Commit-ID:  c806e88734b9e9aea260bf2261c129aa23968fca
Gitweb:     https://git.kernel.org/tip/c806e88734b9e9aea260bf2261c129aa23968fca
Author:     Sebastian Andrzej Siewior <bige...@linutronix.de>
AuthorDate: Wed, 3 Apr 2019 18:41:41 +0200
Committer:  Borislav Petkov <b...@suse.de>
CommitDate: Thu, 11 Apr 2019 15:40:58 +0200

x86/pkeys: Provide *pkru() helpers

Dave Hansen asked for __read_pkru() and __write_pkru() to be
symmetrical.

As part of the series __write_pkru() will read back the value and only
write it if it is different.

In order to make both functions symmetrical, move the function
containing only the opcode asm into a function called like the
instruction itself.

__write_pkru() will just invoke wrpkru() but in a follow-up patch will
also read back the value.

 [ bp: Convert asm opcode wrapper names to rd/wrpkru(). ]

Suggested-by: Dave Hansen <dave.han...@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
Signed-off-by: Borislav Petkov <b...@suse.de>
Reviewed-by: Dave Hansen <dave.han...@intel.com>
Reviewed-by: Thomas Gleixner <t...@linutronix.de>
Cc: Andi Kleen <a...@linux.intel.com>
Cc: Andy Lutomirski <l...@kernel.org>
Cc: "H. Peter Anvin" <h...@zytor.com>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: "Jason A. Donenfeld" <ja...@zx2c4.com>
Cc: Joerg Roedel <jroe...@suse.de>
Cc: Juergen Gross <jgr...@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com>
Cc: kvm ML <k...@vger.kernel.org>
Cc: Michal Hocko <mho...@suse.cz>
Cc: Paolo Bonzini <pbonz...@redhat.com>
Cc: "Radim Krčmář" <rkrc...@redhat.com>
Cc: Rik van Riel <r...@surriel.com>
Cc: x86-ml <x...@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-13-bige...@linutronix.de
---
 arch/x86/include/asm/pgtable.h       |  2 +-
 arch/x86/include/asm/special_insns.h | 12 +++++++++---
 arch/x86/kvm/vmx/vmx.c               |  2 +-
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 2779ace16d23..e8875ca75623 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -127,7 +127,7 @@ static inline int pte_dirty(pte_t pte)
 static inline u32 read_pkru(void)
 {
        if (boot_cpu_has(X86_FEATURE_OSPKE))
-               return __read_pkru();
+               return rdpkru();
        return 0;
 }
 
diff --git a/arch/x86/include/asm/special_insns.h 
b/arch/x86/include/asm/special_insns.h
index 43c029cdc3fe..34897e2b52c9 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -92,7 +92,7 @@ static inline void native_write_cr8(unsigned long val)
 #endif
 
 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
-static inline u32 __read_pkru(void)
+static inline u32 rdpkru(void)
 {
        u32 ecx = 0;
        u32 edx, pkru;
@@ -107,7 +107,7 @@ static inline u32 __read_pkru(void)
        return pkru;
 }
 
-static inline void __write_pkru(u32 pkru)
+static inline void wrpkru(u32 pkru)
 {
        u32 ecx = 0, edx = 0;
 
@@ -118,8 +118,14 @@ static inline void __write_pkru(u32 pkru)
        asm volatile(".byte 0x0f,0x01,0xef\n\t"
                     : : "a" (pkru), "c"(ecx), "d"(edx));
 }
+
+static inline void __write_pkru(u32 pkru)
+{
+       wrpkru(pkru);
+}
+
 #else
-static inline u32 __read_pkru(void)
+static inline u32 rdpkru(void)
 {
        return 0;
 }
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ab432a930ae8..dd1e1eea4f0b 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6501,7 +6501,7 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu)
         */
        if (static_cpu_has(X86_FEATURE_PKU) &&
            kvm_read_cr4_bits(vcpu, X86_CR4_PKE)) {
-               vcpu->arch.pkru = __read_pkru();
+               vcpu->arch.pkru = rdpkru();
                if (vcpu->arch.pkru != vmx->host_pkru)
                        __write_pkru(vmx->host_pkru);
        }

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