From 375074cc736ab1d89a708c0a8d7baa4a70d5d476 Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto@amacapital.net>
Date: Fri, 24 Oct 2014 15:58:07 -0700
Subject: x86: Clean up cr4 manipulation
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: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter 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.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kvm/vmx.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
(limited to 'arch/x86/kvm/vmx.c')
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index d4c58d884838..db77537013d1 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2812,7 +2812,7 @@ static int hardware_enable(void)
/* enable and lock */
wrmsrl(MSR_IA32_FEATURE_CONTROL, old | test_bits);
}
- write_cr4(read_cr4() | X86_CR4_VMXE); /* FIXME: not cpu hotplug safe */
+ cr4_set_bits(X86_CR4_VMXE);
if (vmm_exclusive) {
kvm_cpu_vmxon(phys_addr);
@@ -2849,7 +2849,7 @@ static void hardware_disable(void)
vmclear_local_loaded_vmcss();
kvm_cpu_vmxoff();
}
- write_cr4(read_cr4() & ~X86_CR4_VMXE);
+ cr4_clear_bits(X86_CR4_VMXE);
}
static __init int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt,
--
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