1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 21 Mar 2019 13:15:32 +0100
Subject: [PATCH 12/27] x86/pkru: Provide .*_pkru_ins() functions
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.0/older/patches-5.0.10-rt7.tar.xz
Dave Hansen has 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 into a function with _isn() suffix. __write_pkru() will just invoke
__write_pkru_isn() but in a flowup patch will also read back the value.
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@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(-)
--- 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 __read_pkru_ins();
return 0;
}
--- 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(unsi
#endif
#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
-static inline u32 __read_pkru(void)
+static inline u32 __read_pkru_ins(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 __write_pkru_ins(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)
+{
+ __write_pkru_ins(pkru);
+}
+
#else
-static inline u32 __read_pkru(void)
+static inline u32 __read_pkru_ins(void)
{
return 0;
}
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6632,7 +6632,7 @@ static void vmx_vcpu_run(struct kvm_vcpu
*/
if (static_cpu_has(X86_FEATURE_PKU) &&
kvm_read_cr4_bits(vcpu, X86_CR4_PKE)) {
- vcpu->arch.pkru = __read_pkru();
+ vcpu->arch.pkru = __read_pkru_ins();
if (vcpu->arch.pkru != vmx->host_pkru)
__write_pkru(vmx->host_pkru);
}
|
