CR4 manipulation was split, seemingly at random, between direct
(write_cr4) and using a helper (set/clear_in_cr4).  Unfortunately,
the set_in_cr4 and clear_in_cr4 helpers also poke at the boot code,
which only a small subset of users actually wanted.

This patch replaces all cr4 access in functions that don't leave cr4
exactly the way they found it with new helpers cr4_set_bits,
cr4_clear_bits, and cr4_set_bits_and_update_boot.
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Vince Weaver <vince@deater.net>
Cc: "hillf.zj" <hillf.zj@alibaba-inc.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/495a10bdc9e67016b8fd3945700d46cfd5c12c2f.1414190806.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

Disintegrate asm/system.h for X86.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
cc: x86@kernel.org

MSR_EFER_SVME_MASK, MSR_VM_CR and MSR_VM_HSAVE_PA are set in KVM
specific headers. Linux does have nice header files to collect
EFER bits and MSR IDs, so IMHO we should put them there.

While at it, I also changed the naming scheme to match that
of the other defines.

(introduced in v6)
Acked-by: NJoerg Roedel <joro@8bytes.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This function can be used by the reboot or kdump code to forcibly
disable SVM on the CPU.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Create cpu_svm_disable() function.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Use a trick to keep the printk()s on has_svm() working as before. gcc
will take care of not generating code for the 'msg' stuff when the
function is called with a NULL msg argument.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Add cpu_emergency_vmxoff() and its friends: cpu_vmx_enabled() and
__cpu_emergency_vmxoff().
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Unfortunately we can't use exactly the same code from vmx
hardware_disable(), because the KVM function uses the
__kvm_handle_fault_on_reboot() tricks.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

It will be used by core code on kdump and reboot, to disable
vmx if needed.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>