Commit 3045c483 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86: Do CPU compatibility checks in x86 code 



Move the CPU compatibility checks to pure x86 code, i.e. drop x86's use
of the common kvm_x86_check_cpu_compat() arch hook.  x86 is the only
architecture that "needs" to do per-CPU compatibility checks, moving
the logic to x86 will allow dropping the common code, and will also
give x86 more control over when/how the compatibility checks are
performed, e.g. TDX will need to enable hardware (do VMXON) in order to
perform compatibility checks.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Reviewed-by: default avatarIsaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: default avatarKai Huang <kai.huang@intel.com>
Message-Id: <20221130230934.1014142-32-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 58ca1930

arch/x86/kvm/svm/svm.c

+1 −1
Original line number Diff line number Diff line
@@ -5109,7 +5109,7 @@ static int __init svm_init(void) 
	 * Common KVM initialization _must_ come last, after this, /dev/kvm is

	 * exposed to userspace!

	 */

	r = kvm_init(&svm_init_ops, sizeof(struct vcpu_svm),

	r = kvm_init(NULL, sizeof(struct vcpu_svm),

		     __alignof__(struct vcpu_svm), THIS_MODULE);

	if (r)

		goto err_kvm_init;

arch/x86/kvm/vmx/vmx.c

+1 −1
Original line number Diff line number Diff line
@@ -8635,7 +8635,7 @@ static int __init vmx_init(void) 
	 * Common KVM initialization _must_ come last, after this, /dev/kvm is

	 * exposed to userspace!

	 */

	r = kvm_init(&vmx_init_ops, sizeof(struct vcpu_vmx),

	r = kvm_init(NULL, sizeof(struct vcpu_vmx),

		     __alignof__(struct vcpu_vmx), THIS_MODULE);

	if (r)

		goto err_kvm_init;

arch/x86/kvm/x86.c

+38 −11
Original line number Diff line number Diff line
@@ -9292,10 +9292,36 @@ static inline void kvm_ops_update(struct kvm_x86_init_ops *ops) 
	kvm_pmu_ops_update(ops->pmu_ops);

}



struct kvm_cpu_compat_check {

	struct kvm_x86_init_ops *ops;

	int *ret;

};



static int kvm_x86_check_processor_compatibility(struct kvm_x86_init_ops *ops)

{

	struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());



	WARN_ON(!irqs_disabled());



	if (__cr4_reserved_bits(cpu_has, c) !=

	    __cr4_reserved_bits(cpu_has, &boot_cpu_data))

		return -EIO;



	return ops->check_processor_compatibility();

}



static void kvm_x86_check_cpu_compat(void *data)

{

	struct kvm_cpu_compat_check *c = data;



	*c->ret = kvm_x86_check_processor_compatibility(c->ops);

}



static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops)

{

	struct kvm_cpu_compat_check c;

	u64 host_pat;

	int r;

	int r, cpu;



	if (kvm_x86_ops.hardware_enable) {

		pr_err("kvm: already loaded vendor module '%s'\n", kvm_x86_ops.name);
@@ -9375,6 +9401,14 @@ static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) 
	if (r != 0)

		goto out_mmu_exit;



	c.ret = &r;

	c.ops = ops;

	for_each_online_cpu(cpu) {

		smp_call_function_single(cpu, kvm_x86_check_cpu_compat, &c, 1);

		if (r < 0)

			goto out_hardware_unsetup;

	}



	/*

	 * Point of no return!  DO NOT add error paths below this point unless

	 * absolutely necessary, as most operations from this point forward
@@ -9417,6 +9451,8 @@ static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) 
	kvm_init_msr_list();

	return 0;



out_hardware_unsetup:

	ops->runtime_ops->hardware_unsetup();

out_mmu_exit:

	kvm_mmu_vendor_module_exit();

out_free_percpu:
@@ -12050,16 +12086,7 @@ void kvm_arch_hardware_disable(void) 


int kvm_arch_check_processor_compat(void *opaque)

{

	struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());

	struct kvm_x86_init_ops *ops = opaque;



	WARN_ON(!irqs_disabled());



	if (__cr4_reserved_bits(cpu_has, c) !=

	    __cr4_reserved_bits(cpu_has, &boot_cpu_data))

		return -EIO;



	return ops->check_processor_compatibility();

	return 0;

}



bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu)