From 3008224ca8a7415323f67d58d8c03e69bde49092 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Wed, 30 Apr 2025 15:28:17 +0200 Subject: [PATCH] tests/qtest/libqos: Avoid double swapping when using modern virtio MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The logic in the qvirtio_read/write function is rather a headache, involving byte-swapping when the target is big endian, just to maybe involve another byte-swapping in the qtest_read/write function immediately afterwards (on the QEMU side). Let's do it in a more obvious way here: For virtio 1.0, we know that the values have to be little endian, so let's read/write the bytes in that well known order here. Signed-off-by: Thomas Huth Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Alex Bennée Tested-by: Alex Bennée Message-ID: <20250430132817.610903-1-thuth@redhat.com> Signed-off-by: Fabiano Rosas --- tests/qtest/libqos/virtio.c | 44 ++++++++++++++++++++++++------------- 1 file changed, 29 insertions(+), 15 deletions(-) diff --git a/tests/qtest/libqos/virtio.c b/tests/qtest/libqos/virtio.c index 2e7979652f..5a709d0bc5 100644 --- a/tests/qtest/libqos/virtio.c +++ b/tests/qtest/libqos/virtio.c @@ -25,49 +25,63 @@ */ static uint16_t qvirtio_readw(QVirtioDevice *d, QTestState *qts, uint64_t addr) { - uint16_t val = qtest_readw(qts, addr); + uint16_t val; - if (d->features & (1ull << VIRTIO_F_VERSION_1) && qtest_big_endian(qts)) { - val = bswap16(val); + if (d->features & (1ull << VIRTIO_F_VERSION_1)) { + qtest_memread(qts, addr, &val, sizeof(val)); + val = le16_to_cpu(val); + } else { + val = qtest_readw(qts, addr); } + return val; } static uint32_t qvirtio_readl(QVirtioDevice *d, QTestState *qts, uint64_t addr) { - uint32_t val = qtest_readl(qts, addr); + uint32_t val; - if (d->features & (1ull << VIRTIO_F_VERSION_1) && qtest_big_endian(qts)) { - val = bswap32(val); + if (d->features & (1ull << VIRTIO_F_VERSION_1)) { + qtest_memread(qts, addr, &val, sizeof(val)); + val = le32_to_cpu(val); + } else { + val = qtest_readl(qts, addr); } + return val; } static void qvirtio_writew(QVirtioDevice *d, QTestState *qts, uint64_t addr, uint16_t val) { - if (d->features & (1ull << VIRTIO_F_VERSION_1) && qtest_big_endian(qts)) { - val = bswap16(val); + if (d->features & (1ull << VIRTIO_F_VERSION_1)) { + val = cpu_to_le16(val); + qtest_memwrite(qts, addr, &val, sizeof(val)); + } else { + qtest_writew(qts, addr, val); } - qtest_writew(qts, addr, val); } static void qvirtio_writel(QVirtioDevice *d, QTestState *qts, uint64_t addr, uint32_t val) { - if (d->features & (1ull << VIRTIO_F_VERSION_1) && qtest_big_endian(qts)) { - val = bswap32(val); + if (d->features & (1ull << VIRTIO_F_VERSION_1)) { + val = cpu_to_le32(val); + qtest_memwrite(qts, addr, &val, sizeof(val)); + } else { + qtest_writel(qts, addr, val); } - qtest_writel(qts, addr, val); } static void qvirtio_writeq(QVirtioDevice *d, QTestState *qts, uint64_t addr, uint64_t val) { - if (d->features & (1ull << VIRTIO_F_VERSION_1) && qtest_big_endian(qts)) { - val = bswap64(val); + if (d->features & (1ull << VIRTIO_F_VERSION_1)) { + val = cpu_to_le64(val); + qtest_memwrite(qts, addr, &val, sizeof(val)); + } else { + qtest_writeq(qts, addr, val); } - qtest_writeq(qts, addr, val); } uint8_t qvirtio_config_readb(QVirtioDevice *d, uint64_t addr) -- 2.39.5