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2022-11-23Merge branch 'kvm-dwmw2-fixes' into HEADPaolo Bonzini2-10/+29
This brings in a few important fixes for Xen emulation. While nobody should be enabling it, the bug effectively allows userspace to read arbitrary memory. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-23KVM: Update gfn_to_pfn_cache khva when it moves within the same pageDavid Woodhouse1-1/+6
In the case where a GPC is refreshed to a different location within the same page, we didn't bother to update it. Mostly we don't need to, but since the ->khva field also includes the offset within the page, that does have to be updated. Fixes: 3ba2c95ea180 ("KVM: Do not incorporate page offset into gfn=>pfn cache user address") Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org> Reviewed-by: Sean Christopherson <seanjc@google.com> Cc: stable@kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-23KVM: x86/xen: Only do in-kernel acceleration of hypercalls for guest CPL0David Woodhouse1-1/+11
There are almost no hypercalls which are valid from CPL > 0, and definitely none which are handled by the kernel. Fixes: 2fd6df2f2b47 ("KVM: x86/xen: intercept EVTCHNOP_send from guests") Reported-by: Michal Luczaj <mhal@rbox.co> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Sean Christopherson <seanjc@google.com> Cc: stable@kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-23KVM: x86/xen: Validate port number in SCHEDOP_pollDavid Woodhouse1-8/+12
We shouldn't allow guests to poll on arbitrary port numbers off the end of the event channel table. Fixes: 1a65105a5aba ("KVM: x86/xen: handle PV spinlocks slowpath") [dwmw2: my bug though; the original version did check the validity as a side-effect of an idr_find() which I ripped out in refactoring.] Reported-by: Michal Luczaj <mhal@rbox.co> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Sean Christopherson <seanjc@google.com> Cc: stable@kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-23KVM: x86/mmu: Fix race condition in direct_page_faultKazuki Takiguchi1-6/+7
make_mmu_pages_available() must be called with mmu_lock held for write. However, if the TDP MMU is used, it will be called with mmu_lock held for read. This function does nothing unless shadow pages are used, so there is no race unless nested TDP is used. Since nested TDP uses shadow pages, old shadow pages may be zapped by this function even when the TDP MMU is enabled. Since shadow pages are never allocated by kvm_tdp_mmu_map(), a race condition can be avoided by not calling make_mmu_pages_available() if the TDP MMU is currently in use. I encountered this when repeatedly starting and stopping nested VM. It can be artificially caused by allocating a large number of nested TDP SPTEs. For example, the following BUG and general protection fault are caused in the host kernel. pte_list_remove: 00000000cd54fc10 many->many ------------[ cut here ]------------ kernel BUG at arch/x86/kvm/mmu/mmu.c:963! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:pte_list_remove.cold+0x16/0x48 [kvm] Call Trace: <TASK> drop_spte+0xe0/0x180 [kvm] mmu_page_zap_pte+0x4f/0x140 [kvm] __kvm_mmu_prepare_zap_page+0x62/0x3e0 [kvm] kvm_mmu_zap_oldest_mmu_pages+0x7d/0xf0 [kvm] direct_page_fault+0x3cb/0x9b0 [kvm] kvm_tdp_page_fault+0x2c/0xa0 [kvm] kvm_mmu_page_fault+0x207/0x930 [kvm] npf_interception+0x47/0xb0 [kvm_amd] svm_invoke_exit_handler+0x13c/0x1a0 [kvm_amd] svm_handle_exit+0xfc/0x2c0 [kvm_amd] kvm_arch_vcpu_ioctl_run+0xa79/0x1780 [kvm] kvm_vcpu_ioctl+0x29b/0x6f0 [kvm] __x64_sys_ioctl+0x95/0xd0 do_syscall_64+0x5c/0x90 general protection fault, probably for non-canonical address 0xdead000000000122: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:kvm_mmu_commit_zap_page.part.0+0x4b/0xe0 [kvm] Call Trace: <TASK> kvm_mmu_zap_oldest_mmu_pages+0xae/0xf0 [kvm] direct_page_fault+0x3cb/0x9b0 [kvm] kvm_tdp_page_fault+0x2c/0xa0 [kvm] kvm_mmu_page_fault+0x207/0x930 [kvm] npf_interception+0x47/0xb0 [kvm_amd] CVE: CVE-2022-45869 Fixes: a2855afc7ee8 ("KVM: x86/mmu: Allow parallel page faults for the TDP MMU") Signed-off-by: Kazuki Takiguchi <takiguchi.kazuki171@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17Merge branch 'kvm-svm-harden' into HEADPaolo Bonzini10-57/+172
This fixes three issues in nested SVM: 1) in the shutdown_interception() vmexit handler we call kvm_vcpu_reset(). However, if running nested and L1 doesn't intercept shutdown, the function resets vcpu->arch.hflags without properly leaving the nested state. This leaves the vCPU in inconsistent state and later triggers a kernel panic in SVM code. The same bug can likely be triggered by sending INIT via local apic to a vCPU which runs a nested guest. On VMX we are lucky that the issue can't happen because VMX always intercepts triple faults, thus triple fault in L2 will always be redirected to L1. Plus, handle_triple_fault() doesn't reset the vCPU. INIT IPI can't happen on VMX either because INIT events are masked while in VMX mode. Secondarily, KVM doesn't honour SHUTDOWN intercept bit of L1 on SVM. A normal hypervisor should always intercept SHUTDOWN, a unit test on the other hand might want to not do so. Finally, the guest can trigger a kernel non rate limited printk on SVM from the guest, which is fixed as well. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17KVM: x86: remove exit_int_info warning in svm_handle_exitMaxim Levitsky1-15/+0
It is valid to receive external interrupt and have broken IDT entry, which will lead to #GP with exit_int_into that will contain the index of the IDT entry (e.g any value). Other exceptions can happen as well, like #NP or #SS (if stack switch fails). Thus this warning can be user triggred and has very little value. Cc: stable@vger.kernel.org Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20221103141351.50662-10-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17KVM: selftests: add svm part to triple_fault_testMaxim Levitsky1-17/+56
Add a SVM implementation to triple_fault_test to test that emulated/injected shutdown works. Since instead of the VMX, the SVM allows the hypervisor to avoid intercepting shutdown in guest, don't intercept shutdown to test that KVM suports this correctly. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20221103141351.50662-9-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17KVM: x86: allow L1 to not intercept triple faultMaxim Levitsky3-5/+13
This is SVM correctness fix - although a sane L1 would intercept SHUTDOWN event, it doesn't have to, so we have to honour this. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20221103141351.50662-8-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17kvm: selftests: add svm nested shutdown testMaxim Levitsky3-0/+69
Add test that tests that on SVM if L1 doesn't intercept SHUTDOWN, then L2 crashes L1 and doesn't crash L2 Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20221103141351.50662-7-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17KVM: selftests: move idt_entry to headerMaxim Levitsky2-13/+13
struct idt_entry will be used for a test which will break IDT on purpose. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20221103141351.50662-6-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17KVM: x86: forcibly leave nested mode on vCPU resetMaxim Levitsky1-0/+10
While not obivous, kvm_vcpu_reset() leaves the nested mode by clearing 'vcpu->arch.hflags' but it does so without all the required housekeeping. On SVM, it is possible to have a vCPU reset while in guest mode because unlike VMX, on SVM, INIT's are not latched in SVM non root mode and in addition to that L1 doesn't have to intercept triple fault, which should also trigger L1's reset if happens in L2 while L1 didn't intercept it. If one of the above conditions happen, KVM will continue to use vmcb02 while not having in the guest mode. Later the IA32_EFER will be cleared which will lead to freeing of the nested guest state which will (correctly) free the vmcb02, but since KVM still uses it (incorrectly) this will lead to a use after free and kernel crash. This issue is assigned CVE-2022-3344 Cc: stable@vger.kernel.org Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20221103141351.50662-5-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17KVM: x86: add kvm_leave_nestedMaxim Levitsky3-7/+7
add kvm_leave_nested which wraps a call to nested_ops->leave_nested into a function. Cc: stable@vger.kernel.org Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20221103141351.50662-4-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17KVM: x86: nSVM: harden svm_free_nested against freeing vmcb02 while still in useMaxim Levitsky1-0/+3
Make sure that KVM uses vmcb01 before freeing nested state, and warn if that is not the case. This is a minimal fix for CVE-2022-3344 making the kernel print a warning instead of a kernel panic. Cc: stable@vger.kernel.org Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20221103141351.50662-3-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17KVM: x86: nSVM: leave nested mode on vCPU freeMaxim Levitsky1-0/+1
If the VM was terminated while nested, we free the nested state while the vCPU still is in nested mode. Soon a warning will be added for this condition. Cc: stable@vger.kernel.org Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20221103141351.50662-2-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17KVM: Obey kvm.halt_poll_ns in VMs not using KVM_CAP_HALT_POLLDavid Matlack2-3/+25
Obey kvm.halt_poll_ns in VMs not using KVM_CAP_HALT_POLL on every halt, rather than just sampling the module parameter when the VM is first created. This restore the original behavior of kvm.halt_poll_ns for VMs that have not opted into KVM_CAP_HALT_POLL. Notably, this change restores the ability for admins to disable or change the maximum halt-polling time system wide for VMs not using KVM_CAP_HALT_POLL. Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Fixes: acd05785e48c ("kvm: add capability for halt polling") Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20221117001657.1067231-4-dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17KVM: Avoid re-reading kvm->max_halt_poll_ns during halt-pollingDavid Matlack1-6/+15
Avoid re-reading kvm->max_halt_poll_ns multiple times during halt-polling except when it is explicitly useful, e.g. to check if the max time changed across a halt. kvm->max_halt_poll_ns can be changed at any time by userspace via KVM_CAP_HALT_POLL. This bug is unlikely to cause any serious side-effects. In the worst case one halt polls for shorter or longer than it should, and then is fixed up on the next halt. Furthmore, this is still possible since kvm->max_halt_poll_ns are not synchronized with halts. Fixes: acd05785e48c ("kvm: add capability for halt polling") Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20221117001657.1067231-3-dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-17KVM: Cap vcpu->halt_poll_ns before halting rather than afterDavid Matlack1-4/+6
Cap vcpu->halt_poll_ns based on the max halt polling time just before halting, rather than after the last halt. This arguably provides better accuracy if an admin disables halt polling in between halts, although the improvement is nominal. A side-effect of this change is that grow_halt_poll_ns() no longer needs to access vcpu->kvm->max_halt_poll_ns, which will be useful in a future commit where the max halt polling time can come from the module parameter halt_poll_ns instead. Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20221117001657.1067231-2-dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-11KVM: x86/mmu: Block all page faults during kvm_zap_gfn_range()Sean Christopherson1-2/+2
When zapping a GFN range, pass 0 => ALL_ONES for the to-be-invalidated range to effectively block all page faults while the zap is in-progress. The invalidation helpers take a host virtual address, whereas zapping a GFN obviously provides a guest physical address and with the wrong unit of measurement (frame vs. byte). Alternatively, KVM could walk all memslots to get the associated HVAs, but thanks to SMM, that would require multiple lookups. And practically speaking, kvm_zap_gfn_range() usage is quite rare and not a hot path, e.g. MTRR and CR0.CD are almost guaranteed to be done only on vCPU0 during boot, and APICv inhibits are similarly infrequent operations. Fixes: edb298c663fc ("KVM: x86/mmu: bump mmu notifier count in kvm_zap_gfn_range") Reported-by: Chao Peng <chao.p.peng@linux.intel.com> Cc: stable@vger.kernel.org Cc: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221111001841.2412598-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09Merge tag 'kvm-s390-master-6.1-1' of ↵Paolo Bonzini251-1718/+3474
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD A PCI allocation fix and a PV clock fix.
2022-11-09KVM: x86/pmu: Limit the maximum number of supported AMD GP countersLike Xu3-3/+8
The AMD PerfMonV2 specification allows for a maximum of 16 GP counters, but currently only 6 pairs of MSRs are accepted by KVM. While AMD64_NUM_COUNTERS_CORE is already equal to 6, increasing without adjusting msrs_to_save_all[] could result in out-of-bounds accesses. Therefore introduce a macro (named KVM_AMD_PMC_MAX_GENERIC) to refer to the number of counters supported by KVM. Signed-off-by: Like Xu <likexu@tencent.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <20220919091008.60695-3-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09KVM: x86/pmu: Limit the maximum number of supported Intel GP countersLike Xu4-9/+15
The Intel Architectural IA32_PMCx MSRs addresses range allows for a maximum of 8 GP counters, and KVM cannot address any more. Introduce a local macro (named KVM_INTEL_PMC_MAX_GENERIC) and use it consistently to refer to the number of counters supported by KVM, thus avoiding possible out-of-bound accesses. Suggested-by: Jim Mattson <jmattson@google.com> Signed-off-by: Like Xu <likexu@tencent.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <20220919091008.60695-2-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09KVM: x86/pmu: Do not speculatively query Intel GP PMCs that don't exist yetLike Xu1-12/+2
The SDM lists an architectural MSR IA32_CORE_CAPABILITIES (0xCF) that limits the theoretical maximum value of the Intel GP PMC MSRs allocated at 0xC1 to 14; likewise the Intel April 2022 SDM adds IA32_OVERCLOCKING_STATUS at 0x195 which limits the number of event selection MSRs to 15 (0x186-0x194). Limiting the maximum number of counters to 14 or 18 based on the currently allocated MSRs is clearly fragile, and it seems likely that Intel will even place PMCs 8-15 at a completely different range of MSR indices. So stop at the maximum number of GP PMCs supported today on Intel processors. There are some machines, like Intel P4 with non Architectural PMU, that may indeed have 18 counters, but those counters are in a completely different MSR address range and are not supported by KVM. Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: stable@vger.kernel.org Fixes: cf05a67b68b8 ("KVM: x86: omit "impossible" pmu MSRs from MSR list") Suggested-by: Jim Mattson <jmattson@google.com> Signed-off-by: Like Xu <likexu@tencent.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <20220919091008.60695-1-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09KVM: SVM: Only dump VMSA to klog at KERN_DEBUG levelPeter Gonda1-1/+1
Explicitly print the VMSA dump at KERN_DEBUG log level, KERN_CONT uses KERNEL_DEFAULT if the previous log line has a newline, i.e. if there's nothing to continuing, and as a result the VMSA gets dumped when it shouldn't. The KERN_CONT documentation says it defaults back to KERNL_DEFAULT if the previous log line has a newline. So switch from KERN_CONT to print_hex_dump_debug(). Jarkko pointed this out in reference to the original patch. See: https://lore.kernel.org/all/YuPMeWX4uuR1Tz3M@kernel.org/ print_hex_dump(KERN_DEBUG, ...) was pointed out there, but print_hex_dump_debug() should similar. Fixes: 6fac42f127b8 ("KVM: SVM: Dump Virtual Machine Save Area (VMSA) to klog") Signed-off-by: Peter Gonda <pgonda@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Harald Hoyer <harald@profian.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: x86@kernel.org Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Message-Id: <20221104142220.469452-1-pgonda@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09tools/kvm_stat: update exit reasons for vmx/svm/aarch64/userspaceRong Tao1-14/+82
Update EXIT_REASONS from source, including VMX_EXIT_REASONS, SVM_EXIT_REASONS, AARCH64_EXIT_REASONS, USERSPACE_EXIT_REASONS. Signed-off-by: Rong Tao <rongtao@cestc.cn> Message-Id: <tencent_00082C8BFA925A65E11570F417F1CD404505@qq.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09tools/kvm_stat: fix incorrect detection of debugfsMatthias Gerstner1-1/+1
The first field in /proc/mounts can be influenced by unprivileged users through the widespread `fusermount` setuid-root program. Example: ``` user$ mkdir ~/mydebugfs user$ export _FUSE_COMMFD=0 user$ fusermount ~/mydebugfs -ononempty,fsname=debugfs user$ grep debugfs /proc/mounts debugfs /home/user/mydebugfs fuse rw,nosuid,nodev,relatime,user_id=1000,group_id=100 0 0 ``` If there is no debugfs already mounted in the system then this can be used by unprivileged users to trick kvm_stat into using a user controlled file system location for obtaining KVM statistics. Even though the root user is not allowed to access non-root FUSE mounts for security reasons, the unprivileged user can unmount the FUSE mount before kvm_stat uses the mounted path. If it wins the race, kvm_stat will read from the location where the FUSE mount resided. Note that the files in debugfs are only opened for reading, so the attacker can cause very large data to be read in by kvm_stat, or fake data to be processed, but there should be no viable way to turn this into a privilege escalation. The fix is simply to use the file system type field instead. Whitespace in the mount path is escaped in /proc/mounts thus no further safety measures in the parsing should be necessary to make this correct. Message-Id: <20221103135927.13656-1-matthias.gerstner@suse.de> Signed-off-by: Matthias Gerstner <matthias.gerstner@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09x86, KVM: remove unnecessary argument to x86_virt_spec_ctrl and callersPaolo Bonzini3-8/+8
x86_virt_spec_ctrl only deals with the paravirtualized MSR_IA32_VIRT_SPEC_CTRL now and does not handle MSR_IA32_SPEC_CTRL anymore; remove the corresponding, unused argument. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09KVM: SVM: move MSR_IA32_SPEC_CTRL save/restore to assemblyPaolo Bonzini5-38/+136
Restoration of the host IA32_SPEC_CTRL value is probably too late with respect to the return thunk training sequence. With respect to the user/kernel boundary, AMD says, "If software chooses to toggle STIBP (e.g., set STIBP on kernel entry, and clear it on kernel exit), software should set STIBP to 1 before executing the return thunk training sequence." I assume the same requirements apply to the guest/host boundary. The return thunk training sequence is in vmenter.S, quite close to the VM-exit. On hosts without V_SPEC_CTRL, however, the host's IA32_SPEC_CTRL value is not restored until much later. To avoid this, move the restoration of host SPEC_CTRL to assembly and, for consistency, move the restoration of the guest SPEC_CTRL as well. This is not particularly difficult, apart from some care to cover both 32- and 64-bit, and to share code between SEV-ES and normal vmentry. Cc: stable@vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Suggested-by: Jim Mattson <jmattson@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09KVM: SVM: restore host save area from assemblyPaolo Bonzini5-13/+26
Allow access to the percpu area via the GS segment base, which is needed in order to access the saved host spec_ctrl value. In linux-next FILL_RETURN_BUFFER also needs to access percpu data. For simplicity, the physical address of the save area is added to struct svm_cpu_data. Cc: stable@vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Reported-by: Nathan Chancellor <nathan@kernel.org> Analyzed-by: Andrew Cooper <andrew.cooper3@citrix.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09KVM: SVM: move guest vmsave/vmload back to assemblyPaolo Bonzini3-20/+39
It is error-prone that code after vmexit cannot access percpu data because GSBASE has not been restored yet. It forces MSR_IA32_SPEC_CTRL save/restore to happen very late, after the predictor untraining sequence, and it gets in the way of return stack depth tracking (a retbleed mitigation that is in linux-next as of 2022-11-09). As a first step towards fixing that, move the VMCB VMSAVE/VMLOAD to assembly, essentially undoing commit fb0c4a4fee5a ("KVM: SVM: move VMLOAD/VMSAVE to C code", 2021-03-15). The reason for that commit was that it made it simpler to use a different VMCB for VMLOAD/VMSAVE versus VMRUN; but that is not a big hassle anymore thanks to the kvm-asm-offsets machinery and other related cleanups. The idea on how to number the exception tables is stolen from a prototype patch by Peter Zijlstra. Cc: stable@vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Link: <https://lore.kernel.org/all/f571e404-e625-bae1-10e9-449b2eb4cbd8@citrix.com/> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09KVM: SVM: do not allocate struct svm_cpu_data dynamicallyPaolo Bonzini3-29/+18
The svm_data percpu variable is a pointer, but it is allocated via svm_hardware_setup() when KVM is loaded. Unlike hardware_enable() this means that it is never NULL for the whole lifetime of KVM, and static allocation does not waste any memory compared to the status quo. It is also more efficient and more easily handled from assembly code, so do it and don't look back. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09KVM: SVM: remove dead field from struct svm_cpu_dataPaolo Bonzini2-3/+0
The "cpu" field of struct svm_cpu_data has been write-only since commit 4b656b120249 ("KVM: SVM: force new asid on vcpu migration", 2009-08-05). Remove it. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09KVM: SVM: remove unused field from struct vcpu_svmPaolo Bonzini1-1/+0
The pointer to svm_cpu_data in struct vcpu_svm looks interesting from the point of view of accessing it after vmexit, when the GSBASE is still containing the guest value. However, despite existing since the very first commit of drivers/kvm/svm.c (commit 6aa8b732ca01, "[PATCH] kvm: userspace interface", 2006-12-10), it was never set to anything. Ignore the opportunity to fix a 16 year old "bug" and delete it; doing things the "harder" way makes it possible to remove more old cruft. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09KVM: SVM: retrieve VMCB from assemblyPaolo Bonzini4-15/+16
Continue moving accesses to struct vcpu_svm to vmenter.S. Reducing the number of arguments limits the chance of mistakes due to different registers used for argument passing in 32- and 64-bit ABIs; pushing the VMCB argument and almost immediately popping it into a different register looks pretty weird. 32-bit ABI is not a concern for __svm_sev_es_vcpu_run() which is 64-bit only; however, it will soon need @svm to save/restore SPEC_CTRL so stay consistent with __svm_vcpu_run() and let them share the same prototype. No functional change intended. Cc: stable@vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09KVM: SVM: adjust register allocation for __svm_vcpu_run()Paolo Bonzini1-19/+19
32-bit ABI uses RAX/RCX/RDX as its argument registers, so they are in the way of instructions that hardcode their operands such as RDMSR/WRMSR or VMLOAD/VMRUN/VMSAVE. In preparation for moving vmload/vmsave to __svm_vcpu_run(), keep the pointer to the struct vcpu_svm in %rdi. In particular, it is now possible to load svm->vmcb01.pa in %rax without clobbering the struct vcpu_svm pointer. No functional change intended. Cc: stable@vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09KVM: SVM: replace regs argument of __svm_vcpu_run() with vcpu_svmPaolo Bonzini5-20/+30
Since registers are reachable through vcpu_svm, and we will need to access more fields of that struct, pass it instead of the regs[] array. No functional change intended. Cc: stable@vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09KVM: x86: use a separate asm-offsets.c filePaolo Bonzini5-7/+30
This already removes an ugly #include "" from asm-offsets.c, but especially it avoids a future error when trying to define asm-offsets for KVM's svm/svm.h header. This would not work for kernel/asm-offsets.c, because svm/svm.h includes kvm_cache_regs.h which is not in the include path when compiling asm-offsets.c. The problem is not there if the .c file is in arch/x86/kvm. Suggested-by: Sean Christopherson <seanjc@google.com> Cc: stable@vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-07KVM: s390: pci: Fix allocation size of aift kzdev elementsRafael Mendonca1-1/+1
The 'kzdev' field of struct 'zpci_aift' is an array of pointers to 'kvm_zdev' structs. Allocate the proper size accordingly. Reported by Coccinelle: WARNING: Use correct pointer type argument for sizeof Fixes: 98b1d33dac5f ("KVM: s390: pci: do initial setup for AEN interpretation") Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/20221026013234.960859-1-rafaelmendsr@gmail.com Message-Id: <20221026013234.960859-1-rafaelmendsr@gmail.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2022-11-07KVM: s390: pv: don't allow userspace to set the clock under PVNico Boehr3-10/+20
When running under PV, the guest's TOD clock is under control of the ultravisor and the hypervisor isn't allowed to change it. Hence, don't allow userspace to change the guest's TOD clock by returning -EOPNOTSUPP. When userspace changes the guest's TOD clock, KVM updates its kvm.arch.epoch field and, in addition, the epoch field in all state descriptions of all VCPUs. But, under PV, the ultravisor will ignore the epoch field in the state description and simply overwrite it on next SIE exit with the actual guest epoch. This leads to KVM having an incorrect view of the guest's TOD clock: it has updated its internal kvm.arch.epoch field, but the ultravisor ignores the field in the state description. Whenever a guest is now waiting for a clock comparator, KVM will incorrectly calculate the time when the guest should wake up, possibly causing the guest to sleep for much longer than expected. With this change, kvm_s390_set_tod() will now take the kvm->lock to be able to call kvm_s390_pv_is_protected(). Since kvm_s390_set_tod_clock() also takes kvm->lock, use __kvm_s390_set_tod_clock() instead. The function kvm_s390_set_tod_clock is now unused, hence remove it. Update the documentation to indicate the TOD clock attr calls can now return -EOPNOTSUPP. Fixes: 0f3035047140 ("KVM: s390: protvirt: Do only reset registers that are accessible") Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com> Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20221011160712.928239-2-nrb@linux.ibm.com Message-Id: <20221011160712.928239-2-nrb@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2022-11-06Linux 6.1-rc4v6.1-rc4Linus Torvalds1-1/+1
2022-11-06Merge tag 'cxl-fixes-for-6.1-rc4' of ↵Linus Torvalds8-91/+448
git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl Pull cxl fixes from Dan Williams: "Several fixes for CXL region creation crashes, leaks and failures. This is mainly fallout from the original implementation of dynamic CXL region creation (instantiate new physical memory pools) that arrived in v6.0-rc1. Given the theme of "failures in the presence of pass-through decoders" this also includes new regression test infrastructure for that case. Summary: - Fix region creation crash with pass-through decoders - Fix region creation crash when no decoder allocation fails - Fix region creation crash when scanning regions to enforce the increasing physical address order constraint that CXL mandates - Fix a memory leak for cxl_pmem_region objects, track 1:N instead of 1:1 memory-device-to-region associations. - Fix a memory leak for cxl_region objects when regions with active targets are deleted - Fix assignment of NUMA nodes to CXL regions by CFMWS (CXL Window) emulated proximity domains. - Fix region creation failure for switch attached devices downstream of a single-port host-bridge - Fix false positive memory leak of cxl_region objects by recycling recently used region ids rather than freeing them - Add regression test infrastructure for a pass-through decoder configuration - Fix some mailbox payload handling corner cases" * tag 'cxl-fixes-for-6.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: cxl/region: Recycle region ids cxl/region: Fix 'distance' calculation with passthrough ports tools/testing/cxl: Add a single-port host-bridge regression config tools/testing/cxl: Fix some error exits cxl/pmem: Fix cxl_pmem_region and cxl_memdev leak cxl/region: Fix cxl_region leak, cleanup targets at region delete cxl/region: Fix region HPA ordering validation cxl/pmem: Use size_add() against integer overflow cxl/region: Fix decoder allocation crash ACPI: NUMA: Add CXL CFMWS 'nodes' to the possible nodes set cxl/pmem: Fix failure to account for 8 byte header for writes to the device LSA. cxl/region: Fix null pointer dereference due to pass through decoder commit cxl/mbox: Add a check on input payload size
2022-11-06Merge tag 'hwmon-for-v6.1-rc4' of ↵Linus Torvalds2-14/+103
git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging Pull hwmon fixes from Guenter Roeck: "Fix two regressions: - Commit 54cc3dbfc10d ("hwmon: (pmbus) Add regulator supply into macro") resulted in regulator undercount when disabling regulators. Revert it. - The thermal subsystem rework caused the scmi driver to no longer register with the thermal subsystem because index values no longer match. To fix the problem, the scmi driver now directly registers with the thermal subsystem, no longer through the hwmon core" * tag 'hwmon-for-v6.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: Revert "hwmon: (pmbus) Add regulator supply into macro" hwmon: (scmi) Register explicitly with Thermal Framework
2022-11-06Merge tag 'perf_urgent_for_v6.1_rc4' of ↵Linus Torvalds4-11/+18
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Borislav Petkov: - Add Cooper Lake's stepping to the PEBS guest/host events isolation fixed microcode revisions checking quirk - Update Icelake and Sapphire Rapids events constraints - Use the standard energy unit for Sapphire Rapids in RAPL - Fix the hw_breakpoint test to fail more graciously on !SMP configs * tag 'perf_urgent_for_v6.1_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Add Cooper Lake stepping to isolation_ucodes[] perf/x86/intel: Fix pebs event constraints for SPR perf/x86/intel: Fix pebs event constraints for ICL perf/x86/rapl: Use standard Energy Unit for SPR Dram RAPL domain perf/hw_breakpoint: test: Skip the test if dependencies unmet
2022-11-06Merge tag 'x86_urgent_for_v6.1_rc4' of ↵Linus Torvalds3-9/+29
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Borislav Petkov: - Add new Intel CPU models - Enforce that TDX guests are successfully loaded only on TDX hardware where virtualization exception (#VE) delivery on kernel memory is disabled because handling those in all possible cases is "essentially impossible" - Add the proper include to the syscall wrappers so that BTF can see the real pt_regs definition and not only the forward declaration * tag 'x86_urgent_for_v6.1_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Add several Intel server CPU model numbers x86/tdx: Panic on bad configs that #VE on "private" memory access x86/tdx: Prepare for using "INFO" call for a second purpose x86/syscall: Include asm/ptrace.h in syscall_wrapper header
2022-11-06Merge tag 'kbuild-fixes-v6.1-2' of ↵Linus Torvalds4-21/+16
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - Use POSIX-compatible grep options - Document git-related tips for reproducible builds - Fix a typo in the modpost rule - Suppress SIGPIPE error message from gcc-ar and llvm-ar - Fix segmentation fault in the menuconfig search * tag 'kbuild-fixes-v6.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: fix segmentation fault in menuconfig search kbuild: fix SIGPIPE error message for AR=gcc-ar and AR=llvm-ar kbuild: fix typo in modpost Documentation: kbuild: Add description of git for reproducible builds kbuild: use POSIX-compatible grep option
2022-11-06Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds11-60/+52
Pull kvm fixes from Paolo Bonzini: "ARM: - Fix the pKVM stage-1 walker erronously using the stage-2 accessor - Correctly convert vcpu->kvm to a hyp pointer when generating an exception in a nVHE+MTE configuration - Check that KVM_CAP_DIRTY_LOG_* are valid before enabling them - Fix SMPRI_EL1/TPIDR2_EL0 trapping on VHE - Document the boot requirements for FGT when entering the kernel at EL1 x86: - Use SRCU to protect zap in __kvm_set_or_clear_apicv_inhibit() - Make argument order consistent for kvcalloc() - Userspace API fixes for DEBUGCTL and LBRs" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: Fix a typo about the usage of kvcalloc() KVM: x86: Use SRCU to protect zap in __kvm_set_or_clear_apicv_inhibit() KVM: VMX: Ignore guest CPUID for host userspace writes to DEBUGCTL KVM: VMX: Fold vmx_supported_debugctl() into vcpu_supported_debugctl() KVM: VMX: Advertise PMU LBRs if and only if perf supports LBRs arm64: booting: Document our requirements for fine grained traps with SME KVM: arm64: Fix SMPRI_EL1/TPIDR2_EL0 trapping on VHE KVM: Check KVM_CAP_DIRTY_LOG_{RING, RING_ACQ_REL} prior to enabling them KVM: arm64: Fix bad dereference on MTE-enabled systems KVM: arm64: Use correct accessor to parse stage-1 PTEs
2022-11-06Merge tag 'for-linus-6.1-rc4-tag' of ↵Linus Torvalds2-18/+7
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fixes from Juergen Gross: "One fix for silencing a smatch warning, and a small cleanup patch" * tag 'for-linus-6.1-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/xen: simplify sysenter and syscall setup x86/xen: silence smatch warning in pmu_msr_chk_emulated()
2022-11-06Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds6-7/+21
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 fixes from Ted Ts'o: "Fix a number of bugs, including some regressions, the most serious of which was one which would cause online resizes to fail with file systems with metadata checksums enabled. Also fix a warning caused by the newly added fortify string checker, plus some bugs that were found using fuzzed file systems" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix fortify warning in fs/ext4/fast_commit.c:1551 ext4: fix wrong return err in ext4_load_and_init_journal() ext4: fix warning in 'ext4_da_release_space' ext4: fix BUG_ON() when directory entry has invalid rec_len ext4: update the backup superblock's at the end of the online resize
2022-11-06Merge tag '6.1-rc4-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds6-62/+105
Pull cifs fixes from Steve French: "One symlink handling fix and two fixes foir multichannel issues with iterating channels, including for oplock breaks when leases are disabled" * tag '6.1-rc4-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: cifs: fix use-after-free on the link name cifs: avoid unnecessary iteration of tcp sessions cifs: always iterate smb sessions using primary channel
2022-11-06Merge tag 'trace-v6.1-rc3' of ↵Linus Torvalds5-26/+29
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull `lTracing fixes for 6.1-rc3: - Fixed NULL pointer dereference in the ring buffer wait-waiters code for machines that have less CPUs than what nr_cpu_ids returns. The buffer array is of size nr_cpu_ids, but only the online CPUs get initialized. - Fixed use after free call in ftrace_shutdown. - Fix accounting of if a kprobe is enabled - Fix NULL pointer dereference on error path of fprobe rethook_alloc(). - Fix unregistering of fprobe_kprobe_handler - Fix memory leak in kprobe test module * tag 'trace-v6.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: kprobe: Fix memory leak in test_gen_kprobe/kretprobe_cmd() tracing/fprobe: Fix to check whether fprobe is registered correctly fprobe: Check rethook_alloc() return in rethook initialization kprobe: reverse kp->flags when arm_kprobe failed ftrace: Fix use-after-free for dynamic ftrace_ops ring-buffer: Check for NULL cpu_buffer in ring_buffer_wake_waiters()