From: Kim Phillips <kim.phillips@amd.com>
Date: Tue, 24 Jan 2023 10:33:13 -0600
Subject: KVM: x86: Move open-coded CPUID leaf 0x80000021 EAX bit propagation
code
Git-commit: c35ac8c4bf600ee23bacb20f863aa7830efb23fb
Patch-mainline: v6.3-rc1
References: git-fixes
Move code from __do_cpuid_func() to kvm_set_cpu_caps() in preparation for adding
the features in their native leaf.
Also drop the bit description comments as it will be more self-describing once
the individual features are added.
Whilst there, switch to using the more efficient cpu_feature_enabled() instead
of static_cpu_has().
Note, LFENCE_RDTSC and "NULL selector clears base" are currently synthetic,
Linux-defined feature flags as Linux tracking of the features predates AMD's
definition. Keep the manual propagation of the flags from their synthetic
counterparts until the kernel fully converts to AMD's definition, otherwise KVM
would stop synthesizing the flags as intended.
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20230124163319.2277355-3-kim.phillips@amd.com
Acked-by: Nikolay Borisov <nik.borisov@suse.com>
---
arch/x86/kvm/cpuid.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -395,6 +395,11 @@ static inline int __do_cpuid_ent(struct
F(WBNOINVD) | F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) |
F(AMD_SSB_NO) | F(AMD_STIBP);
+ const u32 kvm_cpuid_8000_0021_eax_x86_features =
+ BIT(0) /* NO_NESTED_DATA_BP */ |
+ BIT(2) /* LFENCE Always serializing */ | 0 /* SmmPgCfgLock */ |
+ BIT(6) /* NULL_SEL_CLR_BASE */ | 0 /* PrefetchCtlMsr */;
+
/* cpuid 0xC0000001.edx */
const u32 kvm_cpuid_C000_0001_edx_x86_features =
F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
@@ -743,8 +748,9 @@ static inline int __do_cpuid_ent(struct
* 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 &= kvm_cpuid_8000_0021_eax_x86_features;
+
+ if (cpu_feature_enabled(X86_FEATURE_LFENCE_RDTSC))
entry->eax |= BIT(2);
if (!static_cpu_has_bug(X86_BUG_NULL_SEG))
entry->eax |= BIT(6);