Re: [PATCH 5.4.y 3/3] KVM: arm64: vgic-its: Clear ITE when DISCARD frees an ITE

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: 7602ffd1d5e8927fadd5187cb4aed2fdc9c47143

WARNING: Author mismatch between patch and upstream commit:
Backport author: Jing Zhang <jingzhangos@google.com>
Commit author: Kunkun Jiang <jiangkunkun@huawei.com>


Status in newer kernel trees:
6.12.y | Present (different SHA1: 98b18dff427f)
6.11.y | Present (different SHA1: 85272e522655)
6.6.y | Present (different SHA1: 9359737ade6c)
6.1.y | Present (different SHA1: 1f6c9a5c3b12)
5.15.y | Present (different SHA1: 04e670725c10)
5.10.y | Present (different SHA1: e428da1e025c)
5.4.y | Not found

Note: The patch differs from the upstream commit:
---
1:  7602ffd1d5e89 ! 1:  8a1b7236c891a KVM: arm64: vgic-its: Clear ITE when DISCARD frees an ITE
    @@ Metadata
      ## Commit message ##
         KVM: arm64: vgic-its: Clear ITE when DISCARD frees an ITE
     
    +    commit 7602ffd1d5e8927fadd5187cb4aed2fdc9c47143 upstream.
    +
         When DISCARD frees an ITE, it does not invalidate the
         corresponding ITE. In the scenario of continuous saves and
         restores, there may be a situation where an ITE is not saved
    @@ Commit message
         Link: https://lore.kernel.org/r/20241107214137.428439-6-jingzhangos@google.com
         Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
     
    - ## arch/arm64/kvm/vgic/vgic-its.c ##
    -@@ arch/arm64/kvm/vgic/vgic-its.c: static int vgic_its_cmd_handle_discard(struct kvm *kvm, struct vgic_its *its,
    + ## virt/kvm/arm/vgic/vgic-its.c ##
    +@@ virt/kvm/arm/vgic/vgic-its.c: static int vgic_its_cmd_handle_discard(struct kvm *kvm, struct vgic_its *its,
      
      	ite = find_ite(its, device_id, event_id);
    - 	if (ite && its_is_collection_mapped(ite->collection)) {
    + 	if (ite && ite->collection) {
     +		struct its_device *device = find_its_device(its, device_id);
     +		int ite_esz = vgic_its_get_abi(its)->ite_esz;
     +		gpa_t gpa = device->itt_addr + ite->event_id * ite_esz;
      		/*
      		 * Though the spec talks about removing the pending state, we
      		 * don't bother here since we clear the ITTE anyway and the
    -@@ arch/arm64/kvm/vgic/vgic-its.c: static int vgic_its_cmd_handle_discard(struct kvm *kvm, struct vgic_its *its,
    - 		vgic_its_invalidate_cache(its);
    +@@ virt/kvm/arm/vgic/vgic-its.c: static int vgic_its_cmd_handle_discard(struct kvm *kvm, struct vgic_its *its,
    + 		vgic_its_invalidate_cache(kvm);
      
      		its_free_ite(kvm, ite);
     -		return 0;
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.4.y        |  Success    |  Success   |