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Re: [Qemu-devel] [PATCH for 2.8 02/11] virtio: convert to use DMA api
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH for 2.8 02/11] virtio: convert to use DMA api |
Date: |
Mon, 5 Sep 2016 05:33:19 +0300 |
On Tue, Aug 30, 2016 at 11:06:50AM +0800, Jason Wang wrote:
> @@ -1587,6 +1595,11 @@ static void virtio_pci_device_plugged(DeviceState *d,
> Error **errp)
> }
>
> if (legacy) {
> + if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) {
> + error_setg(errp, "VIRTIO_F_IOMMU_PLATFORM was supported by"
> + "neither legacy nor transitional device.");
> + return ;
> + }
> /* legacy and transitional */
> pci_set_word(config + PCI_SUBSYSTEM_VENDOR_ID,
> pci_get_word(config + PCI_VENDOR_ID));
We probably should have code to fail init if modern is disabled
since the configuration is inconsistent.
But I do not think we should break transitional devices
with this flag.
> @@ -2452,6 +2465,7 @@ static void virtio_pci_bus_class_init(ObjectClass
> *klass, void *data)
> k->ioeventfd_disabled = virtio_pci_ioeventfd_disabled;
> k->ioeventfd_set_disabled = virtio_pci_ioeventfd_set_disabled;
> k->ioeventfd_assign = virtio_pci_ioeventfd_assign;
> + k->get_dma_as = virtio_pci_get_dma_as;
> }
>
> static const TypeInfo virtio_pci_bus_info = {
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 15ee3a7..99ea97c 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -23,6 +23,7 @@
> #include "hw/virtio/virtio-bus.h"
> #include "migration/migration.h"
> #include "hw/virtio/virtio-access.h"
> +#include "sysemu/dma.h"
>
> /*
> * The alignment to use between consumer and producer parts of vring.
> @@ -122,7 +123,7 @@ void virtio_queue_update_rings(VirtIODevice *vdev, int n)
> static void vring_desc_read(VirtIODevice *vdev, VRingDesc *desc,
> hwaddr desc_pa, int i)
> {
> - address_space_read(&address_space_memory, desc_pa + i *
> sizeof(VRingDesc),
> + address_space_read(virtio_get_dma_as(vdev), desc_pa + i *
> sizeof(VRingDesc),
> MEMTXATTRS_UNSPECIFIED, (void *)desc,
> sizeof(VRingDesc));
> virtio_tswap64s(vdev, &desc->addr);
> virtio_tswap32s(vdev, &desc->len);
> @@ -164,7 +165,7 @@ static inline void vring_used_write(VirtQueue *vq,
> VRingUsedElem *uelem,
> virtio_tswap32s(vq->vdev, &uelem->id);
> virtio_tswap32s(vq->vdev, &uelem->len);
> pa = vq->vring.used + offsetof(VRingUsed, ring[i]);
> - address_space_write(&address_space_memory, pa, MEMTXATTRS_UNSPECIFIED,
> + address_space_write(virtio_get_dma_as(vq->vdev), pa,
> MEMTXATTRS_UNSPECIFIED,
> (void *)uelem, sizeof(VRingUsedElem));
> }
>
> @@ -244,6 +245,7 @@ int virtio_queue_empty(VirtQueue *vq)
> static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem,
> unsigned int len)
> {
> + AddressSpace *dma_as = virtio_get_dma_as(vq->vdev);
> unsigned int offset;
> int i;
>
> @@ -251,17 +253,17 @@ static void virtqueue_unmap_sg(VirtQueue *vq, const
> VirtQueueElement *elem,
> for (i = 0; i < elem->in_num; i++) {
> size_t size = MIN(len - offset, elem->in_sg[i].iov_len);
>
> - cpu_physical_memory_unmap(elem->in_sg[i].iov_base,
> - elem->in_sg[i].iov_len,
> - 1, size);
> + dma_memory_unmap(dma_as, elem->in_sg[i].iov_base,
> elem->in_sg[i].iov_len,
> + DMA_DIRECTION_FROM_DEVICE, size);
>
> offset += size;
> }
>
> for (i = 0; i < elem->out_num; i++)
> - cpu_physical_memory_unmap(elem->out_sg[i].iov_base,
> - elem->out_sg[i].iov_len,
> - 0, elem->out_sg[i].iov_len);
> + dma_memory_unmap(dma_as, elem->out_sg[i].iov_base,
> + elem->out_sg[i].iov_len,
> + DMA_DIRECTION_TO_DEVICE,
> + elem->out_sg[i].iov_len);
> }
>
> void virtqueue_discard(VirtQueue *vq, const VirtQueueElement *elem,
> @@ -451,7 +453,8 @@ int virtqueue_avail_bytes(VirtQueue *vq, unsigned int
> in_bytes,
> return in_bytes <= in_total && out_bytes <= out_total;
> }
>
> -static void virtqueue_map_desc(unsigned int *p_num_sg, hwaddr *addr, struct
> iovec *iov,
> +static void virtqueue_map_desc(VirtIODevice *vdev,
> + unsigned int *p_num_sg, hwaddr *addr, struct
> iovec *iov,
> unsigned int max_num_sg, bool is_write,
> hwaddr pa, size_t sz)
> {
> @@ -471,7 +474,10 @@ static void virtqueue_map_desc(unsigned int *p_num_sg,
> hwaddr *addr, struct iove
> exit(1);
> }
>
> - iov[num_sg].iov_base = cpu_physical_memory_map(pa, &len, is_write);
> + iov[num_sg].iov_base = dma_memory_map(virtio_get_dma_as(vdev), pa,
> &len,
> + is_write ?
> + DMA_DIRECTION_FROM_DEVICE:
> + DMA_DIRECTION_TO_DEVICE);
> iov[num_sg].iov_len = len;
> addr[num_sg] = pa;
>
> @@ -482,9 +488,9 @@ static void virtqueue_map_desc(unsigned int *p_num_sg,
> hwaddr *addr, struct iove
> *p_num_sg = num_sg;
> }
>
> -static void virtqueue_map_iovec(struct iovec *sg, hwaddr *addr,
> - unsigned int *num_sg, unsigned int max_size,
> - int is_write)
> +static void virtqueue_map_iovec(VirtIODevice *vdev, struct iovec *sg,
> + hwaddr *addr, unsigned int *num_sg,
> + unsigned int max_size, int is_write)
> {
> unsigned int i;
> hwaddr len;
> @@ -503,7 +509,10 @@ static void virtqueue_map_iovec(struct iovec *sg, hwaddr
> *addr,
>
> for (i = 0; i < *num_sg; i++) {
> len = sg[i].iov_len;
> - sg[i].iov_base = cpu_physical_memory_map(addr[i], &len, is_write);
> + sg[i].iov_base = dma_memory_map(virtio_get_dma_as(vdev),
> + addr[i], &len, is_write ?
> + DMA_DIRECTION_FROM_DEVICE :
> + DMA_DIRECTION_TO_DEVICE);
> if (!sg[i].iov_base) {
> error_report("virtio: error trying to map MMIO memory");
> exit(1);
> @@ -515,12 +524,15 @@ static void virtqueue_map_iovec(struct iovec *sg,
> hwaddr *addr,
> }
> }
>
> -void virtqueue_map(VirtQueueElement *elem)
> +void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem)
> {
> - virtqueue_map_iovec(elem->in_sg, elem->in_addr, &elem->in_num,
> - VIRTQUEUE_MAX_SIZE, 1);
> - virtqueue_map_iovec(elem->out_sg, elem->out_addr, &elem->out_num,
> - VIRTQUEUE_MAX_SIZE, 0);
> + virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, &elem->in_num,
> + MIN(ARRAY_SIZE(elem->in_sg),
> ARRAY_SIZE(elem->in_addr)),
> + 1);
> + virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, &elem->out_num,
> + MIN(ARRAY_SIZE(elem->out_sg),
> + ARRAY_SIZE(elem->out_addr)),
> + 0);
> }
>
> void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned in_num)
> @@ -594,14 +606,14 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz)
> /* Collect all the descriptors */
> do {
> if (desc.flags & VRING_DESC_F_WRITE) {
> - virtqueue_map_desc(&in_num, addr + out_num, iov + out_num,
> + virtqueue_map_desc(vdev, &in_num, addr + out_num, iov + out_num,
> VIRTQUEUE_MAX_SIZE - out_num, true,
> desc.addr, desc.len);
> } else {
> if (in_num) {
> error_report("Incorrect order for descriptors");
> exit(1);
> }
> - virtqueue_map_desc(&out_num, addr, iov,
> + virtqueue_map_desc(vdev, &out_num, addr, iov,
> VIRTQUEUE_MAX_SIZE, false, desc.addr,
> desc.len);
> }
>
> @@ -647,7 +659,7 @@ typedef struct VirtQueueElementOld {
> struct iovec out_sg[VIRTQUEUE_MAX_SIZE];
> } VirtQueueElementOld;
>
> -void *qemu_get_virtqueue_element(QEMUFile *f, size_t sz)
> +void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz)
> {
> VirtQueueElement *elem;
> VirtQueueElementOld data;
> @@ -678,7 +690,7 @@ void *qemu_get_virtqueue_element(QEMUFile *f, size_t sz)
> elem->out_sg[i].iov_len = data.out_sg[i].iov_len;
> }
>
> - virtqueue_map(elem);
> + virtqueue_map(vdev, elem);
> return elem;
> }
>
> @@ -733,6 +745,10 @@ static int virtio_validate_features(VirtIODevice *vdev)
> {
> VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
>
> + if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM) &&
> + !virtio_vdev_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM))
> + return -EFAULT;
> +
> if (k->validate_features) {
> return k->validate_features(vdev);
> } else {
This will have the effect of breaking all drivers older than 4.8.
I don't think it's necessary since most guests do not enable
the vIOMMU even if it's present. Further, xen guests
are using DMA API even without VIRTIO_F_IOMMU_PLATFORM.
So things will continue to work for many legacy drivers.
> diff --git a/include/hw/virtio/virtio-access.h
> b/include/hw/virtio/virtio-access.h
> index 440b455..4071dad 100644
> --- a/include/hw/virtio/virtio-access.h
> +++ b/include/hw/virtio/virtio-access.h
> @@ -17,12 +17,25 @@
> #define QEMU_VIRTIO_ACCESS_H
>
> #include "hw/virtio/virtio.h"
> +#include "hw/virtio/virtio-bus.h"
> #include "exec/address-spaces.h"
>
> #if defined(TARGET_PPC64) || defined(TARGET_ARM)
> #define LEGACY_VIRTIO_IS_BIENDIAN 1
> #endif
>
> +static inline AddressSpace *virtio_get_dma_as(VirtIODevice *vdev)
> +{
> + BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
> + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
> +
> + if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM) &&
> + k->get_dma_as) {
> + return k->get_dma_as(qbus->parent);
> + }
> + return &address_space_memory;
> +}
> +
> static inline bool virtio_access_is_big_endian(VirtIODevice *vdev)
> {
> #if defined(LEGACY_VIRTIO_IS_BIENDIAN)
> @@ -40,45 +53,55 @@ static inline bool
> virtio_access_is_big_endian(VirtIODevice *vdev)
>
> static inline uint16_t virtio_lduw_phys(VirtIODevice *vdev, hwaddr pa)
> {
> + AddressSpace *dma_as = virtio_get_dma_as(vdev);
> +
> if (virtio_access_is_big_endian(vdev)) {
> - return lduw_be_phys(&address_space_memory, pa);
> + return lduw_be_phys(dma_as, pa);
> }
> - return lduw_le_phys(&address_space_memory, pa);
> + return lduw_le_phys(dma_as, pa);
> }
>
> static inline uint32_t virtio_ldl_phys(VirtIODevice *vdev, hwaddr pa)
> {
> + AddressSpace *dma_as = virtio_get_dma_as(vdev);
> +
> if (virtio_access_is_big_endian(vdev)) {
> - return ldl_be_phys(&address_space_memory, pa);
> + return ldl_be_phys(dma_as, pa);
> }
> - return ldl_le_phys(&address_space_memory, pa);
> + return ldl_le_phys(dma_as, pa);
> }
>
> static inline uint64_t virtio_ldq_phys(VirtIODevice *vdev, hwaddr pa)
> {
> + AddressSpace *dma_as = virtio_get_dma_as(vdev);
> +
> if (virtio_access_is_big_endian(vdev)) {
> - return ldq_be_phys(&address_space_memory, pa);
> + return ldq_be_phys(dma_as, pa);
> }
> - return ldq_le_phys(&address_space_memory, pa);
> + return ldq_le_phys(dma_as, pa);
> }
>
> static inline void virtio_stw_phys(VirtIODevice *vdev, hwaddr pa,
> uint16_t value)
> {
> + AddressSpace *dma_as = virtio_get_dma_as(vdev);
> +
> if (virtio_access_is_big_endian(vdev)) {
> - stw_be_phys(&address_space_memory, pa, value);
> + stw_be_phys(dma_as, pa, value);
> } else {
> - stw_le_phys(&address_space_memory, pa, value);
> + stw_le_phys(dma_as, pa, value);
> }
> }
>
> static inline void virtio_stl_phys(VirtIODevice *vdev, hwaddr pa,
> uint32_t value)
> {
> + AddressSpace *dma_as = virtio_get_dma_as(vdev);
> +
> if (virtio_access_is_big_endian(vdev)) {
> - stl_be_phys(&address_space_memory, pa, value);
> + stl_be_phys(dma_as, pa, value);
> } else {
> - stl_le_phys(&address_space_memory, pa, value);
> + stl_le_phys(dma_as, pa, value);
> }
> }
>
> diff --git a/include/hw/virtio/virtio-bus.h b/include/hw/virtio/virtio-bus.h
> index f3e5ef3..608ff48 100644
> --- a/include/hw/virtio/virtio-bus.h
> +++ b/include/hw/virtio/virtio-bus.h
> @@ -98,6 +98,7 @@ typedef struct VirtioBusClass {
> * Note that changing this will break migration for this transport.
> */
> bool has_variable_vring_alignment;
> + AddressSpace *(*get_dma_as)(DeviceState *d);
> } VirtioBusClass;
>
> struct VirtioBusState {
> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
> index d2490c1..147d062 100644
> --- a/include/hw/virtio/virtio.h
> +++ b/include/hw/virtio/virtio.h
> @@ -157,9 +157,9 @@ void virtqueue_discard(VirtQueue *vq, const
> VirtQueueElement *elem,
> void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
> unsigned int len, unsigned int idx);
>
> -void virtqueue_map(VirtQueueElement *elem);
> +void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem);
> void *virtqueue_pop(VirtQueue *vq, size_t sz);
> -void *qemu_get_virtqueue_element(QEMUFile *f, size_t sz);
> +void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz);
> void qemu_put_virtqueue_element(QEMUFile *f, VirtQueueElement *elem);
> int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
> unsigned int out_bytes);
> @@ -252,7 +252,9 @@ typedef struct VirtIORNGConf VirtIORNGConf;
> DEFINE_PROP_BIT64("notify_on_empty", _state, _field, \
> VIRTIO_F_NOTIFY_ON_EMPTY, true), \
> DEFINE_PROP_BIT64("any_layout", _state, _field, \
> - VIRTIO_F_ANY_LAYOUT, true)
> + VIRTIO_F_ANY_LAYOUT, true), \
> + DEFINE_PROP_BIT64("iommu_platform", _state, _field, \
> + VIRTIO_F_IOMMU_PLATFORM, false)
>
> hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
> hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
> --
> 2.7.4