From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: David Hildenbrand Subject: [PATCH RESEND v2 0/5] virtio-mem: VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE and interaction with memory properties Date: Mon, 20 Sep 2021 15:46:48 +0200 Message-Id: <20210920134653.16412-1-david@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" To: virtio-comment@lists.oasis-open.org Cc: David Hildenbrand , Hui Zhu , Marek Kedzierski , Sebastien Boeuf , Halil Pasic , Cornelia Huck , "Michael S. Tsirkin" , Jason Wang , Pankaj Gupta , Wei Yang List-ID: Looking into supporting virtio-mem a) without a shared zeropage for the memory backing of the device -- not allowing the driver to read unplugged memory b) on architectures with memory properties for RAM (e.g., s390x with storage keys and storage attributes) requires extension of the spec to handle both cases cleanly and describe the expected semantics. I'll open a github issue soon; in the meantime, I'll work on the actual implementation in QEMU and Linux. For a), I already shared a Linux implementation in the past [1], which will be simplified once virito-mem memory can no longer be mapped via /dev/mem [2]. For b), it's actually unlocking virtio-mem on s390x in QEMU/Linux, initially supporting storage keys but not supporting storage attributes for simplicity. [1] https://lkml.kernel.org/r/20210215122421.27964-1-david@redhat.com [2] https://lkml.kernel.org/r/20210902160919.25683-1-david@redhat.com Cc: Hui Zhu Cc: Marek Kedzierski Cc: Sebastien Boeuf Cc: Halil Pasic Cc: Cornelia Huck Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Pankaj Gupta Cc: Wei Yang v1-> v2: - Addressed all feedback from Conny. - Added patch #1-#3 to cleanup and clarify. David Hildenbrand (5): virtio-mem: simplify statements that express unexpected behavior on memory access virtio-mem: rephrase remaining memory access statements virtio-mem: document basic memory access to plugged memory blocks virtio-mem: introduce VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE virtio-mem: describe interaction with memory properties virtio-mem.tex | 72 +++++++++++++++++++++++++++++++++++--------------- 1 file changed, 51 insertions(+), 21 deletions(-) -- 2.31.1