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Diffstat (limited to 'hw/virtio.c')
-rw-r--r--hw/virtio.c99
1 files changed, 17 insertions, 82 deletions
diff --git a/hw/virtio.c b/hw/virtio.c
index 577eb5a4b..8a72d8d21 100644
--- a/hw/virtio.c
+++ b/hw/virtio.c
@@ -16,8 +16,6 @@
#include "virtio.h"
#include "sysemu.h"
-#define VIRTIO_ZERO_COPY
-
/* from Linux's linux/virtio_pci.h */
/* A 32-bit r/o bitmask of the features supported by the host */
@@ -113,43 +111,6 @@ struct VirtQueue
#define VIRTIO_PCI_QUEUE_MAX 16
/* virt queue functions */
-#ifdef VIRTIO_ZERO_COPY
-static void *virtio_map_gpa(target_phys_addr_t addr, size_t size)
-{
- ram_addr_t off;
- target_phys_addr_t addr1;
-
- off = cpu_get_physical_page_desc(addr);
- if ((off & ~TARGET_PAGE_MASK) != IO_MEM_RAM) {
- fprintf(stderr, "virtio DMA to IO ram\n");
- exit(1);
- }
-
- off = (off & TARGET_PAGE_MASK) | (addr & ~TARGET_PAGE_MASK);
-
- for (addr1 = addr + TARGET_PAGE_SIZE;
- addr1 < TARGET_PAGE_ALIGN(addr + size);
- addr1 += TARGET_PAGE_SIZE) {
- ram_addr_t off1;
-
- off1 = cpu_get_physical_page_desc(addr1);
- if ((off1 & ~TARGET_PAGE_MASK) != IO_MEM_RAM) {
- fprintf(stderr, "virtio DMA to IO ram\n");
- exit(1);
- }
-
- off1 = (off1 & TARGET_PAGE_MASK) | (addr1 & ~TARGET_PAGE_MASK);
-
- if (off1 != (off + (addr1 - addr))) {
- fprintf(stderr, "discontigous virtio memory\n");
- exit(1);
- }
- }
-
- return phys_ram_base + off;
-}
-#endif
-
static void virtqueue_init(VirtQueue *vq, target_phys_addr_t pa)
{
vq->vring.desc = pa;
@@ -274,35 +235,22 @@ void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int offset;
int i;
-#ifndef VIRTIO_ZERO_COPY
- for (i = 0; i < elem->out_num; i++)
- qemu_free(elem->out_sg[i].iov_base);
-#endif
-
offset = 0;
for (i = 0; i < elem->in_num; i++) {
size_t size = MIN(len - offset, elem->in_sg[i].iov_len);
-#ifdef VIRTIO_ZERO_COPY
- if (size) {
- ram_addr_t addr = (uint8_t *)elem->in_sg[i].iov_base - phys_ram_base;
- ram_addr_t off;
+ cpu_physical_memory_unmap(elem->in_sg[i].iov_base,
+ elem->in_sg[i].iov_len,
+ 1, size);
- for (off = 0; off < size; off += TARGET_PAGE_SIZE)
- cpu_physical_memory_set_dirty(addr + off);
- }
-#else
- if (size)
- cpu_physical_memory_write(elem->in_addr[i],
- elem->in_sg[i].iov_base,
- size);
-
- qemu_free(elem->in_sg[i].iov_base);
-#endif
-
- offset += size;
+ offset += elem->in_sg[i].iov_len;
}
+ 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);
+
idx = (idx + vring_used_idx(vq)) % vq->vring.num;
/* Get a pointer to the next entry in the used ring. */
@@ -414,6 +362,7 @@ int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes)
int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem)
{
unsigned int i, head;
+ target_phys_addr_t len;
if (!virtqueue_num_heads(vq, vq->last_avail_idx))
return 0;
@@ -424,37 +373,23 @@ int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem)
i = head = virtqueue_get_head(vq, vq->last_avail_idx++);
do {
struct iovec *sg;
+ int is_write = 0;
if (vring_desc_flags(vq, i) & VRING_DESC_F_WRITE) {
elem->in_addr[elem->in_num] = vring_desc_addr(vq, i);
sg = &elem->in_sg[elem->in_num++];
+ is_write = 1;
} else
sg = &elem->out_sg[elem->out_num++];
/* Grab the first descriptor, and check it's OK. */
sg->iov_len = vring_desc_len(vq, i);
+ len = sg->iov_len;
-#ifdef VIRTIO_ZERO_COPY
- sg->iov_base = virtio_map_gpa(vring_desc_addr(vq, i), sg->iov_len);
-#else
- /* cap individual scatter element size to prevent unbounded allocations
- of memory from the guest. Practically speaking, no virtio driver
- will ever pass more than a page in each element. We set the cap to
- be 2MB in case for some reason a large page makes it way into the
- sg list. When we implement a zero copy API, this limitation will
- disappear */
- if (sg->iov_len > (2 << 20))
- sg->iov_len = 2 << 20;
-
- sg->iov_base = qemu_malloc(sg->iov_len);
- if (!(vring_desc_flags(vq, i) & VRING_DESC_F_WRITE)) {
- cpu_physical_memory_read(vring_desc_addr(vq, i),
- sg->iov_base,
- sg->iov_len);
- }
-#endif
- if (sg->iov_base == NULL) {
- fprintf(stderr, "Invalid mapping\n");
+ sg->iov_base = cpu_physical_memory_map(vring_desc_addr(vq, i), &len, is_write);
+
+ if (sg->iov_base == NULL || len != sg->iov_len) {
+ fprintf(stderr, "virtio: trying to map MMIO memory\n");
exit(1);
}