From f272c8de6e47395853caba638065d8b0bb54be4d Mon Sep 17 00:00:00 2001 From: Alfredo Dal'Ava Junior Date: Wed, 5 Feb 2020 20:39:18 +0000 Subject: [PATCH] [virtio] Fix r/w to PCI configuration area on big endian platforms In legacy VirtIO drivers, the header must be PCI endianness (little) and the device-specific region is encoded in the native endian of the guest. This patch makes the access (read/write) to VirtIO header using the little endian order. Other read and write access are native endianness. This also sets the device's IO region as big endian if on big endian machine. PR: 205178 Submitted by: Andre Silva Reported by: Kenneth Salerno Reviewed by: bryanv, bdragon, luporl, alfredo Approved by: jhibbits (mentor) Differential Revision: https://reviews.freebsd.org/D23401 --- sys/dev/virtio/pci/virtio_pci.c | 49 ++++++++++++++++++++++++--------- 1 file changed, 36 insertions(+), 13 deletions(-) diff --git a/sys/dev/virtio/pci/virtio_pci.c b/sys/dev/virtio/pci/virtio_pci.c index d63a3ddedb6..aba35eb38ff 100644 --- a/sys/dev/virtio/pci/virtio_pci.c +++ b/sys/dev/virtio/pci/virtio_pci.c @@ -37,6 +37,7 @@ __FBSDID("$FreeBSD$"); #include #include #include +#include #include #include @@ -184,6 +185,17 @@ static void vtpci_config_intr(void *); #define vtpci_write_config_2(sc, o, v) bus_write_2((sc)->vtpci_res, (o), (v)) #define vtpci_write_config_4(sc, o, v) bus_write_4((sc)->vtpci_res, (o), (v)) +/* + * Legacy VirtIO header is always PCI endianness (little), so if we + * are in a BE machine we need to swap bytes from LE to BE when reading + * and from BE to LE when writing. + * If we are in a LE machine, there will be no swaps. + */ +#define vtpci_read_header_2(sc, o) le16toh(vtpci_read_config_2(sc, o)) +#define vtpci_read_header_4(sc, o) le32toh(vtpci_read_config_4(sc, o)) +#define vtpci_write_header_2(sc, o, v) vtpci_write_config_2(sc, o, (htole16(v))) +#define vtpci_write_header_4(sc, o, v) vtpci_write_config_4(sc, o, (htole32(v))) + /* Tunables. */ static int vtpci_disable_msix = 0; TUNABLE_INT("hw.virtio.pci.disable_msix", &vtpci_disable_msix); @@ -278,6 +290,17 @@ vtpci_attach(device_t dev) return (ENXIO); } +/* + * For legacy VirtIO, the device-specific configuration is guest + * endian, while the common configuration header is always + * PCI (little) endian and will be handled specifically in + * other parts of this file via functions + * 'vtpci_[read|write]_header_[2|4]' + */ +#if _BYTE_ORDER == _BIG_ENDIAN + rman_set_bustag(sc->vtpci_res, &bs_be_tag); +#endif + if (pci_find_cap(dev, PCIY_MSI, NULL) != 0) sc->vtpci_flags |= VTPCI_FLAG_NO_MSI; @@ -447,7 +470,7 @@ vtpci_negotiate_features(device_t dev, uint64_t child_features) sc = device_get_softc(dev); - host_features = vtpci_read_config_4(sc, VIRTIO_PCI_HOST_FEATURES); + host_features = vtpci_read_header_4(sc, VIRTIO_PCI_HOST_FEATURES); vtpci_describe_features(sc, "host", host_features); /* @@ -459,7 +482,7 @@ vtpci_negotiate_features(device_t dev, uint64_t child_features) sc->vtpci_features = features; vtpci_describe_features(sc, "negotiated", features); - vtpci_write_config_4(sc, VIRTIO_PCI_GUEST_FEATURES, features); + vtpci_write_header_4(sc, VIRTIO_PCI_GUEST_FEATURES, features); return (features); } @@ -502,7 +525,7 @@ vtpci_alloc_virtqueues(device_t dev, int flags, int nvqs, info = &vq_info[idx]; vtpci_select_virtqueue(sc, idx); - size = vtpci_read_config_2(sc, VIRTIO_PCI_QUEUE_NUM); + size = vtpci_read_header_2(sc, VIRTIO_PCI_QUEUE_NUM); error = virtqueue_alloc(dev, idx, size, VIRTIO_PCI_VRING_ALIGN, ~(vm_paddr_t)0, info, &vq); @@ -512,7 +535,7 @@ vtpci_alloc_virtqueues(device_t dev, int flags, int nvqs, break; } - vtpci_write_config_4(sc, VIRTIO_PCI_QUEUE_PFN, + vtpci_write_header_4(sc, VIRTIO_PCI_QUEUE_PFN, virtqueue_paddr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT); vqx->vtv_vq = *info->vqai_vq = vq; @@ -646,7 +669,7 @@ vtpci_notify_virtqueue(device_t dev, uint16_t queue) sc = device_get_softc(dev); - vtpci_write_config_2(sc, VIRTIO_PCI_QUEUE_NOTIFY, queue); + vtpci_write_header_2(sc, VIRTIO_PCI_QUEUE_NOTIFY, queue); } static uint8_t @@ -1046,10 +1069,10 @@ vtpci_register_msix_vector(struct vtpci_softc *sc, int offset, } else vector = VIRTIO_MSI_NO_VECTOR; - vtpci_write_config_2(sc, offset, vector); + vtpci_write_header_2(sc, offset, vector); /* Read vector to determine if the host had sufficient resources. */ - if (vtpci_read_config_2(sc, offset) != vector) { + if (vtpci_read_header_2(sc, offset) != vector) { device_printf(dev, "insufficient host resources for MSIX interrupts\n"); return (ENODEV); @@ -1112,13 +1135,13 @@ vtpci_reinit_virtqueue(struct vtpci_softc *sc, int idx) KASSERT(vq != NULL, ("%s: vq %d not allocated", __func__, idx)); vtpci_select_virtqueue(sc, idx); - size = vtpci_read_config_2(sc, VIRTIO_PCI_QUEUE_NUM); + size = vtpci_read_header_2(sc, VIRTIO_PCI_QUEUE_NUM); error = virtqueue_reinit(vq, size); if (error) return (error); - vtpci_write_config_4(sc, VIRTIO_PCI_QUEUE_PFN, + vtpci_write_header_4(sc, VIRTIO_PCI_QUEUE_PFN, virtqueue_paddr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT); return (0); @@ -1182,7 +1205,7 @@ vtpci_free_virtqueues(struct vtpci_softc *sc) vqx = &sc->vtpci_vqs[idx]; vtpci_select_virtqueue(sc, idx); - vtpci_write_config_4(sc, VIRTIO_PCI_QUEUE_PFN, 0); + vtpci_write_header_4(sc, VIRTIO_PCI_QUEUE_PFN, 0); virtqueue_free(vqx->vtv_vq); vqx->vtv_vq = NULL; @@ -1207,12 +1230,12 @@ vtpci_cleanup_setup_intr_attempt(struct vtpci_softc *sc) int idx; if (sc->vtpci_flags & VTPCI_FLAG_MSIX) { - vtpci_write_config_2(sc, VIRTIO_MSI_CONFIG_VECTOR, + vtpci_write_header_2(sc, VIRTIO_MSI_CONFIG_VECTOR, VIRTIO_MSI_NO_VECTOR); for (idx = 0; idx < sc->vtpci_nvqs; idx++) { vtpci_select_virtqueue(sc, idx); - vtpci_write_config_2(sc, VIRTIO_MSI_QUEUE_VECTOR, + vtpci_write_header_2(sc, VIRTIO_MSI_QUEUE_VECTOR, VIRTIO_MSI_NO_VECTOR); } } @@ -1235,7 +1258,7 @@ static void vtpci_select_virtqueue(struct vtpci_softc *sc, int idx) { - vtpci_write_config_2(sc, VIRTIO_PCI_QUEUE_SEL, idx); + vtpci_write_header_2(sc, VIRTIO_PCI_QUEUE_SEL, idx); } static void