Commit ef984060 authored by Oliver Upton's avatar Oliver Upton Committed by Marc Zyngier
Browse files

KVM: arm64: Replace vCPU target with a configuration flag 



The value of kvm_vcpu_arch::target has been used to determine if a vCPU
has actually been initialized. Storing this as an integer is needless at
this point, as KVM doesn't do any microarch-specific emulation in the
first place. Instead, all we care about is whether or not the vCPU has
been initialized.

Delete the field in favor of a vCPU configuration flag indicating if
KVM_ARM_VCPU_INIT has completed for the vCPU.

Reviewed-by: default avatarZenghui Yu <yuzenghui@huawei.com>
Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230710193140.1706399-4-oliver.upton@linux.dev
parent c8a67729

arch/arm64/include/asm/kvm_host.h

+3 −2
Original line number Diff line number Diff line
@@ -567,8 +567,7 @@ struct kvm_vcpu_arch { 
	/* Cache some mmu pages needed inside spinlock regions */

	struct kvm_mmu_memory_cache mmu_page_cache;



	/* Target CPU and feature flags */

	int target;

	/* feature flags */

	DECLARE_BITMAP(features, KVM_VCPU_MAX_FEATURES);



	/* Virtual SError ESR to restore when HCR_EL2.VSE is set */
@@ -669,6 +668,8 @@ struct kvm_vcpu_arch { 
#define VCPU_SVE_FINALIZED	__vcpu_single_flag(cflags, BIT(1))

/* PTRAUTH exposed to guest */

#define GUEST_HAS_PTRAUTH	__vcpu_single_flag(cflags, BIT(2))

/* KVM_ARM_VCPU_INIT completed */

#define VCPU_INITIALIZED	__vcpu_single_flag(cflags, BIT(3))



/* Exception pending */

#define PENDING_EXCEPTION	__vcpu_single_flag(iflags, BIT(0))

arch/arm64/kvm/arm.c

+5 −7
Original line number Diff line number Diff line
@@ -360,7 +360,7 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) 
#endif



	/* Force users to call KVM_ARM_VCPU_INIT */

	vcpu->arch.target = -1;

	vcpu_clear_flag(vcpu, VCPU_INITIALIZED);

	bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);



	vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO;
@@ -569,7 +569,7 @@ unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu) 


static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)

{

	return vcpu->arch.target >= 0;

	return vcpu_get_flag(vcpu, VCPU_INITIALIZED);

}



/*
@@ -1051,7 +1051,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) 
			 * invalid. The VMM can try and fix it by issuing  a

			 * KVM_ARM_VCPU_INIT if it really wants to.

			 */

			vcpu->arch.target = -1;

			vcpu_clear_flag(vcpu, VCPU_INITIALIZED);

			ret = ARM_EXCEPTION_IL;

		}
@@ -1228,20 +1228,18 @@ static int __kvm_vcpu_set_target(struct kvm_vcpu *vcpu, 
	    !bitmap_equal(kvm->arch.vcpu_features, &features, KVM_VCPU_MAX_FEATURES))

		goto out_unlock;



	vcpu->arch.target = init->target;

	bitmap_copy(vcpu->arch.features, &features, KVM_VCPU_MAX_FEATURES);



	/* Now we know what it is, we can reset it. */

	ret = kvm_reset_vcpu(vcpu);

	if (ret) {

		vcpu->arch.target = -1;

		bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);

		goto out_unlock;

	}



	bitmap_copy(kvm->arch.vcpu_features, &features, KVM_VCPU_MAX_FEATURES);

	set_bit(KVM_ARCH_FLAG_VCPU_FEATURES_CONFIGURED, &kvm->arch.flags);



	vcpu_set_flag(vcpu, VCPU_INITIALIZED);

out_unlock:

	mutex_unlock(&kvm->arch.config_lock);

	return ret;
@@ -1259,7 +1257,7 @@ static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu, 
	if (ret)

		return ret;



	if (vcpu->arch.target == -1)

	if (!kvm_vcpu_initialized(vcpu))

		return __kvm_vcpu_set_target(vcpu, init);



	if (kvm_vcpu_init_changed(vcpu, init))

arch/arm64/kvm/hyp/nvhe/switch.c

+1 −1
Original line number Diff line number Diff line
@@ -236,7 +236,7 @@ static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code) 
		 * KVM_ARM_VCPU_INIT, however, this is likely not possible for

		 * protected VMs.

		 */

		vcpu->arch.target = -1;

		vcpu_clear_flag(vcpu, VCPU_INITIALIZED);

		*exit_code &= BIT(ARM_EXIT_WITH_SERROR_BIT);

		*exit_code |= ARM_EXCEPTION_IL;

	}