On Mon, Jan 08, 2018 at 10:52:54AM +0100, Eric Auger wrote:
> Commit 3d1ad640f8c94 ("KVM: arm/arm64: Fix GICv4 ITS initialization
> issues") moved the vgic_supports_direct_msis() check in vgic_v4_init().
> However when vgic_v4_init is called from vgic_its_create(), the has_its
> field is not yet set. Hence vgic_supports_direct_msis returns false and
> vgic_v4_init does nothing.
>
> Let's move the check back to vgic_v4_init caller.
>
> Fixes: 3d1ad640f8c94 ("KVM: arm/arm64: Fix GICv4 ITS initialization issues")
> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
>
> ---
>
> v1 -> v2:
> - move the check to the caller
Why this change, I slightly preferred the first version of this patch,
but I will admit that the "has_its = true; no_wait(); has_its = false;"
things is pretty ugly...
> - identify the right commit this patch fixes
> ---
> virt/kvm/arm/vgic/vgic-init.c | 8 +++++---
> virt/kvm/arm/vgic/vgic-its.c | 2 +-
> virt/kvm/arm/vgic/vgic-v4.c | 3 ---
> 3 files changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
> index 6231012..40be908 100644
> --- a/virt/kvm/arm/vgic/vgic-init.c
> +++ b/virt/kvm/arm/vgic/vgic-init.c
> @@ -285,9 +285,11 @@ int vgic_init(struct kvm *kvm)
> if (ret)
> goto out;
>
> - ret = vgic_v4_init(kvm);
> - if (ret)
> - goto out;
> + if (vgic_supports_direct_msis(kvm)) {
> + ret = vgic_v4_init(kvm);
> + if (ret)
> + goto out;
> + }
>
> kvm_for_each_vcpu(i, vcpu, kvm)
> kvm_vgic_vcpu_enable(vcpu);
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 8e633bd..aebc88d 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -1687,7 +1687,7 @@ static int vgic_its_create(struct kvm_device *dev, u32 type)
> if (!its)
> return -ENOMEM;
>
> - if (vgic_initialized(dev->kvm)) {
> + if (kvm_vgic_global_state.has_gicv4 && vgic_initialized(dev->kvm)) {
... but now we're using vgic_supports_direct_msis() in one part of the
init path and a half-open coded version of that in another path, which
is not very pretty.
So I actually would suggest doing the init stuff more open-coded,
because init of the gic/its/gicv4 is a mess anyway.
Something like this:
diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index 62310122ee78..743ca5cb05ef 100644
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -285,9 +285,11 @@ int vgic_init(struct kvm *kvm)
if (ret)
goto out;
- ret = vgic_v4_init(kvm);
- if (ret)
- goto out;
+ if (vgic_has_its(kvm)) {
+ ret = vgic_v4_init(kvm);
+ if (ret)
+ goto out;
+ }
kvm_for_each_vcpu(i, vcpu, kvm)
kvm_vgic_vcpu_enable(vcpu);
diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index 4a37292855bc..bc4265154bac 100644
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -118,7 +118,7 @@ int vgic_v4_init(struct kvm *kvm)
struct kvm_vcpu *vcpu;
int i, nr_vcpus, ret;
- if (!vgic_supports_direct_msis(kvm))
+ if (!kvm_vgic_global_state.has_gicv4)
return 0; /* Nothing to see here... move along. */
if (dist->its_vm.vpes)
Does that work?
Thanks,
-Christoffer
