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KVM: arm64: vgic: Simplify kvm_vgic_destroy()

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commit 01ad29d224ff73bc4e16e0ef9ece17f28598c4a4 upstream.

When destroying a vgic, we have rather cumbersome rules about
when slots_lock and config_lock are held, resulting in fun
buglets.

The first port of call is to simplify kvm_vgic_map_resources()
so that there is only one call to kvm_vgic_destroy() instead of
two, with the second only holding half of the locks.

For that, we kill the non-locking primitive and move the call
outside of the locking altogether. This doesn't change anything
(we re-acquire the locks and teardown the whole vgic), and
simplifies the code significantly.

Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231207151201.3028710-2-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Marc Zyngier 2023-12-07 15:11:57 +00:00 committed by Greg Kroah-Hartman
parent 3339028dd0
commit 3a0fd93cd9
1 changed files with 15 additions and 16 deletions
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31
arch/arm64/kvm/vgic/vgic-init.c
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@ -382,26 +382,24 @@ void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
vgic_cpu->rd_iodev.base_addr = VGIC_ADDR_UNDEF;
}
static void __kvm_vgic_destroy(struct kvm *kvm)
void kvm_vgic_destroy(struct kvm *kvm)
{
struct kvm_vcpu *vcpu;
unsigned long i;
lockdep_assert_held(&kvm->arch.config_lock);
mutex_lock(&kvm->slots_lock);
vgic_debug_destroy(kvm);
kvm_for_each_vcpu(i, vcpu, kvm)
kvm_vgic_vcpu_destroy(vcpu);
kvm_vgic_dist_destroy(kvm);
}
void kvm_vgic_destroy(struct kvm *kvm)
{
mutex_lock(&kvm->arch.config_lock);
__kvm_vgic_destroy(kvm);
kvm_vgic_dist_destroy(kvm);
mutex_unlock(&kvm->arch.config_lock);
mutex_unlock(&kvm->slots_lock);
}
/**
@ -469,25 +467,26 @@ int kvm_vgic_map_resources(struct kvm *kvm)
type = VGIC_V3;
}
if (ret) {
__kvm_vgic_destroy(kvm);
if (ret)
goto out;
}
dist->ready = true;
dist_base = dist->vgic_dist_base;
mutex_unlock(&kvm->arch.config_lock);
ret = vgic_register_dist_iodev(kvm, dist_base, type);
if (ret) {
if (ret)
kvm_err("Unable to register VGIC dist MMIO regions\n");
kvm_vgic_destroy(kvm);
}
mutex_unlock(&kvm->slots_lock);
return ret;
goto out_slots;
out:
mutex_unlock(&kvm->arch.config_lock);
out_slots:
mutex_unlock(&kvm->slots_lock);
if (ret)
kvm_vgic_destroy(kvm);
return ret;
}