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* | | | | | | Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds2018-02-04
|\ \ \ \ \ \ \ | | |_|_|_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull spectre/meltdown updates from Thomas Gleixner: "The next round of updates related to melted spectrum: - The initial set of spectre V1 mitigations: - Array index speculation blocker and its usage for syscall, fdtable and the n180211 driver. - Speculation barrier and its usage in user access functions - Make indirect calls in KVM speculation safe - Blacklisting of known to be broken microcodes so IPBP/IBSR are not touched. - The initial IBPB support and its usage in context switch - The exposure of the new speculation MSRs to KVM guests. - A fix for a regression in x86/32 related to the cpu entry area - Proper whitelisting for known to be safe CPUs from the mitigations. - objtool fixes to deal proper with retpolines and alternatives - Exclude __init functions from retpolines which speeds up the boot process. - Removal of the syscall64 fast path and related cleanups and simplifications - Removal of the unpatched paravirt mode which is yet another source of indirect unproteced calls. - A new and undisputed version of the module mismatch warning - A couple of cleanup and correctness fixes all over the place Yet another step towards full mitigation. There are a few things still missing like the RBS underflow mitigation for Skylake and other small details, but that's being worked on. That said, I'm taking a belated christmas vacation for a week and hope that everything is magically solved when I'm back on Feb 12th" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES KVM/x86: Add IBPB support KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDX x86/speculation: Fix typo IBRS_ATT, which should be IBRS_ALL x86/pti: Mark constant arrays as __initconst x86/spectre: Simplify spectre_v2 command line parsing x86/retpoline: Avoid retpolines for built-in __init functions x86/kvm: Update spectre-v1 mitigation KVM: VMX: make MSR bitmaps per-VCPU x86/paravirt: Remove 'noreplace-paravirt' cmdline option x86/speculation: Use Indirect Branch Prediction Barrier in context switch x86/cpuid: Fix up "virtual" IBRS/IBPB/STIBP feature bits on Intel x86/spectre: Fix spelling mistake: "vunerable"-> "vulnerable" x86/spectre: Report get_user mitigation for spectre_v1 nl80211: Sanitize array index in parse_txq_params vfs, fdtable: Prevent bounds-check bypass via speculative execution x86/syscall: Sanitize syscall table de-references under speculation x86/get_user: Use pointer masking to limit speculation ...
| * | | | | | KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRLKarimAllah Ahmed2018-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Based on a patch from Paolo Bonzini <pbonzini@redhat.com> ] ... basically doing exactly what we do for VMX: - Passthrough SPEC_CTRL to guests (if enabled in guest CPUID) - Save and restore SPEC_CTRL around VMExit and VMEntry only if the guest actually used it. Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: kvm@vger.kernel.org Cc: Dave Hansen <dave.hansen@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ashok Raj <ashok.raj@intel.com> Link: https://lkml.kernel.org/r/1517669783-20732-1-git-send-email-karahmed@amazon.de
| * | | | | | KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRLKarimAllah Ahmed2018-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Based on a patch from Ashok Raj <ashok.raj@intel.com> ] Add direct access to MSR_IA32_SPEC_CTRL for guests. This is needed for guests that will only mitigate Spectre V2 through IBRS+IBPB and will not be using a retpoline+IBPB based approach. To avoid the overhead of saving and restoring the MSR_IA32_SPEC_CTRL for guests that do not actually use the MSR, only start saving and restoring when a non-zero is written to it. No attempt is made to handle STIBP here, intentionally. Filtering STIBP may be added in a future patch, which may require trapping all writes if we don't want to pass it through directly to the guest. [dwmw2: Clean up CPUID bits, save/restore manually, handle reset] Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: kvm@vger.kernel.org Cc: Dave Hansen <dave.hansen@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ashok Raj <ashok.raj@intel.com> Link: https://lkml.kernel.org/r/1517522386-18410-5-git-send-email-karahmed@amazon.de
| * | | | | | KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIESKarimAllah Ahmed2018-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Intel processors use MSR_IA32_ARCH_CAPABILITIES MSR to indicate RDCL_NO (bit 0) and IBRS_ALL (bit 1). This is a read-only MSR. By default the contents will come directly from the hardware, but user-space can still override it. [dwmw2: The bit in kvm_cpuid_7_0_edx_x86_features can be unconditional] Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: kvm@vger.kernel.org Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Ashok Raj <ashok.raj@intel.com> Link: https://lkml.kernel.org/r/1517522386-18410-4-git-send-email-karahmed@amazon.de
| * | | | | | KVM/x86: Add IBPB supportAshok Raj2018-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Indirect Branch Predictor Barrier (IBPB) is an indirect branch control mechanism. It keeps earlier branches from influencing later ones. Unlike IBRS and STIBP, IBPB does not define a new mode of operation. It's a command that ensures predicted branch targets aren't used after the barrier. Although IBRS and IBPB are enumerated by the same CPUID enumeration, IBPB is very different. IBPB helps mitigate against three potential attacks: * Mitigate guests from being attacked by other guests. - This is addressed by issing IBPB when we do a guest switch. * Mitigate attacks from guest/ring3->host/ring3. These would require a IBPB during context switch in host, or after VMEXIT. The host process has two ways to mitigate - Either it can be compiled with retpoline - If its going through context switch, and has set !dumpable then there is a IBPB in that path. (Tim's patch: https://patchwork.kernel.org/patch/10192871) - The case where after a VMEXIT you return back to Qemu might make Qemu attackable from guest when Qemu isn't compiled with retpoline. There are issues reported when doing IBPB on every VMEXIT that resulted in some tsc calibration woes in guest. * Mitigate guest/ring0->host/ring0 attacks. When host kernel is using retpoline it is safe against these attacks. If host kernel isn't using retpoline we might need to do a IBPB flush on every VMEXIT. Even when using retpoline for indirect calls, in certain conditions 'ret' can use the BTB on Skylake-era CPUs. There are other mitigations available like RSB stuffing/clearing. * IBPB is issued only for SVM during svm_free_vcpu(). VMX has a vmclear and SVM doesn't. Follow discussion here: https://lkml.org/lkml/2018/1/15/146 Please refer to the following spec for more details on the enumeration and control. Refer here to get documentation about mitigations. https://software.intel.com/en-us/side-channel-security-support [peterz: rebase and changelog rewrite] [karahmed: - rebase - vmx: expose PRED_CMD if guest has it in CPUID - svm: only pass through IBPB if guest has it in CPUID - vmx: support !cpu_has_vmx_msr_bitmap()] - vmx: support nested] [dwmw2: Expose CPUID bit too (AMD IBPB only for now as we lack IBRS) PRED_CMD is a write-only MSR] Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: kvm@vger.kernel.org Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: http://lkml.kernel.org/r/1515720739-43819-6-git-send-email-ashok.raj@intel.com Link: https://lkml.kernel.org/r/1517522386-18410-3-git-send-email-karahmed@amazon.de
| * | | | | | KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDXKarimAllah Ahmed2018-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [dwmw2: Stop using KF() for bits in it, too] Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Cc: kvm@vger.kernel.org Cc: Radim Krčmář <rkrcmar@redhat.com> Link: https://lkml.kernel.org/r/1517522386-18410-2-git-send-email-karahmed@amazon.de
| * | | | | | Merge branch 'msr-bitmaps' of git://git.kernel.org/pub/scm/virt/kvm/kvm into ↵Thomas Gleixner2018-02-03
| |\ \ \ \ \ \ | | | |_|_|_|/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | x86/pti Pull the KVM prerequisites so the IBPB patches apply.
| | * | | | | KVM: VMX: make MSR bitmaps per-VCPUPaolo Bonzini2018-01-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Place the MSR bitmap in struct loaded_vmcs, and update it in place every time the x2apic or APICv state can change. This is rare and the loop can handle 64 MSRs per iteration, in a similar fashion as nested_vmx_prepare_msr_bitmap. This prepares for choosing, on a per-VM basis, whether to intercept the SPEC_CTRL and PRED_CMD MSRs. Cc: stable@vger.kernel.org # prereq for Spectre mitigation Suggested-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| | * | | | | KVM: VMX: introduce alloc_loaded_vmcsPaolo Bonzini2018-01-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Group together the calls to alloc_vmcs and loaded_vmcs_init. Soon we'll also allocate an MSR bitmap there. Cc: stable@vger.kernel.org # prereq for Spectre mitigation Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| | * | | | | KVM: nVMX: Eliminate vmcs02 poolJim Mattson2018-01-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The potential performance advantages of a vmcs02 pool have never been realized. To simplify the code, eliminate the pool. Instead, a single vmcs02 is allocated per VCPU when the VCPU enters VMX operation. Cc: stable@vger.kernel.org # prereq for Spectre mitigation Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Mark Kanda <mark.kanda@oracle.com> Reviewed-by: Ameya More <ameya.more@oracle.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | | | | | x86/kvm: Update spectre-v1 mitigationDan Williams2018-02-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 75f139aaf896 "KVM: x86: Add memory barrier on vmcs field lookup" added a raw 'asm("lfence");' to prevent a bounds check bypass of 'vmcs_field_to_offset_table'. The lfence can be avoided in this path by using the array_index_nospec() helper designed for these types of fixes. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Andrew Honig <ahonig@google.com> Cc: kvm@vger.kernel.org Cc: Jim Mattson <jmattson@google.com> Link: https://lkml.kernel.org/r/151744959670.6342.3001723920950249067.stgit@dwillia2-desk3.amr.corp.intel.com
| * | | | | | Merge tag 'v4.15' into x86/pti, to be able to merge dependent changesIngo Molnar2018-01-30
| |\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Time has come to switch PTI development over to a v4.15 base - we'll still try to make sure that all PTI fixes backport cleanly to v4.14 and earlier. Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | Merge tag 'usercopy-v4.16-rc1' of ↵Linus Torvalds2018-02-03
|\ \ \ \ \ \ \ | |_|_|_|_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardened usercopy whitelisting from Kees Cook: "Currently, hardened usercopy performs dynamic bounds checking on slab cache objects. This is good, but still leaves a lot of kernel memory available to be copied to/from userspace in the face of bugs. To further restrict what memory is available for copying, this creates a way to whitelist specific areas of a given slab cache object for copying to/from userspace, allowing much finer granularity of access control. Slab caches that are never exposed to userspace can declare no whitelist for their objects, thereby keeping them unavailable to userspace via dynamic copy operations. (Note, an implicit form of whitelisting is the use of constant sizes in usercopy operations and get_user()/put_user(); these bypass all hardened usercopy checks since these sizes cannot change at runtime.) This new check is WARN-by-default, so any mistakes can be found over the next several releases without breaking anyone's system. The series has roughly the following sections: - remove %p and improve reporting with offset - prepare infrastructure and whitelist kmalloc - update VFS subsystem with whitelists - update SCSI subsystem with whitelists - update network subsystem with whitelists - update process memory with whitelists - update per-architecture thread_struct with whitelists - update KVM with whitelists and fix ioctl bug - mark all other allocations as not whitelisted - update lkdtm for more sensible test overage" * tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (38 commits) lkdtm: Update usercopy tests for whitelisting usercopy: Restrict non-usercopy caches to size 0 kvm: x86: fix KVM_XEN_HVM_CONFIG ioctl kvm: whitelist struct kvm_vcpu_arch arm: Implement thread_struct whitelist for hardened usercopy arm64: Implement thread_struct whitelist for hardened usercopy x86: Implement thread_struct whitelist for hardened usercopy fork: Provide usercopy whitelisting for task_struct fork: Define usercopy region in thread_stack slab caches fork: Define usercopy region in mm_struct slab caches net: Restrict unwhitelisted proto caches to size 0 sctp: Copy struct sctp_sock.autoclose to userspace using put_user() sctp: Define usercopy region in SCTP proto slab cache caif: Define usercopy region in caif proto slab cache ip: Define usercopy region in IP proto slab cache net: Define usercopy region in struct proto slab cache scsi: Define usercopy region in scsi_sense_cache slab cache cifs: Define usercopy region in cifs_request slab cache vxfs: Define usercopy region in vxfs_inode slab cache ufs: Define usercopy region in ufs_inode_cache slab cache ...
| * | | | | | kvm: x86: fix KVM_XEN_HVM_CONFIG ioctlPaolo Bonzini2018-01-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This ioctl is obsolete (it was used by Xenner as far as I know) but still let's not break it gratuitously... Its handler is copying directly into struct kvm. Go through a bounce buffer instead, with the added benefit that we can actually do something useful with the flags argument---the previous code was exiting with -EINVAL but still doing the copy. This technically is a userspace ABI breakage, but since no one should be using the ioctl, it's a good occasion to see if someone actually complains. Cc: kernel-hardening@lists.openwall.com Cc: Kees Cook <keescook@chromium.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org>
* | | | | | | Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds2018-01-29
|\ \ \ \ \ \ \ | | |/ / / / / | |/| / / / / | |_|/ / / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/pti updates from Thomas Gleixner: "Another set of melted spectrum related changes: - Code simplifications and cleanups for RSB and retpolines. - Make the indirect calls in KVM speculation safe. - Whitelist CPUs which are known not to speculate from Meltdown and prepare for the new CPUID flag which tells the kernel that a CPU is not affected. - A less rigorous variant of the module retpoline check which merily warns when a non-retpoline protected module is loaded and reflects that fact in the sysfs file. - Prepare for Indirect Branch Prediction Barrier support. - Prepare for exposure of the Speculation Control MSRs to guests, so guest OSes which depend on those "features" can use them. Includes a blacklist of the broken microcodes. The actual exposure of the MSRs through KVM is still being worked on" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/speculation: Simplify indirect_branch_prediction_barrier() x86/retpoline: Simplify vmexit_fill_RSB() x86/cpufeatures: Clean up Spectre v2 related CPUID flags x86/cpu/bugs: Make retpoline module warning conditional x86/bugs: Drop one "mitigation" from dmesg x86/nospec: Fix header guards names x86/alternative: Print unadorned pointers x86/speculation: Add basic IBPB (Indirect Branch Prediction Barrier) support x86/cpufeature: Blacklist SPEC_CTRL/PRED_CMD on early Spectre v2 microcodes x86/pti: Do not enable PTI on CPUs which are not vulnerable to Meltdown x86/msr: Add definitions for new speculation control MSRs x86/cpufeatures: Add AMD feature bits for Speculation Control x86/cpufeatures: Add Intel feature bits for Speculation Control x86/cpufeatures: Add CPUID_7_EDX CPUID leaf module/retpoline: Warn about missing retpoline in module KVM: VMX: Make indirect call speculation safe KVM: x86: Make indirect calls in emulator speculation safe
| * | | | | KVM: VMX: Make indirect call speculation safePeter Zijlstra2018-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace indirect call with CALL_NOSPEC. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ashok Raj <ashok.raj@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: rga@amazon.de Cc: Dave Hansen <dave.hansen@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: https://lkml.kernel.org/r/20180125095843.645776917@infradead.org
| * | | | | KVM: x86: Make indirect calls in emulator speculation safePeter Zijlstra2018-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace the indirect calls with CALL_NOSPEC. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ashok Raj <ashok.raj@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: rga@amazon.de Cc: Dave Hansen <dave.hansen@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: https://lkml.kernel.org/r/20180125095843.595615683@infradead.org
* | | | | | KVM/x86: Fix wrong macro references of X86_CR0_PG_BIT and X86_CR4_PAE_BIT in ↵Tianyu Lan2018-01-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kvm_valid_sregs() kvm_valid_sregs() should use X86_CR0_PG and X86_CR4_PAE to check bit status rather than X86_CR0_PG_BIT and X86_CR4_PAE_BIT. This patch is to fix it. Fixes: f29810335965a(KVM/x86: Check input paging mode when cs.l is set) Reported-by: Jeremi Piotrowski <jeremi.piotrowski@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* | | | | | Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds2018-01-14
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 pti updates from Thomas Gleixner: "This contains: - a PTI bugfix to avoid setting reserved CR3 bits when PCID is disabled. This seems to cause issues on a virtual machine at least and is incorrect according to the AMD manual. - a PTI bugfix which disables the perf BTS facility if PTI is enabled. The BTS AUX buffer is not globally visible and causes the CPU to fault when the mapping disappears on switching CR3 to user space. A full fix which restores BTS on PTI is non trivial and will be worked on. - PTI bugfixes for EFI and trusted boot which make sure that the user space visible page table entries have the NX bit cleared - removal of dead code in the PTI pagetable setup functions - add PTI documentation - add a selftest for vsyscall to verify that the kernel actually implements what it advertises. - a sysfs interface to expose vulnerability and mitigation information so there is a coherent way for users to retrieve the status. - the initial spectre_v2 mitigations, aka retpoline: + The necessary ASM thunk and compiler support + The ASM variants of retpoline and the conversion of affected ASM code + Make LFENCE serializing on AMD so it can be used as speculation trap + The RSB fill after vmexit - initial objtool support for retpoline As I said in the status mail this is the most of the set of patches which should go into 4.15 except two straight forward patches still on hold: - the retpoline add on of LFENCE which waits for ACKs - the RSB fill after context switch Both should be ready to go early next week and with that we'll have covered the major holes of spectre_v2 and go back to normality" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (28 commits) x86,perf: Disable intel_bts when PTI security/Kconfig: Correct the Documentation reference for PTI x86/pti: Fix !PCID and sanitize defines selftests/x86: Add test_vsyscall x86/retpoline: Fill return stack buffer on vmexit x86/retpoline/irq32: Convert assembler indirect jumps x86/retpoline/checksum32: Convert assembler indirect jumps x86/retpoline/xen: Convert Xen hypercall indirect jumps x86/retpoline/hyperv: Convert assembler indirect jumps x86/retpoline/ftrace: Convert ftrace assembler indirect jumps x86/retpoline/entry: Convert entry assembler indirect jumps x86/retpoline/crypto: Convert crypto assembler indirect jumps x86/spectre: Add boot time option to select Spectre v2 mitigation x86/retpoline: Add initial retpoline support objtool: Allow alternatives to be ignored objtool: Detect jumps to retpoline thunks x86/pti: Make unpoison of pgd for trusted boot work for real x86/alternatives: Fix optimize_nops() checking sysfs/cpu: Fix typos in vulnerability documentation x86/cpu/AMD: Use LFENCE_RDTSC in preference to MFENCE_RDTSC ...
| * | | | | x86/retpoline: Fill return stack buffer on vmexitDavid Woodhouse2018-01-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In accordance with the Intel and AMD documentation, we need to overwrite all entries in the RSB on exiting a guest, to prevent malicious branch target predictions from affecting the host kernel. This is needed both for retpoline and for IBRS. [ak: numbers again for the RSB stuffing labels] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: gnomes@lxorguk.ukuu.org.uk Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: thomas.lendacky@amd.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: https://lkml.kernel.org/r/1515755487-8524-1-git-send-email-dwmw@amazon.co.uk
* | | | | | Merge branch 'kvm-insert-lfence' into kvm-masterPaolo Bonzini2018-01-11
|\ \ \ \ \ \ | | |_|_|_|/ | |/| | | | | | | | | | Topic branch for CVE-2017-5753, avoiding conflicts in the next merge window.
| * | | | | KVM: x86: Add memory barrier on vmcs field lookupAndrew Honig2018-01-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds a memory barrier when performing a lookup into the vmcs_field_to_offset_table. This is related to CVE-2017-5753. Signed-off-by: Andrew Honig <ahonig@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | | | | KVM: x86: emulate #UD while in guest modePaolo Bonzini2018-01-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commits ae1f57670703656cc9f293722c3b8b6782f8ab3f and ac9b305caa0df6f5b75d294e4b86c1027648991e. If the hardware doesn't support MOVBE, but L0 sets CPUID.01H:ECX.MOVBE in L1's emulated CPUID information, then L1 is likely to pass that CPUID bit through to L2. L2 will expect MOVBE to work, but if L1 doesn't intercept #UD, then any MOVBE instruction executed in L2 will raise #UD, and the exception will be delivered in L2. Commit ac9b305caa0df6f5b75d294e4b86c1027648991e is a better and more complete version of ae1f57670703 ("KVM: nVMX: Do not emulate #UD while in guest mode"); however, neither considers the above case. Suggested-by: Jim Mattson <jmattson@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | | | | x86: kvm: propagate register_shrinker return codeArnd Bergmann2018-01-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch "mm,vmscan: mark register_shrinker() as __must_check" is queued for 4.16 in linux-mm and adds a warning about the unchecked call to register_shrinker: arch/x86/kvm/mmu.c:5485:2: warning: ignoring return value of 'register_shrinker', declared with attribute warn_unused_result [-Wunused-result] This changes the kvm_mmu_module_init() function to fail itself when the call to register_shrinker fails. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | | | | KVM MMU: check pending exception before injecting APFHaozhong Zhang2018-01-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For example, when two APF's for page ready happen after one exit and the first one becomes pending, the second one will result in #DF. Instead, just handle the second page fault synchronously. Reported-by: Ross Zwisler <zwisler@gmail.com> Message-ID: <CAOxpaSUBf8QoOZQ1p4KfUp0jq76OKfGY4Uxs-Gg8ngReD99xww@mail.gmail.com> Reported-by: Alec Blayne <ab@tevsa.net> Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | | | | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2018-01-06
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull KVM fixes from Radim Krčmář: "s390: - Two fixes for potential bitmap overruns in the cmma migration code x86: - Clear guest provided GPRs to defeat the Project Zero PoC for CVE 2017-5715" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: kvm: vmx: Scrub hardware GPRs at VM-exit KVM: s390: prevent buffer overrun on memory hotplug during migration KVM: s390: fix cmma migration for multiple memory slots
| * | | | | | kvm: vmx: Scrub hardware GPRs at VM-exitJim Mattson2018-01-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Guest GPR values are live in the hardware GPRs at VM-exit. Do not leave any guest values in hardware GPRs after the guest GPR values are saved to the vcpu_vmx structure. This is a partial mitigation for CVE 2017-5715 and CVE 2017-5753. Specifically, it defeats the Project Zero PoC for CVE 2017-5715. Suggested-by: Eric Northup <digitaleric@google.com> Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Eric Northup <digitaleric@google.com> Reviewed-by: Benjamin Serebrin <serebrin@google.com> Reviewed-by: Andrew Honig <ahonig@google.com> [Paolo: Add AMD bits, Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | | | | | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2017-12-21
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull KVM fixes from Paolo Bonzini: "ARM fixes: - A bug in handling of SPE state for non-vhe systems - A fix for a crash on system shutdown - Three timer fixes, introduced by the timer optimizations for v4.15 x86 fixes: - fix for a WARN that was introduced in 4.15 - fix for SMM when guest uses PCID - fixes for several bugs found by syzkaller ... and a dozen papercut fixes for the kvm_stat tool" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits) tools/kvm_stat: sort '-f help' output kvm: x86: fix RSM when PCID is non-zero KVM: Fix stack-out-of-bounds read in write_mmio KVM: arm/arm64: Fix timer enable flow KVM: arm/arm64: Properly handle arch-timer IRQs after vtimer_save_state KVM: arm/arm64: timer: Don't set irq as forwarded if no usable GIC KVM: arm/arm64: Fix HYP unmapping going off limits arm64: kvm: Prevent restoring stale PMSCR_EL1 for vcpu KVM/x86: Check input paging mode when cs.l is set tools/kvm_stat: add line for totals tools/kvm_stat: stop ignoring unhandled arguments tools/kvm_stat: suppress usage information on command line errors tools/kvm_stat: handle invalid regular expressions tools/kvm_stat: add hint on '-f help' to man page tools/kvm_stat: fix child trace events accounting tools/kvm_stat: fix extra handling of 'help' with fields filter tools/kvm_stat: fix missing field update after filter change tools/kvm_stat: fix drilldown in events-by-guests mode tools/kvm_stat: fix command line option '-g' kvm: x86: fix WARN due to uninitialized guest FPU state ...
| * | | | | | kvm: x86: fix RSM when PCID is non-zeroPaolo Bonzini2017-12-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rsm_load_state_64() and rsm_enter_protected_mode() load CR3, then CR4 & ~PCIDE, then CR0, then CR4. However, setting CR4.PCIDE fails if CR3[11:0] != 0. It's probably easier in the long run to replace rsm_enter_protected_mode() with an emulator callback that sets all the special registers (like KVM_SET_SREGS would do). For now, set the PCID field of CR3 only after CR4.PCIDE is 1. Reported-by: Laszlo Ersek <lersek@redhat.com> Tested-by: Laszlo Ersek <lersek@redhat.com> Fixes: 660a5d517aaab9187f93854425c4c63f4a09195c Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: Fix stack-out-of-bounds read in write_mmioWanpeng Li2017-12-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reported by syzkaller: BUG: KASAN: stack-out-of-bounds in write_mmio+0x11e/0x270 [kvm] Read of size 8 at addr ffff8803259df7f8 by task syz-executor/32298 CPU: 6 PID: 32298 Comm: syz-executor Tainted: G OE 4.15.0-rc2+ #18 Hardware name: LENOVO ThinkCentre M8500t-N000/SHARKBAY, BIOS FBKTC1AUS 02/16/2016 Call Trace: dump_stack+0xab/0xe1 print_address_description+0x6b/0x290 kasan_report+0x28a/0x370 write_mmio+0x11e/0x270 [kvm] emulator_read_write_onepage+0x311/0x600 [kvm] emulator_read_write+0xef/0x240 [kvm] emulator_fix_hypercall+0x105/0x150 [kvm] em_hypercall+0x2b/0x80 [kvm] x86_emulate_insn+0x2b1/0x1640 [kvm] x86_emulate_instruction+0x39a/0xb90 [kvm] handle_exception+0x1b4/0x4d0 [kvm_intel] vcpu_enter_guest+0x15a0/0x2640 [kvm] kvm_arch_vcpu_ioctl_run+0x549/0x7d0 [kvm] kvm_vcpu_ioctl+0x479/0x880 [kvm] do_vfs_ioctl+0x142/0x9a0 SyS_ioctl+0x74/0x80 entry_SYSCALL_64_fastpath+0x23/0x9a The path of patched vmmcall will patch 3 bytes opcode 0F 01 C1(vmcall) to the guest memory, however, write_mmio tracepoint always prints 8 bytes through *(u64 *)val since kvm splits the mmio access into 8 bytes. This leaks 5 bytes from the kernel stack (CVE-2017-17741). This patch fixes it by just accessing the bytes which we operate on. Before patch: syz-executor-5567 [007] .... 51370.561696: kvm_mmio: mmio write len 3 gpa 0x10 val 0x1ffff10077c1010f After patch: syz-executor-13416 [002] .... 51302.299573: kvm_mmio: mmio write len 3 gpa 0x10 val 0xc1010f Reported-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM/x86: Check input paging mode when cs.l is setLan Tianyu2017-12-15
| | |_|_|/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reported by syzkaller: WARNING: CPU: 0 PID: 27962 at arch/x86/kvm/emulate.c:5631 x86_emulate_insn+0x557/0x15f0 [kvm] Modules linked in: kvm_intel kvm [last unloaded: kvm] CPU: 0 PID: 27962 Comm: syz-executor Tainted: G B W 4.15.0-rc2-next-20171208+ #32 Hardware name: Intel Corporation S1200SP/S1200SP, BIOS S1200SP.86B.01.03.0006.040720161253 04/07/2016 RIP: 0010:x86_emulate_insn+0x557/0x15f0 [kvm] RSP: 0018:ffff8807234476d0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff88072d0237a0 RCX: ffffffffa0065c4d RDX: 1ffff100e5a046f9 RSI: 0000000000000003 RDI: ffff88072d0237c8 RBP: ffff880723447728 R08: ffff88072d020000 R09: ffffffffa008d240 R10: 0000000000000002 R11: ffffed00e7d87db3 R12: ffff88072d0237c8 R13: ffff88072d023870 R14: ffff88072d0238c2 R15: ffffffffa008d080 FS: 00007f8a68666700(0000) GS:ffff880802200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002009506c CR3: 000000071fec4005 CR4: 00000000003626f0 Call Trace: x86_emulate_instruction+0x3bc/0xb70 [kvm] ? reexecute_instruction.part.162+0x130/0x130 [kvm] vmx_handle_exit+0x46d/0x14f0 [kvm_intel] ? trace_event_raw_event_kvm_entry+0xe7/0x150 [kvm] ? handle_vmfunc+0x2f0/0x2f0 [kvm_intel] ? wait_lapic_expire+0x25/0x270 [kvm] vcpu_enter_guest+0x720/0x1ef0 [kvm] ... When CS.L is set, vcpu should run in the 64 bit paging mode. Current kvm set_sregs function doesn't have such check when userspace inputs sreg values. This will lead unexpected behavior. This patch is to add checks for CS.L, EFER.LME, EFER.LMA and CR4.PAE when get SREG inputs from userspace in order to avoid unexpected behavior. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jim Mattson <jmattson@google.com> Signed-off-by: Tianyu Lan <tianyu.lan@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | kvm: x86: fix WARN due to uninitialized guest FPU statePeter Xu2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ------------[ cut here ]------------ Bad FPU state detected at kvm_put_guest_fpu+0xd8/0x2d0 [kvm], reinitializing FPU registers. WARNING: CPU: 1 PID: 4594 at arch/x86/mm/extable.c:103 ex_handler_fprestore+0x88/0x90 CPU: 1 PID: 4594 Comm: qemu-system-x86 Tainted: G B OE 4.15.0-rc2+ #10 RIP: 0010:ex_handler_fprestore+0x88/0x90 Call Trace: fixup_exception+0x4e/0x60 do_general_protection+0xff/0x270 general_protection+0x22/0x30 RIP: 0010:kvm_put_guest_fpu+0xd8/0x2d0 [kvm] RSP: 0018:ffff8803d5627810 EFLAGS: 00010246 kvm_vcpu_reset+0x3b4/0x3c0 [kvm] kvm_apic_accept_events+0x1c0/0x240 [kvm] kvm_arch_vcpu_ioctl_run+0x1658/0x2fb0 [kvm] kvm_vcpu_ioctl+0x479/0x880 [kvm] do_vfs_ioctl+0x142/0x9a0 SyS_ioctl+0x74/0x80 do_syscall_64+0x15f/0x600 where kvm_put_guest_fpu is called without a prior kvm_load_guest_fpu. To fix it, move kvm_load_guest_fpu to the very beginning of kvm_arch_vcpu_ioctl_run. Cc: stable@vger.kernel.org Fixes: f775b13eedee2f7f3c6fdd4e90fb79090ce5d339 Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | KVM: X86: Fix load RFLAGS w/o the fixed bitWanpeng Li2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | *** Guest State *** CR0: actual=0x0000000000000030, shadow=0x0000000060000010, gh_mask=fffffffffffffff7 CR4: actual=0x0000000000002050, shadow=0x0000000000000000, gh_mask=ffffffffffffe871 CR3 = 0x00000000fffbc000 RSP = 0x0000000000000000 RIP = 0x0000000000000000 RFLAGS=0x00000000 DR7 = 0x0000000000000400 ^^^^^^^^^^ The failed vmentry is triggered by the following testcase when ept=Y: #include <unistd.h> #include <sys/syscall.h> #include <string.h> #include <stdint.h> #include <linux/kvm.h> #include <fcntl.h> #include <sys/ioctl.h> long r[5]; int main() { r[2] = open("/dev/kvm", O_RDONLY); r[3] = ioctl(r[2], KVM_CREATE_VM, 0); r[4] = ioctl(r[3], KVM_CREATE_VCPU, 7); struct kvm_regs regs = { .rflags = 0, }; ioctl(r[4], KVM_SET_REGS, &regs); ioctl(r[4], KVM_RUN, 0); } X86 RFLAGS bit 1 is fixed set, userspace can simply clearing bit 1 of RFLAGS with KVM_SET_REGS ioctl which results in vmentry fails. This patch fixes it by oring X86_EFLAGS_FIXED during ioctl. Cc: stable@vger.kernel.org Suggested-by: Jim Mattson <jmattson@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Quan Xu <quan.xu0@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Jim Mattson <jmattson@google.com> Cc: stable@vger.kernel.org Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | KVM: MMU: Fix infinite loop when there is no available mmu pageWanpeng Li2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The below test case can cause infinite loop in kvm when ept=0. #include <unistd.h> #include <sys/syscall.h> #include <string.h> #include <stdint.h> #include <linux/kvm.h> #include <fcntl.h> #include <sys/ioctl.h> long r[5]; int main() { r[2] = open("/dev/kvm", O_RDONLY); r[3] = ioctl(r[2], KVM_CREATE_VM, 0); r[4] = ioctl(r[3], KVM_CREATE_VCPU, 7); ioctl(r[4], KVM_RUN, 0); } It doesn't setup the memory regions, mmu_alloc_shadow/direct_roots() in kvm return 1 when kvm fails to allocate root page table which can result in beblow infinite loop: vcpu_run() { for (;;) { r = vcpu_enter_guest()::kvm_mmu_reload() returns 1 if (r <= 0) break; if (need_resched()) cond_resched(); } } This patch fixes it by returning -ENOSPC when there is no available kvm mmu page for root page table. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: stable@vger.kernel.org Fixes: 26eeb53cf0f (KVM: MMU: Bail out immediately if there is no available mmu page) Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | | | | Merge branch 'WIP.x86-pti.entry-for-linus' of ↵Linus Torvalds2017-12-18
|\ \ \ \ \ \ | |/ / / / / |/| | / / / | | |/ / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 syscall entry code changes for PTI from Ingo Molnar: "The main changes here are Andy Lutomirski's changes to switch the x86-64 entry code to use the 'per CPU entry trampoline stack'. This, besides helping fix KASLR leaks (the pending Page Table Isolation (PTI) work), also robustifies the x86 entry code" * 'WIP.x86-pti.entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits) x86/cpufeatures: Make CPU bugs sticky x86/paravirt: Provide a way to check for hypervisors x86/paravirt: Dont patch flush_tlb_single x86/entry/64: Make cpu_entry_area.tss read-only x86/entry: Clean up the SYSENTER_stack code x86/entry/64: Remove the SYSENTER stack canary x86/entry/64: Move the IST stacks into struct cpu_entry_area x86/entry/64: Create a per-CPU SYSCALL entry trampoline x86/entry/64: Return to userspace from the trampoline stack x86/entry/64: Use a per-CPU trampoline stack for IDT entries x86/espfix/64: Stop assuming that pt_regs is on the entry stack x86/entry/64: Separate cpu_current_top_of_stack from TSS.sp0 x86/entry: Remap the TSS into the CPU entry area x86/entry: Move SYSENTER_stack to the beginning of struct tss_struct x86/dumpstack: Handle stack overflow on all stacks x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tss x86/kasan/64: Teach KASAN about the cpu_entry_area x86/mm/fixmap: Generalize the GDT fixmap mechanism, introduce struct cpu_entry_area x86/entry/gdt: Put per-CPU GDT remaps in ascending order x86/dumpstack: Add get_stack_info() support for the SYSENTER stack ...
| * | | | x86/entry: Remap the TSS into the CPU entry areaAndy Lutomirski2017-12-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This has a secondary purpose: it puts the entry stack into a region with a well-controlled layout. A subsequent patch will take advantage of this to streamline the SYSCALL entry code to be able to find it more easily. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bpetkov@suse.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Link: https://lkml.kernel.org/r/20171204150605.962042855@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tssAndy Lutomirski2017-12-17
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A future patch will move SYSENTER_stack to the beginning of cpu_tss to help detect overflow. Before this can happen, fix several code paths that hardcode assumptions about the old layout. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Link: https://lkml.kernel.org/r/20171204150605.722425540@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | KVM: x86: fix APIC page invalidationRadim Krčmář2017-12-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implementation of the unpinned APIC page didn't update the VMCS address cache when invalidation was done through range mmu notifiers. This became a problem when the page notifier was removed. Re-introduce the arch-specific helper and call it from ...range_start. Reported-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Fixes: 38b9917350cb ("kvm: vmx: Implement set_apic_access_page_addr") Fixes: 369ea8242c0f ("mm/rmap: update to new mmu_notifier semantic v2") Cc: <stable@vger.kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Tested-by: Wanpeng Li <wanpeng.li@hotmail.com> Tested-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* | | | KVM: VMX: fix page leak in hardware_setup()Jim Mattson2017-12-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | vmx_io_bitmap_b should not be allocated twice. Fixes: 23611332938d ("KVM: VMX: refactor setup of global page-sized bitmaps") Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* | | | KVM: VMX: remove I/O port 0x80 bypass on Intel hostsAndrew Honig2017-12-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes CVE-2017-1000407. KVM allows guests to directly access I/O port 0x80 on Intel hosts. If the guest floods this port with writes it generates exceptions and instability in the host kernel, leading to a crash. With this change guest writes to port 0x80 on Intel will behave the same as they currently behave on AMD systems. Prevent the flooding by removing the code that sets port 0x80 as a passthrough port. This is essentially the same as upstream patch 99f85a28a78e96d28907fe036e1671a218fee597, except that patch was for AMD chipsets and this patch is for Intel. Signed-off-by: Andrew Honig <ahonig@google.com> Signed-off-by: Jim Mattson <jmattson@google.com> Fixes: fdef3ad1b386 ("KVM: VMX: Enable io bitmaps to avoid IO port 0x80 VMEXITs") Cc: <stable@vger.kernel.org> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* | | | x86,kvm: remove KVM emulator get_fpu / put_fpuRik van Riel2017-12-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that get_fpu and put_fpu do nothing, because the scheduler will automatically load and restore the guest FPU context for us while we are in this code (deep inside the vcpu_run main loop), we can get rid of the get_fpu and put_fpu hooks. Signed-off-by: Rik van Riel <riel@redhat.com> Suggested-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | | x86,kvm: move qemu/guest FPU switching out to vcpu_runRik van Riel2017-12-05
| |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, every time a VCPU is scheduled out, the host kernel will first save the guest FPU/xstate context, then load the qemu userspace FPU context, only to then immediately save the qemu userspace FPU context back to memory. When scheduling in a VCPU, the same extraneous FPU loads and saves are done. This could be avoided by moving from a model where the guest FPU is loaded and stored with preemption disabled, to a model where the qemu userspace FPU is swapped out for the guest FPU context for the duration of the KVM_RUN ioctl. This is done under the VCPU mutex, which is also taken when other tasks inspect the VCPU FPU context, so the code should already be safe for this change. That should come as no surprise, given that s390 already has this optimization. This can fix a bug where KVM calls get_user_pages while owning the FPU, and the file system ends up requesting the FPU again: [258270.527947] __warn+0xcb/0xf0 [258270.527948] warn_slowpath_null+0x1d/0x20 [258270.527951] kernel_fpu_disable+0x3f/0x50 [258270.527953] __kernel_fpu_begin+0x49/0x100 [258270.527955] kernel_fpu_begin+0xe/0x10 [258270.527958] crc32c_pcl_intel_update+0x84/0xb0 [258270.527961] crypto_shash_update+0x3f/0x110 [258270.527968] crc32c+0x63/0x8a [libcrc32c] [258270.527975] dm_bm_checksum+0x1b/0x20 [dm_persistent_data] [258270.527978] node_prepare_for_write+0x44/0x70 [dm_persistent_data] [258270.527985] dm_block_manager_write_callback+0x41/0x50 [dm_persistent_data] [258270.527988] submit_io+0x170/0x1b0 [dm_bufio] [258270.527992] __write_dirty_buffer+0x89/0x90 [dm_bufio] [258270.527994] __make_buffer_clean+0x4f/0x80 [dm_bufio] [258270.527996] __try_evict_buffer+0x42/0x60 [dm_bufio] [258270.527998] dm_bufio_shrink_scan+0xc0/0x130 [dm_bufio] [258270.528002] shrink_slab.part.40+0x1f5/0x420 [258270.528004] shrink_node+0x22c/0x320 [258270.528006] do_try_to_free_pages+0xf5/0x330 [258270.528008] try_to_free_pages+0xe9/0x190 [258270.528009] __alloc_pages_slowpath+0x40f/0xba0 [258270.528011] __alloc_pages_nodemask+0x209/0x260 [258270.528014] alloc_pages_vma+0x1f1/0x250 [258270.528017] do_huge_pmd_anonymous_page+0x123/0x660 [258270.528021] handle_mm_fault+0xfd3/0x1330 [258270.528025] __get_user_pages+0x113/0x640 [258270.528027] get_user_pages+0x4f/0x60 [258270.528063] __gfn_to_pfn_memslot+0x120/0x3f0 [kvm] [258270.528108] try_async_pf+0x66/0x230 [kvm] [258270.528135] tdp_page_fault+0x130/0x280 [kvm] [258270.528149] kvm_mmu_page_fault+0x60/0x120 [kvm] [258270.528158] handle_ept_violation+0x91/0x170 [kvm_intel] [258270.528162] vmx_handle_exit+0x1ca/0x1400 [kvm_intel] No performance changes were detected in quick ping-pong tests on my 4 socket system, which is expected since an FPU+xstate load is on the order of 0.1us, while ping-ponging between CPUs is on the order of 20us, and somewhat noisy. Cc: stable@vger.kernel.org Signed-off-by: Rik van Riel <riel@redhat.com> Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [Fixed a bug where reset_vcpu called put_fpu without preceding load_fpu, which happened inside from KVM_CREATE_VCPU ioctl. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* | | KVM: Let KVM_SET_SIGNAL_MASK work as advertisedJan H. Schönherr2017-11-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KVM API says for the signal mask you set via KVM_SET_SIGNAL_MASK, that "any unblocked signal received [...] will cause KVM_RUN to return with -EINTR" and that "the signal will only be delivered if not blocked by the original signal mask". This, however, is only true, when the calling task has a signal handler registered for a signal. If not, signal evaluation is short-circuited for SIG_IGN and SIG_DFL, and the signal is either ignored without KVM_RUN returning or the whole process is terminated. Make KVM_SET_SIGNAL_MASK behave as advertised by utilizing logic similar to that in do_sigtimedwait() to avoid short-circuiting of signals. Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | KVM: VMX: Fix vmx->nested freeing when no SMI handlerWanpeng Li2017-11-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reported by syzkaller: ------------[ cut here ]------------ WARNING: CPU: 5 PID: 2939 at arch/x86/kvm/vmx.c:3844 free_loaded_vmcs+0x77/0x80 [kvm_intel] CPU: 5 PID: 2939 Comm: repro Not tainted 4.14.0+ #26 RIP: 0010:free_loaded_vmcs+0x77/0x80 [kvm_intel] Call Trace: vmx_free_vcpu+0xda/0x130 [kvm_intel] kvm_arch_destroy_vm+0x192/0x290 [kvm] kvm_put_kvm+0x262/0x560 [kvm] kvm_vm_release+0x2c/0x30 [kvm] __fput+0x190/0x370 task_work_run+0xa1/0xd0 do_exit+0x4d2/0x13e0 do_group_exit+0x89/0x140 get_signal+0x318/0xb80 do_signal+0x8c/0xb40 exit_to_usermode_loop+0xe4/0x140 syscall_return_slowpath+0x206/0x230 entry_SYSCALL_64_fastpath+0x98/0x9a The syzkaller testcase will execute VMXON/VMLAUCH instructions, so the vmx->nested stuff is populated, it will also issue KVM_SMI ioctl. However, the testcase is just a simple c program and not be lauched by something like seabios which implements smi_handler. Commit 05cade71cf (KVM: nSVM: fix SMI injection in guest mode) gets out of guest mode and set nested.vmxon to false for the duration of SMM according to SDM 34.14.1 "leave VMX operation" upon entering SMM. We can't alloc/free the vmx->nested stuff each time when entering/exiting SMM since it will induce more overhead. So the function vmx_pre_enter_smm() marks nested.vmxon false even if vmx->nested stuff is still populated. What it expected is em_rsm() can mark nested.vmxon to be true again. However, the smi_handler/rsm will not execute since there is no something like seabios in this scenario. The function free_nested() fails to free the vmx->nested stuff since the vmx->nested.vmxon is false which results in the above warning. This patch fixes it by also considering the no SMI handler case, luckily vmx->nested.smm.vmxon is marked according to the value of vmx->nested.vmxon in vmx_pre_enter_smm(), we can take advantage of it and free vmx->nested stuff when L1 goes down. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Fixes: 05cade71cf (KVM: nSVM: fix SMI injection in guest mode) Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | KVM: VMX: Fix rflags cache during vCPU resetWanpeng Li2017-11-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reported by syzkaller: *** Guest State *** CR0: actual=0x0000000080010031, shadow=0x0000000060000010, gh_mask=fffffffffffffff7 CR4: actual=0x0000000000002061, shadow=0x0000000000000000, gh_mask=ffffffffffffe8f1 CR3 = 0x000000002081e000 RSP = 0x000000000000fffa RIP = 0x0000000000000000 RFLAGS=0x00023000 DR7 = 0x00000000000000 ^^^^^^^^^^ ------------[ cut here ]------------ WARNING: CPU: 6 PID: 24431 at /home/kernel/linux/arch/x86/kvm//x86.c:7302 kvm_arch_vcpu_ioctl_run+0x651/0x2ea0 [kvm] CPU: 6 PID: 24431 Comm: reprotest Tainted: G W OE 4.14.0+ #26 RIP: 0010:kvm_arch_vcpu_ioctl_run+0x651/0x2ea0 [kvm] RSP: 0018:ffff880291d179e0 EFLAGS: 00010202 Call Trace: kvm_vcpu_ioctl+0x479/0x880 [kvm] do_vfs_ioctl+0x142/0x9a0 SyS_ioctl+0x74/0x80 entry_SYSCALL_64_fastpath+0x23/0x9a The failed vmentry is triggered by the following beautified testcase: #include <unistd.h> #include <sys/syscall.h> #include <string.h> #include <stdint.h> #include <linux/kvm.h> #include <fcntl.h> #include <sys/ioctl.h> long r[5]; int main() { struct kvm_debugregs dr = { 0 }; r[2] = open("/dev/kvm", O_RDONLY); r[3] = ioctl(r[2], KVM_CREATE_VM, 0); r[4] = ioctl(r[3], KVM_CREATE_VCPU, 7); struct kvm_guest_debug debug = { .control = 0xf0403, .arch = { .debugreg[6] = 0x2, .debugreg[7] = 0x2 } }; ioctl(r[4], KVM_SET_GUEST_DEBUG, &debug); ioctl(r[4], KVM_RUN, 0); } which testcase tries to setup the processor specific debug registers and configure vCPU for handling guest debug events through KVM_SET_GUEST_DEBUG. The KVM_SET_GUEST_DEBUG ioctl will get and set rflags in order to set TF bit if single step is needed. All regs' caches are reset to avail and GUEST_RFLAGS vmcs field is reset to 0x2 during vCPU reset. However, the cache of rflags is not reset during vCPU reset. The function vmx_get_rflags() returns an unreset rflags cache value since the cache is marked avail, it is 0 after boot. Vmentry fails if the rflags reserved bit 1 is 0. This patch fixes it by resetting both the GUEST_RFLAGS vmcs field and its cache to 0x2 during vCPU reset. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | KVM: X86: Fix softlockup when get the current kvmclockWanpeng Li2017-11-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | watchdog: BUG: soft lockup - CPU#6 stuck for 22s! [qemu-system-x86:10185] CPU: 6 PID: 10185 Comm: qemu-system-x86 Tainted: G OE 4.14.0-rc4+ #4 RIP: 0010:kvm_get_time_scale+0x4e/0xa0 [kvm] Call Trace: get_time_ref_counter+0x5a/0x80 [kvm] kvm_hv_process_stimers+0x120/0x5f0 [kvm] kvm_arch_vcpu_ioctl_run+0x4b4/0x1690 [kvm] kvm_vcpu_ioctl+0x33a/0x620 [kvm] do_vfs_ioctl+0xa1/0x5d0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x1e/0xa9 This can be reproduced when running kvm-unit-tests/hyperv_stimer.flat and cpu-hotplug stress simultaneously. __this_cpu_read(cpu_tsc_khz) returns 0 (set in kvmclock_cpu_down_prep()) when the pCPU is unhotplug which results in kvm_get_time_scale() gets into an infinite loop. This patch fixes it by treating the unhotplug pCPU as not using master clock. Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | KVM: lapic: Fixup LDR on load in x2apicDr. David Alan Gilbert2017-11-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In x2apic mode the LDR is fixed based on the ID rather than separately loadable like it was before x2. When kvm_apic_set_state is called, the base is set, and if it has the X2APIC_ENABLE flag set then the LDR is calculated; however that value gets overwritten by the memcpy a few lines below overwriting it with the value that came from userland. The symptom is a lack of EOI after loading the state (e.g. after a QEMU migration) and is due to the EOI bitmap being wrong due to the incorrect LDR. This was seen with a Win2016 guest under Qemu with irqchip=split whose USB mouse didn't work after a VM migration. This corresponds to RH bug: https://bugzilla.redhat.com/show_bug.cgi?id=1502591 Reported-by: Yiqian Wei <yiwei@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Cc: stable@vger.kernel.org [Applied fixup from Liran Alon. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | KVM: lapic: Split out x2apic ldr calculationDr. David Alan Gilbert2017-11-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | Split out the ldr calculation from kvm_apic_set_x2apic_id since we're about to reuse it in the following patch. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | KVM: vmx: use X86_CR4_UMIP and X86_FEATURE_UMIPPaolo Bonzini2017-11-17
| | | | | | | | | | | | | | | | | | | | | These bits were not defined until now in common code, but they are now that the kernel supports UMIP too. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | KVM: x86: Fix CPUID function for word 6 (80000001_ECX)Janakarajan Natarajan2017-11-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function for CPUID 80000001 ECX is set to 0xc0000001. Set it to 0x80000001. Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com> Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Borislav Petkov <bp@suse.de> Fixes: d6321d493319 ("KVM: x86: generalize guest_cpuid_has_ helpers") Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>