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2019-10-04Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds8-116/+167
Pull KVM fixes from Paolo Bonzini: "ARM and x86 bugfixes of all kinds. The most visible one is that migrating a nested hypervisor has always been busted on Broadwell and newer processors, and that has finally been fixed" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits) KVM: x86: omit "impossible" pmu MSRs from MSR list KVM: nVMX: Fix consistency check on injected exception error code KVM: x86: omit absent pmu MSRs from MSR list selftests: kvm: Fix libkvm build error kvm: vmx: Limit guest PMCs to those supported on the host kvm: x86, powerpc: do not allow clearing largepages debugfs entry KVM: selftests: x86: clarify what is reported on KVM_GET_MSRS failure KVM: VMX: Set VMENTER_L1D_FLUSH_NOT_REQUIRED if !X86_BUG_L1TF selftests: kvm: add test for dirty logging inside nested guests KVM: x86: fix nested guest live migration with PML KVM: x86: assign two bits to track SPTE kinds KVM: x86: Expose XSAVEERPTR to the guest kvm: x86: Enumerate support for CLZERO instruction kvm: x86: Use AMD CPUID semantics for AMD vCPUs kvm: x86: Improve emulation of CPUID leaves 0BH and 1FH KVM: X86: Fix userspace set invalid CR4 kvm: x86: Fix a spurious -E2BIG in __do_cpuid_func KVM: LAPIC: Loosen filter for adaptive tuning of lapic_timer_advance_ns KVM: arm/arm64: vgic: Use the appropriate TRACE_INCLUDE_PATH arm64: KVM: Kill hyp_alternate_select() ...
2019-10-04Merge tag 'for-linus-5.4-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tipLinus Torvalds1-13/+1
Pull xen fixes and cleanups from Juergen Gross: - a fix in the Xen balloon driver avoiding hitting a BUG_ON() in some cases, plus a follow-on cleanup series for that driver - a patch for introducing non-blocking EFI callbacks in Xen's EFI driver, plu a cleanup patch for Xen EFI handling merging the x86 and ARM arch specific initialization into the Xen EFI driver - a fix of the Xen xenbus driver avoiding a self-deadlock when cleaning up after a user process has died - a fix for Xen on ARM after removal of ZONE_DMA - a cleanup patch for avoiding build warnings for Xen on ARM * tag 'for-linus-5.4-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/xenbus: fix self-deadlock after killing user process xen/efi: have a common runtime setup function arm: xen: mm: use __GPF_DMA32 for arm64 xen/balloon: Clear PG_offline in balloon_retrieve() xen/balloon: Mark pages PG_offline in balloon_append() xen/balloon: Drop __balloon_append() xen/balloon: Set pages PageOffline() in balloon_add_region() ARM: xen: unexport HYPERVISOR_platform_op function xen/efi: Set nonblocking callbacks
2019-10-04KVM: x86: omit "impossible" pmu MSRs from MSR listPaolo Bonzini1-16/+2
INTEL_PMC_MAX_GENERIC is currently 32, which exceeds the 18 contiguous MSR indices reserved by Intel for event selectors. Since some machines actually have MSRs past the reserved range, filtering them against x86_pmu.num_counters_gp may have false positives. Cut the list to 18 entries to avoid this. Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com> Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Jim Mattson <jamttson@google.com> Fixes: e2ada66ec418 ("kvm: x86: Add Intel PMU MSRs to msrs_to_save[]", 2019-08-21) Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-03KVM: nVMX: Fix consistency check on injected exception error codeSean Christopherson1-1/+1
Current versions of Intel's SDM incorrectly state that "bits 31:15 of the VM-Entry exception error-code field" must be zero. In reality, bits 31:16 must be zero, i.e. error codes are 16-bit values. The bogus error code check manifests as an unexpected VM-Entry failure due to an invalid code field (error number 7) in L1, e.g. when injecting a #GP with error_code=0x9f00. Nadav previously reported the bug[*], both to KVM and Intel, and fixed the associated kvm-unit-test. [*] https://patchwork.kernel.org/patch/11124749/ Reported-by: Nadav Amit <namit@vmware.com> Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-03KVM: x86: omit absent pmu MSRs from MSR listPaolo Bonzini1-2/+12
INTEL_PMC_MAX_GENERIC is currently 32, which exceeds the 18 contiguous MSR indices reserved by Intel for event selectors. Since some machines actually have MSRs past the reserved range, these may survive the filtering of msrs_to_save array and would be rejected by KVM_GET/SET_MSR. To avoid this, cut the list to whatever CPUID reports for the host's architectural PMU. Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com> Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Jim Mattson <jmattson@google.com> Fixes: e2ada66ec418 ("kvm: x86: Add Intel PMU MSRs to msrs_to_save[]", 2019-08-21) Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-02xen/efi: have a common runtime setup functionJuergen Gross1-15/+1
Today the EFI runtime functions are setup in architecture specific code (x86 and arm), with the functions themselves living in drivers/xen as they are not architecture dependent. As the setup is exactly the same for arm and x86 move the setup to drivers/xen, too. This at once removes the need to make the single functions global visible. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> [boris: "Dropped EXPORT_SYMBOL_GPL(xen_efi_runtime_setup)"] Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2019-10-01kvm: vmx: Limit guest PMCs to those supported on the hostJim Mattson1-2/+5
KVM can only virtualize as many PMCs as the host supports. Limit the number of generic counters and fixed counters to the number of corresponding counters supported on the host, rather than to INTEL_PMC_MAX_GENERIC and INTEL_PMC_MAX_FIXED, respectively. Note that INTEL_PMC_MAX_GENERIC is currently 32, which exceeds the 18 contiguous MSR indices reserved by Intel for event selectors. Since the existing code relies on a contiguous range of MSR indices for event selectors, it can't possibly work for more than 18 general purpose counters. Fixes: f5132b01386b5a ("KVM: Expose a version 2 architectural PMU to a guests") Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Marc Orr <marcorr@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-01xen/efi: Set nonblocking callbacksRoss Lagerwall1-0/+2
Other parts of the kernel expect these nonblocking EFI callbacks to exist and crash when running under Xen. Since the implementations of xen_efi_set_variable() and xen_efi_query_variable_info() do not take any locks, use them for the nonblocking callbacks too. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-09-30kvm: x86, powerpc: do not allow clearing largepages debugfs entryPaolo Bonzini1-3/+3
The largepages debugfs entry is incremented/decremented as shadow pages are created or destroyed. Clearing it will result in an underflow, which is harmless to KVM but ugly (and could be misinterpreted by tools that use debugfs information), so make this particular statistic read-only. Cc: kvm-ppc@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-28Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+1
Pull x86 fix from Ingo Molnar: "A kexec fix for the case when GCC_PLUGIN_STACKLEAK=y is enabled" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/purgatory: Disable the stackleak GCC plugin for the purgatory
2019-09-28Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-securityLinus Torvalds11-15/+66
Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ...
2019-09-27Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds22-384/+731
Pull more KVM updates from Paolo Bonzini: "x86 KVM changes: - The usual accuracy improvements for nested virtualization - The usual round of code cleanups from Sean - Added back optimizations that were prematurely removed in 5.2 (the bare minimum needed to fix the regression was in 5.3-rc8, here comes the rest) - Support for UMWAIT/UMONITOR/TPAUSE - Direct L2->L0 TLB flushing when L0 is Hyper-V and L1 is KVM - Tell Windows guests if SMT is disabled on the host - More accurate detection of vmexit cost - Revert a pvqspinlock pessimization" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (56 commits) KVM: nVMX: cleanup and fix host 64-bit mode checks KVM: vmx: fix build warnings in hv_enable_direct_tlbflush() on i386 KVM: x86: Don't check kvm_rebooting in __kvm_handle_fault_on_reboot() KVM: x86: Drop ____kvm_handle_fault_on_reboot() KVM: VMX: Add error handling to VMREAD helper KVM: VMX: Optimize VMX instruction error and fault handling KVM: x86: Check kvm_rebooting in kvm_spurious_fault() KVM: selftests: fix ucall on x86 Revert "locking/pvqspinlock: Don't wait if vCPU is preempted" kvm: nvmx: limit atomic switch MSRs kvm: svm: Intercept RDPRU kvm: x86: Add "significant index" flag to a few CPUID leaves KVM: x86/mmu: Skip invalid pages during zapping iff root_count is zero KVM: x86/mmu: Explicitly track only a single invalid mmu generation KVM: x86/mmu: Revert "KVM: x86/mmu: Remove is_obsolete() call" KVM: x86/mmu: Revert "Revert "KVM: MMU: reclaim the zapped-obsolete page first"" KVM: x86/mmu: Revert "Revert "KVM: MMU: collapse TLB flushes when zap all pages"" KVM: x86/mmu: Revert "Revert "KVM: MMU: zap pages in batch"" KVM: x86/mmu: Revert "Revert "KVM: MMU: add tracepoint for kvm_mmu_invalidate_all_pages"" KVM: x86/mmu: Revert "Revert "KVM: MMU: show mmu_valid_gen in shadow page related tracepoints"" ...
2019-09-27KVM: VMX: Set VMENTER_L1D_FLUSH_NOT_REQUIRED if !X86_BUG_L1TFWaiman Long1-6/+9
The l1tf_vmx_mitigation is only set to VMENTER_L1D_FLUSH_NOT_REQUIRED when the ARCH_CAPABILITIES MSR indicates that L1D flush is not required. However, if the CPU is not affected by L1TF, l1tf_vmx_mitigation will still be set to VMENTER_L1D_FLUSH_AUTO. This is certainly not the best option for a !X86_BUG_L1TF CPU. So force l1tf_vmx_mitigation to VMENTER_L1D_FLUSH_NOT_REQUIRED to make it more explicit in case users are checking the vmentry_l1d_flush parameter. Signed-off-by: Waiman Long <longman@redhat.com> [Patch rewritten accoring to Borislav Petkov's suggestion. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-27KVM: x86: fix nested guest live migration with PMLPaolo Bonzini1-7/+32
Shadow paging is fundamentally incompatible with the page-modification log, because the GPAs in the log come from the wrong memory map. In particular, for the EPT page-modification log, the GPAs in the log come from L2 rather than L1. (If there was a non-EPT page-modification log, we couldn't use it for shadow paging because it would log GVAs rather than GPAs). Therefore, we need to rely on write protection to record dirty pages. This has the side effect of bypassing PML, since writes now result in an EPT violation vmexit. This is relatively easy to add to KVM, because pretty much the only place that needs changing is spte_clear_dirty. The first access to the page already goes through the page fault path and records the correct GPA; it's only subsequent accesses that are wrong. Therefore, we can equip set_spte (where the first access happens) to record that the SPTE will have to be write protected, and then spte_clear_dirty will use this information to do the right thing. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-27KVM: x86: assign two bits to track SPTE kindsPaolo Bonzini2-17/+18
Currently, we are overloading SPTE_SPECIAL_MASK to mean both "A/D bits unavailable" and MMIO, where the difference between the two is determined by mio_mask and mmio_value. However, the next patch will need two bits to distinguish availability of A/D bits from write protection. So, while at it give MMIO its own bit pattern, and move the two bits from bit 62 to bits 52..53 since Intel is allocating EPT page table bits from the top. Reviewed-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-26mm: treewide: clarify pgtable_page_{ctor,dtor}() namingMark Rutland1-1/+1
The naming of pgtable_page_{ctor,dtor}() seems to have confused a few people, and until recently arm64 used these erroneously/pointlessly for other levels of page table. To make it incredibly clear that these only apply to the PTE level, and to align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them to pgtable_pte_page_{ctor,dtor}(). These changes were generated with the following shell script: ---- git grep -lw 'pgtable_page_.tor' | while read FILE; do sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE; sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE; done ---- ... with the documentation re-flowed to remain under 80 columns, and whitespace fixed up in macros to keep backslashes aligned. There should be no functional change as a result of this patch. Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.com Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-26KVM: x86: Expose XSAVEERPTR to the guestSebastian Andrzej Siewior1-3/+3
I was surprised to see that the guest reported `fxsave_leak' while the host did not. After digging deeper I noticed that the bits are simply masked out during enumeration. The XSAVEERPTR feature is actually a bug fix on AMD which means the kernel can disable a workaround. Pass XSAVEERPTR to the guest if available on the host. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-26kvm: x86: Enumerate support for CLZERO instructionJim Mattson1-2/+3
CLZERO is available to the guest if it is supported on the host. Therefore, enumerate support for the instruction in KVM_GET_SUPPORTED_CPUID whenever it is supported on the host. Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-26kvm: x86: Use AMD CPUID semantics for AMD vCPUsJim Mattson1-2/+4
When the guest CPUID information represents an AMD vCPU, return all zeroes for queries of undefined CPUID leaves, whether or not they are in range. Signed-off-by: Jim Mattson <jmattson@google.com> Fixes: bd22f5cfcfe8f6 ("KVM: move and fix substitue search for missing CPUID entries") Reviewed-by: Marc Orr <marcorr@google.com> Reviewed-by: Peter Shier <pshier@google.com> Reviewed-by: Jacob Xu <jacobhxu@google.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-26kvm: x86: Improve emulation of CPUID leaves 0BH and 1FHJim Mattson1-36/+47
For these CPUID leaves, the EDX output is not dependent on the ECX input (i.e. the SIGNIFCANT_INDEX flag doesn't apply to EDX). Furthermore, the low byte of the ECX output is always identical to the low byte of the ECX input. KVM does not produce the correct ECX and EDX outputs for any undefined subleaves beyond the first. Special-case these CPUID leaves in kvm_cpuid, so that the ECX and EDX outputs are properly generated for all undefined subleaves. Fixes: 0771671749b59a ("KVM: Enhance guest cpuid management") Fixes: a87f2d3a6eadab ("KVM: x86: Add Intel CPUID.1F cpuid emulation support") Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Marc Orr <marcorr@google.com> Reviewed-by: Peter Shier <pshier@google.com> Reviewed-by: Jacob Xu <jacobhxu@google.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-26KVM: X86: Fix userspace set invalid CR4Wanpeng Li1-17/+21
Reported by syzkaller: WARNING: CPU: 0 PID: 6544 at /home/kernel/data/kvm/arch/x86/kvm//vmx/vmx.c:4689 handle_desc+0x37/0x40 [kvm_intel] CPU: 0 PID: 6544 Comm: a.out Tainted: G OE 5.3.0-rc4+ #4 RIP: 0010:handle_desc+0x37/0x40 [kvm_intel] Call Trace: vmx_handle_exit+0xbe/0x6b0 [kvm_intel] vcpu_enter_guest+0x4dc/0x18d0 [kvm] kvm_arch_vcpu_ioctl_run+0x407/0x660 [kvm] kvm_vcpu_ioctl+0x3ad/0x690 [kvm] do_vfs_ioctl+0xa2/0x690 ksys_ioctl+0x6d/0x80 __x64_sys_ioctl+0x1a/0x20 do_syscall_64+0x74/0x720 entry_SYSCALL_64_after_hwframe+0x49/0xbe When CR4.UMIP is set, guest should have UMIP cpuid flag. Current kvm set_sregs function doesn't have such check when userspace inputs sregs values. SECONDARY_EXEC_DESC is enabled on writes to CR4.UMIP in vmx_set_cr4 though guest doesn't have UMIP cpuid flag. The testcast triggers handle_desc warning when executing ltr instruction since guest architectural CR4 doesn't set UMIP. This patch fixes it by adding valid CR4 and CPUID combination checking in __set_sregs. syzkaller source: https://syzkaller.appspot.com/x/repro.c?x=138efb99600000 Reported-by: syzbot+0f1819555fbdce992df9@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-26kvm: x86: Fix a spurious -E2BIG in __do_cpuid_funcJim Mattson1-6/+10
Don't return -E2BIG from __do_cpuid_func when processing function 0BH or 1FH and the last interesting subleaf occupies the last allocated entry in the result array. Cc: Paolo Bonzini <pbonzini@redhat.com> Fixes: 831bf664e9c1fc ("KVM: Refactor and simplify kvm_dev_ioctl_get_supported_cpuid") Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Peter Shier <pshier@google.com> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-26KVM: LAPIC: Loosen filter for adaptive tuning of lapic_timer_advance_nsWanpeng Li1-6/+7
5000 guest cycles delta is easy to encounter on desktop, per-vCPU lapic_timer_advance_ns always keeps at 1000ns initial value, let's loosen the filter a bit to let adaptive tuning make progress. Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-25augmented rbtree: add new RB_DECLARE_CALLBACKS_MAX macroMichel Lespinasse1-16/+3
Add RB_DECLARE_CALLBACKS_MAX, which generates augmented rbtree callbacks for the case where the augmented value is a scalar whose definition follows a max(f(node)) pattern. This actually covers all present uses of RB_DECLARE_CALLBACKS, and saves some (source) code duplication in the various RBCOMPUTE function definitions. [walken@google.com: fix mm/vmalloc.c] Link: http://lkml.kernel.org/r/CANN689FXgK13wDYNh1zKxdipeTuALG4eKvKpsdZqKFJ-rvtGiQ@mail.gmail.com [walken@google.com: re-add check to check_augmented()] Link: http://lkml.kernel.org/r/20190727022027.GA86863@google.com Link: http://lkml.kernel.org/r/20190703040156.56953-3-walken@google.com Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David Howells <dhowells@redhat.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Uladzislau Rezki <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-25KVM: nVMX: cleanup and fix host 64-bit mode checksPaolo Bonzini1-31/+19
KVM was incorrectly checking vmcs12->host_ia32_efer even if the "load IA32_EFER" exit control was reset. Also, some checks were not using the new CC macro for tracing. Cleanup everything so that the vCPU's 64-bit mode is determined directly from EFER_LMA and the VMCS checks are based on that, which matches section 26.2.4 of the SDM. Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Krish Sadhukhan <krish.sadhukhan@oracle.com> Fixes: 5845038c111db27902bc220a4f70070fe945871c Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-25KVM: vmx: fix build warnings in hv_enable_direct_tlbflush() on i386Vitaly Kuznetsov1-9/+5
The following was reported on i386: arch/x86/kvm/vmx/vmx.c: In function 'hv_enable_direct_tlbflush': arch/x86/kvm/vmx/vmx.c:503:10: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] pr_debugs() in this function are more or less useless, let's just remove them. evmcs->hv_vm_id can use 'unsigned long' instead of 'u64'. Also, simplify the code a little bit. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-25KVM: x86: Don't check kvm_rebooting in __kvm_handle_fault_on_reboot()Sean Christopherson1-7/+1
Remove the kvm_rebooting check from VMX/SVM instruction exception fixup now that kvm_spurious_fault() conditions its BUG() on !kvm_rebooting. Because the 'cleanup_insn' functionally is also gone, deferring to kvm_spurious_fault() means __kvm_handle_fault_on_reboot() can eliminate its .fixup code entirely and have its exception table entry branch directly to the call to kvm_spurious_fault(). Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-25KVM: x86: Drop ____kvm_handle_fault_on_reboot()Sean Christopherson1-5/+1
Remove the variation of __kvm_handle_fault_on_reboot() that accepts a post-fault cleanup instruction now that its sole user (VMREAD) uses a different method for handling faults. Acked-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-25KVM: VMX: Add error handling to VMREAD helperSean Christopherson2-4/+25
Now that VMREAD flows require a taken branch, courtesy of commit 3901336ed9887 ("x86/kvm: Don't call kvm_spurious_fault() from .fixup") bite the bullet and add full error handling to VMREAD, i.e. replace the JMP added by __ex()/____kvm_handle_fault_on_reboot() with a hinted Jcc. To minimize the code footprint, add a helper function, vmread_error(), to handle both faults and failures so that the inline flow has a single CALL. Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-25KVM: VMX: Optimize VMX instruction error and fault handlingSean Christopherson2-32/+74
Rework the VMX instruction helpers using asm-goto to branch directly to error/fault "handlers" in lieu of using __ex(), i.e. the generic ____kvm_handle_fault_on_reboot(). Branching directly to fault handling code during fixup avoids the extra JMP that is inserted after every VMX instruction when using the generic "fault on reboot" (see commit 3901336ed9887, "x86/kvm: Don't call kvm_spurious_fault() from .fixup"). Opportunistically clean up the helpers so that they all have consistent error handling and messages. Leave the usage of ____kvm_handle_fault_on_reboot() (via __ex()) in kvm_cpu_vmxoff() and nested_vmx_check_vmentry_hw() as is. The VMXOFF case is not a fast path, i.e. the cleanliness of __ex() is worth the JMP, and the extra JMP in nested_vmx_check_vmentry_hw() is unavoidable. Note, VMREAD cannot get the asm-goto treatment as output operands aren't compatible with GCC's asm-goto due to internal compiler restrictions. Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-25KVM: x86: Check kvm_rebooting in kvm_spurious_fault()Sean Christopherson2-2/+3
Explicitly check kvm_rebooting in kvm_spurious_fault() prior to invoking BUG(), as opposed to assuming the caller has already done so. Letting kvm_spurious_fault() be called "directly" will allow VMX to better optimize its low level assembly flows. As a happy side effect, kvm_spurious_fault() no longer needs to be marked as a dead end since it doesn't unconditionally BUG(). Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24mm: consolidate pgtable_cache_init() and pgd_cache_init()Mike Rapoport3-8/+1
Both pgtable_cache_init() and pgd_cache_init() are used to initialize kmem cache for page table allocations on several architectures that do not use PAGE_SIZE tables for one or more levels of the page table hierarchy. Most architectures do not implement these functions and use __weak default NOP implementation of pgd_cache_init(). Since there is no such default for pgtable_cache_init(), its empty stub is duplicated among most architectures. Rename the definitions of pgd_cache_init() to pgtable_cache_init() and drop empty stubs of pgtable_cache_init(). Link: http://lkml.kernel.org/r/1566457046-22637-1-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Will Deacon <will@kernel.org> [arm64] Acked-by: Thomas Gleixner <tglx@linutronix.de> [x86] Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: remove quicklist page table cachesNicholas Piggin2-2/+0
Patch series "mm: remove quicklist page table caches". A while ago Nicholas proposed to remove quicklist page table caches [1]. I've rebased his patch on the curren upstream and switched ia64 and sh to use generic versions of PTE allocation. [1] https://lore.kernel.org/linux-mm/20190711030339.20892-1-npiggin@gmail.com This patch (of 3): Remove page table allocator "quicklists". These have been around for a long time, but have not got much traction in the last decade and are only used on ia64 and sh architectures. The numbers in the initial commit look interesting but probably don't apply anymore. If anybody wants to resurrect this it's in the git history, but it's unhelpful to have this code and divergent allocator behaviour for minor archs. Also it might be better to instead make more general improvements to page allocator if this is still so slow. Link: http://lkml.kernel.org/r/1565250728-21721-2-git-send-email-rppt@linux.ibm.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24kvm: nvmx: limit atomic switch MSRsMarc Orr2-11/+33
Allowing an unlimited number of MSRs to be specified via the VMX load/store MSR lists (e.g., vm-entry MSR load list) is bad for two reasons. First, a guest can specify an unreasonable number of MSRs, forcing KVM to process all of them in software. Second, the SDM bounds the number of MSRs allowed to be packed into the atomic switch MSR lists. Quoting the "Miscellaneous Data" section in the "VMX Capability Reporting Facility" appendix: "Bits 27:25 is used to compute the recommended maximum number of MSRs that should appear in the VM-exit MSR-store list, the VM-exit MSR-load list, or the VM-entry MSR-load list. Specifically, if the value bits 27:25 of IA32_VMX_MISC is N, then 512 * (N + 1) is the recommended maximum number of MSRs to be included in each list. If the limit is exceeded, undefined processor behavior may result (including a machine check during the VMX transition)." Because KVM needs to protect itself and can't model "undefined processor behavior", arbitrarily force a VM-entry to fail due to MSR loading when the MSR load list is too large. Similarly, trigger an abort during a VM exit that encounters an MSR load list or MSR store list that is too large. The MSR list size is intentionally not pre-checked so as to maintain compatibility with hardware inasmuch as possible. Test these new checks with the kvm-unit-test "x86: nvmx: test max atomic switch MSRs". Suggested-by: Jim Mattson <jmattson@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Peter Shier <pshier@google.com> Signed-off-by: Marc Orr <marcorr@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24kvm: svm: Intercept RDPRUJim Mattson3-0/+10
The RDPRU instruction gives the guest read access to the IA32_APERF MSR and the IA32_MPERF MSR. According to volume 3 of the APM, "When virtualization is enabled, this instruction can be intercepted by the Hypervisor. The intercept bit is at VMCB byte offset 10h, bit 14." Since we don't enumerate the instruction in KVM_SUPPORTED_CPUID, intercept it and synthesize #UD. Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Drew Schmitt <dasch@google.com> Reviewed-by: Jacob Xu <jacobhxu@google.com> Reviewed-by: Peter Shier <pshier@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24kvm: x86: Add "significant index" flag to a few CPUID leavesJim Mattson1-0/+6
According to the Intel SDM, volume 2, "CPUID," the index is significant (or partially significant) for CPUID leaves 0FH, 10H, 12H, 17H, 18H, and 1FH. Add the corresponding flag to these CPUID leaves in do_host_cpuid(). Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Peter Shier <pshier@google.com> Reviewed-by: Steve Rutherford <srutherford@google.com> Fixes: a87f2d3a6eadab ("KVM: x86: Add Intel CPUID.1F cpuid emulation support") Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM: x86/mmu: Skip invalid pages during zapping iff root_count is zeroSean Christopherson1-4/+5
Do not skip invalid shadow pages when zapping obsolete pages if the pages' root_count has reached zero, in which case the page can be immediately zapped and freed. Update the comment accordingly. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM: x86/mmu: Explicitly track only a single invalid mmu generationSean Christopherson3-12/+22
Toggle mmu_valid_gen between '0' and '1' instead of blindly incrementing the generation. Because slots_lock is held for the entire duration of zapping obsolete pages, it's impossible for there to be multiple invalid generations associated with shadow pages at any given time. Toggling between the two generations (valid vs. invalid) allows changing mmu_valid_gen from an unsigned long to a u8, which reduces the size of struct kvm_mmu_page from 160 to 152 bytes on 64-bit KVM, i.e. reduces KVM's memory footprint by 8 bytes per shadow page. Set sp->mmu_valid_gen before it is added to active_mmu_pages. Functionally this has no effect as kvm_mmu_alloc_page() has a single caller that sets sp->mmu_valid_gen soon thereafter, but visually it is jarring to see a shadow page being added to the list without its mmu_valid_gen first being set. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM: x86/mmu: Revert "KVM: x86/mmu: Remove is_obsolete() call"Sean Christopherson2-6/+24
Now that the fast invalidate mechanism has been reintroduced, restore the performance tweaks for fast invalidation that existed prior to its removal. Paraphrasing the original changelog (commit 5ff0568374ed2 was itself a partial revert): Don't force reloading the remote mmu when zapping an obsolete page, as a MMU_RELOAD request has already been issued by kvm_mmu_zap_all_fast() immediately after incrementing mmu_valid_gen, i.e. after marking pages obsolete. This reverts commit 5ff0568374ed2e585376a3832857ade5daccd381. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM: x86/mmu: Revert "Revert "KVM: MMU: reclaim the zapped-obsolete page first""Sean Christopherson1-0/+1
Now that the fast invalidate mechanism has been reintroduced, restore the performance tweaks for fast invalidation that existed prior to its removal. Paraphrashing the original changelog: Introduce a per-VM list to track obsolete shadow pages, i.e. pages which have been deleted from the mmu cache but haven't yet been freed. When page reclaiming is needed, zap/free the deleted pages first. This reverts commit 52d5dedc79bdcbac2976159a172069618cf31be5. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM: x86/mmu: Revert "Revert "KVM: MMU: collapse TLB flushes when zap all pages""Sean Christopherson1-3/+22
Now that the fast invalidate mechanism has been reintroduced, restore the performance tweaks for fast invalidation that existed prior to its removal. Paraphrashing the original changelog: Reload the mmu on all vCPUs after updating the generation number so that obsolete pages are not used by any vCPUs. This allows collapsing all TLB flushes during obsolete page zapping into a single flush, as there is no need to flush when dropping mmu_lock (to reschedule). Note: a remote TLB flush is still needed before freeing the pages as other vCPUs may be doing a lockless shadow page walk. Opportunstically improve the comments restored by the revert (the code itself is a true revert). This reverts commit f34d251d66ba263c077ed9d2bbd1874339a4c887. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM: x86/mmu: Revert "Revert "KVM: MMU: zap pages in batch""Sean Christopherson1-26/+9
Now that the fast invalidate mechanism has been reintroduced, restore the performance tweaks for fast invalidation that existed prior to its removal. Paraphrashing the original changelog: Zap at least 10 shadow pages before releasing mmu_lock to reduce the overhead associated with re-acquiring the lock. Note: "10" is an arbitrary number, speculated to be high enough so that a vCPU isn't stuck zapping obsolete pages for an extended period, but small enough so that other vCPUs aren't starved waiting for mmu_lock. This reverts commit 43d2b14b105fb00b8864c7b0ee7043cc1cc4a969. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM: x86/mmu: Revert "Revert "KVM: MMU: add tracepoint for kvm_mmu_invalidate_all_pages""Sean Christopherson2-0/+22
Now that the fast invalidate mechanism has been reintroduced, restore the tracepoint associated with said mechanism. Note, the name of the tracepoint deviates from the original tracepoint so as to match KVM's current nomenclature. This reverts commit 42560fb1f3c6c7f730897b7fa7a478bc37e0be50. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM: x86/mmu: Revert "Revert "KVM: MMU: show mmu_valid_gen in shadow page related tracepoints""Sean Christopherson1-9/+12
Now that the fast invalidate mechanism has been reintroduced, restore tracing of the generation number in shadow page tracepoints. This reverts commit b59c4830ca185ba0e9f9e046fb1cd10a4a92627a. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM: x86/mmu: Use fast invalidate mechanism to zap MMIO sptesSean Christopherson1-14/+3
Use the fast invalidate mechasim to zap MMIO sptes on a MMIO generation wrap. The fast invalidate flow was reintroduced to fix a livelock bug in kvm_mmu_zap_all() that can occur if kvm_mmu_zap_all() is invoked when the guest has live vCPUs. I.e. using kvm_mmu_zap_all() to handle the MMIO generation wrap is theoretically susceptible to the livelock bug. This effectively reverts commit 4771450c345dc ("Revert "KVM: MMU: drop kvm_mmu_zap_mmio_sptes""), i.e. restores the behavior of commit a8eca9dcc656a ("KVM: MMU: drop kvm_mmu_zap_mmio_sptes"). Note, this actually fixes commit 571c5af06e303 ("KVM: x86/mmu: Voluntarily reschedule as needed when zapping MMIO sptes"), but there is no need to incrementally revert back to using fast invalidate, e.g. doing so doesn't provide any bisection or stability benefits. Fixes: 571c5af06e303 ("KVM: x86/mmu: Voluntarily reschedule as needed when zapping MMIO sptes") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM: x86/mmu: Treat invalid shadow pages as obsoleteSean Christopherson1-2/+3
Treat invalid shadow pages as obsolete to fix a bug where an obsolete and invalid page with a non-zero root count could become non-obsolete due to mmu_valid_gen wrapping. The bug is largely theoretical with the current code base, as an unsigned long will effectively never wrap on 64-bit KVM, and userspace would have to deliberately stall a vCPU in order to keep an obsolete invalid page on the active list while simultaneously modifying memslots billions of times to trigger a wrap. The obvious alternative is to use a 64-bit value for mmu_valid_gen, but it's actually desirable to go in the opposite direction, i.e. using a smaller 8-bit value to reduce KVM's memory footprint by 8 bytes per shadow page, and relying on proper treatment of invalid pages instead of preventing the generation from wrapping. Note, "Fixes" points at a commit that was at one point reverted, but has since been restored. Fixes: 5304b8d37c2a5 ("KVM: MMU: fast invalidate all pages") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM: LAPIC: Tune lapic_timer_advance_ns smoothlyWanpeng Li2-15/+14
Filter out drastic fluctuation and random fluctuation, remove timer_advance_adjust_done altogether, the adjustment would be continuous. Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM: vmx: Introduce handle_unexpected_vmexit and handle WAITPKG vmexitTao Xu3-17/+21
As the latest Intel 64 and IA-32 Architectures Software Developer's Manual, UMWAIT and TPAUSE instructions cause a VM exit if the RDTSC exiting and enable user wait and pause VM-execution controls are both 1. Because KVM never enable RDTSC exiting, the vm-exit for UMWAIT and TPAUSE should never happen. Considering EXIT_REASON_XSAVES and EXIT_REASON_XRSTORS is also unexpected VM-exit for KVM. Introduce a common exit helper handle_unexpected_vmexit() to handle these unexpected VM-exit. Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Jingqi Liu <jingqi.liu@intel.com> Signed-off-by: Jingqi Liu <jingqi.liu@intel.com> Signed-off-by: Tao Xu <tao3.xu@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM: vmx: Emulate MSR IA32_UMWAIT_CONTROLTao Xu4-0/+53
UMWAIT and TPAUSE instructions use 32bit IA32_UMWAIT_CONTROL at MSR index E1H to determines the maximum time in TSC-quanta that the processor can reside in either C0.1 or C0.2. This patch emulates MSR IA32_UMWAIT_CONTROL in guest and differentiate IA32_UMWAIT_CONTROL between host and guest. The variable mwait_control_cached in arch/x86/kernel/cpu/umwait.c caches the MSR value, so this patch uses it to avoid frequently rdmsr of IA32_UMWAIT_CONTROL. Co-developed-by: Jingqi Liu <jingqi.liu@intel.com> Signed-off-by: Jingqi Liu <jingqi.liu@intel.com> Signed-off-by: Tao Xu <tao3.xu@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM: x86: Add support for user wait instructionsTao Xu5-1/+27
UMONITOR, UMWAIT and TPAUSE are a set of user wait instructions. This patch adds support for user wait instructions in KVM. Availability of the user wait instructions is indicated by the presence of the CPUID feature flag WAITPKG CPUID.0x07.0x0:ECX[5]. User wait instructions may be executed at any privilege level, and use 32bit IA32_UMWAIT_CONTROL MSR to set the maximum time. The behavior of user wait instructions in VMX non-root operation is determined first by the setting of the "enable user wait and pause" secondary processor-based VM-execution control bit 26. If the VM-execution control is 0, UMONITOR/UMWAIT/TPAUSE cause an invalid-opcode exception (#UD). If the VM-execution control is 1, treatment is based on the setting of the “RDTSC exiting†VM-execution control. Because KVM never enables RDTSC exiting, if the instruction causes a delay, the amount of time delayed is called here the physical delay. The physical delay is first computed by determining the virtual delay. If IA32_UMWAIT_CONTROL[31:2] is zero, the virtual delay is the value in EDX:EAX minus the value that RDTSC would return; if IA32_UMWAIT_CONTROL[31:2] is not zero, the virtual delay is the minimum of that difference and AND(IA32_UMWAIT_CONTROL,FFFFFFFCH). Because umwait and tpause can put a (psysical) CPU into a power saving state, by default we dont't expose it to kvm and enable it only when guest CPUID has it. Detailed information about user wait instructions can be found in the latest Intel 64 and IA-32 Architectures Software Developer's Manual. Co-developed-by: Jingqi Liu <jingqi.liu@intel.com> Signed-off-by: Jingqi Liu <jingqi.liu@intel.com> Signed-off-by: Tao Xu <tao3.xu@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>