github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-28 09:04:39 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

KVM: x86: Add a macro to precisely handle aliased 0x1.EDX CPUID features

Browse Source 
Add a macro to precisely handle CPUID features that AMD duplicated from
CPUID.0x1.EDX into CPUID.0x8000_0001.EDX.  This will allow adding an
assert that all features passed to kvm_cpu_cap_init() match the word being
processed, e.g. to prevent passing a feature from CPUID 0x7 to CPUID 0x1.

Because the kernel simply reuses the X86_FEATURE_* definitions from
CPUID.0x1.EDX, KVM's use of the aliased features would result in false
positives from such an assert.

No functional change intended.

Link: https://lore.kernel.org/r/20241128013424.4096668-26-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Sean Christopherson 2024-11-27 17:33:52 -08:00
parent 6eac4d99a9
commit 264969b48a
1 changed files with 29 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
arch/x86/kvm/cpuid.c
View File

@ -669,6 +669,16 @@ static __always_inline void kvm_cpu_cap_init(enum cpuid_leafs leaf, u32 mask)
(IS_ENABLED(CONFIG_X86_64) ? F(name) : 0); \
})
/*
* Aliased Features - For features in 0x8000_0001.EDX that are duplicates of
* identical 0x1.EDX features, and thus are aliased from 0x1 to 0x8000_0001.
*/
#define ALIASED_1_EDX_F(name) \
({ \
BUILD_BUG_ON(__feature_leaf(X86_FEATURE_##name) != CPUID_1_EDX); \
feature_bit(name); \
})
void kvm_set_cpu_caps(void)
{
memset(kvm_cpu_caps, 0, sizeof(kvm_cpu_caps));
@ -913,30 +923,30 @@ void kvm_set_cpu_caps(void)
);
kvm_cpu_cap_init(CPUID_8000_0001_EDX,
F(FPU) |
F(VME) |
F(DE) |
F(PSE) |
F(TSC) |
F(MSR) |
F(PAE) |
F(MCE) |
F(CX8) |
F(APIC) |
ALIASED_1_EDX_F(FPU) |
ALIASED_1_EDX_F(VME) |
ALIASED_1_EDX_F(DE) |
ALIASED_1_EDX_F(PSE) |
ALIASED_1_EDX_F(TSC) |
ALIASED_1_EDX_F(MSR) |
ALIASED_1_EDX_F(PAE) |
ALIASED_1_EDX_F(MCE) |
ALIASED_1_EDX_F(CX8) |
ALIASED_1_EDX_F(APIC) |
0 /* Reserved */ |
F(SYSCALL) |
F(MTRR) |
F(PGE) |
F(MCA) |
F(CMOV) |
F(PAT) |
F(PSE36) |
ALIASED_1_EDX_F(MTRR) |
ALIASED_1_EDX_F(PGE) |
ALIASED_1_EDX_F(MCA) |
ALIASED_1_EDX_F(CMOV) |
ALIASED_1_EDX_F(PAT) |
ALIASED_1_EDX_F(PSE36) |
0 /* Reserved */ |
F(NX) |
0 /* Reserved */ |
F(MMXEXT) |
F(MMX) |
F(FXSR) |
ALIASED_1_EDX_F(MMX) |
ALIASED_1_EDX_F(FXSR) |
F(FXSR_OPT) |
X86_64_F(GBPAGES) |
F(RDTSCP) |
@ -1076,6 +1086,7 @@ EXPORT_SYMBOL_GPL(kvm_set_cpu_caps);
#undef F
#undef SF
#undef X86_64_F
#undef ALIASED_1_EDX_F
struct kvm_cpuid_array {
struct kvm_cpuid_entry2 *entries;