From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794469376; b=wdJ9QTiNtBp9kpLHIyIKIjyX+OXsu6PRMd7jQYWUGpBXxr2/FkrhvjYNAana38UZ7+nv ArQQl6fmj1ZKsteCCmix7iUS1XGSE5l/Dv4aU+GmqxplHdXrz3ZNnfn8W4vMCaxGUH0Qy yq7uQ0Y7ljAo6juyZFMhYaxVSWY1LGKVOJu9Nh4Ez0E/TuO8oFq3Ydt7hIoOPQyknSuk/ Awjttd7J+XxMvJpIKuvwcxCrkgTP2rsrRZ/Q4E+jKxXB5jV2lOUhKeH70bGp/8PMViHfR I4KlcYiCwHFP82YVVyqQEQ/93owK5GdC7AswCqxDU04KrgvNh62sp3OsMfIEN7LaiGg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794469376; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=Pxnr80fWS+ZWZIzsZX1b3FRLCLNebt7uApoQNfIHwI0=; b=fDxZZqzMA7Nq7DNfNMl4PGE0H2vJHCcDyn06F56SIDRrSi+oRTA337C5H3WNS9df0tQT +YBDKJrS0JidGEh19h4Zy3tny+0IsbyOmqMuBkpLjLsjXx/Oip/1KIBRI2wvyfnr1I1MR iWuJzz4/tWnRJNEIYEILyWpVYL9k3xEK4wu9CbS6ae4R3M+OO5fvwFaeZ+2dVQY3jJvoa mRLtq1fRoyn5+ZVSnuqUBNWPDsdaGTvhTBgEa4iMF4+IRRpDs7x19enYwuHAXushOFj1l Si4n2sSIeaTtKM6IE131pXrMoVUUQLmnk6HlYBf/SrMpuHZBSTkN8O2eYYZHN26EeRg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=AacrlaxT; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8C663606A327; Thu, 12 Nov 2026 07:42:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=AacrlaxT Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D37B1F00A05; Thu, 12 Nov 2026 07:42:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794469376; bh=Pxnr80fWS+ZWZIzsZX1b3FRLCLNebt7uApoQNfIHwI0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=AacrlaxTG2uHmH8rzhmGWRsg1KMtpEwisvSqvKHrV+bYsISwbsbe++F4lr9LVyvTb o73pFIZQdAGtYOV3kWc2NdbRvk7M+NHAHutKM9DzSULfKnrk9UcC/gHEhChn48GDcj UvTNGKVVq7pEpn/yPWy2Uq5LApJ2ywGwiZJ50PkJnxociwT36Ms0nFdLj7INlzT7VK qf1F4Ip1sK+ISoZC94AXMfySPi3v8H6is3NPg1OCB1W9F70MMhDTiRq1NuduFmJ0FR JnMRCHMOW/UpRXpkuZ6o1xqIh6xvfmoVrbAN1ezyVxYyFPfN6YB0sJMMfaTuA+8dr2 hCZ2tih/X8Ohw== From: "Aneesh Kumar K.V (Arm)" To: linux-coco@lists.linux.dev Cc: "Aneesh Kumar K.V (Arm)" , Ackerley Tng , David Woodhouse , David Hildenbrand , Jason Gunthorpe , Kevin Tian , Paolo Bonzini , Sean Christopherson , Alexey Kardashevskiy , Xu Yilun , Catalin Marinas , Suzuki K Poulose , Steven Price , Fred Griffoul , iommu@lists.linux.dev, kvm@vger.kernel.org, patches@lists.linux.dev Subject: [RFC PATCH v5 16/16] KVM: guest_memfd: Invalidate mappings before memslot unbind Date: Thu, 12 Nov 2026 13:11:20 +0530 Message-ID: <20261112074120.1570072-17-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261112074120.1570072-1-aneesh.kumar@kernel.org> References: <20261112074120.1570072-1-aneesh.kumar@kernel.org> X-Mailing-List: kvm@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Use the generic invalidate_start/end helpers to remove shared and private device mappings before removing the memslot's guest_memfd binding. Hold gmem_provider_lock_updates() across invalidation and binding removal to prevent device unlock from racing with teardown. Keep the file attributes and has_private_ranges unchanged. Deleting a memslot removes mappings but does not share the memory range. Device unlock remains blocked until userspace shares the private ranges or closes the last guest_memfd reference. Cc: Paolo Bonzini Cc: Sean Christopherson Cc: David Hildenbrand Cc: kvm@vger.kernel.org Cc: patches@lists.linux.dev Signed-off-by: Aneesh Kumar K.V (Arm) --- virt/kvm/guest_memfd.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index bdee42ff6b26..93e2ccfc4540 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -1877,6 +1877,8 @@ void kvm_gmem_unbind(struct kvm_memory_slot *slot) unsigned long start = slot->gmem.pgoff; unsigned long end = start + slot->npages; struct gmem_file *f; + struct gmem_inode *gi; + enum kvm_gfn_range_filter filter; /* * Nothing to do if the underlying file was _already_ closed, as @@ -1896,8 +1898,13 @@ void kvm_gmem_unbind(struct kvm_memory_slot *slot) * drops slots_lock, so there's no need to verify the file is live. */ f = file->private_data; + gi = GMEM_I(file_inode(file)); + filter = kvm_gmem_get_all_gfns_filter(file_inode(file)); filemap_invalidate_lock(file->f_mapping); + gmem_provider_lock_updates(gi); + __kvm_gmem_invalidate_start(f, start, end, filter); + __kvm_gmem_invalidate_end(f, start, end); xa_store_range(&f->bindings, start, end - 1, NULL, GFP_KERNEL); /* @@ -1906,6 +1913,7 @@ void kvm_gmem_unbind(struct kvm_memory_slot *slot) * to guarantee kvm_gmem_get_pfn() can't see the slot+file. */ WRITE_ONCE(slot->gmem.file, NULL); + gmem_provider_unlock_updates(gi); filemap_invalidate_unlock(file->f_mapping); } -- 2.43.0