[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v4 2/9] util: Introduce vfio helpers
From: |
Fam Zheng |
Subject: |
Re: [Qemu-devel] [PATCH v4 2/9] util: Introduce vfio helpers |
Date: |
Fri, 12 Jan 2018 09:28:14 +0800 |
User-agent: |
Mutt/1.9.1 (2017-09-22) |
On Wed, 01/10 16:52, Stefan Hajnoczi wrote:
> On Wed, Jan 10, 2018 at 05:18:39PM +0800, Fam Zheng wrote:
> > +/* Map [host, host + size) area into a contiguous IOVA address space, and
> > store
> > + * the result in @iova if not NULL. The caller need to make sure the area
> > is
> > + * aligned to page size, and mustn't overlap with existing mapping areas
> > (split
> > + * mapping status within this area is not allowed).
> > + */
> > +int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,
> > + bool temporary, uint64_t *iova)
> > +{
> > + int ret = 0;
> > + int index;
> > + IOVAMapping *mapping;
> > + uint64_t iova0;
> > +
> > + assert(QEMU_PTR_IS_ALIGNED(host, getpagesize()));
> > + assert(QEMU_IS_ALIGNED(size, getpagesize()));
> > + trace_qemu_vfio_dma_map(s, host, size, temporary, iova);
> > + qemu_mutex_lock(&s->lock);
> > + mapping = qemu_vfio_find_mapping(s, host, &index);
> > + if (mapping) {
> > + iova0 = mapping->iova + ((uint8_t *)host - (uint8_t
> > *)mapping->host);
> > + } else {
> > + if (s->high_water_mark - s->low_water_mark + 1 < size) {
> > + ret = -ENOMEM;
> > + goto out;
> > + }
> > + if (!temporary) {
> > + iova0 = s->low_water_mark;
> > + mapping = qemu_vfio_add_mapping(s, host, size, index + 1,
> > iova0);
> > + if (!mapping) {
> > + ret = -ENOMEM;
> > + goto out;
> > + }
> > + assert(qemu_vfio_verify_mappings(s));
> > + ret = qemu_vfio_do_mapping(s, host, size, iova0);
> > + if (ret) {
> > + qemu_vfio_undo_mapping(s, mapping, NULL);
> > + goto out;
> > + }
> > + s->low_water_mark += size;
> > + qemu_vfio_dump_mappings(s);
> > + } else {
> > + iova0 = s->high_water_mark - size;
> > + ret = qemu_vfio_do_mapping(s, host, size, iova0);
> > + if (ret) {
> > + goto out;
> > + }
> > + s->high_water_mark -= size;
> > + }
> > + }
> > + if (iova) {
> > + *iova = iova0;
> > + }
> > + qemu_mutex_unlock(&s->lock);
> > +out:
>
> Unlock needs to be here to avoid leaking the lock.
Yes, will fix.
Fam