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KVM: x86: Remove all direct usage of cpuid_entry2_find()
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Convert all use of cpuid_entry2_find() to kvm_find_cpuid_entry{,index}()
now that cpuid_entry2_find() operates on the vCPU state, i.e. now that
there is no need to use cpuid_entry2_find() directly in order to pass in
non-vCPU state.

To help prevent unwanted usage of cpuid_entry2_find(), #undef
KVM_CPUID_INDEX_NOT_SIGNIFICANT, i.e. force KVM to use
kvm_find_cpuid_entry().

No functional change intended.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20241128013424.4096668-37-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Sean Christopherson committed Dec 18, 2024
1 parent 8b30cb3 commit 136d605
Showing 1 changed file with 16 additions and 12 deletions.
28 changes: 16 additions & 12 deletions arch/x86/kvm/cpuid.c
Original file line number Diff line number Diff line change
Expand Up @@ -156,6 +156,12 @@ struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
}
EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);

/*
* cpuid_entry2_find() and KVM_CPUID_INDEX_NOT_SIGNIFICANT should never be used
* directly outside of kvm_find_cpuid_entry() and kvm_find_cpuid_entry_index().
*/
#undef KVM_CPUID_INDEX_NOT_SIGNIFICANT

static int kvm_check_cpuid(struct kvm_vcpu *vcpu)
{
struct kvm_cpuid_entry2 *best;
Expand All @@ -165,8 +171,7 @@ static int kvm_check_cpuid(struct kvm_vcpu *vcpu)
* The existing code assumes virtual address is 48-bit or 57-bit in the
* canonical address checks; exit if it is ever changed.
*/
best = cpuid_entry2_find(vcpu, 0x80000008,
KVM_CPUID_INDEX_NOT_SIGNIFICANT);
best = kvm_find_cpuid_entry(vcpu, 0x80000008);
if (best) {
int vaddr_bits = (best->eax & 0xff00) >> 8;

Expand All @@ -178,7 +183,7 @@ static int kvm_check_cpuid(struct kvm_vcpu *vcpu)
* Exposing dynamic xfeatures to the guest requires additional
* enabling in the FPU, e.g. to expand the guest XSAVE state size.
*/
best = cpuid_entry2_find(vcpu, 0xd, 0);
best = kvm_find_cpuid_entry_index(vcpu, 0xd, 0);
if (!best)
return 0;

Expand Down Expand Up @@ -232,7 +237,7 @@ static struct kvm_hypervisor_cpuid kvm_get_hypervisor_cpuid(struct kvm_vcpu *vcp
u32 base;

for_each_possible_hypervisor_cpuid_base(base) {
entry = cpuid_entry2_find(vcpu, base, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
entry = kvm_find_cpuid_entry(vcpu, base);

if (entry) {
u32 signature[3];
Expand Down Expand Up @@ -279,7 +284,7 @@ static u64 cpuid_get_supported_xcr0(struct kvm_vcpu *vcpu)
{
struct kvm_cpuid_entry2 *best;

best = cpuid_entry2_find(vcpu, 0xd, 0);
best = kvm_find_cpuid_entry_index(vcpu, 0xd, 0);
if (!best)
return 0;

Expand All @@ -290,7 +295,7 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
{
struct kvm_cpuid_entry2 *best;

best = cpuid_entry2_find(vcpu, 1, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
best = kvm_find_cpuid_entry(vcpu, 1);
if (best) {
/* Update OSXSAVE bit */
if (boot_cpu_has(X86_FEATURE_XSAVE))
Expand All @@ -301,22 +306,22 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE);
}

best = cpuid_entry2_find(vcpu, 7, 0);
best = kvm_find_cpuid_entry_index(vcpu, 7, 0);
if (best && boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7)
cpuid_entry_change(best, X86_FEATURE_OSPKE,
kvm_is_cr4_bit_set(vcpu, X86_CR4_PKE));

best = cpuid_entry2_find(vcpu, 0xD, 0);
best = kvm_find_cpuid_entry_index(vcpu, 0xD, 0);
if (best)
best->ebx = xstate_required_size(vcpu->arch.xcr0, false);

best = cpuid_entry2_find(vcpu, 0xD, 1);
best = kvm_find_cpuid_entry_index(vcpu, 0xD, 1);
if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) ||
cpuid_entry_has(best, X86_FEATURE_XSAVEC)))
best->ebx = xstate_required_size(vcpu->arch.xcr0, true);

if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) {
best = cpuid_entry2_find(vcpu, 0x1, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
best = kvm_find_cpuid_entry(vcpu, 0x1);
if (best)
cpuid_entry_change(best, X86_FEATURE_MWAIT,
vcpu->arch.ia32_misc_enable_msr &
Expand All @@ -330,8 +335,7 @@ static bool kvm_cpuid_has_hyperv(struct kvm_vcpu *vcpu)
#ifdef CONFIG_KVM_HYPERV
struct kvm_cpuid_entry2 *entry;

entry = cpuid_entry2_find(vcpu, HYPERV_CPUID_INTERFACE,
KVM_CPUID_INDEX_NOT_SIGNIFICANT);
entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_INTERFACE);
return entry && entry->eax == HYPERV_CPUID_SIGNATURE_EAX;
#else
return false;
Expand Down

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