[Xen-devel] [PATCH 01/10] x86/hvm: pkeys, add pkeys support for cpuid handling

[Huaitong Han <huaitong.han@xxxxxxxxx>]

This patch adds pkeys support for cpuid handing.

Pkeys hardware support is CPUID.7.0.ECX[3]:PKU. software support is
CPUID.7.0.ECX[4]:OSPKE and it reflects the support setting of CR4.PKE.

Signed-off-by: Huaitong Han <huaitong.han@xxxxxxxxx>

diff --git a/tools/libxc/xc_cpufeature.h b/tools/libxc/xc_cpufeature.h
index c3ddc80..f6a9778 100644
--- a/tools/libxc/xc_cpufeature.h
+++ b/tools/libxc/xc_cpufeature.h
@@ -141,5 +141,7 @@
 #define X86_FEATURE_ADX         19 /* ADCX, ADOX instructions */
 #define X86_FEATURE_SMAP        20 /* Supervisor Mode Access Protection */
 
+/* Intel-defined CPU features, CPUID level 0x00000007:0 (ecx) */
+#define X86_FEATURE_PKU     3
 
 #endif /* __LIBXC_CPUFEATURE_H */
diff --git a/tools/libxc/xc_cpuid_x86.c b/tools/libxc/xc_cpuid_x86.c
index e146a3e..34bb964 100644
--- a/tools/libxc/xc_cpuid_x86.c
+++ b/tools/libxc/xc_cpuid_x86.c
@@ -367,9 +367,11 @@ static void xc_cpuid_hvm_policy(
                         bitmaskof(X86_FEATURE_ADX)  |
                         bitmaskof(X86_FEATURE_SMAP) |
                         bitmaskof(X86_FEATURE_FSGSBASE));
+            regs[2] &= bitmaskof(X86_FEATURE_PKU);
         } else
-            regs[1] = 0;
-        regs[0] = regs[2] = regs[3] = 0;
+            regs[1] = regs[2] = 0;
+
+        regs[0] = regs[3] = 0;
         break;
 
     case 0x0000000d:
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 615fa89..66917ff 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4518,6 +4518,12 @@ void hvm_cpuid(unsigned int input, unsigned int *eax, 
unsigned int *ebx,
         /* Don't expose INVPCID to non-hap hvm. */
         if ( (count == 0) && !hap_enabled(d) )
             *ebx &= ~cpufeat_mask(X86_FEATURE_INVPCID);
+
+        if ( (count == 0) && !(cpu_has_pku && hap_enabled(d)) )
+            *ecx &= ~cpufeat_mask(X86_FEATURE_PKU);
+        if ( (count == 0) && cpu_has_pku )
+            *ecx |= (v->arch.hvm_vcpu.guest_cr[4] & X86_CR4_PKE) ?
+                     cpufeat_mask(X86_FEATURE_OSPKE) : 0;
         break;
     case 0xb:
         /* Fix the x2APIC identifier. */
diff --git a/xen/include/asm-x86/cpufeature.h b/xen/include/asm-x86/cpufeature.h
index 9a01563..3c3b95f 100644
--- a/xen/include/asm-x86/cpufeature.h
+++ b/xen/include/asm-x86/cpufeature.h
@@ -154,6 +154,10 @@
 #define X86_FEATURE_ADX                (7*32+19) /* ADCX, ADOX instructions */
 #define X86_FEATURE_SMAP       (7*32+20) /* Supervisor Mode Access Prevention 
*/
 
+/* Intel-defined CPU features, CPUID level 0x00000007:0 (ecx), word 8 */
+#define X86_FEATURE_PKU        (8*32+ 3) /* Protection Keys for Userspace */
+#define X86_FEATURE_OSPKE      (8*32+ 4) /* OS Protection Keys Enable */
+
 #if !defined(__ASSEMBLY__) && !defined(X86_FEATURES_ONLY)
 #include <xen/bitops.h>
 
@@ -193,6 +197,7 @@
 
 #define cpu_has_smep            boot_cpu_has(X86_FEATURE_SMEP)
 #define cpu_has_smap            boot_cpu_has(X86_FEATURE_SMAP)
+#define cpu_has_pku             boot_cpu_has(X86_FEATURE_PKU)
 #define cpu_has_fpu_sel         (!boot_cpu_has(X86_FEATURE_NO_FPU_SEL))
 
 #define cpu_has_ffxsr           ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) \
-- 
2.4.3


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