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Date: Wed, 30 Nov 2022 19:50:00 -0600
From: Kim Phillips <kim.phillips@....com>
To: <x86@...nel.org>
CC: Kim Phillips <kim.phillips@....com>,
Babu Moger <Babu.Moger@....com>,
Borislav Petkov <bp@...en8.de>, Borislav Petkov <bp@...e.de>,
Boris Ostrovsky <boris.ostrovsky@...cle.com>,
Dave Hansen <dave.hansen@...ux.intel.com>,
"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...hat.com>,
Joao Martins <joao.m.martins@...cle.com>,
Jonathan Corbet <corbet@....net>,
"Konrad Rzeszutek Wilk" <konrad.wilk@...cle.com>,
Paolo Bonzini <pbonzini@...hat.com>,
Sean Christopherson <seanjc@...gle.com>,
Thomas Gleixner <tglx@...utronix.de>,
David Woodhouse <dwmw@...zon.co.uk>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Juergen Gross <jgross@...e.com>,
Peter Zijlstra <peterz@...radead.org>,
Tony Luck <tony.luck@...el.com>,
Tom Lendacky <thomas.lendacky@....com>,
Alexey Kardashevskiy <aik@....com>, <kvm@...r.kernel.org>,
<linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: [PATCH v4 4/7] x86/cpu, kvm: Move CPUID 0x80000021 EAX feature bits propagation to kvm_set_cpu_caps()
Move CPUID 0x80000021 EAX feature bits guest propagation to
kvm_set_cpu_caps() instead of open-coding them in __do_cpuid_func().
Drop the bit description comments now the code is more self-describing.
Whilst there, switch to using the more efficient cpu_feature_enabled()
instead of static_cpu_has().
Signed-off-by: Kim Phillips <kim.phillips@....com>
---
arch/x86/kvm/cpuid.c | 25 ++++++++++---------------
arch/x86/kvm/reverse_cpuid.h | 22 ++++++++++++++++------
2 files changed, 26 insertions(+), 21 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index c92c49a0b35b..dd0fe79521eb 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -730,6 +730,15 @@ void kvm_set_cpu_caps(void)
0 /* SME */ | F(SEV) | 0 /* VM_PAGE_FLUSH */ | F(SEV_ES) |
F(SME_COHERENT));
+ kvm_cpu_cap_init_scattered(CPUID_8000_0021_EAX,
+ SF(NO_NESTED_DATA_BP) | SF(LFENCE_RDTSC) | 0 /* SmmPgCfgLock */ |
+ SF(NULL_SEL_CLR_BASE) | 0 /* PrefetchCtlMsr */
+ );
+ if (cpu_feature_enabled(X86_FEATURE_LFENCE_RDTSC))
+ kvm_cpu_cap_set(X86_FEATURE_LFENCE_RDTSC);
+ if (!static_cpu_has_bug(X86_BUG_NULL_SEG))
+ kvm_cpu_cap_set(X86_FEATURE_NULL_SEL_CLR_BASE);
+
kvm_cpu_cap_mask(CPUID_C000_0001_EDX,
F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
@@ -1211,21 +1220,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
break;
case 0x80000021:
entry->ebx = entry->ecx = entry->edx = 0;
- /*
- * Pass down these bits:
- * EAX 0 NNDBP, Processor ignores nested data breakpoints
- * EAX 2 LAS, LFENCE always serializing
- * EAX 6 NSCB, Null selector clear base
- *
- * Other defined bits are for MSRs that KVM does not expose:
- * EAX 3 SPCL, SMM page configuration lock
- * EAX 13 PCMSR, Prefetch control MSR
- */
- entry->eax &= BIT(0) | BIT(2) | BIT(6);
- if (static_cpu_has(X86_FEATURE_LFENCE_RDTSC))
- entry->eax |= BIT(2);
- if (!static_cpu_has_bug(X86_BUG_NULL_SEG))
- entry->eax |= BIT(6);
+ cpuid_entry_override(entry, CPUID_8000_0021_EAX);
break;
/*Add support for Centaur's CPUID instruction*/
case 0xC0000000:
diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h
index 4e5b8444f161..184614e27d5b 100644
--- a/arch/x86/kvm/reverse_cpuid.h
+++ b/arch/x86/kvm/reverse_cpuid.h
@@ -13,6 +13,7 @@
*/
enum kvm_only_cpuid_leafs {
CPUID_12_EAX = NCAPINTS,
+ CPUID_8000_0021_EAX,
NR_KVM_CPU_CAPS,
NKVMCAPINTS = NR_KVM_CPU_CAPS - NCAPINTS,
@@ -25,6 +26,11 @@ enum kvm_only_cpuid_leafs {
#define KVM_X86_FEATURE_SGX2 KVM_X86_FEATURE(CPUID_12_EAX, 1)
#define KVM_X86_FEATURE_SGX_EDECCSSA KVM_X86_FEATURE(CPUID_12_EAX, 11)
+/* AMD-defined Extended Feature 2 EAX, CPUID level 0x80000021 (EAX) */
+#define KVM_X86_FEATURE_NO_NESTED_DATA_BP KVM_X86_FEATURE(CPUID_8000_0021_EAX, 0)
+#define KVM_X86_FEATURE_LFENCE_RDTSC KVM_X86_FEATURE(CPUID_8000_0021_EAX, 2)
+#define KVM_X86_FEATURE_NULL_SEL_CLR_BASE KVM_X86_FEATURE(CPUID_8000_0021_EAX, 6)
+
struct cpuid_reg {
u32 function;
u32 index;
@@ -49,6 +55,7 @@ static const struct cpuid_reg reverse_cpuid[] = {
[CPUID_7_1_EAX] = { 7, 1, CPUID_EAX},
[CPUID_12_EAX] = {0x00000012, 0, CPUID_EAX},
[CPUID_8000_001F_EAX] = {0x8000001f, 0, CPUID_EAX},
+ [CPUID_8000_0021_EAX] = {0x80000021, 0, CPUID_EAX},
};
/*
@@ -75,12 +82,15 @@ static __always_inline void reverse_cpuid_check(unsigned int x86_leaf)
*/
static __always_inline u32 __feature_translate(int x86_feature)
{
- if (x86_feature == X86_FEATURE_SGX1)
- return KVM_X86_FEATURE_SGX1;
- else if (x86_feature == X86_FEATURE_SGX2)
- return KVM_X86_FEATURE_SGX2;
- else if (x86_feature == X86_FEATURE_SGX_EDECCSSA)
- return KVM_X86_FEATURE_SGX_EDECCSSA;
+ switch (x86_feature) {
+ case X86_FEATURE_SGX1: return KVM_X86_FEATURE_SGX1;
+ case X86_FEATURE_SGX2: return KVM_X86_FEATURE_SGX2;
+ case X86_FEATURE_SGX_EDECCSSA: return KVM_X86_FEATURE_SGX_EDECCSSA;
+ case X86_FEATURE_NO_NESTED_DATA_BP: return KVM_X86_FEATURE_NO_NESTED_DATA_BP;
+ case X86_FEATURE_LFENCE_RDTSC: return KVM_X86_FEATURE_LFENCE_RDTSC;
+ case X86_FEATURE_NULL_SEL_CLR_BASE: return KVM_X86_FEATURE_NULL_SEL_CLR_BASE;
+ default: break;
+ }
return x86_feature;
}
--
2.34.1
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