[PATCH v2 2/8] x86/prot-key: Enumeration for Protection Key Supervisor

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Protection Key Supervisor works in a very similar way to Protection Key User,
except that instead of a PKRU register used by the {RD,WR}PKRU instructions,
the supervisor protection settings live in MSR_PKRS and is accessed using
normal {RD,WR}MSR instructions.

PKS has the same problematic interactions with PV guests as PKU (more infact,
given the guest kernel's CPL), so we'll only support this for HVM guests for
now.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
---
 tools/libs/light/libxl_cpuid.c              | 1 +
 tools/misc/xen-cpuid.c                      | 2 +-
 xen/arch/x86/include/asm/cpufeature.h       | 1 +
 xen/arch/x86/include/asm/msr-index.h        | 2 ++
 xen/arch/x86/include/asm/x86-defns.h        | 1 +
 xen/include/public/arch-x86/cpufeatureset.h | 1 +
 6 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/libs/light/libxl_cpuid.c b/tools/libs/light/libxl_cpuid.c
index 2aa23225f42c..cbd4e511e8ab 100644
--- a/tools/libs/light/libxl_cpuid.c
+++ b/tools/libs/light/libxl_cpuid.c
@@ -211,6 +211,7 @@ int libxl_cpuid_parse_config(libxl_cpuid_policy_list 
*cpuid, const char* str)
         {"avx512-vpopcntdq",0x00000007,0,CPUID_REG_ECX, 14,  1},
         {"rdpid",        0x00000007,  0, CPUID_REG_ECX, 22,  1},
         {"cldemote",     0x00000007,  0, CPUID_REG_ECX, 25,  1},
+        {"pks",          0x00000007,  0, CPUID_REG_ECX, 31,  1},
 
         {"avx512-4vnniw",0x00000007,  0, CPUID_REG_EDX,  2,  1},
         {"avx512-4fmaps",0x00000007,  0, CPUID_REG_EDX,  3,  1},
diff --git a/tools/misc/xen-cpuid.c b/tools/misc/xen-cpuid.c
index d5833e9ce879..ea7ff320e0e4 100644
--- a/tools/misc/xen-cpuid.c
+++ b/tools/misc/xen-cpuid.c
@@ -134,7 +134,7 @@ static const char *const str_7c0[32] =
     /* 24 */                   [25] = "cldemote",
     /* 26 */                   [27] = "movdiri",
     [28] = "movdir64b",        [29] = "enqcmd",
-    [30] = "sgx-lc",
+    [30] = "sgx-lc",           [31] = "pks",
 };
 
 static const char *const str_e7d[32] =
diff --git a/xen/arch/x86/include/asm/cpufeature.h 
b/xen/arch/x86/include/asm/cpufeature.h
index 044cfd9f882d..0a301013c3d9 100644
--- a/xen/arch/x86/include/asm/cpufeature.h
+++ b/xen/arch/x86/include/asm/cpufeature.h
@@ -121,6 +121,7 @@
 #define cpu_has_movdiri         boot_cpu_has(X86_FEATURE_MOVDIRI)
 #define cpu_has_movdir64b       boot_cpu_has(X86_FEATURE_MOVDIR64B)
 #define cpu_has_enqcmd          boot_cpu_has(X86_FEATURE_ENQCMD)
+#define cpu_has_pks             boot_cpu_has(X86_FEATURE_PKS)
 
 /* CPUID level 0x80000007.edx */
 #define cpu_has_hw_pstate       boot_cpu_has(X86_FEATURE_HW_PSTATE)
diff --git a/xen/arch/x86/include/asm/msr-index.h 
b/xen/arch/x86/include/asm/msr-index.h
index 0a8852f3c246..7615d8087f46 100644
--- a/xen/arch/x86/include/asm/msr-index.h
+++ b/xen/arch/x86/include/asm/msr-index.h
@@ -148,6 +148,8 @@
 #define MSR_PL3_SSP                         0x000006a7
 #define MSR_INTERRUPT_SSP_TABLE             0x000006a8
 
+#define MSR_PKRS                            0x000006e1
+
 #define MSR_X2APIC_FIRST                    0x00000800
 #define MSR_X2APIC_LAST                     0x000008ff
 
diff --git a/xen/arch/x86/include/asm/x86-defns.h 
b/xen/arch/x86/include/asm/x86-defns.h
index 42b5f382d438..fe1caba6f819 100644
--- a/xen/arch/x86/include/asm/x86-defns.h
+++ b/xen/arch/x86/include/asm/x86-defns.h
@@ -74,6 +74,7 @@
 #define X86_CR4_SMAP       0x00200000 /* enable SMAP */
 #define X86_CR4_PKE        0x00400000 /* enable PKE */
 #define X86_CR4_CET        0x00800000 /* Control-flow Enforcement Technology */
+#define X86_CR4_PKS        0x01000000 /* Protection Key Supervisor */
 
 /*
  * XSTATE component flags in XCR0
diff --git a/xen/include/public/arch-x86/cpufeatureset.h 
b/xen/include/public/arch-x86/cpufeatureset.h
index 7915f5826f57..ad7e89dd4c40 100644
--- a/xen/include/public/arch-x86/cpufeatureset.h
+++ b/xen/include/public/arch-x86/cpufeatureset.h
@@ -227,6 +227,7 @@ XEN_CPUFEATURE(CLDEMOTE,      6*32+25) /*A  CLDEMOTE 
instruction */
 XEN_CPUFEATURE(MOVDIRI,       6*32+27) /*a  MOVDIRI instruction */
 XEN_CPUFEATURE(MOVDIR64B,     6*32+28) /*a  MOVDIR64B instruction */
 XEN_CPUFEATURE(ENQCMD,        6*32+29) /*   ENQCMD{,S} instructions */
+XEN_CPUFEATURE(PKS,           6*32+31) /*   Protection Key for Supervisor */
 
 /* AMD-defined CPU features, CPUID level 0x80000007.edx, word 7 */
 XEN_CPUFEATURE(HW_PSTATE,     7*32+ 7) /*   Hardware Pstates */
-- 
2.11.0