search for: page_xb

...is pointed to by > > > @@ -79,6 +81,9 @@ struct virtio_balloon { > > > /* Synchronize access/update to this struct virtio_balloon elements */ > > > struct mutex balloon_lock; > > > + /* The xbitmap used to record balloon pages */ > > > + struct xb page_xb; > > > + > > > /* The array of pfns we tell the Host about. */ > > > unsigned int num_pfns; > > > __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; > > > @@ -141,13 +146,111 @@ static void set_page_pfns(struct virtio_balloon *vb, > > >...

...is pointed to by > > > @@ -79,6 +81,9 @@ struct virtio_balloon { > > > /* Synchronize access/update to this struct virtio_balloon elements */ > > > struct mutex balloon_lock; > > > + /* The xbitmap used to record balloon pages */ > > > + struct xb page_xb; > > > + > > > /* The array of pfns we tell the Host about. */ > > > unsigned int num_pfns; > > > __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; > > > @@ -141,13 +146,111 @@ static void set_page_pfns(struct virtio_balloon *vb, > > >...

...tmap.h> /* * Balloon device works in 4K page units. So each page is pointed to by @@ -79,6 +80,9 @@ struct virtio_balloon { /* Synchronize access/update to this struct virtio_balloon elements */ struct mutex balloon_lock; + /* The xbitmap used to record ballooned pages */ + struct xb page_xb; + /* The array of pfns we tell the Host about. */ unsigned int num_pfns; __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; @@ -141,13 +145,90 @@ static void set_page_pfns(struct virtio_balloon *vb, page_to_balloon_pfn(page) + i); } +static void send_one_sg(struct virtio_balloon *vb,...

...device works in 4K page units. So each page is pointed to by > @@ -79,6 +81,9 @@ struct virtio_balloon { > /* Synchronize access/update to this struct virtio_balloon elements */ > struct mutex balloon_lock; > > + /* The xbitmap used to record balloon pages */ > + struct xb page_xb; > + > /* The array of pfns we tell the Host about. */ > unsigned int num_pfns; > __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; > @@ -141,15 +146,121 @@ static void set_page_pfns(struct virtio_balloon *vb, > page_to_balloon_pfn(page) + i); > } > > +stat...

...device works in 4K page units. So each page is pointed to by > @@ -79,6 +81,9 @@ struct virtio_balloon { > /* Synchronize access/update to this struct virtio_balloon elements */ > struct mutex balloon_lock; > > + /* The xbitmap used to record balloon pages */ > + struct xb page_xb; > + > /* The array of pfns we tell the Host about. */ > unsigned int num_pfns; > __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; > @@ -141,15 +146,121 @@ static void set_page_pfns(struct virtio_balloon *vb, > page_to_balloon_pfn(page) + i); > } > > +stat...

...+81,9 @@ struct virtio_balloon { > > > > > /* Synchronize access/update to this struct virtio_balloon elements */ > > > > > struct mutex balloon_lock; > > > > > + /* The xbitmap used to record balloon pages */ > > > > > + struct xb page_xb; > > > > > + > > > > > /* The array of pfns we tell the Host about. */ > > > > > unsigned int num_pfns; > > > > > __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; > > > > > @@ -141,13 +146,111 @@ static void set_p...

...+81,9 @@ struct virtio_balloon { > > > > > /* Synchronize access/update to this struct virtio_balloon elements */ > > > > > struct mutex balloon_lock; > > > > > + /* The xbitmap used to record balloon pages */ > > > > > + struct xb page_xb; > > > > > + > > > > > /* The array of pfns we tell the Host about. */ > > > > > unsigned int num_pfns; > > > > > __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; > > > > > @@ -141,13 +146,111 @@ static void set_p...

...evice works in 4K page units. So each page is pointed to by > @@ -79,6 +80,9 @@ struct virtio_balloon { > /* Synchronize access/update to this struct virtio_balloon elements */ > struct mutex balloon_lock; > > + /* The xbitmap used to record ballooned pages */ > + struct xb page_xb; > + > /* The array of pfns we tell the Host about. */ > unsigned int num_pfns; > __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; > @@ -141,13 +145,90 @@ static void set_page_pfns(struct virtio_balloon *vb, > page_to_balloon_pfn(page) + i); > } > > +stati...

...evice works in 4K page units. So each page is pointed to by > @@ -79,6 +80,9 @@ struct virtio_balloon { > /* Synchronize access/update to this struct virtio_balloon elements */ > struct mutex balloon_lock; > > + /* The xbitmap used to record ballooned pages */ > + struct xb page_xb; > + > /* The array of pfns we tell the Host about. */ > unsigned int num_pfns; > __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; > @@ -141,13 +145,90 @@ static void set_page_pfns(struct virtio_balloon *vb, > page_to_balloon_pfn(page) + i); > } > > +stati...

...m/page.h> /* * Balloon device works in 4K page units. So each page is pointed to by @@ -79,6 +81,9 @@ struct virtio_balloon { /* Synchronize access/update to this struct virtio_balloon elements */ struct mutex balloon_lock; + /* The xbitmap used to record balloon pages */ + struct xb page_xb; + /* The array of pfns we tell the Host about. */ unsigned int num_pfns; __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; @@ -141,13 +146,128 @@ static void set_page_pfns(struct virtio_balloon *vb, page_to_balloon_pfn(page) + i); } + +static void kick_and_wait(struct virtqueue *vq,...

...tmap.h> /* * Balloon device works in 4K page units. So each page is pointed to by @@ -79,6 +80,9 @@ struct virtio_balloon { /* Synchronize access/update to this struct virtio_balloon elements */ struct mutex balloon_lock; + /* The xbitmap used to record ballooned pages */ + struct xb page_xb; + /* The array of pfns we tell the Host about. */ unsigned int num_pfns; __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; @@ -141,13 +145,71 @@ static void set_page_pfns(struct virtio_balloon *vb, page_to_balloon_pfn(page) + i); } +/* + * Send balloon pages in sgs to host. + * The...

...m/page.h> /* * Balloon device works in 4K page units. So each page is pointed to by @@ -79,6 +81,9 @@ struct virtio_balloon { /* Synchronize access/update to this struct virtio_balloon elements */ struct mutex balloon_lock; + /* The xbitmap used to record balloon pages */ + struct xb page_xb; + /* The array of pfns we tell the Host about. */ unsigned int num_pfns; __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; @@ -141,15 +146,121 @@ static void set_page_pfns(struct virtio_balloon *vb, page_to_balloon_pfn(page) + i); } +static void kick_and_wait(struct virtqueue *vq, w...

...m/page.h> /* * Balloon device works in 4K page units. So each page is pointed to by @@ -79,6 +81,9 @@ struct virtio_balloon { /* Synchronize access/update to this struct virtio_balloon elements */ struct mutex balloon_lock; + /* The xbitmap used to record balloon pages */ + struct xb page_xb; + /* The array of pfns we tell the Host about. */ unsigned int num_pfns; __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; @@ -141,15 +146,129 @@ static void set_page_pfns(struct virtio_balloon *vb, page_to_balloon_pfn(page) + i); } +static void kick_and_wait(struct virtqueue *vq, w...

...m/page.h> /* * Balloon device works in 4K page units. So each page is pointed to by @@ -79,6 +81,9 @@ struct virtio_balloon { /* Synchronize access/update to this struct virtio_balloon elements */ struct mutex balloon_lock; + /* The xbitmap used to record balloon pages */ + struct xb page_xb; + /* The array of pfns we tell the Host about. */ unsigned int num_pfns; __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; @@ -141,15 +146,130 @@ static void set_page_pfns(struct virtio_balloon *vb, page_to_balloon_pfn(page) + i); } + +static void kick_and_wait(struct virtqueue *vq,...

...m/page.h> /* * Balloon device works in 4K page units. So each page is pointed to by @@ -79,6 +81,9 @@ struct virtio_balloon { /* Synchronize access/update to this struct virtio_balloon elements */ struct mutex balloon_lock; + /* The xbitmap used to record balloon pages */ + struct xb page_xb; + /* The array of pfns we tell the Host about. */ unsigned int num_pfns; __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; @@ -141,15 +146,128 @@ static void set_page_pfns(struct virtio_balloon *vb, page_to_balloon_pfn(page) + i); } +static void kick_and_wait(struct virtqueue *vq, w...

...unsigned long *pfn_max) > > +{ > > + unsigned long pfn = page_to_pfn(page); > > + int ret; > > + > > + *pfn_min = min(pfn, *pfn_min); > > + *pfn_max = max(pfn, *pfn_max); > > + > > + do { > > + ret = xb_preload_and_set_bit(&vb->page_xb, pfn, > > + GFP_NOWAIT | __GFP_NOWARN); > > It is a bit of pity that __GFP_NOWARN here is applied to only xb_preload(). > Memory allocation by xb_set_bit() will after all emit warnings. Maybe > > xb_init(&vb->page_xb); > vb->page_xb.gfp_mask |= __GFP...

...to by >>>> @@ -79,6 +81,9 @@ struct virtio_balloon { >>>> /* Synchronize access/update to this struct virtio_balloon elements */ >>>> struct mutex balloon_lock; >>>> + /* The xbitmap used to record balloon pages */ >>>> + struct xb page_xb; >>>> + >>>> /* The array of pfns we tell the Host about. */ >>>> unsigned int num_pfns; >>>> __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX]; >>>> @@ -141,13 +146,111 @@ static void set_page_pfns(struct virtio_balloon *vb, >...

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

...pages in sgs to host. The balloon pages are recorded in the > + * page xbitmap. Each bit in the 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...