1. Oct 26, 2021
  2. Oct 25, 2021
  3. Oct 23, 2021
  4. Oct 22, 2021
    • Paolo Bonzini's avatar
      KVM: SEV-ES: go over the sev_pio_data buffer in multiple passes if needed · 95e16b47
      Paolo Bonzini authored
      The PIO scratch buffer is larger than a single page, and therefore
      it is not possible to copy it in a single step to vcpu->arch/pio_data.
      Bound each call to emulator_pio_in/out to a single page; keep
      track of how many I/O operations are left in vcpu->arch.sev_pio_count,
      so that the operation can be restarted in the complete_userspace_io
      callback.
      
      For OUT, this means that the previous kvm_sev_es_outs implementation
      becomes an iterator of the loop, and we can consume the sev_pio_data
      buffer before leaving to userspace.
      
      For IN, instead, consuming the buffer and decreasing sev_pio_count
      is always done in the complete_userspace_io callback, because that
      is when the memcpy is done into sev_pio_data.
      
      Cc: stable@vger.kernel.org
      Fixes: 7ed9abfe
      
       ("KVM: SVM: Support string IO operations for an SEV-ES guest")
      Reported-by: default avatarFelix Wilhelm <fwilhelm@google.com>
      Reviewed-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      95e16b47