The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 7602ffd1d5e8927fadd5187cb4aed2fdc9c47143 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024120229-backshift-recolor-5b9b@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 7602ffd1d5e8927fadd5187cb4aed2fdc9c47143 Mon Sep 17 00:00:00 2001 From: Kunkun Jiang jiangkunkun@huawei.com Date: Thu, 7 Nov 2024 13:41:37 -0800 Subject: [PATCH] KVM: arm64: vgic-its: Clear ITE when DISCARD frees an ITE

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 but is restored. This is unreasonable and may cause restore to fail. This patch clears the corresponding ITE when DISCARD frees an ITE.

Cc: stable@vger.kernel.org Fixes: eff484e0298d ("KVM: arm64: vgic-its: ITT save and restore") Signed-off-by: Kunkun Jiang jiangkunkun@huawei.com [Jing: Update with entry write helper] Signed-off-by: Jing Zhang jingzhangos@google.com Link: https://lore.kernel.org/r/20241107214137.428439-6-jingzhangos@google.com Signed-off-by: Oliver Upton oliver.upton@linux.dev

diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index b77fa99eafed..198296933e7e 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -782,6 +782,9 @@ 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)) { + 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 @@ -790,7 +793,8 @@ static int vgic_its_cmd_handle_discard(struct kvm *kvm, struct vgic_its *its, vgic_its_invalidate_cache(its);

its_free_ite(kvm, ite); - return 0; + + return vgic_its_write_entry_lock(its, gpa, 0, ite_esz); }

return E_ITS_DISCARD_UNMAPPED_INTERRUPT;