Reply-To: Sean Christopherson <seanjc@google.com>
Date:   Fri, 10 Mar 2023 16:22:46 -0800
In-Reply-To: <20230311002258.852397-1-seanjc@google.com>
Mime-Version: 1.0
References: <20230311002258.852397-1-seanjc@google.com>
Message-ID: <20230311002258.852397-16-seanjc@google.com>
Subject: [PATCH v2 15/27] drm/i915/gvt: Don't bother removing write-protection
 on to-be-deleted slot
From:   Sean Christopherson <seanjc@google.com>
To:     Sean Christopherson <seanjc@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Zhenyu Wang <zhenyuw@linux.intel.com>,
        Zhi Wang <zhi.a.wang@intel.com>
Cc:     kvm@vger.kernel.org, intel-gvt-dev@lists.freedesktop.org,
        intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        Yan Zhao <yan.y.zhao@intel.com>,
        Ben Gardon <bgardon@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

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.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 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 292750dc819f..577712ea4893 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -1644,14 +1644,8 @@ 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);
 }
-- 
2.40.0.rc1.284.g88254d51c5-goog