Re: [PATCH v4 17/29] drm/i915/gvt: Don't bother removing write-protection on to-be-deleted slot

From: Wang, Zhi A
Date: Tue Aug 01 2023 - 07:37:48 EST


On 7/29/2023 4:35 AM, Sean Christopherson wrote:
When handling a slot "flush", don't call back into KVM to drop write
protection for gfns in the slot. Now that KVM rejects attempts to move
memory slots while KVMGT is attached, the only time a slot is "flushed"
is when it's being removed, i.e. the memslot and all its write-tracking
metadata is about to be deleted.

Reviewed-by: Yan Zhao <yan.y.zhao@xxxxxxxxx>
Tested-by: Yongwei Ma <yongwei.ma@xxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
drivers/gpu/drm/i915/gvt/kvmgt.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index e9276500435d..3ea3cb9eb599 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -1630,14 +1630,8 @@ static void kvmgt_page_track_flush_slot(struct kvm *kvm,
for (i = 0; i < slot->npages; i++) {
gfn = slot->base_gfn + i;
- if (kvmgt_gfn_is_write_protected(info, gfn)) {
- write_lock(&kvm->mmu_lock);
- kvm_slot_page_track_remove_page(kvm, slot, gfn,
- KVM_PAGE_TRACK_WRITE);
- write_unlock(&kvm->mmu_lock);
-
+ if (kvmgt_gfn_is_write_protected(info, gfn))
kvmgt_protect_table_del(info, gfn);
- }
}
mutex_unlock(&info->vgpu_lock);
}
Reviewed-by: Zhi Wang <zhi.a.wang@xxxxxxxxx>