virtio-blk storage via mmio using virtio-drivers [v3] #635
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Use the latest version of the zerocopy crate, to match the one used by the virtio-drivers crate. Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Add mmio read and write functions. ToDo: Improve read_buffer() to be similar to write_buffer(). Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Import a minimized version of the rcore-os/virtio-drivers crate into the codebase, as a sub-crate. See https://github.com/osteffenrh/virtio-drivers/tree/minimize for changes made to the upstream branch. Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Implement a Hal for Coconut that uses the ghcb mmio functions and manages bounce-buffers in host-shared memory. The buffers use SharedBox and are currently limited to 1 page in size. The SharedBoxes need to be kept around between the share() and unshare() calls, thus a global manager was added that holds them. ToDo: Allow arbitrary buffer sizes. Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Add a simple block layer api trait. Co-developed-by: Oliver Steffen <osteffen@redhat.com> Signed-off-by: Oliver Steffen <osteffen@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Add command line option to add a virtio-blk MMIO device to the CVM. Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Make use of the fw_cfg file "etc/hardware-info" to obtain the MMIO base addresses for virtio devices. This mechanism was/is being added to OVMF [1] and Qemu [2] to pass information about hardware devices to the firmware, which can not be communicated in other ways. We introduce a new device type for SVSM for use in that file which specifies a MMIO address. [1] https://edk2.groups.io/g/devel/message/86051 [2] https://lists.nongnu.org/archive/html/qemu-devel/2025-02/msg03923.html Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Add a block device driver that uses the virito-blk via mmio transport. ToDo: Return proper error codes. Co-developed-by: Oliver Steffen <osteffen@redhat.com> Signed-off-by: Oliver Steffen <osteffen@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Add simple write+readback tests for the VirtioBlkDriver. Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Add a virtio-blk device to the in-svsm test setup to allow the VirtioBlkDriver tests to run. Signed-off-by: Oliver Steffen <osteffen@redhat.com>
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This PR adds support for virtio-blk storage devices using the virtio-mmio transport.
MMIO accesses are done via explicit vmgexits. Interrupts are not used (-> polling).
A minimized version of the rcore-os/virtio-drivers crate (MIT License) is added
to the codebase as a sub-crate. Most of the unused code was removed (PCI support, unused device types,
example programs,...), resulting in about 3800 lines of code, see osteffenrh/virtio-drivers#3
This PR requires a patched version of Qemu (coconut-svsm/qemu#13), which features virtio-mmio slots in the Q35 machine model (thanks @kraxel).
Qemu communicates the MMIO base address via the fw_cfg interface, making use of OVMF's
HardwareInfoLib. Work is already ongoing to add this to upstream Qemu.
Device information are stored in the
etc/hardware-infofw_cfg file in a simple binary format.Building on top of that, the PR introduces a new device type to store MMIO addresses for use by the SVSM.
How to test:
Fixes since V2 (#542):
Things for future PRs: