Re: [PATCH] drm/i915/gvt/kvmgt: Fix the build failure in kvmgt.

From: Zhenyu Wang
Date: Mon Feb 08 2021 - 20:26:04 EST


On 2021.02.09 02:52:10 +0800, Yu Zhang wrote:
> Previously, commit 531810caa9f4 ("KVM: x86/mmu: Use
> an rwlock for the x86 MMU") replaced KVM's mmu_lock
> with type rwlock_t. This will cause a build failure
> in kvmgt, which uses the same lock when trying to add/
> remove some GFNs to/from the page tracker. Fix it with
> write_lock/unlocks in kvmgt.

Thanks for the fix! I saw Paolo has already carried one
in -next, so we are fine.

>
> Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
> Signed-off-by: Yu Zhang <yu.c.zhang@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/i915/gvt/kvmgt.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
> index 60f1a386dd06..b4348256ae95 100644
> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
> @@ -1703,7 +1703,7 @@ static int kvmgt_page_track_add(unsigned long handle, u64 gfn)
> return -EINVAL;
> }
>
> - spin_lock(&kvm->mmu_lock);
> + write_lock(&kvm->mmu_lock);
>
> if (kvmgt_gfn_is_write_protected(info, gfn))
> goto out;
> @@ -1712,7 +1712,7 @@ static int kvmgt_page_track_add(unsigned long handle, u64 gfn)
> kvmgt_protect_table_add(info, gfn);
>
> out:
> - spin_unlock(&kvm->mmu_lock);
> + write_unlock(&kvm->mmu_lock);
> srcu_read_unlock(&kvm->srcu, idx);
> return 0;
> }
> @@ -1737,7 +1737,7 @@ static int kvmgt_page_track_remove(unsigned long handle, u64 gfn)
> return -EINVAL;
> }
>
> - spin_lock(&kvm->mmu_lock);
> + write_lock(&kvm->mmu_lock);
>
> if (!kvmgt_gfn_is_write_protected(info, gfn))
> goto out;
> @@ -1746,7 +1746,7 @@ static int kvmgt_page_track_remove(unsigned long handle, u64 gfn)
> kvmgt_protect_table_del(info, gfn);
>
> out:
> - spin_unlock(&kvm->mmu_lock);
> + write_unlock(&kvm->mmu_lock);
> srcu_read_unlock(&kvm->srcu, idx);
> return 0;
> }
> @@ -1772,7 +1772,7 @@ static void kvmgt_page_track_flush_slot(struct kvm *kvm,
> struct kvmgt_guest_info *info = container_of(node,
> struct kvmgt_guest_info, track_node);
>
> - spin_lock(&kvm->mmu_lock);
> + write_lock(&kvm->mmu_lock);
> for (i = 0; i < slot->npages; i++) {
> gfn = slot->base_gfn + i;
> if (kvmgt_gfn_is_write_protected(info, gfn)) {
> @@ -1781,7 +1781,7 @@ static void kvmgt_page_track_flush_slot(struct kvm *kvm,
> kvmgt_protect_table_del(info, gfn);
> }
> }
> - spin_unlock(&kvm->mmu_lock);
> + write_unlock(&kvm->mmu_lock);
> }
>
> static bool __kvmgt_vgpu_exist(struct intel_vgpu *vgpu, struct kvm *kvm)
> --
> 2.17.1
>

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