linux-dev/arch/x86/include/asm/fpu/api.h, branch linus/master

x86/prctl: Remove pointless task argument

2022-05-13T10:56:28Z

The functions invoked via do_arch_prctl_common() can only operate on the current task and none of these function uses the task argument. Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/87lev7vtxj.ffs@tglx

x86/fpu: Fix inline prefix warnings

2022-01-14T18:48:38Z

Fix sparse warnings in xstate and remove inline prefix. Fixes: 980fe2fddcff ("x86/fpu: Extend fpu_xstate_prctl() with guest permissions") Signed-off-by: Yang Zhong Reported-by: kernel test robot Message-Id: <20220113180825.322333-1-yang.zhong@intel.com> Signed-off-by: Paolo Bonzini

x86/fpu: Provide fpu_sync_guest_vmexit_xfd_state()

2022-01-14T18:44:42Z

KVM can disable the write emulation for the XFD MSR when the vCPU's fpstate is already correctly sized to reduce the overhead. When write emulation is disabled the XFD MSR state after a VMEXIT is unknown and therefore not in sync with the software states in fpstate and the per CPU XFD cache. Provide fpu_sync_guest_vmexit_xfd_state() which has to be invoked after a VMEXIT before enabling interrupts when write emulation is disabled for the XFD MSR. It could be invoked unconditionally even when write emulation is enabled for the price of a pointless MSR read. Signed-off-by: Thomas Gleixner Signed-off-by: Jing Liu Signed-off-by: Yang Zhong Message-Id: <20220105123532.12586-21-yang.zhong@intel.com> Signed-off-by: Paolo Bonzini

x86/fpu: Provide fpu_update_guest_xfd() for IA32_XFD emulation

2022-01-14T18:43:22Z

Guest XFD can be updated either in the emulation path or in the restore path. Provide a wrapper to update guest_fpu::fpstate::xfd. If the guest fpstate is currently in-use, also update the per-cpu xfd cache and the actual MSR. Signed-off-by: Kevin Tian Signed-off-by: Jing Liu Signed-off-by: Yang Zhong Message-Id: <20220105123532.12586-10-yang.zhong@intel.com> Signed-off-by: Paolo Bonzini

x86/fpu: Provide fpu_enable_guest_xfd_features() for KVM

2022-01-14T18:43:21Z

Provide a wrapper for expanding the guest fpstate buffer according to requested xfeatures. KVM wants to call this wrapper to manage any dynamic xstate used by the guest. Suggested-by: Sean Christopherson Signed-off-by: Sean Christopherson Signed-off-by: Kevin Tian Signed-off-by: Yang Zhong Reviewed-by: Paolo Bonzini Message-Id: <20220105123532.12586-8-yang.zhong@intel.com> [Remove unnecessary 32-bit check. - Paolo] Signed-off-by: Paolo Bonzini

x86/fpu: Extend fpu_xstate_prctl() with guest permissions

2022-01-07T18:33:03Z

KVM requires a clear separation of host user space and guest permissions for dynamic XSTATE components. Add a guest permissions member to struct fpu and a separate set of prctl() arguments: ARCH_GET_XCOMP_GUEST_PERM and ARCH_REQ_XCOMP_GUEST_PERM. The semantics are equivalent to the host user space permission control except for the following constraints: 1) Permissions have to be requested before the first vCPU is created 2) Permissions are frozen when the first vCPU is created to ensure consistency. Any attempt to expand permissions via the prctl() after that point is rejected. Signed-off-by: Thomas Gleixner Signed-off-by: Jing Liu Signed-off-by: Yang Zhong Message-Id: <20220105123532.12586-2-yang.zhong@intel.com> Signed-off-by: Paolo Bonzini

iommu/vt-d: Remove unused PASID_DISABLED

2021-11-26T21:54:20Z

The macro is unused after commit 00ecd5401349a so it can be removed. Reported-by: Linus Torvalds Fixes: 00ecd5401349a ("iommu/vt-d: Clean up unused PASID updating functions") Signed-off-by: Joerg Roedel Reviewed-by: Lu Baolu Link: https://lore.kernel.org/r/20211123105507.7654-2-joro@8bytes.org

Merge tag 'iommu-updates-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

2021-11-04T18:11:24Z

Pull iommu updates from Joerg Roedel: - Intel IOMMU Updates fro Lu Baolu: - Dump DMAR translation structure when DMA fault occurs - An optimization in the page table manipulation code - Use second level for GPA->HPA translation - Various cleanups - Arm SMMU Updates from Will - Minor optimisations to SMMUv3 command creation and submission - Numerous new compatible string for Qualcomm SMMUv2 implementations - Fixes for the SWIOTLB based implemenation of dma-iommu code for untrusted devices - Add support for r8a779a0 to the Renesas IOMMU driver and DT matching code for r8a77980 - A couple of cleanups and fixes for the Apple DART IOMMU driver - Make use of generic report_iommu_fault() interface in the AMD IOMMU driver - Various smaller fixes and cleanups * tag 'iommu-updates-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (35 commits) iommu/dma: Fix incorrect error return on iommu deferred attach iommu/dart: Initialize DART_STREAMS_ENABLE iommu/dma: Use kvcalloc() instead of kvzalloc() iommu/tegra-smmu: Use devm_bitmap_zalloc when applicable iommu/dart: Use kmemdup instead of kzalloc and memcpy iommu/vt-d: Avoid duplicate removing in __domain_mapping() iommu/vt-d: Convert the return type of first_pte_in_page to bool iommu/vt-d: Clean up unused PASID updating functions iommu/vt-d: Delete dev_has_feat callback iommu/vt-d: Use second level for GPA->HPA translation iommu/vt-d: Check FL and SL capability sanity in scalable mode iommu/vt-d: Remove duplicate identity domain flag iommu/vt-d: Dump DMAR translation structure when DMA fault occurs iommu/vt-d: Do not falsely log intel_iommu is unsupported kernel option iommu/arm-smmu-qcom: Request direct mapping for modem device iommu: arm-smmu-qcom: Add compatible for QCM2290 dt-bindings: arm-smmu: Add compatible for QCM2290 SoC iommu/arm-smmu-qcom: Add SM6350 SMMU compatible dt-bindings: arm-smmu: Add compatible for SM6350 SoC iommu/arm-smmu-v3: Properly handle the return value of arm_smmu_cmdq_build_cmd() ...

x86/fpu/xstate: Add fpstate_realloc()/free()

2021-10-26T08:53:02Z

The fpstate embedded in struct fpu is the default state for storing the FPU registers. It's sized so that the default supported features can be stored. For dynamically enabled features the register buffer is too small. The #NM handler detects first use of a feature which is disabled in the XFD MSR. After handling permission checks it recalculates the size for kernel space and user space state and invokes fpstate_realloc() which tries to reallocate fpstate and install it. Provide the allocator function which checks whether the current buffer size is sufficient and if not allocates one. If allocation is successful the new fpstate is initialized with the new features and sizes and the now enabled features is removed from the task's XFD mask. realloc_fpstate() uses vzalloc(). If use of this mechanism grows to re-allocate buffers larger than 64KB, a more sophisticated allocation scheme that includes purpose-built reclaim capability might be justified. Signed-off-by: Chang S. Bae Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/20211021225527.10184-19-chang.seok.bae@intel.com

x86/arch_prctl: Add controls for dynamic XSTATE components

2021-10-26T08:18:09Z

Dynamically enabled XSTATE features are by default disabled for all processes. A process has to request permission to use such a feature. To support this implement a architecture specific prctl() with the options: - ARCH_GET_XCOMP_SUPP Copies the supported feature bitmap into the user space provided u64 storage. The pointer is handed in via arg2 - ARCH_GET_XCOMP_PERM Copies the process wide permitted feature bitmap into the user space provided u64 storage. The pointer is handed in via arg2 - ARCH_REQ_XCOMP_PERM Request permission for a feature set. A feature set can be mapped to a facility, e.g. AMX, and can require one or more XSTATE components to be enabled. The feature argument is the number of the highest XSTATE component which is required for a facility to work. The request argument is not a user supplied bitmap because that makes filtering harder (think seccomp) and even impossible because to support 32bit tasks the argument would have to be a pointer. The permission mechanism works this way: Task asks for permission for a facility and kernel checks whether that's supported. If supported it does: 1) Check whether permission has already been granted 2) Compute the size of the required kernel and user space buffer (sigframe) size. 3) Validate that no task has a sigaltstack installed which is smaller than the resulting sigframe size 4) Add the requested feature bit(s) to the permission bitmap of current->group_leader->fpu and store the sizes in the group leaders fpu struct as well. If that is successful then the feature is still not enabled for any of the tasks. The first usage of a related instruction will result in a #NM trap. The trap handler validates the permission bit of the tasks group leader and if permitted it installs a larger kernel buffer and transfers the permission and size info to the new fpstate container which makes all the FPU functions which require per task information aware of the extended feature set. [ tglx: Adopted to new base code, added missing serialization, massaged namings, comments and changelog ] Signed-off-by: Chang S. Bae Signed-off-by: Thomas Gleixner Signed-off-by: Chang S. Bae Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20211021225527.10184-7-chang.seok.bae@intel.com