x86: pvclock kvm: align allocation size to page size

To match whats mapped via vsyscalls to userspace.

Reported-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Revert "KVM: MMU: lazily drop large spte"

This reverts commit caf6900f2d8aaebe404c976753f6813ccd31d95e.

It is causing migration failures, reference
https://bugzilla.kernel.org/show_bug.cgi?id=54061.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
KVM: nVMX: Improve I/O exit handling

This prevents trapping L2 I/O exits if L1 has neither unconditional nor
bitmap-based exiting enabled. Furthermore, it implements I/O bitmap
handling.

Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
KVM: nVMX: Trap unconditionally if msr bitmap access fails

This avoids basing decisions on uninitialized variables, potentially
leaking kernel data to the L1 guest.

Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
KVM: PPC: move tsr update in a separate function

This is done so that same function can be called from SREGS and
ONE_REG interface (follow up patch).

Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
KVM: PPC: Added one_reg interface for timer registers

If userspace wants to change some specific bits of TSR
(timer status register) then it uses GET/SET_SREGS ioctl interface.
So the steps will be:
      i)   user-space will make get ioctl,
      ii)  change TSR in userspace
      iii) then make set ioctl.
It can happen that TSR gets changed by kernel after step i) and
before step iii).

To avoid this we have added below one_reg ioctls for oring and clearing
specific bits in TSR. This patch adds one registerface for:
     1) setting specific bit in TSR (timer status register)
     2) clearing specific bit in TSR (timer status register)
     3) setting/getting the TCR register. There are cases where we want to only
        change TCR and not TSR. Although we can uses SREGS without
        KVM_SREGS_E_UPDATE_TSR flag but I think one reg is better. I am open
        if someone feels we should use SREGS only here.
     4) getting/setting TSR register

Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>