1. 26 Oct, 2021 9 commits
  2. 23 Oct, 2021 4 commits
    • Thomas Gleixner's avatar
    • Thomas Gleixner's avatar
      x86/kvm: Convert FPU handling to a single swap buffer · d69c1382
      Thomas Gleixner authored
      For the upcoming AMX support it's necessary to do a proper integration with
      KVM. Currently KVM allocates two FPU structs which are used for saving the user
      state of the vCPU thread and restoring the guest state when entering
      vcpu_run() and doing the reverse operation before leaving vcpu_run().
      
      With the new fpstate mechanism this can be reduced to one extra buffer by
      swapping the fpstate pointer in current::thread::fpu. This makes the
      upcoming support for AMX and XFD simpler because then fpstate information
      (features, sizes, xfd) are always consistent and it does not require any
      nasty workarounds.
      
      Convert the KVM FPU code over to this new scheme.
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Link: https://lkml.kernel.org/r/20211022185313.019454292@linutronix.de
      d69c1382
    • Thomas Gleixner's avatar
      x86/fpu: Provide infrastructure for KVM FPU cleanup · 69f6ed1d
      Thomas Gleixner authored
      For the upcoming AMX support it's necessary to do a proper integration with
      KVM. Currently KVM allocates two FPU structs which are used for saving the user
      state of the vCPU thread and restoring the guest state when entering
      vcpu_run() and doing the reverse operation before leaving vcpu_run().
      
      With the new fpstate mechanism this can be reduced to one extra buffer by
      swapping the fpstate pointer in current::thread::fpu. This makes the
      upcoming support for AMX and XFD simpler because then fpstate information
      (features, sizes, xfd) are always consistent and it does not require any
      nasty workarounds.
      
      Provide:
      
        - An allocator which initializes the state properly
      
        - A replacement for the existing FPU swap mechanim
      
      Aside of the reduced memory footprint, this also makes state switching
      more efficient when TIF_FPU_NEED_LOAD is set. It does not require a
      memcpy as the state is already correct in the to be swapped out fpstate.
      
      The existing interfaces will be removed once KVM is converted over.
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Link: https://lkml.kernel.org/r/20211022185312.954684740@linutronix.de
      69f6ed1d
    • Thomas Gleixner's avatar
      x86/fpu: Prepare for sanitizing KVM FPU code · 75c52dad
      Thomas Gleixner authored
      For the upcoming AMX support it's necessary to do a proper integration with
      KVM. To avoid more nasty hackery in KVM which violate encapsulation extend
      struct fpu and fpstate so the fpstate switching can be consolidated and
      simplified.
      
      Currently KVM allocates two FPU structs which are used for saving the user
      state of the vCPU thread and restoring the guest state when entering
      vcpu_run() and doing the reverse operation before leaving vcpu_run().
      
      With the new fpstate mechanism this can be reduced to one extra buffer by
      swapping the fpstate pointer in current::thread::fpu. This makes the
      upcoming support for AMX and XFD simpler because then fpstate information
      (features, sizes, xfd) are always consistent and it does not require any
      nasty workarounds.
      
      Add fpu::__task_fpstate to save the regular fpstate pointer while the task
      is inside vcpu_run(). Add some state fields to fpstate to indicate the
      nature of the state.
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Link: https://lkml.kernel.org/r/20211022185312.896403942@linutronix.de
      75c52dad
  3. 22 Oct, 2021 3 commits
  4. 21 Oct, 2021 15 commits
  5. 20 Oct, 2021 9 commits