Commit 48639df8 authored by Paul Durrant's avatar Paul Durrant Committed by Sean Christopherson
Browse files

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



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: default avatarPaul Durrant <pdurrant@amazon.com>
Reviewed-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20230106103600.528-2-pdurrant@amazon.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent ee661d8e

arch/x86/include/asm/kvm_host.h

+6 −1
Original line number Diff line number Diff line
@@ -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;

arch/x86/kvm/cpuid.c

+13 −11
Original line number Diff line number Diff line
@@ -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;