CET xsaves component size is queried through CPUID.(EAX=0xD, ECX=11)
and CPUID.(EAX=0xD, ECX=12).
Signed-off-by: Zhang Yi Z <yi.z.zhang@xxxxxxxxxxxxxxx>
Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx>
---
arch/x86/kvm/cpuid.c | 60 +++++++++++++++++++++++++++++++++-----------
arch/x86/kvm/x86.c | 4 +++
arch/x86/kvm/x86.h | 4 +++
3 files changed, 54 insertions(+), 14 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index cb1aece25b17..dbeb4e7904eb 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -27,6 +27,8 @@
#include "trace.h"
#include "pmu.h"
+extern u64 host_xss;
+
static u32 xstate_required_size(u64 xstate_bv, bool compacted)
{
int feature_bit = 0;
@@ -65,6 +67,19 @@ u64 kvm_supported_xcr0(void)
return xcr0;
}
+u64 kvm_supported_xss(void)
+{
+ u64 xss = host_xss & KVM_SUPPORTED_XSS;
+
+ /*
+ * Either SHSTK or IBT feature depends on the xsaves component.
+ */
+ if (!boot_cpu_has(X86_FEATURE_SHSTK) && !boot_cpu_has(X86_FEATURE_IBT))
+ xss &= ~(XFEATURE_MASK_SHSTK_USER | XFEATURE_MASK_SHSTK_KERNEL);
+
+ return xss;
+}
+
#define F(x) bit(X86_FEATURE_##x)
/* For scattered features from cpufeatures.h; we currently expose none */
@@ -503,6 +518,16 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
* if the host doesn't support it.
*/
entry->edx |= F(ARCH_CAPABILITIES);
+ /*
+ * If host doesn't have CET capability,
+ * do not report CET related info.
+ */
+ if (!boot_cpu_has(X86_FEATURE_SHSTK))
+ entry->ecx &= ~F(SHSTK);
+
+ if (!boot_cpu_has(X86_FEATURE_IBT))
+ entry->edx &= ~F(IBT);
+
} else {
entry->ebx = 0;
entry->ecx = 0;
@@ -564,14 +589,17 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
}
case 0xd: {
int idx, i;
- u64 supported = kvm_supported_xcr0();
+ u64 u_supported = kvm_supported_xcr0();
+ u64 s_supported = kvm_supported_xss();
+ u64 supported;
+ int compacted;
- entry->eax &= supported;
- entry->ebx = xstate_required_size(supported, false);
+ entry->eax &= u_supported;
+ entry->ebx = xstate_required_size(u_supported, false);
entry->ecx = entry->ebx;
- entry->edx &= supported >> 32;
+ entry->edx &= u_supported >> 32;
entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
- if (!supported)
+ if (!u_supported)
break;
for (idx = 1, i = 1; idx < 64; ++idx) {
@@ -583,19 +611,23 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
if (idx == 1) {
entry[i].eax &= kvm_cpuid_D_1_eax_x86_features;
cpuid_mask(&entry[i].eax, CPUID_D_1_EAX);
- entry[i].ebx = 0;
- if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
- entry[i].ebx =
- xstate_required_size(supported,
- true);
+ supported = u_supported | s_supported;
+ compacted = entry[i].eax &
+ (F(XSAVES) | F(XSAVEC));
+ entry[i].ebx = xstate_required_size(supported,
+ compacted);
+ entry[i].ecx &= s_supported;
+ entry[i].edx = 0;
} else {
+ supported = (entry[i].ecx & 1) ? s_supported :
+ u_supported;
if (entry[i].eax == 0 || !(supported & mask))
continue;
- if (WARN_ON_ONCE(entry[i].ecx & 1))
- continue;
+ entry[i].ecx &= 1;
+ entry[i].edx = 0;
+ if (entry[i].ecx)
+ entry[i].ebx = 0;
}
- entry[i].ecx = 0;
- entry[i].edx = 0;
entry[i].flags |=
KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
++*nent;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a0f8b71b2132..b0ae24913423 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -212,6 +212,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
};
u64 __read_mostly host_xcr0;
+u64 __read_mostly host_xss;
static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt);
@@ -6838,6 +6839,9 @@ int kvm_arch_init(void *opaque)
if (boot_cpu_has(X86_FEATURE_XSAVE))
host_xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ if (boot_cpu_has(X86_FEATURE_XSAVES))
+ rdmsrl(MSR_IA32_XSS, host_xss);
+
kvm_lapic_init();
#ifdef CONFIG_X86_64
pvclock_gtod_register_notifier(&pvclock_gtod_notifier);
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 224cd0a47568..c61da41c3c5c 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -283,6 +283,10 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2,
| XFEATURE_MASK_YMM | XFEATURE_MASK_BNDREGS \
| XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512 \
| XFEATURE_MASK_PKRU)
+
+#define KVM_SUPPORTED_XSS (XFEATURE_MASK_SHSTK_USER \
+ | XFEATURE_MASK_SHSTK_KERNEL)
+
extern u64 host_xcr0;
extern u64 kvm_supported_xcr0(void);
--
2.17.1
