Commit 87562052 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Sean Christopherson
Browse files

KVM: x86/xen: Remove unneeded xen context from kvm_arch when !CONFIG_KVM_XEN 



Saving a few bytes of memory per KVM VM is certainly great but what's more
important is the ability to see where the code accesses Xen emulation
context while CONFIG_KVM_XEN is not enabled. Currently, kvm_cpu_get_extint()
is the only such place and it is harmless: kvm_xen_has_interrupt() always
returns '0' when !CONFIG_KVM_XEN.

No functional change intended.

Reviewed-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Tested-by: default avatarJeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20231205103630.1391318-2-vkuznets@redhat.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 0277022a

arch/x86/include/asm/kvm_host.h

+5 −0
Original line number Diff line number Diff line
@@ -1136,6 +1136,7 @@ struct msr_bitmap_range { 
	unsigned long *bitmap;

};



#ifdef CONFIG_KVM_XEN

/* Xen emulation context */

struct kvm_xen {

	struct mutex xen_lock;
@@ -1147,6 +1148,7 @@ struct kvm_xen { 
	struct idr evtchn_ports;

	unsigned long poll_mask[BITS_TO_LONGS(KVM_MAX_VCPUS)];

};

#endif



enum kvm_irqchip_mode {

	KVM_IRQCHIP_NONE,
@@ -1349,7 +1351,10 @@ struct kvm_arch { 
	struct hlist_head mask_notifier_list;



	struct kvm_hv hyperv;



#ifdef CONFIG_KVM_XEN

	struct kvm_xen xen;

#endif



	bool backwards_tsc_observed;

	bool boot_vcpu_runs_old_kvmclock;

arch/x86/kvm/irq.c

+2 −0
Original line number Diff line number Diff line
@@ -118,8 +118,10 @@ static int kvm_cpu_get_extint(struct kvm_vcpu *v) 
	if (!lapic_in_kernel(v))

		return v->arch.interrupt.nr;



#ifdef CONFIG_KVM_XEN

	if (kvm_xen_has_interrupt(v))

		return v->kvm->arch.xen.upcall_vector;

#endif



	if (irqchip_split(v->kvm)) {

		int vector = v->arch.pending_external_vector;