search for: tell_host_sg

...84,8 +307,12 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num) > > num_allocated_pages = vb->num_pfns; > /* Did we get any? */ > - if (vb->num_pfns != 0) > - tell_host(vb, vb->inflate_vq); > + if (vb->num_pfns) { > + if (use_sg) > + tell_host_sgs(vb, vb->inflate_vq, pfn_min, pfn_max); Please describe why tell_host_sgs() can work without __GFP_DIRECT_RECLAIM allocation, for tell_host_sgs() is called with vb->balloon_lock mutex held. > + else > + tell_host(vb, vb->inflate_vq); > + } > mutex_unlock(&vb->ball...

...84,8 +307,12 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num) > > num_allocated_pages = vb->num_pfns; > /* Did we get any? */ > - if (vb->num_pfns != 0) > - tell_host(vb, vb->inflate_vq); > + if (vb->num_pfns) { > + if (use_sg) > + tell_host_sgs(vb, vb->inflate_vq, pfn_min, pfn_max); Please describe why tell_host_sgs() can work without __GFP_DIRECT_RECLAIM allocation, for tell_host_sgs() is called with vb->balloon_lock mutex held. > + else > + tell_host(vb, vb->inflate_vq); > + } > mutex_unlock(&vb->ball...

...l_balloon(struct virtio_balloon *vb, size_t num) >> >> num_allocated_pages = vb->num_pfns; >> /* Did we get any? */ >> - if (vb->num_pfns != 0) >> - tell_host(vb, vb->inflate_vq); >> + if (vb->num_pfns) { >> + if (use_sg) >> + tell_host_sgs(vb, vb->inflate_vq, pfn_min, pfn_max); > Please describe why tell_host_sgs() can work without __GFP_DIRECT_RECLAIM allocation, > for tell_host_sgs() is called with vb->balloon_lock mutex held. Essentially, tell_host_sgs()-->send_balloon_page_sg()-->add_one_sg()-->virtqueue_a...

...e_t num) > >> > >> num_allocated_pages = vb->num_pfns; > >> /* Did we get any? */ > >> - if (vb->num_pfns != 0) > >> - tell_host(vb, vb->inflate_vq); > >> + if (vb->num_pfns) { > >> + if (use_sg) > >> + tell_host_sgs(vb, vb->inflate_vq, pfn_min, pfn_max); > > Please describe why tell_host_sgs() can work without __GFP_DIRECT_RECLAIM allocation, > > for tell_host_sgs() is called with vb->balloon_lock mutex held. > > Essentially, > tell_host_sgs()-->send_balloon_page_sg()-->add_...

...e_t num) > >> > >> num_allocated_pages = vb->num_pfns; > >> /* Did we get any? */ > >> - if (vb->num_pfns != 0) > >> - tell_host(vb, vb->inflate_vq); > >> + if (vb->num_pfns) { > >> + if (use_sg) > >> + tell_host_sgs(vb, vb->inflate_vq, pfn_min, pfn_max); > > Please describe why tell_host_sgs() can work without __GFP_DIRECT_RECLAIM allocation, > > for tell_host_sgs() is called with vb->balloon_lock mutex held. > > Essentially, > tell_host_sgs()-->send_balloon_page_sg()-->add_...

...e bitmap corresponds to a page of PAGE_SIZE. + * The page xbitmap is searched for continuous "1" bits, which correspond + * to continuous pages, to chunk into sgs. + * + * @page_xb_start and @page_xb_end form the range of bits in the xbitmap that + * need to be searched. + */ +static void tell_host_sgs(struct virtio_balloon *vb, + struct virtqueue *vq, + unsigned long page_xb_start, + unsigned long page_xb_end) +{ + unsigned long sg_pfn_start, sg_pfn_end; + void *sg_addr; + uint32_t sg_len, sg_max_len = round_down(UINT_MAX, PAGE_SIZE); + + sg_pfn_start = page_xb_start; + while (sg_pf...

...e bitmap corresponds to a page of PAGE_SIZE. + * The page xbitmap is searched for continuous "1" bits, which correspond + * to continuous pages, to chunk into sgs. + * + * @page_xb_start and @page_xb_end form the range of bits in the xbitmap that + * need to be searched. + */ +static void tell_host_sgs(struct virtio_balloon *vb, + struct virtqueue *vq, + unsigned long page_xb_start, + unsigned long page_xb_end) +{ + unsigned long sg_pfn_start, sg_pfn_end; + void *sg_addr; + uint32_t sg_len, sg_max_len = round_down(UINT_MAX, PAGE_SIZE); + int err = 0; + + sg_pfn_start = page_xb_start;...

...e bitmap corresponds to a page of PAGE_SIZE. + * The page xbitmap is searched for continuous "1" bits, which correspond + * to continuous pages, to chunk into sgs. + * + * @page_xb_start and @page_xb_end form the range of bits in the xbitmap that + * need to be searched. + */ +static void tell_host_sgs(struct virtio_balloon *vb, + struct virtqueue *vq, + unsigned long page_xb_start, + unsigned long page_xb_end) +{ + unsigned long pfn_start, pfn_end; + uint64_t addr; + uint32_t len, max_len = round_down(UINT_MAX, PAGE_SIZE); + + pfn_start = page_xb_start; + while (pfn_start < page_...

...AGE_SIZE. > + * The page xbitmap is searched for continuous "1" bits, which correspond > + * to continuous pages, to chunk into sgs. > + * > + * @page_xb_start and @page_xb_end form the range of bits in the xbitmap that > + * need to be searched. > + */ > +static void tell_host_sgs(struct virtio_balloon *vb, > + struct virtqueue *vq, > + unsigned long page_xb_start, > + unsigned long page_xb_end) > +{ > + unsigned long pfn_start, pfn_end; > + uint64_t addr; > + uint32_t len, max_len = round_down(UINT_MAX, PAGE_SIZE); > + > + pfn_start =...

...AGE_SIZE. > + * The page xbitmap is searched for continuous "1" bits, which correspond > + * to continuous pages, to chunk into sgs. > + * > + * @page_xb_start and @page_xb_end form the range of bits in the xbitmap that > + * need to be searched. > + */ > +static void tell_host_sgs(struct virtio_balloon *vb, > + struct virtqueue *vq, > + unsigned long page_xb_start, > + unsigned long page_xb_end) > +{ > + unsigned long pfn_start, pfn_end; > + uint64_t addr; > + uint32_t len, max_len = round_down(UINT_MAX, PAGE_SIZE); > + > + pfn_start =...

...e bitmap corresponds to a page of PAGE_SIZE. + * The page xbitmap is searched for continuous "1" bits, which correspond + * to continuous pages, to chunk into sgs. + * + * @page_xb_start and @page_xb_end form the range of bits in the xbitmap that + * need to be searched. + */ +static void tell_host_sgs(struct virtio_balloon *vb, + struct virtqueue *vq, + unsigned long page_xb_start, + unsigned long page_xb_end) +{ + unsigned long pfn_start, pfn_end; + uint32_t max_len = round_down(UINT_MAX, PAGE_SIZE); + uint64_t len; + + pfn_start = page_xb_start; + while (pfn_start < page_xb_end...

...e bitmap corresponds to a page of PAGE_SIZE. + * The page xbitmap is searched for continuous "1" bits, which correspond + * to continuous pages, to chunk into sgs. + * + * @page_xb_start and @page_xb_end form the range of bits in the xbitmap that + * need to be searched. + */ +static void tell_host_sgs(struct virtio_balloon *vb, + struct virtqueue *vq, + unsigned long page_xb_start, + unsigned long page_xb_end) +{ + unsigned long sg_pfn_start, sg_pfn_end; + void *sg_addr; + uint32_t sg_len, sg_max_len = round_down(UINT_MAX, PAGE_SIZE); + + sg_pfn_start = page_xb_start; + while (sg_pf...

...e bitmap corresponds to a page of PAGE_SIZE. + * The page xbitmap is searched for continuous "1" bits, which correspond + * to continuous pages, to chunk into sgs. + * + * @page_xb_start and @page_xb_end form the range of bits in the xbitmap that + * need to be searched. + */ +static void tell_host_sgs(struct virtio_balloon *vb, + struct virtqueue *vq, + unsigned long page_xb_start, + unsigned long page_xb_end) +{ + unsigned long pfn_start, pfn_end; + uint32_t max_len = round_down(UINT_MAX, PAGE_SIZE); + uint64_t len; + + pfn_start = page_xb_start; + while (pfn_start < page_xb_end...

...AGE_SIZE. > + * The page xbitmap is searched for continuous "1" bits, which correspond > + * to continuous pages, to chunk into sgs. > + * > + * @page_xb_start and @page_xb_end form the range of bits in the xbitmap that > + * need to be searched. > + */ > +static void tell_host_sgs(struct virtio_balloon *vb, > + struct virtqueue *vq, > + unsigned long page_xb_start, > + unsigned long page_xb_end) > +{ > + unsigned long sg_pfn_start, sg_pfn_end; > + void *sg_addr; > + uint32_t sg_len, sg_max_len = round_down(UINT_MAX, PAGE_SIZE); > + int er...

...AGE_SIZE. > + * The page xbitmap is searched for continuous "1" bits, which correspond > + * to continuous pages, to chunk into sgs. > + * > + * @page_xb_start and @page_xb_end form the range of bits in the xbitmap that > + * need to be searched. > + */ > +static void tell_host_sgs(struct virtio_balloon *vb, > + struct virtqueue *vq, > + unsigned long page_xb_start, > + unsigned long page_xb_end) > +{ > + unsigned long sg_pfn_start, sg_pfn_end; > + void *sg_addr; > + uint32_t sg_len, sg_max_len = round_down(UINT_MAX, PAGE_SIZE); > + int er...

...AGE_SIZE. > + * The page xbitmap is searched for continuous "1" bits, which correspond > + * to continuous pages, to chunk into sgs. > + * > + * @page_xb_start and @page_xb_end form the range of bits in the xbitmap that > + * need to be searched. > + */ > +static void tell_host_sgs(struct virtio_balloon *vb, > + struct virtqueue *vq, > + unsigned long page_xb_start, > + unsigned long page_xb_end) > +{ > + unsigned long sg_pfn_start, sg_pfn_end; > + void *sg_addr; > + uint32_t sg_len, sg_max_len = round_down(UINT_MAX, PAGE_SIZE); > + > +...

...AGE_SIZE. > + * The page xbitmap is searched for continuous "1" bits, which correspond > + * to continuous pages, to chunk into sgs. > + * > + * @page_xb_start and @page_xb_end form the range of bits in the xbitmap that > + * need to be searched. > + */ > +static void tell_host_sgs(struct virtio_balloon *vb, > + struct virtqueue *vq, > + unsigned long page_xb_start, > + unsigned long page_xb_end) > +{ > + unsigned long sg_pfn_start, sg_pfn_end; > + void *sg_addr; > + uint32_t sg_len, sg_max_len = round_down(UINT_MAX, PAGE_SIZE); > + > +...

...tmap + * corresponds to a page of PAGE_SIZE. The page xbitmap is searched for + * continuous "1" bits, which correspond to continuous pages, to chunk into + * sgs. + * + * @page_xb_start and @page_xb_end form the range of bits in the xbitmap that + * need to be serached. + */ +static void tell_host_sgs(struct virtio_balloon *vb, + struct virtqueue *vq, + unsigned long page_xb_start, + unsigned long page_xb_end) +{ + unsigned int head_id = VIRTQUEUE_DESC_ID_INIT, + prev_id = VIRTQUEUE_DESC_ID_INIT; + unsigned long sg_pfn_start, sg_pfn_end; + uint64_t sg_addr; + uint32_t sg_size;...

This patch series enhances the existing virtio-balloon with the following new features: 1) fast ballooning: transfer ballooned pages between the guest and host in chunks using sgs, instead of one by one; and 2) free_page_vq: a new virtqueue to report guest free pages to the host. The second feature can be used to accelerate live migration of VMs. Here are some details: Live migration needs to

This patch series enhances the existing virtio-balloon with the following new features: 1) fast ballooning: transfer ballooned pages between the guest and host in chunks using sgs, instead of one by one; and 2) free_page_vq: a new virtqueue to report guest free pages to the host. The second feature can be used to accelerate live migration of VMs. Here are some details: Live migration needs to