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2022-01-14kvm: x86: Add support for getting/setting expanded xstate bufferGuang Zeng1-0/+2
With KVM_CAP_XSAVE, userspace uses a hardcoded 4KB buffer to get/set xstate data from/to KVM. This doesn't work when dynamic xfeatures (e.g. AMX) are exposed to the guest as they require a larger buffer size. Introduce a new capability (KVM_CAP_XSAVE2). Userspace VMM gets the required xstate buffer size via KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2). KVM_SET_XSAVE is extended to work with both legacy and new capabilities by doing properly-sized memdup_user() based on the guest fpu container. KVM_GET_XSAVE is kept for backward-compatible reason. Instead, KVM_GET_XSAVE2 is introduced under KVM_CAP_XSAVE2 as the preferred interface for getting xstate buffer (4KB or larger size) from KVM (Link: https://lkml.org/lkml/2021/12/15/510) Also, update the api doc with the new KVM_GET_XSAVE2 ioctl. Signed-off-by: Guang Zeng <guang.zeng@intel.com> Signed-off-by: Wei Wang <wei.w.wang@intel.com> Signed-off-by: Jing Liu <jing2.liu@intel.com> Signed-off-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Yang Zhong <yang.zhong@intel.com> Message-Id: <20220105123532.12586-19-yang.zhong@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-26KVM: x86: Move reverse CPUID helpers to separate header fileRicardo Koller1-176/+1
Split out the reverse CPUID machinery to a dedicated header file so that KVM selftests can reuse the reverse CPUID definitions without introducing any '#ifdef __KERNEL__' pollution. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Message-Id: <20210422005626.564163-2-ricarkol@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-23KVM: x86: Fix implicit enum conversion goof in scattered reverse CPUID codeSean Christopherson1-1/+1
Take "enum kvm_only_cpuid_leafs" in scattered specific CPUID helpers (which is obvious in hindsight), and use "unsigned int" for leafs that can be the kernel's standard "enum cpuid_leaf" or the aforementioned KVM-only variant. Loss of the enum params is a bit disapponting, but gcc obviously isn't providing any extra sanity checks, and the various BUILD_BUG_ON() assertions ensure the input is in range. This fixes implicit enum conversions that are detected by clang-11: arch/x86/kvm/cpuid.c:499:29: warning: implicit conversion from enumeration type 'enum kvm_only_cpuid_leafs' to different enumeration type 'enum cpuid_leafs' [-Wenum-conversion] kvm_cpu_cap_init_scattered(CPUID_12_EAX, ~~~~~~~~~~~~~~~~~~~~~~~~~~ ^~~~~~~~~~~~ arch/x86/kvm/cpuid.c:837:31: warning: implicit conversion from enumeration type 'enum kvm_only_cpuid_leafs' to different enumeration type 'enum cpuid_leafs' [-Wenum-conversion] cpuid_entry_override(entry, CPUID_12_EAX); ~~~~~~~~~~~~~~~~~~~~ ^~~~~~~~~~~~ 2 warnings generated. Fixes: 4e66c0cb79b7 ("KVM: x86: Add support for reverse CPUID lookup of scattered features") Cc: Kai Huang <kai.huang@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210421010850.3009718-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-20KVM: x86: Add reverse-CPUID lookup support for scattered SGX featuresSean Christopherson1-2/+13
Define a new KVM-only feature word for advertising and querying SGX sub-features in CPUID.0x12.0x0.EAX. Because SGX1 and SGX2 are scattered in the kernel's feature word, they need to be translated so that the bit numbers match those of hardware. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Kai Huang <kai.huang@intel.com> Message-Id: <e797c533f4c71ae89265bbb15a02aef86b67cbec.1618196135.git.kai.huang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-20KVM: x86: Add support for reverse CPUID lookup of scattered featuresSean Christopherson1-5/+34
Introduce a scheme that allows KVM's CPUID magic to support features that are scattered in the kernel's feature words. To advertise and/or query guest support for CPUID-based features, KVM requires the bit number of an X86_FEATURE_* to match the bit number in its associated CPUID entry. For scattered features, this does not hold true. Add a framework to allow defining KVM-only words, stored in kvm_cpu_caps after the shared kernel caps, that can be used to gather the scattered feature bits by translating X86_FEATURE_* flags into their KVM-defined feature. Note, because reverse_cpuid_check() effectively forces kvm_cpu_caps lookups to be resolved at compile time, there is no runtime cost for translating from kernel-defined to kvm-defined features. More details here: https://lkml.kernel.org/r/X/jxCOLG+HUO4QlZ@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Kai Huang <kai.huang@intel.com> Message-Id: <16cad8d00475f67867fb36701fc7fb7c1ec86ce1.1618196135.git.kai.huang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-17KVM: x86: add guest_cpuid_is_intelMaxim Levitsky1-0/+8
This is similar to existing 'guest_cpuid_is_amd_or_hygon' Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210401111928.996871-2-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04KVM: x86: Add helper to consolidate "raw" reserved GPA mask calculationsSean Christopherson1-0/+1
Add a helper to generate the mask of reserved GPA bits _without_ any adjustments for repurposed bits, and use it to replace a variety of open coded variants in the MTRR and APIC_BASE flows. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210204000117.3303214-11-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04KVM: x86: SEV: Treat C-bit as legal GPA bit regardless of vCPU modeSean Christopherson1-1/+1
Rename cr3_lm_rsvd_bits to reserved_gpa_bits, and use it for all GPA legality checks. AMD's APM states: If the C-bit is an address bit, this bit is masked from the guest physical address when it is translated through the nested page tables. Thus, any access that can conceivably be run through NPT should ignore the C-bit when checking for validity. For features that KVM emulates in software, e.g. MTRRs, there is no clear direction in the APM for how the C-bit should be handled. For such cases, follow the SME behavior inasmuch as possible, since SEV is is essentially a VM-specific variant of SME. For SME, the APM states: In this case the upper physical address bits are treated as reserved when the feature is enabled except where otherwise indicated. Collecting the various relavant SME snippets in the APM and cross- referencing the omissions with Linux kernel code, this leaves MTTRs and APIC_BASE as the only flows that KVM emulates that should _not_ ignore the C-bit. Note, this means the reserved bit checks in the page tables are technically broken. This will be remedied in a future patch. Although the page table checks are technically broken, in practice, it's all but guaranteed to be irrelevant. NPT is required for SEV, i.e. shadowing page tables isn't needed in the common case. Theoretically, the checks could be in play for nested NPT, but it's extremely unlikely that anyone is running nested VMs on SEV, as doing so would require L1 to expose sensitive data to L0, e.g. the entire VMCB. And if anyone is running nested VMs, L0 can't read the guest's encrypted memory, i.e. L1 would need to put its NPT in shared memory, in which case the C-bit will never be set. Or, L1 could use shadow paging, but again, if L0 needs to read page tables, e.g. to load PDPTRs, the memory can't be encrypted if L1 has any expectation of L0 doing the right thing. Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210204000117.3303214-8-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04KVM: x86: Add a helper to handle legal GPA with an alignment requirementSean Christopherson1-1/+7
Add a helper to genericize checking for a legal GPA that also must conform to an arbitrary alignment, and use it in the existing page_address_valid(). Future patches will replace open coded variants in VMX and SVM. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210204000117.3303214-5-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04KVM: x86: Add a helper to check for a legal GPASean Christopherson1-6/+11
Add a helper to check for a legal GPA, and use it to consolidate code in existing, related helpers. Future patches will extend usage to VMX and SVM code, properly handle exceptions to the maxphyaddr rule, and add more helpers. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210204000117.3303214-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-11KVM: x86: reinstate vendor-agnostic check on SPEC_CTRL cpuid bitsPaolo Bonzini1-0/+14
Until commit e7c587da1252 ("x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP"), KVM was testing both Intel and AMD CPUID bits before allowing the guest to write MSR_IA32_SPEC_CTRL and MSR_IA32_PRED_CMD. Testing only Intel bits on VMX processors, or only AMD bits on SVM processors, fails if the guests are created with the "opposite" vendor as the host. While at it, also tweak the host CPU check to use the vendor-agnostic feature bit X86_FEATURE_IBPB, since we only care about the availability of the MSR on the host here and not about specific CPUID bits. Fixes: e7c587da1252 ("x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP") Cc: stable@vger.kernel.org Reported-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-08kvm: x86: ensure pv_cpuid.features is initialized when enabling capOliver Upton1-0/+1
Make the paravirtual cpuid enforcement mechanism idempotent to ioctl() ordering by updating pv_cpuid.features whenever userspace requests the capability. Extract this update out of kvm_update_cpuid_runtime() into a new helper function and move its other call site into kvm_vcpu_after_set_cpuid() where it more likely belongs. Fixes: 66570e966dd9 ("kvm: x86: only provide PV features if enabled in guest's CPUID") Signed-off-by: Oliver Upton <oupton@google.com> Reviewed-by: Peter Shier <pshier@google.com> Message-Id: <20201027231044.655110-5-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21kvm: x86: only provide PV features if enabled in guest's CPUIDOliver Upton1-0/+10
KVM unconditionally provides PV features to the guest, regardless of the configured CPUID. An unwitting guest that doesn't check KVM_CPUID_FEATURES before use could access paravirt features that userspace did not intend to provide. Fix this by checking the guest's CPUID before performing any paravirtual operations. Introduce a capability, KVM_CAP_ENFORCE_PV_FEATURE_CPUID, to gate the aforementioned enforcement. Migrating a VM from a host w/o this patch to a host with this patch could silently change the ABI exposed to the guest, warranting that we default to the old behavior and opt-in for the new one. Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Peter Shier <pshier@google.com> Signed-off-by: Oliver Upton <oupton@google.com> Change-Id: I202a0926f65035b872bfe8ad15307c026de59a98 Message-Id: <20200818152429.1923996-4-oupton@google.com> Reviewed-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28KVM: x86: Move illegal GPA helper out of the MMU codeSean Christopherson1-0/+5
Rename kvm_mmu_is_illegal_gpa() to kvm_vcpu_is_illegal_gpa() and move it to cpuid.h so that's it's colocated with cpuid_maxphyaddr(). The helper is not MMU specific and will gain a user that is completely unrelated to the MMU in a future patch. No functional change intended. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200924194250.19137-5-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-09KVM: x86: Extract kvm_update_cpuid_runtime() from kvm_update_cpuid()Xiaoyao Li1-1/+1
Beside called in kvm_vcpu_ioctl_set_cpuid*(), kvm_update_cpuid() is also called 5 places else in x86.c and 1 place else in lapic.c. All those 6 places only need the part of updating guest CPUIDs (OSXSAVE, OSPKE, APIC, KVM_FEATURE_PV_UNHALT, ...) based on the runtime vcpu state, so extract them as a separate kvm_update_cpuid_runtime(). Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> Message-Id: <20200709043426.92712-3-xiaoyao.li@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-09KVM: x86: Introduce kvm_check_cpuid()Xiaoyao Li1-1/+1
Use kvm_check_cpuid() to validate if userspace provides legal cpuid settings and call it before KVM take any action to update CPUID or update vcpu states based on given CPUID settings. Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> Message-Id: <20200709043426.92712-2-xiaoyao.li@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATEPaolo Bonzini1-0/+5
Similar to VMX, the state that is captured through the currently available IOCTLs is a mix of L1 and L2 state, dependent on whether the L2 guest was running at the moment when the process was interrupted to save its state. In particular, the SVM-specific state for nested virtualization includes the L1 saved state (including the interrupt flag), the cached L2 controls, and the GIF. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-31KVM: x86: Fix BUILD_BUG() in __cpuid_entry_get_reg() w/ CONFIG_UBSAN=ySean Christopherson1-4/+4
Take the target reg in __cpuid_entry_get_reg() instead of a pointer to a struct cpuid_reg. When building with -fsanitize=alignment (enabled by CONFIG_UBSAN=y), some versions of gcc get tripped up on the pointer and trigger the BUILD_BUG(). Reported-by: Randy Dunlap <rdunlap@infradead.org> Fixes: d8577a4c238f8 ("KVM: x86: Do host CPUID at load time to mask KVM cpu caps") Fixes: 4c61534aaae2a ("KVM: x86: Introduce cpuid_entry_{get,has}() accessors") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200325191259.23559-1-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: x86: Refactor kvm_cpuid() param that controls out-of-range logicSean Christopherson1-1/+1
Invert and rename the kvm_cpuid() param that controls out-of-range logic to better reflect the semantics of the affected callers, i.e. callers that bypass the out-of-range logic do so because they are looking up an exact guest CPUID entry, e.g. to query the maxphyaddr. Similarly, rename kvm_cpuid()'s internal "found" to "exact" to clarify that it tracks whether or not the exact requested leaf was found, as opposed to any usable leaf being found. No functional change intended. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM x86: Extend AMD specific guest behavior to Hygon virtual CPUsSean Christopherson1-2/+4
Extend guest_cpuid_is_amd() to cover Hygon virtual CPUs and rename it accordingly. Hygon CPUs use an AMD-based core and so have the same basic behavior as AMD CPUs. Fixes: b8f4abb652146 ("x86/kvm: Add Hygon Dhyana support to KVM") Cc: Pu Wen <puwen@hygon.cn> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: x86: Add helpers to perform CPUID-based guest vendor checkSean Christopherson1-1/+1
Add helpers to provide CPUID-based guest vendor checks, i.e. to do the ugly register comparisons. Use the new helpers to check for an AMD guest vendor in guest_cpuid_is_amd() as well as in the existing emulator flows. Using the new helpers fixes a _very_ theoretical bug where guest_cpuid_is_amd() would get a false positive on a non-AMD virtual CPU with a vendor string beginning with "Auth" due to the previous logic only checking EBX. It also fixes a marginally less theoretically bug where guest_cpuid_is_amd() would incorrectly return false for a guest CPU with "AMDisbetter!" as its vendor string. Fixes: a0c0feb57992c ("KVM: x86: reserve bit 8 of non-leaf PDPEs and PML4Es in 64-bit mode on AMD") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: x86: Override host CPUID results with kvm_cpu_capsSean Christopherson1-3/+3
Override CPUID entries with kvm_cpu_caps during KVM_GET_SUPPORTED_CPUID instead of masking the host CPUID result, which is redundant now that the host CPUID is incorporated into kvm_cpu_caps at runtime. No functional change intended. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: x86: Use KVM cpu caps to mark CR4.LA57 as not-reservedSean Christopherson1-0/+13
Add accessor(s) for KVM cpu caps and use said accessor to detect hardware support for LA57 instead of manually querying CPUID. Note, the explicit conversion to bool via '!!' in kvm_cpu_cap_has() is technically unnecessary, but it gives people a warm fuzzy feeling. No functional change intended. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: x86: Add a helper to check kernel support when setting cpu capSean Christopherson1-0/+6
Add a helper, kvm_cpu_cap_check_and_set(), to query boot_cpu_has() as part of setting a KVM cpu capability. VMX in particular has a number of features that are dependent on both a VMCS capability and kernel support. No functional change intended. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: x86: Introduce kvm_cpu_caps to replace runtime CPUID maskingSean Christopherson1-1/+21
Calculate the CPUID masks for KVM_GET_SUPPORTED_CPUID at load time using what is effectively a KVM-adjusted copy of boot_cpu_data, or more precisely, the x86_capability array in boot_cpu_data. In terms of KVM support, the vast majority of CPUID feature bits are constant, and *all* feature support is known at KVM load time. Rather than apply boot_cpu_data, which is effectively read-only after init, at runtime, copy it into a KVM-specific array and use *that* to mask CPUID registers. In additional to consolidating the masking, kvm_cpu_caps can be adjusted by SVM/VMX at load time and thus eliminate all feature bit manipulation in ->set_supported_cpuid(). Opportunistically clean up a few warts: - Replace bare "unsigned" with "unsigned int" when a feature flag is captured in a local variable, e.g. f_nx. - Sort the CPUID masks by function, index and register (alphabetically for registers, i.e. EBX comes before ECX/EDX). - Remove the superfluous /* cpuid 7.0.ecx */ comments. No functional change intended. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> [Call kvm_set_cpu_caps from kvm_x86_ops->hardware_setup due to fixed GBPAGES patch. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: x86: Refactor cpuid_mask() to auto-retrieve the registerSean Christopherson1-0/+8
Use the recently introduced cpuid_entry_get_reg() to automatically get the appropriate register when masking a CPUID entry. No functional change intended. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: x86: Introduce cpuid_entry_{change,set,clear}() mutatorsSean Christopherson1-0/+32
Introduce mutators to modify feature bits in CPUID entries and use the new mutators where applicable. Using the mutators eliminates the need to manually specify the register to modify query at no extra cost and will allow adding runtime consistency checks on the function/index in a future patch. No functional change intended. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: x86: Introduce cpuid_entry_{get,has}() accessorsSean Christopherson1-10/+38
Introduce accessors to retrieve feature bits from CPUID entries and use the new accessors where applicable. Using the accessors eliminates the need to manually specify the register to be queried at no extra cost (binary output is identical) and will allow adding runtime consistency checks on the function and index in a future patch. No functional change intended. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: x86: Replace bare "unsigned" with "unsigned int" in cpuid helpersSean Christopherson1-6/+9
Replace "unsigned" with "unsigned int" to make checkpatch and people everywhere a little bit happier, and to avoid propagating the filth when future patches add more cpuid helpers that work with unsigned (ints). No functional change intended. Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: x86: Use u32 for holding CPUID register value in helpersSean Christopherson1-3/+3
Change the intermediate CPUID output register values from "int" to "u32" to match both hardware and the storage type in struct cpuid_reg. No functional change intended. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: x86: Make kvm_mpx_supported() an inline functionSean Christopherson1-1/+0
Expose kvm_mpx_supported() as a static inline so that it can be inlined in kvm_intel.ko. No functional change intended. Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-21KVM: x86: Refactor and rename bit() to feature_bit() macroSean Christopherson1-3/+5
Rename bit() to __feature_bit() to give it a more descriptive name, and add a macro, feature_bit(), to stuff the X68_FEATURE_ prefix to keep line lengths manageable for code that hardcodes the bit to be retrieved. No functional change intended. Cc: Jim Mattson <jmattson@google.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-21KVM: x86: Expand build-time assertion on reverse CPUID usageSean Christopherson1-5/+28
Add build-time checks to ensure KVM isn't trying to do a reverse CPUID lookup on Linux-defined feature bits, along with comments to explain the gory details of X86_FEATUREs and bit(). No functional change intended. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-21KVM: x86: Add CPUID_7_1_EAX to the reverse CPUID tableSean Christopherson1-0/+1
Add an entry for CPUID_7_1_EAX in the reserve_cpuid array in preparation for incorporating the array in bit() build-time assertions, specifically to avoid an assertion on F(AVX512_BF16) in do_cpuid_7_mask(). No functional change intended. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-21KVM: x86: Move bit() helper to cpuid.hSean Christopherson1-0/+5
Move bit() to cpuid.h in preparation for incorporating the reverse_cpuid array in bit() build-time assertions. Opportunistically use the BIT() macro instead of open-coding the shift. No functional change intended. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-21KVM: x86: Drop special XSAVE handling from guest_cpuid_has()Sean Christopherson1-4/+0
Now that KVM prevents setting host-reserved CR4 bits, drop the dedicated XSAVE check in guest_cpuid_has() in favor of open coding similar checks in the SVM/VMX XSAVES enabling flows. Note, checking boot_cpu_has(X86_FEATURE_XSAVE) in the XSAVES flows is technically redundant with respect to the CR4 reserved bit checks, e.g. XSAVES #UDs if CR4.OSXSAVE=0 and arch.xsaves_enabled is consumed if and only if CR4.OXSAVE=1 in guest. Keep (add?) the explicit boot_cpu_has() checks to help document KVM's usage of arch.xsaves_enabled. No functional change intended. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-06-20x86/cpufeatures: Combine word 11 and 12 into a new scattered features wordFenghua Yu1-2/+0
It's a waste for the four X86_FEATURE_CQM_* feature bits to occupy two whole feature bits words. To better utilize feature words, re-define word 11 to host scattered features and move the four X86_FEATURE_CQM_* features into Linux defined word 11. More scattered features can be added in word 11 in the future. Rename leaf 11 in cpuid_leafs to CPUID_LNX_4 to reflect it's a Linux-defined leaf. Rename leaf 12 as CPUID_DUMMY which will be replaced by a meaningful name in the next patch when CPUID.7.1:EAX occupies world 12. Maximum number of RMID and cache occupancy scale are retrieved from CPUID.0xf.1 after scattered CQM features are enumerated. Carve out the code into a separate function. KVM doesn't support resctrl now. So it's safe to move the X86_FEATURE_CQM_* features to scattered features word 11 for KVM. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Aaron Lewis <aaronlewis@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Babu Moger <babu.moger@amd.com> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: "Sean J Christopherson" <sean.j.christopherson@intel.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Juergen Gross <jgross@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Ravi V Shankar <ravi.v.shankar@intel.com> Cc: Sherry Hurwitz <sherry.hurwitz@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Lendacky <Thomas.Lendacky@amd.com> Cc: x86 <x86@kernel.org> Link: https://lkml.kernel.org/r/1560794416-217638-2-git-send-email-fenghua.yu@intel.com
2018-02-03KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDXKarimAllah Ahmed1-0/+1
[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
2017-11-17KVM: x86: Fix CPUID function for word 6 (80000001_ECX)Janakarajan Natarajan1-1/+1
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>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-13KVM: x86: fix clang buildRadim Krčmář1-1/+0
Clang resolves __builtin_constant_p() to false even if the expression is constant in the end. The only purpose of that expression was to differentiate a case where the following expression couldn't be checked at compile-time, so we can just remove the check. Clang handles the following two correctly. Turn it into BUG_ON if there are any more problems with this. Fixes: d6321d493319 ("KVM: x86: generalize guest_cpuid_has_ helpers") Reported-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-08-24KVM: x86: Add return value to kvm_cpuid().Yu Zhang1-1/+2
Return false in kvm_cpuid() when it fails to find the cpuid entry. Also, this routine(and its caller) is optimized with a new argument - check_limit, so that the check_cpuid_limit() fall back can be avoided. Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-07KVM: x86: use general helpers for some cpuid manipulationRadim Krčmář1-0/+9
Add guest_cpuid_clear() and use it instead of kvm_find_cpuid_entry(). Also replace some uses of kvm_find_cpuid_entry() with guest_cpuid_has(). Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-07KVM: x86: generalize guest_cpuid_has_ helpersRadim Krčmář1-113/+57
This patch turns guest_cpuid_has_XYZ(cpuid) into guest_cpuid_has(cpuid, X86_FEATURE_XYZ), which gets rid of many very similar helpers. When seeing a X86_FEATURE_*, we can know which cpuid it belongs to, but this information isn't in common code, so we recreate it for KVM. Add some BUILD_BUG_ONs to make sure that it runs nicely. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-07KVM: x86: X86_FEATURE_NRIPS is not scattered anymoreRadim Krčmář1-13/+1
bit(X86_FEATURE_NRIPS) is 3 since 2ccd71f1b278 ("x86/cpufeature: Move some of the scattered feature bits to x86_capability"), so we can simplify the code. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-07kvm: x86: Guest BNDCFGS requires guest MPX supportJim Mattson1-0/+8
The BNDCFGS MSR should only be exposed to the guest if the guest supports MPX. (cf. the TSC_AUX MSR and RDTSCP.) Fixes: 0dd376e709975779 ("KVM: x86: add MSR_IA32_BNDCFGS to msrs_to_save") Change-Id: I3ad7c01bda616715137ceac878f3fa7e66b6b387 Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-04-21KVM: x86: virtualize cpuid faultingKyle Huey1-0/+11
Hardware support for faulting on the cpuid instruction is not required to emulate it, because cpuid triggers a VM exit anyways. KVM handles the relevant MSRs (MSR_PLATFORM_INFO and MSR_MISC_FEATURES_ENABLE) and upon a cpuid-induced VM exit checks the cpuid faulting state and the CPL. kvm_require_cpl is even kind enough to inject the GP fault for us. Signed-off-by: Kyle Huey <khuey@kylehuey.com> Reviewed-by: David Matlack <dmatlack@google.com> [Return "1" from kvm_emulate_cpuid, it's not void. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-23Revert "KVM: x86: add pcommit support"Dan Williams1-8/+0
This reverts commit 8b3e34e46aca9b6d349b331cd9cf71ccbdc91b2e. Given the deprecation of the pcommit instruction, the relevant VMX features and CPUID bits are not going to be rolled into the SDM. Remove their usage from KVM. Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-03-22KVM, pkeys: expose CPUID/CR4 to guestHuaitong Han1-0/+8
X86_FEATURE_PKU is referred to as "PKU" in the hardware documentation: CPUID.7.0.ECX[3]:PKU. X86_FEATURE_OSPKE is software support for pkeys, enumerated with CPUID.7.0.ECX[4]:OSPKE, and it reflects the setting of CR4.PKE(bit 22). This patch disables CPUID:PKU without ept, because pkeys is not yet implemented for shadow paging. Signed-off-by: Huaitong Han <huaitong.han@intel.com> Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-09KVM: x86: disable MPX if host did not enable MPX XSAVE featuresPaolo Bonzini1-8/+1
When eager FPU is disabled, KVM will still see the MPX bit in CPUID and presumably the MPX vmentry and vmexit controls. However, it will not be able to expose the MPX XSAVE features to the guest, because the guest's accessible XSAVE features are always a subset of host_xcr0. In this case, we should disable the MPX CPUID bit, the BNDCFGS MSR, and the MPX vmentry and vmexit controls for nested virtualization. It is then unnecessary to enable guest eager FPU if the guest has the MPX CPUID bit set. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-08-28 15:27:23 +0000