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KVM: x86/cpuid: generalize kvm_update_kvm_cpuid_base() and also capture limit

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A subsequent patch will need to acquire the CPUID leaf range for emulated
Xen so explicitly pass the signature of the hypervisor we're interested in
to the new function. Also introduce a new kvm_hypervisor_cpuid structure
so we can neatly store both the base and limit leaf indices.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20230106103600.528-2-pdurrant@amazon.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Paul Durrant 2023-01-06 10:35:59 +00:00 committed by Sean Christopherson
parent ee661d8ea9
commit 48639df8a9
2 changed files with 19 additions and 12 deletions
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7
arch/x86/include/asm/kvm_host.h
View File

@ -678,6 +678,11 @@ struct kvm_vcpu_hv {
} nested;
};
struct kvm_hypervisor_cpuid {
u32 base;
u32 limit;
};
/* Xen HVM per vcpu emulation context */
struct kvm_vcpu_xen {
u64 hypercall_rip;
@ -826,7 +831,7 @@ struct kvm_vcpu_arch {
int cpuid_nent;
struct kvm_cpuid_entry2 *cpuid_entries;
u32 kvm_cpuid_base;
struct kvm_hypervisor_cpuid kvm_cpuid;
u64 reserved_gpa_bits;
int maxphyaddr;

24
arch/x86/kvm/cpuid.c
View File

@ -181,15 +181,15 @@ static int kvm_cpuid_check_equal(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2
return 0;
}
static void kvm_update_kvm_cpuid_base(struct kvm_vcpu *vcpu)
static struct kvm_hypervisor_cpuid kvm_get_hypervisor_cpuid(struct kvm_vcpu *vcpu,
const char *sig)
{
u32 function;
struct kvm_hypervisor_cpuid cpuid = {};
struct kvm_cpuid_entry2 *entry;
u32 base;
vcpu->arch.kvm_cpuid_base = 0;
for_each_possible_hypervisor_cpuid_base(function) {
entry = kvm_find_cpuid_entry(vcpu, function);
for_each_possible_hypervisor_cpuid_base(base) {
entry = kvm_find_cpuid_entry(vcpu, base);
if (entry) {
u32 signature[3];
@ -198,19 +198,21 @@ static void kvm_update_kvm_cpuid_base(struct kvm_vcpu *vcpu)
signature[1] = entry->ecx;
signature[2] = entry->edx;
BUILD_BUG_ON(sizeof(signature) > sizeof(KVM_SIGNATURE));
if (!memcmp(signature, KVM_SIGNATURE, sizeof(signature))) {
vcpu->arch.kvm_cpuid_base = function;
if (!memcmp(signature, sig, sizeof(signature))) {
cpuid.base = base;
cpuid.limit = entry->eax;
break;
}
}
}
return cpuid;
}
static struct kvm_cpuid_entry2 *__kvm_find_kvm_cpuid_features(struct kvm_vcpu *vcpu,
struct kvm_cpuid_entry2 *entries, int nent)
{
u32 base = vcpu->arch.kvm_cpuid_base;
u32 base = vcpu->arch.kvm_cpuid.base;
if (!base)
return NULL;
@ -440,7 +442,7 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2,
vcpu->arch.cpuid_entries = e2;
vcpu->arch.cpuid_nent = nent;
kvm_update_kvm_cpuid_base(vcpu);
vcpu->arch.kvm_cpuid = kvm_get_hypervisor_cpuid(vcpu, KVM_SIGNATURE);
kvm_vcpu_after_set_cpuid(vcpu);
return 0;