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[RFC v3 4/5] virtio: add in_xlat_addr & out_xlat_addr VirtQueueElement m
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From: |
Jonah Palmer |
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Subject: |
[RFC v3 4/5] virtio: add in_xlat_addr & out_xlat_addr VirtQueueElement members |
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Date: |
Fri, 10 Jan 2025 12:08:33 -0500 |
Adds the in_xlat_addr & out_xlat_addr hwaddr arrays to the
VirtQueueElement struct and introduces an optional GPA output parameter
to dma_memory_map().
These arrays will store a VirtQueueElement's input/output descriptors'
GPA of the mapped memory region, if it's backed by guest memory, via
dma_memory_map().
The GPA will always correspond 1:1 to the iovec entry when translating
addresses between Qemu VAs and SVQ IOVAs in vhost_svq_translate_addr().
This helps to avoid extra complicated code in SVQ's
vhost_svq_vring_write_descs() function (e.g. splitting up iovec into
multiple buffers, not breaking devices using aliased mapping, etc.).
Since the translation is only done once inside the DMA API alongside
virtqueue_pop(), the cost should be minimal.
Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
---
hw/display/virtio-gpu.c | 5 ++--
hw/hyperv/vmbus.c | 8 +++---
hw/ide/ahci.c | 7 +++---
hw/usb/libhw.c | 2 +-
hw/virtio/virtio.c | 50 ++++++++++++++++++++++++++-----------
include/hw/pci/pci_device.h | 2 +-
include/hw/virtio/virtio.h | 2 ++
include/system/dma.h | 25 ++++++++++++++++++-
system/dma-helpers.c | 2 +-
9 files changed, 77 insertions(+), 26 deletions(-)
diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index 11a7a85750..afb9a8b69f 100644
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -839,7 +839,7 @@ int virtio_gpu_create_mapping_iov(VirtIOGPU *g,
len = l;
map = dma_memory_map(VIRTIO_DEVICE(g)->dma_as, a, &len,
DMA_DIRECTION_TO_DEVICE,
- MEMTXATTRS_UNSPECIFIED);
+ MEMTXATTRS_UNSPECIFIED, NULL);
if (!map) {
qemu_log_mask(LOG_GUEST_ERROR, "%s: failed to map MMIO memory
for"
" element %d\n", __func__, e);
@@ -1258,7 +1258,8 @@ static bool virtio_gpu_load_restore_mapping(VirtIOGPU *g,
hwaddr len = res->iov[i].iov_len;
res->iov[i].iov_base =
dma_memory_map(VIRTIO_DEVICE(g)->dma_as, res->addrs[i], &len,
- DMA_DIRECTION_TO_DEVICE, MEMTXATTRS_UNSPECIFIED);
+ DMA_DIRECTION_TO_DEVICE, MEMTXATTRS_UNSPECIFIED,
+ NULL);
if (!res->iov[i].iov_base || len != res->iov[i].iov_len) {
/* Clean up the half-a-mapping we just created... */
diff --git a/hw/hyperv/vmbus.c b/hw/hyperv/vmbus.c
index 12a7dc4312..c3308a1bfd 100644
--- a/hw/hyperv/vmbus.c
+++ b/hw/hyperv/vmbus.c
@@ -374,7 +374,7 @@ static ssize_t gpadl_iter_io(GpadlIter *iter, void *buf,
uint32_t len)
maddr = (iter->gpadl->gfns[idx] << TARGET_PAGE_BITS) | off_in_page;
iter->map = dma_memory_map(iter->as, maddr, &mlen, iter->dir,
- MEMTXATTRS_UNSPECIFIED);
+ MEMTXATTRS_UNSPECIFIED, NULL);
if (mlen != pgleft) {
dma_memory_unmap(iter->as, iter->map, mlen, iter->dir, 0);
iter->map = NULL;
@@ -492,7 +492,8 @@ int vmbus_map_sgl(VMBusChanReq *req, DMADirection dir,
struct iovec *iov,
}
iov[ret_cnt].iov_base = dma_memory_map(sgl->as, a, &l, dir,
- MEMTXATTRS_UNSPECIFIED);
+ MEMTXATTRS_UNSPECIFIED,
+ NULL);
if (!l) {
ret = -EFAULT;
goto err;
@@ -568,7 +569,8 @@ static vmbus_ring_buffer
*ringbuf_map_hdr(VMBusRingBufCommon *ringbuf)
dma_addr_t mlen = sizeof(*rb);
rb = dma_memory_map(ringbuf->as, ringbuf->rb_addr, &mlen,
- DMA_DIRECTION_FROM_DEVICE, MEMTXATTRS_UNSPECIFIED);
+ DMA_DIRECTION_FROM_DEVICE, MEMTXATTRS_UNSPECIFIED,
+ NULL);
if (mlen != sizeof(*rb)) {
dma_memory_unmap(ringbuf->as, rb, mlen,
DMA_DIRECTION_FROM_DEVICE, 0);
diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index 1303c21cb7..aeea2dc61d 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -221,7 +221,7 @@ static void map_page(AddressSpace *as, uint8_t **ptr,
uint64_t addr,
}
*ptr = dma_memory_map(as, addr, &len, DMA_DIRECTION_FROM_DEVICE,
- MEMTXATTRS_UNSPECIFIED);
+ MEMTXATTRS_UNSPECIFIED, NULL);
if (len < wanted && *ptr) {
dma_memory_unmap(as, *ptr, len, DMA_DIRECTION_FROM_DEVICE, len);
*ptr = NULL;
@@ -928,7 +928,7 @@ static int ahci_populate_sglist(AHCIDevice *ad, QEMUSGList
*sglist,
/* map PRDT */
if (!(prdt = dma_memory_map(ad->hba->as, prdt_addr, &prdt_len,
DMA_DIRECTION_TO_DEVICE,
- MEMTXATTRS_UNSPECIFIED))){
+ MEMTXATTRS_UNSPECIFIED, NULL))) {
trace_ahci_populate_sglist_no_map(ad->hba, ad->port_no);
return -1;
}
@@ -1338,7 +1338,8 @@ static void handle_cmd(AHCIState *s, int port, uint8_t
slot)
tbl_addr = le64_to_cpu(cmd->tbl_addr);
cmd_len = 0x80;
cmd_fis = dma_memory_map(s->as, tbl_addr, &cmd_len,
- DMA_DIRECTION_TO_DEVICE, MEMTXATTRS_UNSPECIFIED);
+ DMA_DIRECTION_TO_DEVICE, MEMTXATTRS_UNSPECIFIED,
+ NULL);
if (!cmd_fis) {
trace_handle_cmd_badfis(s, port);
return;
diff --git a/hw/usb/libhw.c b/hw/usb/libhw.c
index 4f03ef4ba9..762d70b419 100644
--- a/hw/usb/libhw.c
+++ b/hw/usb/libhw.c
@@ -37,7 +37,7 @@ int usb_packet_map(USBPacket *p, QEMUSGList *sgl)
while (len) {
dma_addr_t xlen = len;
mem = dma_memory_map(sgl->as, base, &xlen, dir,
- MEMTXATTRS_UNSPECIFIED);
+ MEMTXATTRS_UNSPECIFIED, NULL);
if (!mem) {
goto err;
}
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 85110bce37..be756f3ac8 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -1553,9 +1553,9 @@ int virtqueue_avail_bytes(VirtQueue *vq, unsigned int
in_bytes,
}
static bool 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)
+ hwaddr *addr, hwaddr *xlat_addr,
+ struct iovec *iov, unsigned int max_num_sg,
+ bool is_write, hwaddr pa, size_t sz)
{
bool ok = false;
unsigned num_sg = *p_num_sg;
@@ -1579,7 +1579,8 @@ static bool virtqueue_map_desc(VirtIODevice *vdev,
unsigned int *p_num_sg,
is_write ?
DMA_DIRECTION_FROM_DEVICE :
DMA_DIRECTION_TO_DEVICE,
- MEMTXATTRS_UNSPECIFIED);
+ MEMTXATTRS_UNSPECIFIED,
+ &xlat_addr[num_sg]);
if (!iov[num_sg].iov_base) {
virtio_error(vdev, "virtio: bogus descriptor or out of resources");
goto out;
@@ -1618,7 +1619,7 @@ static void virtqueue_undo_map_desc(unsigned int out_num,
unsigned int in_num,
static void virtqueue_map_iovec(VirtIODevice *vdev, struct iovec *sg,
hwaddr *addr, unsigned int num_sg,
- bool is_write)
+ hwaddr *xlat_addr, bool is_write)
{
unsigned int i;
hwaddr len;
@@ -1629,7 +1630,8 @@ static void virtqueue_map_iovec(VirtIODevice *vdev,
struct iovec *sg,
addr[i], &len, is_write ?
DMA_DIRECTION_FROM_DEVICE :
DMA_DIRECTION_TO_DEVICE,
- MEMTXATTRS_UNSPECIFIED);
+ MEMTXATTRS_UNSPECIFIED,
+ &xlat_addr[i]);
if (!sg[i].iov_base) {
error_report("virtio: error trying to map MMIO memory");
exit(1);
@@ -1643,9 +1645,10 @@ static void virtqueue_map_iovec(VirtIODevice *vdev,
struct iovec *sg,
void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem)
{
- virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, elem->in_num, true);
+ virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, elem->in_num,
+ elem->in_xlat_addr, true);
virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, elem->out_num,
- false);
+ elem->out_xlat_addr, false);
}
static void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned
in_num)
@@ -1654,7 +1657,14 @@ static void *virtqueue_alloc_element(size_t sz, unsigned
out_num, unsigned in_nu
size_t in_addr_ofs = QEMU_ALIGN_UP(sz, __alignof__(elem->in_addr[0]));
size_t out_addr_ofs = in_addr_ofs + in_num * sizeof(elem->in_addr[0]);
size_t out_addr_end = out_addr_ofs + out_num * sizeof(elem->out_addr[0]);
- size_t in_sg_ofs = QEMU_ALIGN_UP(out_addr_end,
__alignof__(elem->in_sg[0]));
+ size_t in_xlat_addr_ofs =
+ QEMU_ALIGN_UP(out_addr_end, __alignof__(elem->in_xlat_addr[0]));
+ size_t out_xlat_addr_ofs = in_xlat_addr_ofs + in_num *
+ sizeof(elem->in_xlat_addr[0]);
+ size_t out_xlat_addr_end = out_xlat_addr_ofs + out_num *
+ sizeof(elem->out_xlat_addr[0]);
+ size_t in_sg_ofs =
+ QEMU_ALIGN_UP(out_xlat_addr_end, __alignof__(elem->in_sg[0]));
size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]);
size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]);
@@ -1665,6 +1675,8 @@ static void *virtqueue_alloc_element(size_t sz, unsigned
out_num, unsigned in_nu
elem->in_num = in_num;
elem->in_addr = (void *)elem + in_addr_ofs;
elem->out_addr = (void *)elem + out_addr_ofs;
+ elem->in_xlat_addr = (void *)elem + in_xlat_addr_ofs;
+ elem->out_xlat_addr = (void *)elem + out_xlat_addr_ofs;
elem->in_sg = (void *)elem + in_sg_ofs;
elem->out_sg = (void *)elem + out_sg_ofs;
return elem;
@@ -1681,6 +1693,7 @@ static void *virtqueue_split_pop(VirtQueue *vq, size_t sz)
VirtQueueElement *elem = NULL;
unsigned out_num, in_num, elem_entries;
hwaddr addr[VIRTQUEUE_MAX_SIZE];
+ hwaddr xlat_addr[VIRTQUEUE_MAX_SIZE];
struct iovec iov[VIRTQUEUE_MAX_SIZE];
VRingDesc desc;
int rc;
@@ -1754,7 +1767,7 @@ static void *virtqueue_split_pop(VirtQueue *vq, size_t sz)
if (desc.flags & VRING_DESC_F_WRITE) {
map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num,
- iov + out_num,
+ xlat_addr + out_num, iov + out_num,
VIRTQUEUE_MAX_SIZE - out_num, true,
desc.addr, desc.len);
} else {
@@ -1762,8 +1775,8 @@ static void *virtqueue_split_pop(VirtQueue *vq, size_t sz)
virtio_error(vdev, "Incorrect order for descriptors");
goto err_undo_map;
}
- map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov,
- VIRTQUEUE_MAX_SIZE, false,
+ map_ok = virtqueue_map_desc(vdev, &out_num, addr, xlat_addr,
+ iov, VIRTQUEUE_MAX_SIZE, false,
desc.addr, desc.len);
}
if (!map_ok) {
@@ -1790,10 +1803,12 @@ static void *virtqueue_split_pop(VirtQueue *vq, size_t
sz)
for (i = 0; i < out_num; i++) {
elem->out_addr[i] = addr[i];
elem->out_sg[i] = iov[i];
+ elem->out_xlat_addr[i] = xlat_addr[i];
}
for (i = 0; i < in_num; i++) {
elem->in_addr[i] = addr[out_num + i];
elem->in_sg[i] = iov[out_num + i];
+ elem->in_xlat_addr[i] = xlat_addr[out_num + i];
}
if (virtio_vdev_has_feature(vdev, VIRTIO_F_IN_ORDER)) {
@@ -1827,6 +1842,7 @@ static void *virtqueue_packed_pop(VirtQueue *vq, size_t
sz)
VirtQueueElement *elem = NULL;
unsigned out_num, in_num, elem_entries;
hwaddr addr[VIRTQUEUE_MAX_SIZE];
+ hwaddr xlat_addr[VIRTQUEUE_MAX_SIZE];
struct iovec iov[VIRTQUEUE_MAX_SIZE];
VRingPackedDesc desc;
uint16_t id;
@@ -1891,7 +1907,7 @@ static void *virtqueue_packed_pop(VirtQueue *vq, size_t
sz)
if (desc.flags & VRING_DESC_F_WRITE) {
map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num,
- iov + out_num,
+ xlat_addr + out_num, iov + out_num,
VIRTQUEUE_MAX_SIZE - out_num, true,
desc.addr, desc.len);
} else {
@@ -1899,7 +1915,7 @@ static void *virtqueue_packed_pop(VirtQueue *vq, size_t
sz)
virtio_error(vdev, "Incorrect order for descriptors");
goto err_undo_map;
}
- map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov,
+ map_ok = virtqueue_map_desc(vdev, &out_num, addr, xlat_addr, iov,
VIRTQUEUE_MAX_SIZE, false,
desc.addr, desc.len);
}
@@ -1928,10 +1944,12 @@ static void *virtqueue_packed_pop(VirtQueue *vq, size_t
sz)
for (i = 0; i < out_num; i++) {
elem->out_addr[i] = addr[i];
elem->out_sg[i] = iov[i];
+ elem->out_xlat_addr[i] = xlat_addr[i];
}
for (i = 0; i < in_num; i++) {
elem->in_addr[i] = addr[out_num + i];
elem->in_sg[i] = iov[out_num + i];
+ elem->in_xlat_addr[i] = xlat_addr[out_num + i];
}
elem->index = id;
@@ -2117,10 +2135,14 @@ void *qemu_get_virtqueue_element(VirtIODevice *vdev,
QEMUFile *f, size_t sz)
elem->index = data.index;
for (i = 0; i < elem->in_num; i++) {
+ /* xlat_addr is overwritten by virtqueue_map */
+ elem->in_xlat_addr[i] = 0;
elem->in_addr[i] = data.in_addr[i];
}
for (i = 0; i < elem->out_num; i++) {
+ /* xlat_addr is overwritten by virtqueue_map */
+ elem->out_xlat_addr[i] = 0;
elem->out_addr[i] = data.out_addr[i];
}
diff --git a/include/hw/pci/pci_device.h b/include/hw/pci/pci_device.h
index 8eaf0d58bb..e2bb453dcc 100644
--- a/include/hw/pci/pci_device.h
+++ b/include/hw/pci/pci_device.h
@@ -328,7 +328,7 @@ static inline void *pci_dma_map(PCIDevice *dev, dma_addr_t
addr,
dma_addr_t *plen, DMADirection dir)
{
return dma_memory_map(pci_get_address_space(dev), addr, plen, dir,
- MEMTXATTRS_UNSPECIFIED);
+ MEMTXATTRS_UNSPECIFIED, NULL);
}
static inline void pci_dma_unmap(PCIDevice *dev, void *buffer, dma_addr_t len,
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 6386910280..e822aafd91 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -75,6 +75,8 @@ typedef struct VirtQueueElement
hwaddr *out_addr;
struct iovec *in_sg;
struct iovec *out_sg;
+ hwaddr *in_xlat_addr;
+ hwaddr *out_xlat_addr;
} VirtQueueElement;
#define VIRTIO_QUEUE_MAX 1024
diff --git a/include/system/dma.h b/include/system/dma.h
index 5a49a30628..b5d4c07452 100644
--- a/include/system/dma.h
+++ b/include/system/dma.h
@@ -12,6 +12,7 @@
#include "exec/memory.h"
#include "exec/address-spaces.h"
+#include "exec/ramblock.h"
#include "block/block.h"
#include "block/accounting.h"
@@ -201,10 +202,12 @@ MemTxResult dma_memory_set(AddressSpace *as, dma_addr_t
addr,
* @len: pointer to length of buffer; updated on return
* @dir: indicates the transfer direction
* @attrs: memory attributes
+ * @guest_addr: optional output for GPA
*/
static inline void *dma_memory_map(AddressSpace *as,
dma_addr_t addr, dma_addr_t *len,
- DMADirection dir, MemTxAttrs attrs)
+ DMADirection dir, MemTxAttrs attrs,
+ hwaddr *guest_addr)
{
hwaddr xlen = *len;
void *p;
@@ -212,6 +215,26 @@ static inline void *dma_memory_map(AddressSpace *as,
p = address_space_map(as, addr, &xlen, dir == DMA_DIRECTION_FROM_DEVICE,
attrs);
*len = xlen;
+
+ /* Attempt to find a backing GPA for this HVA */
+ if (guest_addr) {
+ if (p) {
+ RAMBlock *rb;
+ ram_addr_t offset;
+
+ rb = qemu_ram_block_from_host(p, false, &offset);
+ if (rb) {
+ /* HVA corresponds to guest memory */
+ *guest_addr = rb->offset + offset;
+ } else {
+ /* HVA doesn't correspond to guest memory */
+ *guest_addr = 0;
+ }
+ } else {
+ /* Mapping failed */
+ *guest_addr = 0;
+ }
+ }
return p;
}
diff --git a/system/dma-helpers.c b/system/dma-helpers.c
index f6403242f5..a6d2352c0f 100644
--- a/system/dma-helpers.c
+++ b/system/dma-helpers.c
@@ -135,7 +135,7 @@ static void dma_blk_cb(void *opaque, int ret)
cur_addr = dbs->sg->sg[dbs->sg_cur_index].base + dbs->sg_cur_byte;
cur_len = dbs->sg->sg[dbs->sg_cur_index].len - dbs->sg_cur_byte;
mem = dma_memory_map(dbs->sg->as, cur_addr, &cur_len, dbs->dir,
- MEMTXATTRS_UNSPECIFIED);
+ MEMTXATTRS_UNSPECIFIED, NULL);
/*
* Make reads deterministic in icount mode. Windows sometimes issues
* disk read requests with overlapping SGs. It leads
--
2.43.5