From 60ce3a40fc18423d6c3ba330e60ca03fc74f9d21 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 23 Oct 2019 11:04:11 +0100 Subject: [PATCH] libqos: read QVIRTIO_MMIO_VERSION register There was no real virtio-mmio ABI change between Legacy and VIRTIO 1.0 except that the Version field was incremented from 1 to 2. However, QEMU does not allow Legacy drivers to perform VIRTIO 1.0 operations like accessing 64-bit feature bits. Since we will introduce 64-bit feature bit support we need a way to differentiate between virtio-mmio Version 1 and 2 to avoid upsetting QEMU when we operate in Legacy mode. Stash away the Version field so later patches can change behavior depending on the version. Signed-off-by: Stefan Hajnoczi Reviewed-by: Thomas Huth Message-Id: <20191023100425.12168-3-stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- tests/libqos/virtio-mmio.c | 3 +++ tests/libqos/virtio-mmio.h | 1 + 2 files changed, 4 insertions(+) diff --git a/tests/libqos/virtio-mmio.c b/tests/libqos/virtio-mmio.c index d0047876a8ad..7154b03c1dac 100644 --- a/tests/libqos/virtio-mmio.c +++ b/tests/libqos/virtio-mmio.c @@ -223,6 +223,9 @@ void qvirtio_mmio_init_device(QVirtioMMIODevice *dev, QTestState *qts, magic = qtest_readl(qts, addr + QVIRTIO_MMIO_MAGIC_VALUE); g_assert(magic == ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)); + dev->version = qtest_readl(qts, addr + QVIRTIO_MMIO_VERSION); + g_assert(dev->version == 1 || dev->version == 2); + dev->qts = qts; dev->addr = addr; dev->page_size = page_size; diff --git a/tests/libqos/virtio-mmio.h b/tests/libqos/virtio-mmio.h index 17a17141c3da..0e45778b07de 100644 --- a/tests/libqos/virtio-mmio.h +++ b/tests/libqos/virtio-mmio.h @@ -40,6 +40,7 @@ typedef struct QVirtioMMIODevice { uint64_t addr; uint32_t page_size; uint32_t features; /* As it cannot be read later, save it */ + uint32_t version; } QVirtioMMIODevice; extern const QVirtioBus qvirtio_mmio;