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.hansen@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-13-bigeasy@linutronix.de

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 2779ace16d23f21d5cb7b65faf87f384b3b05268..e8875ca7562360ced86c7990431b160224eff658 100644 (file)
--- 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 43c029cdc3fe8764a8b812084b943129a66e0e58..34897e2b52c95a65db0002744132cd34aa32e0b5 100644 (file)
--- 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 ab432a930ae865d0000d8273643de236d0738fb8..dd1e1eea4f0b671715f700c7a316235ae1071286 100644 (file)
--- 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);
        }