From 48d7c97577498657f9ccbcbf1f990fdb4b79501f Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Fri, 19 Jan 2018 10:39:20 +0000 Subject: [PATCH] vhost: Merge sections added to temporary list As sections are reported by the listener to the _nop and _add methods, add them to the temporary section list but now merge them with the previous section if the new one abuts and the backend allows. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Igor Mammedov Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/trace-events | 4 +++ hw/virtio/vhost.c | 76 +++++++++++++++++++++++++++++++++++++----- 2 files changed, 71 insertions(+), 9 deletions(-) diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events index 775461ae98..ab9da06244 100644 --- a/hw/virtio/trace-events +++ b/hw/virtio/trace-events @@ -1,5 +1,9 @@ # See docs/devel/tracing.txt for syntax documentation. +# hw/virtio/vhost.c +vhost_region_add_section(const char *name, uint64_t gpa, uint64_t size, uint64_t host) "%s: 0x%"PRIx64"+0x%"PRIx64" @ 0x%"PRIx64 +vhost_region_add_section_abut(const char *name, uint64_t new_size) "%s: 0x%"PRIx64 + # hw/virtio/virtio.c virtqueue_alloc_element(void *elem, size_t sz, unsigned in_num, unsigned out_num) "elem %p size %zd in_num %u out_num %u" virtqueue_fill(void *vq, const void *elem, unsigned int len, unsigned int idx) "vq %p elem %p len %u idx %u" diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 91cab5131c..351c691439 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -709,14 +709,71 @@ out: return; } -static void vhost_add_section(struct vhost_dev *dev, - MemoryRegionSection *section) +/* Adds the section data to the tmp_section structure. + * It relies on the listener calling us in memory address order + * and for each region (via the _add and _nop methods) to + * join neighbours. + */ +static void vhost_region_add_section(struct vhost_dev *dev, + MemoryRegionSection *section) { - ++dev->n_tmp_sections; - dev->tmp_sections = g_renew(MemoryRegionSection, dev->tmp_sections, - dev->n_tmp_sections); - dev->tmp_sections[dev->n_tmp_sections - 1] = *section; - memory_region_ref(section->mr); + bool need_add = true; + uint64_t mrs_size = int128_get64(section->size); + uint64_t mrs_gpa = section->offset_within_address_space; + uintptr_t mrs_host = (uintptr_t)memory_region_get_ram_ptr(section->mr) + + section->offset_within_region; + + trace_vhost_region_add_section(section->mr->name, mrs_gpa, mrs_size, + mrs_host); + + bool log_dirty = memory_region_get_dirty_log_mask(section->mr) & + ~(1 << DIRTY_MEMORY_MIGRATION); + if (log_dirty) { + return; + } + + if (dev->n_tmp_sections) { + /* Since we already have at least one section, lets see if + * this extends it; since we're scanning in order, we only + * have to look at the last one, and the FlatView that calls + * us shouldn't have overlaps. + */ + MemoryRegionSection *prev_sec = dev->tmp_sections + + (dev->n_tmp_sections - 1); + uint64_t prev_gpa_start = prev_sec->offset_within_address_space; + uint64_t prev_size = int128_get64(prev_sec->size); + uint64_t prev_gpa_end = range_get_last(prev_gpa_start, prev_size); + uint64_t prev_host_start = + (uintptr_t)memory_region_get_ram_ptr(prev_sec->mr) + + prev_sec->offset_within_region; + uint64_t prev_host_end = range_get_last(prev_host_start, prev_size); + + if (prev_gpa_end + 1 == mrs_gpa && + prev_host_end + 1 == mrs_host && + section->mr == prev_sec->mr && + (!dev->vhost_ops->vhost_backend_can_merge || + dev->vhost_ops->vhost_backend_can_merge(dev, + mrs_host, mrs_size, + prev_host_start, prev_size))) { + /* The two sections abut */ + need_add = false; + prev_sec->size = int128_add(prev_sec->size, section->size); + trace_vhost_region_add_section_abut(section->mr->name, + mrs_size + prev_size); + } + } + + if (need_add) { + ++dev->n_tmp_sections; + dev->tmp_sections = g_renew(MemoryRegionSection, dev->tmp_sections, + dev->n_tmp_sections); + dev->tmp_sections[dev->n_tmp_sections - 1] = *section; + /* The flatview isn't stable and we don't use it, making it NULL + * means we can memcmp the list. + */ + dev->tmp_sections[dev->n_tmp_sections - 1].fv = NULL; + memory_region_ref(section->mr); + } } static void vhost_region_add(MemoryListener *listener, @@ -728,11 +785,12 @@ static void vhost_region_add(MemoryListener *listener, if (!vhost_section(section)) { return; } + vhost_region_add_section(dev, section); - vhost_add_section(dev, section); vhost_set_memory(listener, section, true); } +/* Called on regions that have not changed */ static void vhost_region_nop(MemoryListener *listener, MemoryRegionSection *section) { @@ -743,7 +801,7 @@ static void vhost_region_nop(MemoryListener *listener, return; } - vhost_add_section(dev, section); + vhost_region_add_section(dev, section); } static void vhost_region_del(MemoryListener *listener,