMCSv1 is in use. And define the auxiliary functions for Tertiary control field here, using the new BUILD_CONTROLS_SHADOW(). Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com> Message-Id: <20220419153400.11642-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: VMX: Extend BUILD_CONTROLS_SHADOW macro to support 64-bit variationRobert Hoo
The Tertiary VM-Exec Control, different from previous control fields, is 64 bit. So extend BUILD_CONTROLS_SHADOW() by adding a 'bit' parameter, to support both 32 bit and 64 bit fields' auxiliary functions building. Suggested-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com> Message-Id: <20220419153318.11595-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08x86/cpu: Add new VMX feature, Tertiary VM-Execution controlRobert Hoo
A new 64-bit control field "tertiary processor-based VM-execution controls", is defined [1]. It's controlled by bit 17 of the primary processor-based VM-execution controls. Different from its brother VM-execution fields, this tertiary VM- execution controls field is 64 bit. So it occupies 2 vmx_feature_leafs, TERTIARY_CTLS_LOW and TERTIARY_CTLS_HIGH. Its companion VMX capability reporting MSR,MSR_IA32_VMX_PROCBASED_CTLS3 (0x492), is also semantically different from its brothers, whose 64 bits consist of all allow-1, rather than 32-bit allow-0 and 32-bit allow-1 [1][2]. Therefore, its init_vmx_capabilities() is a little different from others. [1] ISE 6.2 "VMCS Changes" https://www.intel.com/content/www/us/en/develop/download/intel-architecture-instruction-set-extensions-programming-reference.html [2] SDM Vol3. Appendix A.3 Reviewed-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com> Message-Id: <20220419153240.11549-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: x86/mmu: Comment FNAME(sync_page) to document TLB flushing logicSean Christopherson
Add a comment to FNAME(sync_page) to explain why the TLB flushing logic conspiculously doesn't handle the scenario of guest protections being reduced. Specifically, if synchronizing a SPTE drops execute protections, KVM will not emit a TLB flush, whereas dropping writable or clearing A/D bits does trigger a flush via mmu_spte_update(). Architecturally, until the GPTE is implicitly or explicitly flushed from the guest's perspective, KVM is not required to flush any old, stale translations. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <20220513195000.99371-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: x86/mmu: Drop RWX=0 SPTEs during ept_sync_page()Sean Christopherson
All of sync_page()'s existing checks filter out only !PRESENT gPTE, because without execute-only, all upper levels are guaranteed to be at least READABLE. However, if EPT with execute-only support is in use by L1, KVM can create an SPTE that is shadow-present but guest-inaccessible (RWX=0) if the upper level combined permissions are R (or RW) and the leaf EPTE is changed from R (or RW) to X. Because the EPTE is considered present when viewed in isolation, and no reserved bits are set, FNAME(prefetch_invalid_gpte) will consider the GPTE valid, and cause a not-present SPTE to be created. The SPTE is "correct": the guest translation is inaccessible because the combined protections of all levels yield RWX=0, and KVM will just redirect any vmexits to the guest. If EPT A/D bits are disabled, KVM can mistake the SPTE for an access-tracked SPTE, but again such confusion isn't fatal, as the "saved" protections are also RWX=0. However, creating a useless SPTE in general means that KVM messed up something, even if this particular goof didn't manifest as a functional bug. So, drop SPTEs whose new protections will yield a RWX=0 SPTE, and add a WARN in make_spte() to detect creation of SPTEs that will result in RWX=0 protections. Fixes: d95c55687e11 ("kvm: mmu: track read permission explicitly for shadow EPT page tables") Cc: David Matlack <dmatlack@google.com> Cc: Ben Gardon <bgardon@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220513195000.99371-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: selftests: nSVM: Add svm_nested_soft_inject_testMaciej S. Szmigiero
Add a KVM self-test that checks whether a nSVM L1 is able to successfully inject a software interrupt, a soft exception and a NMI into its L2 guest. In practice, this tests both the next_rip field consistency and L1-injected event with intervening L0 VMEXIT during its delivery: the first nested VMRUN (that's also trying to inject a software interrupt) will immediately trigger a L0 NPF. This L0 NPF will have zero in its CPU-returned next_rip field, which if incorrectly reused by KVM will trigger a #PF when trying to return to such address 0 from the interrupt handler. For NMI injection this tests whether the L1 NMI state isn't getting incorrectly mixed with the L2 NMI state if a L1 -> L2 NMI needs to be re-injected. Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> [sean: check exact L2 RIP on first soft interrupt] Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <d5f3d56528558ad8e28a9f1e1e4187f5a1e6770a.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: nSVM: Transparently handle L1 -> L2 NMI re-injectionMaciej S. Szmigiero
A NMI that L1 wants to inject into its L2 should be directly re-injected, without causing L0 side effects like engaging NMI blocking for L1. It's also worth noting that in this case it is L1 responsibility to track the NMI window status for its L2 guest. Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <f894d13501cd48157b3069a4b4c7369575ddb60e.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: x86: Differentiate Soft vs. Hard IRQs vs. reinjected in tracepointSean Christopherson
In the IRQ injection tracepoint, differentiate between Hard IRQs and Soft "IRQs", i.e. interrupts that are reinjected after incomplete delivery of a software interrupt from an INTn instruction. Tag reinjected interrupts as such, even though the information is usually redundant since soft interrupts are only ever reinjected by KVM. Though rare in practice, a hard IRQ can be reinjected. Signed-off-by: Sean Christopherson <seanjc@google.com> [MSS: change "kvm_inj_virq" event "reinjected" field type to bool] Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <9664d49b3bd21e227caa501cff77b0569bebffe2.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: x86: Print error code in exception injection tracepoint iff validSean Christopherson
Print the error code in the exception injection tracepoint if and only if the exception has an error code. Define the entire error code sequence as a set of formatted strings, print empty strings if there's no error code, and abuse __print_symbolic() by passing it an empty array to coerce it into printing the error code as a hex string. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <e8f0511733ed2a0410cbee8a0a7388eac2ee5bac.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: x86: Trace re-injected exceptionsSean Christopherson
Trace exceptions that are re-injected, not just those that KVM is injecting for the first time. Debugging re-injection bugs is painful enough as is, not having visibility into what KVM is doing only makes things worse. Delay propagating pending=>injected in the non-reinjection path so that the tracing can properly identify reinjected exceptions. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <25470690a38b4d2b32b6204875dd35676c65c9f2.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: SVM: Re-inject INTn instead of retrying the insn on "failure"Sean Christopherson
Re-inject INTn software interrupts instead of retrying the instruction if the CPU encountered an intercepted exception while vectoring the INTn, e.g. if KVM intercepted a #PF when utilizing shadow paging. Retrying the instruction is architecturally wrong e.g. will result in a spurious #DB if there's a code breakpoint on the INT3/O, and lack of re-injection also breaks nested virtualization, e.g. if L1 injects a software interrupt and vectoring the injected interrupt encounters an exception that is intercepted by L0 but not L1. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <1654ad502f860948e4f2d57b8bd881d67301f785.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: SVM: Re-inject INT3/INTO instead of retrying the instructionSean Christopherson
Re-inject INT3/INTO instead of retrying the instruction if the CPU encountered an intercepted exception while vectoring the software exception, e.g. if vectoring INT3 encounters a #PF and KVM is using shadow paging. Retrying the instruction is architecturally wrong, e.g. will result in a spurious #DB if there's a code breakpoint on the INT3/O, and lack of re-injection also breaks nested virtualization, e.g. if L1 injects a software exception and vectoring the injected exception encounters an exception that is intercepted by L0 but not L1. Due to, ahem, deficiencies in the SVM architecture, acquiring the next RIP may require flowing through the emulator even if NRIPS is supported, as the CPU clears next_rip if the VM-Exit is due to an exception other than "exceptions caused by the INT3, INTO, and BOUND instructions". To deal with this, "skip" the instruction to calculate next_rip (if it's not already known), and then unwind the RIP write and any side effects (RFLAGS updates). Save the computed next_rip and use it to re-stuff next_rip if injection doesn't complete. This allows KVM to do the right thing if next_rip was known prior to injection, e.g. if L1 injects a soft event into L2, and there is no backing INTn instruction, e.g. if L1 is injecting an arbitrary event. Note, it's impossible to guarantee architectural correctness given SVM's architectural flaws. E.g. if the guest executes INTn (no KVM injection), an exit occurs while vectoring the INTn, and the guest modifies the code stream while the exit is being handled, KVM will compute the incorrect next_rip due to "skipping" the wrong instruction. A future enhancement to make this less awful would be for KVM to detect that the decoded instruction is not the correct INTn and drop the to-be-injected soft event (retrying is a lesser evil compared to shoving the wrong RIP on the exception stack). Reported-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <65cb88deab40bc1649d509194864312a89bbe02e.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: SVM: Stuff next_rip on emulated INT3 injection if NRIPS is supportedSean Christopherson
If NRIPS is supported in hardware but disabled in KVM, set next_rip to the next RIP when advancing RIP as part of emulating INT3 injection. There is no flag to tell the CPU that KVM isn't using next_rip, and so leaving next_rip is left as is will result in the CPU pushing garbage onto the stack when vectoring the injected event. Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Fixes: 66b7138f9136 ("KVM: SVM: Emulate nRIP feature when reinjecting INT3") Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <cd328309a3b88604daa2359ad56f36cb565ce2d4.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: SVM: Unwind "speculative" RIP advancement if INTn injection "fails"Sean Christopherson
Unwind the RIP advancement done by svm_queue_exception() when injecting an INT3 ultimately "fails" due to the CPU encountering a VM-Exit while vectoring the injected event, even if the exception reported by the CPU isn't the same event that was injected. If vectoring INT3 encounters an exception, e.g. #NP, and vectoring the #NP encounters an intercepted exception, e.g. #PF when KVM is using shadow paging, then the #NP will be reported as the event that was in-progress. Note, this is still imperfect, as it will get a false positive if the INT3 is cleanly injected, no VM-Exit occurs before the IRET from the INT3 handler in the guest, the instruction following the INT3 generates an exception (directly or indirectly), _and_ vectoring that exception encounters an exception that is intercepted by KVM. The false positives could theoretically be solved by further analyzing the vectoring event, e.g. by comparing the error code against the expected error code were an exception to occur when vectoring the original injected exception, but SVM without NRIPS is a complete disaster, trying to make it 100% correct is a waste of time. Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Fixes: 66b7138f9136 ("KVM: SVM: Emulate nRIP feature when reinjecting INT3") Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <450133cf0a026cb9825a2ff55d02cb136a1cb111.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: SVM: Don't BUG if userspace injects an interrupt with GIF=0Maciej S. Szmigiero
Don't BUG/WARN on interrupt injection due to GIF being cleared, since it's trivial for userspace to force the situation via KVM_SET_VCPU_EVENTS (even if having at least a WARN there would be correct for KVM internally generated injections). kernel BUG at arch/x86/kvm/svm/svm.c:3386! invalid opcode: 0000 [#1] SMP CPU: 15 PID: 926 Comm: smm_test Not tainted 5.17.0-rc3+ #264 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:svm_inject_irq+0xab/0xb0 [kvm_amd] Code: <0f> 0b 0f 1f 00 0f 1f 44 00 00 80 3d ac b3 01 00 00 55 48 89 f5 53 RSP: 0018:ffffc90000b37d88 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88810a234ac0 RCX: 0000000000000006 RDX: 0000000000000000 RSI: ffffc90000b37df7 RDI: ffff88810a234ac0 RBP: ffffc90000b37df7 R08: ffff88810a1fa410 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888109571000 R14: ffff88810a234ac0 R15: 0000000000000000 FS: 0000000001821380(0000) GS:ffff88846fdc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f74fc550008 CR3: 000000010a6fe000 CR4: 0000000000350ea0 Call Trace: <TASK> inject_pending_event+0x2f7/0x4c0 [kvm] kvm_arch_vcpu_ioctl_run+0x791/0x17a0 [kvm] kvm_vcpu_ioctl+0x26d/0x650 [kvm] __x64_sys_ioctl+0x82/0xb0 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae </TASK> Fixes: 219b65dcf6c0 ("KVM: SVM: Improve nested interrupt injection") Cc: stable@vger.kernel.org Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <35426af6e123cbe91ec7ce5132ce72521f02b1b5.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: nSVM: Sync next_rip field from vmcb12 to vmcb02Maciej S. Szmigiero
The next_rip field of a VMCB is *not* an output-only field for a VMRUN. This field value (instead of the saved guest RIP) in used by the CPU for the return address pushed on stack when injecting a software interrupt or INT3 or INTO exception. Make sure this field gets synced from vmcb12 to vmcb02 when entering L2 or loading a nested state and NRIPS is exposed to L1. If NRIPS is supported in hardware but not exposed to L1 (nrips=0 or hidden by userspace), stuff vmcb02's next_rip from the new L2 RIP to emulate a !NRIPS CPU (which saves RIP on the stack as-is). Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <c2e0a3d78db3ae30530f11d4e9254b452a89f42b.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: x86: do not report a vCPU as preempted outside instruction boundariesPaolo Bonzini
If a vCPU is outside guest mode and is scheduled out, it might be in the process of making a memory access. A problem occurs if another vCPU uses the PV TLB flush feature during the period when the vCPU is scheduled out, and a virtual address has already been translated but has not yet been accessed, because this is equivalent to using a stale TLB entry. To avoid this, only report a vCPU as preempted if sure that the guest is at an instruction boundary. A rescheduling request will be delivered to the host physical CPU as an external interrupt, so for simplicity consider any vmexit *not* instruction boundary except for external interrupts. It would in principle be okay to report the vCPU as preempted also if it is sleeping in kvm_vcpu_block(): a TLB flush IPI will incur the vmentry/vmexit overhead unnecessarily, and optimistic spinning is also unlikely to succeed. However, leave it for later because right now kvm_vcpu_check_block() is doing memory accesses. Even though the TLB flush issue only applies to virtual memory address, it's very much preferrable to be conservative. Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08KVM: x86: do not set st->preempted when going back to user spacePaolo Bonzini
Similar to the Xen path, only change the vCPU's reported state if the vCPU was actually preempted. The reason for KVM's behavior is that for example optimistic spinning might not be a good idea if the guest is doing repeated exits to userspace; however, it is confusing and unlikely to make a difference, because well-tuned guests will hardly ever exit KVM_RUN in the first place. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-07Merge tag 'kvm-s390-next-5.19-2' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: pvdump and selftest improvements - add an interface to provide a hypervisor dump for secure guests - improve selftests to show tests
2022-06-07Merge branch 'kvm-5.20-early-patches' into HEADPaolo Bonzini
2022-06-07Merge branch 'kvm-5.19-early-fixes' into HEADPaolo Bonzini
2022-06-07KVM: SVM: fix tsc scaling cache logicMaxim Levitsky
SVM uses a per-cpu variable to cache the current value of the tsc scaling multiplier msr on each cpu. Commit 1ab9287add5e2 ("KVM: X86: Add vendor callbacks for writing the TSC multiplier") broke this caching logic. Refactor the code so that all TSC scaling multiplier writes go through a single function which checks and updates the cache. This fixes the following scenario: 1. A CPU runs a guest with some tsc scaling ratio. 2. New guest with different tsc scaling ratio starts on this CPU and terminates almost immediately. This ensures that the short running guest had set the tsc scaling ratio just once when it was set via KVM_SET_TSC_KHZ. Due to the bug, the per-cpu cache is not updated. 3. The original guest continues to run, it doesn't restore the msr value back to its own value, because the cache matches, and thus continues to run with a wrong tsc scaling ratio. Fixes: 1ab9287add5e2 ("KVM: X86: Add vendor callbacks for writing the TSC multiplier") Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20220606181149.103072-1-mlevitsk@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-07KVM: selftests: Make hyperv_clock selftest more stableVitaly Kuznetsov
hyperv_clock doesn't always give a stable test result, especially with AMD CPUs. The test compares Hyper-V MSR clocksource (acquired either with rdmsr() from within the guest or KVM_GET_MSRS from the host) against rdtsc(). To increase the accuracy, increase the measured delay (done with nop loop) by two orders of magnitude and take the mean rdtsc() value before and after rdmsr()/KVM_GET_MSRS. Reported-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Tested-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20220601144322.1968742-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-07KVM: x86/MMU: Zap non-leaf SPTEs when disabling dirty loggingBen Gardon
Currently disabling dirty logging with the TDP MMU is extremely slow. On a 96 vCPU / 96G VM backed with gigabyte pages, it takes ~200 seconds to disable dirty logging with the TDP MMU, as opposed to ~4 seconds with the shadow MMU. When disabling dirty logging, zap non-leaf parent entries to allow replacement with huge pages instead of recursing and zapping all of the child, leaf entries. This reduces the number of TLB flushes required. and reduces the disable dirty log time with the TDP MMU to ~3 seconds. Opportunistically add a WARN() to catch GFNs that are mapped at a higher level than their max level. Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20220525230904.1584480-1-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-07x86: drop bogus "cc" clobber from __try_cmpxchg_user_asm()Jan Beulich
As noted (and fixed) a couple of times in the past, "=@cc<cond>" outputs and clobbering of "cc" don't work well together. The compiler appears to mean to reject such, but doesn't - in its upstream form - quite manage to yet for "cc". Furthermore two similar macros don't clobber "cc", and clobbering "cc" is pointless in asm()-s for x86 anyway - the compiler always assumes status flags to be clobbered there. Fixes: 989b5db215a2 ("x86/uaccess: Implement macros for CMPXCHG on user addresses") Signed-off-by: Jan Beulich <jbeulich@suse.com> Message-Id: <485c0c0b-a3a7-0b7c-5264-7d00c01de032@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-07KVM: x86/mmu: Check every prev_roots in __kvm_mmu_free_obsolete_roots()Shaoqin Huang
When freeing obsolete previous roots, check prev_roots as intended, not the current root. Signed-off-by: Shaoqin Huang <shaoqin.huang@intel.com> Fixes: 527d5cd7eece ("KVM: x86/mmu: Zap only obsolete roots if a root shadow page is zapped") Message-Id: <20220607005905.2933378-1-shaoqin.huang@intel.com> Cc: stable@vger.kernel.org Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-07KVM: arm64: Don't read a HW interrupt pending state in user contextMarc Zyngier
Since 5bfa685e62e9 ("KVM: arm64: vgic: Read HW interrupt pending state from the HW"), we're able to source the pending bit for an interrupt that is stored either on the physical distributor or on a device. However, this state is only available when the vcpu is loaded, and is not intended to be accessed from userspace. Unfortunately, the GICv2 emulation doesn't provide specific userspace accessors, and we fallback with the ones that are intended for the guest, with fatal consequences. Add a new vgic_uaccess_read_pending() accessor for userspace to use, build on top of the existing vgic_mmio_read_pending(). Reported-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Fixes: 5bfa685e62e9 ("KVM: arm64: vgic: Read HW interrupt pending state from the HW") Link: https://lore.kernel.org/r/20220607131427.1164881-2-maz@kernel.org Cc: stable@vger.kernel.org
2022-06-07entry/kvm: Exit to user mode when TIF_NOTIFY_SIGNAL is setSeth Forshee
A livepatch transition may stall indefinitely when a kvm vCPU is heavily loaded. To the host, the vCPU task is a user thread which is spending a very long time in the ioctl(KVM_RUN) syscall. During livepatch transition, set_notify_signal() will be called on such tasks to interrupt the syscall so that the task can be transitioned. This interrupts guest execution, but when xfer_to_guest_mode_work() sees that TIF_NOTIFY_SIGNAL is set but not TIF_SIGPENDING it concludes that an exit to user mode is unnecessary, and guest execution is resumed without transitioning the task for the livepatch. This handling of TIF_NOTIFY_SIGNAL is incorrect, as set_notify_signal() is expected to break tasks out of interruptible kernel loops and cause them to return to userspace. Change xfer_to_guest_mode_work() to handle TIF_NOTIFY_SIGNAL the same as TIF_SIGPENDING, signaling to the vCPU run loop that an exit to userpsace is needed. Any pending task_work will be run when get_signal() is called from exit_to_user_mode_loop(), so there is no longer any need to run task work from xfer_to_guest_mode_work(). Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Petr Mladek <pmladek@suse.com> Signed-off-by: Seth Forshee <sforshee@digitalocean.com> Message-Id: <20220504180840.2907296-1-sforshee@digitalocean.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-07KVM: Don't null dereference ops->destroyAlexey Kardashevskiy
A KVM device cleanup happens in either of two callbacks: 1) destroy() which is called when the VM is being destroyed; 2) release() which is called when a device fd is closed. Most KVM devices use 1) but Book3s's interrupt controller KVM devices (XICS, XIVE, XIVE-native) use 2) as they need to close and reopen during the machine execution. The error handling in kvm_ioctl_create_device() assumes destroy() is always defined which leads to NULL dereference as discovered by Syzkaller. This adds a checks for destroy!=NULL and adds a missing release(). This is not changing kvm_destroy_devices() as devices with defined release() should have been removed from the KVM devices list by then. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-07KVM: arm64: Fix inconsistent indentingsunliming
Fix the following smatch warnings: arch/arm64/kvm/vmid.c:62 flush_context() warn: inconsistent indenting Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: sunliming <sunliming@kylinos.cn> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220602024805.511457-1-sunliming@kylinos.cn
2022-06-07KVM: arm64: Always start with clearing SME flag on loadMarc Zyngier
On each vcpu load, we set the KVM_ARM64_HOST_SME_ENABLED flag if SME is enabled for EL0 on the host. This is used to restore the correct state on vpcu put. However, it appears that nothing ever clears this flag. Once set, it will stick until the vcpu is destroyed, which has the potential to spuriously enable SME for userspace. As it turns out, this is due to the SME code being more or less copied from SVE, and inheriting the same shortcomings. We never saw the issue because nothing uses SME, and the amount of testing is probably still pretty low. Fixes: 861262ab8627 ("KVM: arm64: Handle SME host state when running guests") Signed-off-by: Marc Zyngier <maz@kernel.org> Reviwed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20220528113829.1043361-3-maz@kernel.org
2022-06-07KVM: arm64: Always start with clearing SVE flag on loadMarc Zyngier
On each vcpu load, we set the KVM_ARM64_HOST_SVE_ENABLED flag if SVE is enabled for EL0 on the host. This is used to restore the correct state on vpcu put. However, it appears that nothing ever clears this flag. Once set, it will stick until the vcpu is destroyed, which has the potential to spuriously enable SVE for userspace. We probably never saw the issue because no VMM uses SVE, but that's still pretty bad. Unconditionally clearing the flag on vcpu load addresses the issue. Fixes: 8383741ab2e7 ("KVM: arm64: Get rid of host SVE tracking/saving") Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Reviewed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20220528113829.1043361-2-maz@kernel.org
2022-06-05Linux 5.19-rc1v5.19-rc1Linus Torvalds
2022-06-05Merge tag 'pull-work.fd-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull file descriptor fix from Al Viro: "Fix for breakage in #work.fd this window" * tag 'pull-work.fd-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fix the breakage in close_fd_get_file() calling conventions change
2022-06-05Merge tag 'mm-hotfixes-stable-2022-06-05' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm hotfixes from Andrew Morton: "Fixups for various recently-added and longer-term issues and a few minor tweaks: - fixes for material merged during this merge window - cc:stable fixes for more longstanding issues - minor mailmap and MAINTAINERS updates" * tag 'mm-hotfixes-stable-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/oom_kill.c: fix vm_oom_kill_table[] ifdeffery x86/kexec: fix memory leak of elf header buffer mm/memremap: fix missing call to untrack_pfn() in pagemap_range() mm: page_isolation: use compound_nr() correctly in isolate_single_pageblock() mm: hugetlb_vmemmap: fix CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON MAINTAINERS: add maintainer information for z3fold mailmap: update Josh Poimboeuf's email
2022-06-05Merge tag 'mm-nonmm-stable-2022-06-05' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull delay-accounting update from Andrew Morton: "A single featurette for delay accounting. Delayed a bit because, unusually, it had dependencies on both the mm-stable and mm-nonmm-stable queues" * tag 'mm-nonmm-stable-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: delayacct: track delays from write-protect copy
2022-06-05bluetooth: don't use bitmaps for random flag accessesLinus Torvalds
The bluetooth code uses our bitmap infrastructure for the two bits (!) of connection setup flags, and in the process causes odd problems when it converts between a bitmap and just the regular values of said bits. It's completely pointless to do things like bitmap_to_arr32() to convert a bitmap into a u32. It shoudln't have been a bitmap in the first place. The reason to use bitmaps is if you have arbitrary number of bits you want to manage (not two!), or if you rely on the atomicity guarantees of the bitmap setting and clearing. The code could use an "atomic_t" and use "atomic_or/andnot()" to set and clear the bit values, but considering that it then copies the bitmaps around with "bitmap_to_arr32()" and friends, there clearly cannot be a lot of atomicity requirements. So just use a regular integer. In the process, this avoids the warnings about erroneous use of bitmap_from_u64() which were triggered on 32-bit architectures when conversion from a u64 would access two words (and, surprise, surprise, only one word is needed - and indeed overkill - for a 2-bit bitmap). That was always problematic, but the compiler seems to notice it and warn about the invalid pattern only after commit 0a97953fd221 ("lib: add bitmap_{from,to}_arr64") changed the exact implementation details of 'bitmap_from_u64()', as reported by Sudip Mukherjee and Stephen Rothwell. Fixes: fe92ee6425a2 ("Bluetooth: hci_core: Rework hci_conn_params flags") Link: https://lore.kernel.org/all/YpyJ9qTNHJzz0FHY@debian/ Link: https://lore.kernel.org/all/20220606080631.0c3014f2@canb.auug.org.au/ Link: https://lore.kernel.org/all/20220605162537.1604762-1-yury.norov@gmail.com/ Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Reviewed-by: Yury Norov <yury.norov@gmail.com> Cc: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Cc: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-06-05fix the breakage in close_fd_get_file() calling conventions changeAl Viro
It used to grab an extra reference to struct file rather than just transferring to caller the one it had removed from descriptor table. New variant doesn't, and callers need to be adjusted. Reported-and-tested-by: syzbot+47dd250f527cb7bebf24@syzkaller.appspotmail.com Fixes: 6319194ec57b ("Unify the primitives for file descriptor closing") Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-06-05Merge tag 'x86-urgent-2022-06-05' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 SGX fix from Thomas Gleixner: "A single fix for x86/SGX to prevent that memory which is allocated for an SGX enclave is accounted to the wrong memory control group" * tag 'x86-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sgx: Set active memcg prior to shmem allocation
2022-06-05Merge tag 'x86-mm-2022-06-05' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm cleanup from Thomas Gleixner: "Use PAGE_ALIGNED() instead of open coding it in the x86/mm code" * tag 'x86-mm-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Use PAGE_ALIGNED(x) instead of IS_ALIGNED(x, PAGE_SIZE)
2022-06-05Merge tag 'x86-microcode-2022-06-05' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 microcode updates from Thomas Gleixner: - Disable late microcode loading by default. Unless the HW people get their act together and provide a required minimum version in the microcode header for making a halfways informed decision its just lottery and broken. - Warn and taint the kernel when microcode is loaded late - Remove the old unused microcode loader interface - Remove a redundant perf callback from the microcode loader * tag 'x86-microcode-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode: Remove unnecessary perf callback x86/microcode: Taint and warn on late loading x86/microcode: Default-disable late loading x86/microcode: Rip out the OLD_INTERFACE
2022-06-05Merge tag 'x86-cleanups-2022-06-05' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Thomas Gleixner: "A set of small x86 cleanups: - Remove unused headers in the IDT code - Kconfig indendation and comment fixes - Fix all 'the the' typos in one go instead of waiting for bots to fix one at a time" * tag 'x86-cleanups-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Fix all occurences of the "the the" typo x86/idt: Remove unused headers x86/Kconfig: Fix indentation of arch/x86/Kconfig.debug x86/Kconfig: Fix indentation and add endif comments to arch/x86/Kconfig
2022-06-05Merge tag 'x86-boot-2022-06-05' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot update from Thomas Gleixner: "Use strlcpy() instead of strscpy() in arch_setup()" * tag 'x86-boot-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/setup: Use strscpy() to replace deprecated strlcpy()
2022-06-05Merge tag 'timers-core-2022-06-05' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull clockevent/clocksource updates from Thomas Gleixner: - Device tree bindings for MT8186 - Tell the kernel that the RISC-V SBI timer stops in deeper power states - Make device tree parsing in sp804 more robust - Dead code removal and tiny fixes here and there - Add the missing SPDX identifiers * tag 'timers-core-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource/drivers/oxnas-rps: Fix irq_of_parse_and_map() return value clocksource/drivers/timer-ti-dm: Remove unnecessary NULL check clocksource/drivers/timer-sun5i: Convert to SPDX identifier clocksource/drivers/timer-sun4i: Convert to SPDX identifier clocksource/drivers/pistachio: Convert to SPDX identifier clocksource/drivers/orion: Convert to SPDX identifier clocksource/drivers/lpc32xx: Convert to SPDX identifier clocksource/drivers/digicolor: Convert to SPDX identifier clocksource/drivers/armada-370-xp: Convert to SPDX identifier clocksource/drivers/mips-gic-timer: Convert to SPDX identifier clocksource/drivers/jcore: Convert to SPDX identifier clocksource/drivers/bcm_kona: Convert to SPDX identifier clocksource/drivers/sp804: Avoid error on multiple instances clocksource/drivers/riscv: Events are stopped during CPU suspend clocksource/drivers/ixp4xx: Drop boardfile probe path dt-bindings: timer: Add compatible for Mediatek MT8186
2022-06-05Merge tag 'sched-urgent-2022-06-05' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Thomas Gleixner: "Fix the fallout of sysctl code move which placed the init function wrong" * tag 'sched-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/autogroup: Fix sysctl move