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2020-01-08KVM: x86: Add a WARN on TIF_NEED_FPU_LOAD in kvm_load_guest_fpu()Sean Christopherson
WARN once in kvm_load_guest_fpu() if TIF_NEED_FPU_LOAD is observed, as that would mean that KVM is corrupting userspace's FPU by saving unknown register state into arch.user_fpu. Add a comment to explain why KVM WARNs on TIF_NEED_FPU_LOAD instead of implementing logic similar to fpu__copy(). Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: x86: Fix potential put_fpu() w/o load_fpu() on MPX platformSean Christopherson
Unlike most state managed by XSAVE, MPX is initialized to zero on INIT. Because INITs are usually recognized in the context of a VCPU_RUN call, kvm_vcpu_reset() puts the guest's FPU so that the FPU state is resident in memory, zeros the MPX state, and reloads FPU state to hardware. But, in the unlikely event that an INIT is recognized during kvm_arch_vcpu_ioctl_get_mpstate() via kvm_apic_accept_events(), kvm_vcpu_reset() will call kvm_put_guest_fpu() without a preceding kvm_load_guest_fpu() and corrupt the guest's FPU state (and possibly userspace's FPU state as well). Given that MPX is being removed from the kernel[*], fix the bug with the simple-but-ugly approach of loading the guest's FPU during KVM_GET_MP_STATE. [*] See commit f240652b6032b ("x86/mpx: Remove MPX APIs"). Fixes: f775b13eedee2 ("x86,kvm: move qemu/guest FPU switching out to vcpu_run") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08kvm: nVMX: Aesthetic cleanup of handle_vmread and handle_vmwriteJim Mattson
Apply reverse fir tree declaration order, shorten some variable names to avoid line wrap, reformat a block comment, delete an extra blank line, and use BIT(10) instead of (1u << 10). Signed-off-by: Jim Mattson <jmattson@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Peter Shier <pshier@google.com> Reviewed-by: Oliver Upton <oupton@google.com> Reviewed-by: Jon Cargille <jcargill@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08kvm: nVMX: VMWRITE checks unsupported field before read-only fieldJim Mattson
According to the SDM, VMWRITE checks to see if the secondary source operand corresponds to an unsupported VMCS field before it checks to see if the secondary source operand corresponds to a VM-exit information field and the processor does not support writing to VM-exit information fields. Fixes: 49f705c5324aa ("KVM: nVMX: Implement VMREAD and VMWRITE") Signed-off-by: Jim Mattson <jmattson@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Peter Shier <pshier@google.com> Reviewed-by: Oliver Upton <oupton@google.com> Reviewed-by: Jon Cargille <jcargill@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08kvm: nVMX: VMWRITE checks VMCS-link pointer before VMCS fieldJim Mattson
According to the SDM, a VMWRITE in VMX non-root operation with an invalid VMCS-link pointer results in VMfailInvalid before the validity of the VMCS field in the secondary source operand is checked. For consistency, modify both handle_vmwrite and handle_vmread, even though there was no problem with the latter. Fixes: 6d894f498f5d1 ("KVM: nVMX: vmread/vmwrite: Use shadow vmcs12 if running L2") Signed-off-by: Jim Mattson <jmattson@google.com> Cc: Liran Alon <liran.alon@oracle.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Peter Shier <pshier@google.com> Reviewed-by: Oliver Upton <oupton@google.com> Reviewed-by: Jon Cargille <jcargill@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: VMX: Fix the spelling of CPU_BASED_USE_TSC_OFFSETTINGXiaoyao Li
The mis-spelling is found by checkpatch.pl, so fix them. Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: VMX: Rename NMI_PENDING to NMI_WINDOWXiaoyao Li
Rename the NMI-window exiting related definitions to match the latest Intel SDM. No functional changes. Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: VMX: Rename INTERRUPT_PENDING to INTERRUPT_WINDOWXiaoyao Li
Rename interrupt-windown exiting related definitions to match the latest Intel SDM. No functional changes. Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: x86: Fix some comment typosMiaohe Lin
Fix some typos in comment. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: X86: Convert the last users of "shorthand = 0" to use macrosPeter Xu
Change the last users of "shorthand = 0" to use APIC_DEST_NOSHORT. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: X86: Fix callers of kvm_apic_match_dest() to use correct macrosPeter Xu
Callers of kvm_apic_match_dest() should always pass in APIC_DEST_* macros for either dest_mode and short_hand parameters. Fix up all the callers of kvm_apic_match_dest() that are not following the rule. Since at it, rename the parameter from short_hand to shorthand in kvm_apic_match_dest(), as suggested by Vitaly. Reported-by: Sean Christopherson <sean.j.christopherson@intel.com> Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: X86: Drop KVM_APIC_SHORT_MASK and KVM_APIC_DEST_MASKPeter Xu
We have both APIC_SHORT_MASK and KVM_APIC_SHORT_MASK defined for the shorthand mask. Similarly, we have both APIC_DEST_MASK and KVM_APIC_DEST_MASK defined for the destination mode mask. Drop the KVM_APIC_* macros and replace the only user of them to use the APIC_DEST_* macros instead. At the meantime, move APIC_SHORT_MASK and APIC_DEST_MASK from lapic.c to lapic.h. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: X86: Use APIC_DEST_* macros properly in kvm_lapic_irq.dest_modePeter Xu
We were using either APIC_DEST_PHYSICAL|APIC_DEST_LOGICAL or 0|1 to fill in kvm_lapic_irq.dest_mode. It's fine only because in most cases when we check against dest_mode it's against APIC_DEST_PHYSICAL (which equals to 0). However, that's not consistent. We'll have problem when we want to start checking against APIC_DEST_LOGICAL, which does not equals to 1. This patch firstly introduces kvm_lapic_irq_dest_mode() helper to take any boolean of destination mode and return the APIC_DEST_* macro. Then, it replaces the 0|1 settings of irq.dest_mode with the helper. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: X86: Move irrelevant declarations out of ioapic.hPeter Xu
kvm_apic_match_dest() is declared in both ioapic.h and lapic.h. Remove the declaration in ioapic.h. kvm_apic_compare_prio() is declared in ioapic.h but defined in lapic.c. Move the declaration to lapic.h. kvm_irq_delivery_to_apic() is declared in ioapic.h but defined in irq_comm.c. Move the declaration to irq.h. hyperv.c needs to use kvm_irq_delivery_to_apic(). Include irq.h in hyperv.c. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: X86: Fix kvm_bitmap_or_dest_vcpus() to use irq shorthandPeter Xu
The 3rd parameter of kvm_apic_match_dest() is the irq shorthand, rather than the irq delivery mode. Fixes: 7ee30bc132c6 ("KVM: x86: deliver KVM IOAPIC scan request to target vCPUs") Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: explicitly set rmap_head->val to 0 in pte_list_desc_remove_entry()Miaohe Lin
When we reach here, we have desc->sptes[j] = NULL with j = 0. So we can replace desc->sptes[0] with 0 to make it more clear. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: vmx: remove unreachable statement in vmx_get_msr_feature()Miaohe Lin
We have no way to reach the final statement, remove it. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: x86: use CPUID to locate host page table reserved bitsPaolo Bonzini
The comment in kvm_get_shadow_phys_bits refers to MKTME, but the same is actually true of SME and SEV. Just use CPUID[0x8000_0008].EAX[7:0] unconditionally if available, it is simplest and works even if memory is not encrypted. Cc: stable@vger.kernel.org Reported-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-12-22Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Paolo Bonzini: "PPC: - Fix a bug where we try to do an ultracall on a system without an ultravisor KVM: - Fix uninitialised sysreg accessor - Fix handling of demand-paged device mappings - Stop spamming the console on IMPDEF sysregs - Relax mappings of writable memslots - Assorted cleanups MIPS: - Now orphan, James Hogan is stepping down x86: - MAINTAINERS change, so long Radim and thanks for all the fish - supported CPUID fixes for AMD machines without SPEC_CTRL" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: MAINTAINERS: remove Radim from KVM maintainers MAINTAINERS: Orphan KVM for MIPS kvm: x86: Host feature SSBD doesn't imply guest feature AMD_SSBD kvm: x86: Host feature SSBD doesn't imply guest feature SPEC_CTRL_SSBD KVM: PPC: Book3S HV: Don't do ultravisor calls on systems without ultravisor KVM: arm/arm64: Properly handle faulting of device mappings KVM: arm64: Ensure 'params' is initialised when looking up sys register KVM: arm/arm64: Remove excessive permission check in kvm_arch_prepare_memory_region KVM: arm64: Don't log IMP DEF sysreg traps KVM: arm64: Sanely ratelimit sysreg messages KVM: arm/arm64: vgic: Use wrapper function to lock/unlock all vcpus in kvm_vgic_create() KVM: arm/arm64: vgic: Fix potential double free dist->spis in __kvm_vgic_destroy() KVM: arm/arm64: Get rid of unused arg in cpu_init_hyp_mode()
2019-12-22Merge tag 'kvm-ppc-fixes-5.5-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-master PPC KVM fix for 5.5 - Fix a bug where we try to do an ultracall on a system without an ultravisor.
2019-12-18kvm: x86: Host feature SSBD doesn't imply guest feature AMD_SSBDJim Mattson
The host reports support for the synthetic feature X86_FEATURE_SSBD when any of the three following hardware features are set: CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] CPUID.80000008H:EBX.AMD_SSBD[bit 24] CPUID.80000008H:EBX.VIRT_SSBD[bit 25] Either of the first two hardware features implies the existence of the IA32_SPEC_CTRL MSR, but CPUID.80000008H:EBX.VIRT_SSBD[bit 25] does not. Therefore, CPUID.80000008H:EBX.AMD_SSBD[bit 24] should only be set in the guest if CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] or CPUID.80000008H:EBX.AMD_SSBD[bit 24] is set on the host. Fixes: 4c6903a0f9d76 ("KVM: x86: fix reporting of AMD speculation bug CPUID leaf") Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Jacob Xu <jacobhxu@google.com> Reviewed-by: Peter Shier <pshier@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: stable@vger.kernel.org Reported-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-12-18kvm: x86: Host feature SSBD doesn't imply guest feature SPEC_CTRL_SSBDJim Mattson
The host reports support for the synthetic feature X86_FEATURE_SSBD when any of the three following hardware features are set: CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] CPUID.80000008H:EBX.AMD_SSBD[bit 24] CPUID.80000008H:EBX.VIRT_SSBD[bit 25] Either of the first two hardware features implies the existence of the IA32_SPEC_CTRL MSR, but CPUID.80000008H:EBX.VIRT_SSBD[bit 25] does not. Therefore, CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] should only be set in the guest if CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] or CPUID.80000008H:EBX.AMD_SSBD[bit 24] is set on the host. Fixes: 0c54914d0c52a ("KVM: x86: use Intel speculation bugs and features as derived in generic x86 code") Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Jacob Xu <jacobhxu@google.com> Reviewed-by: Peter Shier <pshier@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: stable@vger.kernel.org Reported-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-12-10x86/mm/pat: Rename <asm/pat.h> => <asm/memtype.h>Ingo Molnar
pat.h is a file whose main purpose is to provide the memtype_*() APIs. PAT is the low level hardware mechanism - but the high level abstraction is memtype. So name the header <memtype.h> as well - this goes hand in hand with memtype.c and memtype_interval.c. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-12-04Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull more KVM updates from Paolo Bonzini: - PPC secure guest support - small x86 cleanup - fix for an x86-specific out-of-bounds write on a ioctl (not guest triggerable, data not attacker-controlled) * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: kvm: vmx: Stop wasting a page for guest_msrs KVM: x86: fix out-of-bounds write in KVM_GET_EMULATED_CPUID (CVE-2019-19332) Documentation: kvm: Fix mention to number of ioctls classes powerpc: Ultravisor: Add PPC_UV config option KVM: PPC: Book3S HV: Support reset of secure guest KVM: PPC: Book3S HV: Handle memory plug/unplug to secure VM KVM: PPC: Book3S HV: Radix changes for secure guest KVM: PPC: Book3S HV: Shared pages support for secure guests KVM: PPC: Book3S HV: Support for running secure guests mm: ksm: Export ksm_madvise() KVM x86: Move kvm cpuid support out of svm
2019-12-04kvm: vmx: Stop wasting a page for guest_msrsJim Mattson
We will never need more guest_msrs than there are indices in vmx_msr_index. Thus, at present, the guest_msrs array will not exceed 168 bytes. Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-12-04KVM: x86: fix out-of-bounds write in KVM_GET_EMULATED_CPUID (CVE-2019-19332)Paolo Bonzini
The bounds check was present in KVM_GET_SUPPORTED_CPUID but not KVM_GET_EMULATED_CPUID. Reported-by: syzbot+e3f4897236c4eeb8af4f@syzkaller.appspotmail.com Fixes: 84cffe499b94 ("kvm: Emulate MOVBE", 2013-10-29) Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-27KVM x86: Move kvm cpuid support out of svmPeter Gonda
Memory encryption support does not have module parameter dependencies and can be moved into the general x86 cpuid __do_cpuid_ent function. This changes maintains current behavior of passing through all of CPUID.8000001F. Suggested-by: Jim Mattson <jmattson@google.com> Signed-off-by: Peter Gonda <pgonda@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-26Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The main changes in this cycle were: - Dynamic tick (nohz) updates, perhaps most notably changes to force the tick on when needed due to lengthy in-kernel execution on CPUs on which RCU is waiting. - Linux-kernel memory consistency model updates. - Replace rcu_swap_protected() with rcu_prepace_pointer(). - Torture-test updates. - Documentation updates. - Miscellaneous fixes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits) security/safesetid: Replace rcu_swap_protected() with rcu_replace_pointer() net/sched: Replace rcu_swap_protected() with rcu_replace_pointer() net/netfilter: Replace rcu_swap_protected() with rcu_replace_pointer() net/core: Replace rcu_swap_protected() with rcu_replace_pointer() bpf/cgroup: Replace rcu_swap_protected() with rcu_replace_pointer() fs/afs: Replace rcu_swap_protected() with rcu_replace_pointer() drivers/scsi: Replace rcu_swap_protected() with rcu_replace_pointer() drm/i915: Replace rcu_swap_protected() with rcu_replace_pointer() x86/kvm/pmu: Replace rcu_swap_protected() with rcu_replace_pointer() rcu: Upgrade rcu_swap_protected() to rcu_replace_pointer() rcu: Suppress levelspread uninitialized messages rcu: Fix uninitialized variable in nocb_gp_wait() rcu: Update descriptions for rcu_future_grace_period tracepoint rcu: Update descriptions for rcu_nocb_wake tracepoint rcu: Remove obsolete descriptions for rcu_barrier tracepoint rcu: Ensure that ->rcu_urgent_qs is set before resched IPI workqueue: Convert for_each_wq to use built-in list check rcu: Several rcu_segcblist functions can be static rcu: Remove unused function hlist_bl_del_init_rcu() Documentation: Rename rcu_node_context_switch() to rcu_note_context_switch() ...
2019-11-26Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "The main kernel side changes in this cycle were: - Various Intel-PT updates and optimizations (Alexander Shishkin) - Prohibit kprobes on Xen/KVM emulate prefixes (Masami Hiramatsu) - Add support for LSM and SELinux checks to control access to the perf syscall (Joel Fernandes) - Misc other changes, optimizations, fixes and cleanups - see the shortlog for details. There were numerous tooling changes as well - 254 non-merge commits. Here are the main changes - too many to list in detail: - Enhancements to core tooling infrastructure, perf.data, libperf, libtraceevent, event parsing, vendor events, Intel PT, callchains, BPF support and instruction decoding. - There were updates to the following tools: perf annotate perf diff perf inject perf kvm perf list perf maps perf parse perf probe perf record perf report perf script perf stat perf test perf trace - And a lot of other changes: please see the shortlog and Git log for more details" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (279 commits) perf parse: Fix potential memory leak when handling tracepoint errors perf probe: Fix spelling mistake "addrees" -> "address" libtraceevent: Fix memory leakage in copy_filter_type libtraceevent: Fix header installation perf intel-bts: Does not support AUX area sampling perf intel-pt: Add support for decoding AUX area samples perf intel-pt: Add support for recording AUX area samples perf pmu: When using default config, record which bits of config were changed by the user perf auxtrace: Add support for queuing AUX area samples perf session: Add facility to peek at all events perf auxtrace: Add support for dumping AUX area samples perf inject: Cut AUX area samples perf record: Add aux-sample-size config term perf record: Add support for AUX area sampling perf auxtrace: Add support for AUX area sample recording perf auxtrace: Move perf_evsel__find_pmu() perf record: Add a function to test for kernel support for AUX area sampling perf tools: Add kernel AUX area sampling definitions perf/core: Make the mlock accounting simple again perf report: Jump to symbol source view from total cycles view ...
2019-11-26Merge branch 'x86-iopl-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 iopl updates from Ingo Molnar: "This implements a nice simplification of the iopl and ioperm code that Thomas Gleixner discovered: we can implement the IO privilege features of the iopl system call by using the IO permission bitmap in permissive mode, while trapping CLI/STI/POPF/PUSHF uses in user-space if they change the interrupt flag. This implements that feature, with testing facilities and related cleanups" [ "Simplification" may be an over-statement. The main goal is to avoid the cli/sti of iopl by effectively implementing the IO port access parts of iopl in terms of ioperm. This may end up not workign well in case people actually depend on cli/sti being available, or if there are mixed uses of iopl and ioperm. We will see.. - Linus ] * 'x86-iopl-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) x86/ioperm: Fix use of deprecated config option x86/entry/32: Clarify register saving in __switch_to_asm() selftests/x86/iopl: Extend test to cover IOPL emulation x86/ioperm: Extend IOPL config to control ioperm() as well x86/iopl: Remove legacy IOPL option x86/iopl: Restrict iopl() permission scope x86/iopl: Fixup misleading comment selftests/x86/ioperm: Extend testing so the shared bitmap is exercised x86/ioperm: Share I/O bitmap if identical x86/ioperm: Remove bitmap if all permissions dropped x86/ioperm: Move TSS bitmap update to exit to user work x86/ioperm: Add bitmap sequence number x86/ioperm: Move iobitmap data into a struct x86/tss: Move I/O bitmap data into a seperate struct x86/io: Speedup schedule out of I/O bitmap user x86/ioperm: Avoid bitmap allocation if no permissions are set x86/ioperm: Simplify first ioperm() invocation logic x86/iopl: Cleanup include maze x86/tss: Fix and move VMX BUILD_BUG_ON() x86/cpu: Unify cpu_init() ...
2019-11-26Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "The main changes in this cycle were: - Cross-arch changes to move the linker sections for NOTES and EXCEPTION_TABLE into the RO_DATA area, where they belong on most architectures. (Kees Cook) - Switch the x86 linker fill byte from x90 (NOP) to 0xcc (INT3), to trap jumps into the middle of those padding areas instead of sliding execution. (Kees Cook) - A thorough cleanup of symbol definitions within x86 assembler code. The rather randomly named macros got streamlined around a (hopefully) straightforward naming scheme: SYM_START(name, linkage, align...) SYM_END(name, sym_type) SYM_FUNC_START(name) SYM_FUNC_END(name) SYM_CODE_START(name) SYM_CODE_END(name) SYM_DATA_START(name) SYM_DATA_END(name) etc - with about three times of these basic primitives with some label, local symbol or attribute variant, expressed via postfixes. No change in functionality intended. (Jiri Slaby) - Misc other changes, cleanups and smaller fixes" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (67 commits) x86/entry/64: Remove pointless jump in paranoid_exit x86/entry/32: Remove unused resume_userspace label x86/build/vdso: Remove meaningless CFLAGS_REMOVE_*.o m68k: Convert missed RODATA to RO_DATA x86/vmlinux: Use INT3 instead of NOP for linker fill bytes x86/mm: Report actual image regions in /proc/iomem x86/mm: Report which part of kernel image is freed x86/mm: Remove redundant address-of operators on addresses xtensa: Move EXCEPTION_TABLE to RO_DATA segment powerpc: Move EXCEPTION_TABLE to RO_DATA segment parisc: Move EXCEPTION_TABLE to RO_DATA segment microblaze: Move EXCEPTION_TABLE to RO_DATA segment ia64: Move EXCEPTION_TABLE to RO_DATA segment h8300: Move EXCEPTION_TABLE to RO_DATA segment c6x: Move EXCEPTION_TABLE to RO_DATA segment arm64: Move EXCEPTION_TABLE to RO_DATA segment alpha: Move EXCEPTION_TABLE to RO_DATA segment x86/vmlinux: Move EXCEPTION_TABLE to RO_DATA segment x86/vmlinux: Actually use _etext for the end of the text segment vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA ...
2019-11-25Merge branch 'x86/core' into perf/core, to resolve conflicts and to pick up ↵Ingo Molnar
completed topic tree Conflicts: tools/perf/check-headers.sh Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-23kvm: nVMX: Relax guest IA32_FEATURE_CONTROL constraintsJim Mattson
Commit 37e4c997dadf ("KVM: VMX: validate individual bits of guest MSR_IA32_FEATURE_CONTROL") broke the KVM_SET_MSRS ABI by instituting new constraints on the data values that kvm would accept for the guest MSR, IA32_FEATURE_CONTROL. Perhaps these constraints should have been opt-in via a new KVM capability, but they were applied indiscriminately, breaking at least one existing hypervisor. Relax the constraints to allow either or both of FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX and FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX to be set when nVMX is enabled. This change is sufficient to fix the aforementioned breakage. Fixes: 37e4c997dadf ("KVM: VMX: validate individual bits of guest MSR_IA32_FEATURE_CONTROL") Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-23KVM: x86: Grab KVM's srcu lock when setting nested stateSean Christopherson
Acquire kvm->srcu for the duration of ->set_nested_state() to fix a bug where nVMX derefences ->memslots without holding ->srcu or ->slots_lock. The other half of nested migration, ->get_nested_state(), does not need to acquire ->srcu as it is a purely a dump of internal KVM (and CPU) state to userspace. Detected as an RCU lockdep splat that is 100% reproducible by running KVM's state_test selftest with CONFIG_PROVE_LOCKING=y. Note that the failing function, kvm_is_visible_gfn(), is only checking the validity of a gfn, it's not actually accessing guest memory (which is more or less unsupported during vmx_set_nested_state() due to incorrect MMU state), i.e. vmx_set_nested_state() itself isn't fundamentally broken. In any case, setting nested state isn't a fast path so there's no reason to go out of our way to avoid taking ->srcu. ============================= WARNING: suspicious RCU usage 5.4.0-rc7+ #94 Not tainted ----------------------------- include/linux/kvm_host.h:626 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by evmcs_test/10939: #0: ffff88826ffcb800 (&vcpu->mutex){+.+.}, at: kvm_vcpu_ioctl+0x85/0x630 [kvm] stack backtrace: CPU: 1 PID: 10939 Comm: evmcs_test Not tainted 5.4.0-rc7+ #94 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Call Trace: dump_stack+0x68/0x9b kvm_is_visible_gfn+0x179/0x180 [kvm] mmu_check_root+0x11/0x30 [kvm] fast_cr3_switch+0x40/0x120 [kvm] kvm_mmu_new_cr3+0x34/0x60 [kvm] nested_vmx_load_cr3+0xbd/0x1f0 [kvm_intel] nested_vmx_enter_non_root_mode+0xab8/0x1d60 [kvm_intel] vmx_set_nested_state+0x256/0x340 [kvm_intel] kvm_arch_vcpu_ioctl+0x491/0x11a0 [kvm] kvm_vcpu_ioctl+0xde/0x630 [kvm] do_vfs_ioctl+0xa2/0x6c0 ksys_ioctl+0x66/0x70 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x54/0x200 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f59a2b95f47 Fixes: 8fcc4b5923af5 ("kvm: nVMX: Introduce KVM_CAP_NESTED_STATE") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-23KVM: x86: Open code shared_msr_update() in its only callerSean Christopherson
Fold shared_msr_update() into its sole user to eliminate its pointless bounds check, its godawful printk, its misleading comment (it's called under a global lock), and its woefully inaccurate name. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-23KVM: x86: Remove a spurious export of a static functionSean Christopherson
A recent change inadvertently exported a static function, which results in modpost throwing a warning. Fix it. Fixes: cbbaa2727aa3 ("KVM: x86: fix presentation of TSX feature in ARCH_CAPABILITIES") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Cc: stable@vger.kernel.org Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-21KVM: x86: create mmu/ subdirectoryPaolo Bonzini
Preparatory work for shattering mmu.c into multiple files. Besides making it easier to follow, this will also make it possible to write unit tests for various parts. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-21KVM: nVMX: Remove unnecessary TLB flushes on L1<->L2 switches when L1 use ↵Liran Alon
apic-access-page According to Intel SDM section 28.3.3.3/28.3.3.4 Guidelines for Use of the INVVPID/INVEPT Instruction, the hypervisor needs to execute INVVPID/INVEPT X in case CPU executes VMEntry with VPID/EPTP X and either: "Virtualize APIC accesses" VM-execution control was changed from 0 to 1, OR the value of apic_access_page was changed. In the nested case, the burden falls on L1, unless L0 enables EPT in vmcs02 but L1 enables neither EPT nor VPID in vmcs12. For this reason prepare_vmcs02() and load_vmcs12_host_state() have special code to request a TLB flush in case L1 does not use EPT but it uses "virtualize APIC accesses". This special case however is not necessary. On a nested vmentry the physical TLB will already be flushed except if all the following apply: * L0 uses VPID * L1 uses VPID * L0 can guarantee TLB entries populated while running L1 are tagged differently than TLB entries populated while running L2. If the first condition is false, the processor will flush the TLB on vmentry to L2. If the second or third condition are false, prepare_vmcs02() will request KVM_REQ_TLB_FLUSH. However, even if both are true, no extra TLB flush is needed to handle the APIC access page: * if L1 doesn't use VPID, the second condition doesn't hold and the TLB will be flushed anyway. * if L1 uses VPID, it has to flush the TLB itself with INVVPID and section 28.3.3.3 doesn't apply to L0. * even INVEPT is not needed because, if L0 uses EPT, it uses different EPTP when running L2 than L1 (because guest_mode is part of mmu-role). In this case SDM section 28.3.3.4 doesn't apply. Similarly, examining nested_vmx_vmexit()->load_vmcs12_host_state(), one could note that L0 won't flush TLB only in cases where SDM sections 28.3.3.3 and 28.3.3.4 don't apply. In particular, if L0 uses different VPIDs for L1 and L2 (i.e. vmx->vpid != vmx->nested.vpid02), section 28.3.3.3 doesn't apply. Thus, remove this flush from prepare_vmcs02() and nested_vmx_vmexit(). Side-note: This patch can be viewed as removing parts of commit fb6c81984313 ("kvm: vmx: Flush TLB when the APIC-access address changes”) that is not relevant anymore since commit 1313cc2bd8f6 ("kvm: mmu: Add guest_mode to kvm_mmu_page_role”). i.e. The first commit assumes that if L0 use EPT and L1 doesn’t use EPT, then L0 will use same EPTP for both L0 and L1. Which indeed required L0 to execute INVEPT before entering L2 guest. This assumption is not true anymore since when guest_mode was added to mmu-role. Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-21KVM: x86: remove set but not used variable 'called'Mao Wenan
Fixes gcc '-Wunused-but-set-variable' warning: arch/x86/kvm/x86.c: In function kvm_make_scan_ioapic_request_mask: arch/x86/kvm/x86.c:7911:7: warning: variable called set but not used [-Wunused-but-set-variable] It is not used since commit 7ee30bc132c6 ("KVM: x86: deliver KVM IOAPIC scan request to target vCPUs") Signed-off-by: Mao Wenan <maowenan@huawei.com> Fixes: 7ee30bc132c6 ("KVM: x86: deliver KVM IOAPIC scan request to target vCPUs") Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-21KVM: nVMX: Do not mark vmcs02->apic_access_page as dirty when unpinningLiran Alon
vmcs->apic_access_page is simply a token that the hypervisor puts into the PFN of a 4KB EPTE (or PTE if using shadow-paging) that triggers APIC-access VMExit or APIC virtualization logic whenever a CPU running in VMX non-root mode read/write from/to this PFN. As every write either triggers an APIC-access VMExit or write is performed on vmcs->virtual_apic_page, the PFN pointed to by vmcs->apic_access_page should never actually be touched by CPU. Therefore, there is no need to mark vmcs02->apic_access_page as dirty after unpin it on L2->L1 emulated VMExit or when L1 exit VMX operation. Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-21Merge branch 'kvm-tsx-ctrl' into HEADPaolo Bonzini
Conflicts: arch/x86/kvm/vmx/vmx.c
2019-11-21KVM: vmx: use MSR_IA32_TSX_CTRL to hard-disable TSX on guest that lack itPaolo Bonzini
If X86_FEATURE_RTM is disabled, the guest should not be able to access MSR_IA32_TSX_CTRL. We can therefore use it in KVM to force all transactions from the guest to abort. Tested-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-21KVM: vmx: implement MSR_IA32_TSX_CTRL disable RTM functionalityPaolo Bonzini
The current guest mitigation of TAA is both too heavy and not really sufficient. It is too heavy because it will cause some affected CPUs (those that have MDS_NO but lack TAA_NO) to fall back to VERW and get the corresponding slowdown. It is not really sufficient because it will cause the MDS_NO bit to disappear upon microcode update, so that VMs started before the microcode update will not be runnable anymore afterwards, even with tsx=on. Instead, if tsx=on on the host, we can emulate MSR_IA32_TSX_CTRL for the guest and let it run without the VERW mitigation. Even though MSR_IA32_TSX_CTRL is quite heavyweight, and we do not want to write it on every vmentry, we can use the shared MSR functionality because the host kernel need not protect itself from TSX-based side-channels. Tested-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-21KVM: x86: implement MSR_IA32_TSX_CTRL effect on CPUIDPaolo Bonzini
Because KVM always emulates CPUID, the CPUID clear bit (bit 1) of MSR_IA32_TSX_CTRL must be emulated "manually" by the hypervisor when performing said emulation. Right now neither kvm-intel.ko nor kvm-amd.ko implement MSR_IA32_TSX_CTRL but this will change in the next patch. Reviewed-by: Jim Mattson <jmattson@google.com> Tested-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-21KVM: x86: do not modify masked bits of shared MSRsPaolo Bonzini
"Shared MSRs" are guest MSRs that are written to the host MSRs but keep their value until the next return to userspace. They support a mask, so that some bits keep the host value, but this mask is only used to skip an unnecessary MSR write and the value written to the MSR is always the guest MSR. Fix this and, while at it, do not update smsr->values[slot].curr if for whatever reason the wrmsr fails. This should only happen due to reserved bits, so the value written to smsr->values[slot].curr will not match when the user-return notifier and the host value will always be restored. However, it is untidy and in rare cases this can actually avoid spurious WRMSRs on return to userspace. Cc: stable@vger.kernel.org Reviewed-by: Jim Mattson <jmattson@google.com> Tested-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-21KVM: x86: fix presentation of TSX feature in ARCH_CAPABILITIESPaolo Bonzini
KVM does not implement MSR_IA32_TSX_CTRL, so it must not be presented to the guests. It is also confusing to have !ARCH_CAP_TSX_CTRL_MSR && !RTM && ARCH_CAP_TAA_NO: lack of MSR_IA32_TSX_CTRL suggests TSX was not hidden (it actually was), yet the value says that TSX is not vulnerable to microarchitectural data sampling. Fix both. Cc: stable@vger.kernel.org Tested-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-20KVM: nVMX: Assume TLB entries of L1 and L2 are tagged differently if L0 use EPTLiran Alon
Since commit 1313cc2bd8f6 ("kvm: mmu: Add guest_mode to kvm_mmu_page_role"), guest_mode was added to mmu-role and therefore if L0 use EPT, it will always run L1 and L2 with different EPTP. i.e. EPTP01!=EPTP02. Because TLB entries are tagged with EP4TA, KVM can assume TLB entries populated while running L2 are tagged differently than TLB entries populated while running L1. Therefore, update nested_has_guest_tlb_tag() to consider if L0 use EPT instead of if L1 use EPT. Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-20KVM: x86: Unexport kvm_vcpu_reload_apic_access_page()Liran Alon
The function is only used in kvm.ko module. Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-20KVM: nVMX: add CR4_LA57 bit to nested CR4_FIXED1Chenyi Qiang
When L1 guest uses 5-level paging, it fails vm-entry to L2 due to invalid host-state. It needs to add CR4_LA57 bit to nested CR4_FIXED1 MSR. Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-20KVM: nVMX: Use semi-colon instead of comma for exit-handlers initializationLiran Alon
Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>