Message ID | 20190719160120.26581-3-david@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | virtio-balloon: PartialBalloonedPage rework | expand |
On Fri, Jul 19, 2019 at 06:01:19PM +0200, David Hildenbrand wrote: > "host_page_base" is really confusing, let's make this clearer, also > rename the other offsets to indicate to which base they apply. > > offset -> mr_offset > ram_offset -> rb_offset > host_page_base -> rb_aligned_offset > > While at it, use QEMU_ALIGN_DOWN() instead of a handcrafted computation > and move the computation to the place where it is needed. > > Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: David Gibson <david@gibson.dropbear.id.au> > --- > hw/virtio/virtio-balloon.c | 26 +++++++++++++------------- > 1 file changed, 13 insertions(+), 13 deletions(-) > > diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c > index 287d5d4c97..29cee344b2 100644 > --- a/hw/virtio/virtio-balloon.c > +++ b/hw/virtio/virtio-balloon.c > @@ -47,24 +47,23 @@ static void virtio_balloon_reset_pbp(VirtIOBalloon *balloon) > } > > static void balloon_inflate_page(VirtIOBalloon *balloon, > - MemoryRegion *mr, hwaddr offset) > + MemoryRegion *mr, hwaddr mr_offset) > { > - void *addr = memory_region_get_ram_ptr(mr) + offset; > + void *addr = memory_region_get_ram_ptr(mr) + mr_offset; > + ram_addr_t rb_offset, rb_aligned_offset; > RAMBlock *rb; > size_t rb_page_size; > int subpages; > - ram_addr_t ram_offset, host_page_base; > > /* XXX is there a better way to get to the RAMBlock than via a > * host address? */ > - rb = qemu_ram_block_from_host(addr, false, &ram_offset); > + rb = qemu_ram_block_from_host(addr, false, &rb_offset); > rb_page_size = qemu_ram_pagesize(rb); > - host_page_base = ram_offset & ~(rb_page_size - 1); > > if (rb_page_size == BALLOON_PAGE_SIZE) { > /* Easy case */ > > - ram_block_discard_range(rb, ram_offset, rb_page_size); > + ram_block_discard_range(rb, rb_offset, rb_page_size); > /* We ignore errors from ram_block_discard_range(), because it > * has already reported them, and failing to discard a balloon > * page is not fatal */ > @@ -80,11 +79,12 @@ static void balloon_inflate_page(VirtIOBalloon *balloon, > warn_report_once( > "Balloon used with backing page size > 4kiB, this may not be reliable"); > > + rb_aligned_offset = QEMU_ALIGN_DOWN(rb_offset, rb_page_size); > subpages = rb_page_size / BALLOON_PAGE_SIZE; > > if (balloon->pbp > && (rb != balloon->pbp->rb > - || host_page_base != balloon->pbp->base)) { > + || rb_aligned_offset != balloon->pbp->base)) { > /* We've partially ballooned part of a host page, but now > * we're trying to balloon part of a different one. Too hard, > * give up on the old partial page */ > @@ -96,10 +96,10 @@ static void balloon_inflate_page(VirtIOBalloon *balloon, > size_t bitlen = BITS_TO_LONGS(subpages) * sizeof(unsigned long); > balloon->pbp = g_malloc0(sizeof(PartiallyBalloonedPage) + bitlen); > balloon->pbp->rb = rb; > - balloon->pbp->base = host_page_base; > + balloon->pbp->base = rb_aligned_offset; > } > > - set_bit((ram_offset - balloon->pbp->base) / BALLOON_PAGE_SIZE, > + set_bit((rb_offset - balloon->pbp->base) / BALLOON_PAGE_SIZE, > balloon->pbp->bitmap); > > if (bitmap_full(balloon->pbp->bitmap, subpages)) { > @@ -116,18 +116,18 @@ static void balloon_inflate_page(VirtIOBalloon *balloon, > } > > static void balloon_deflate_page(VirtIOBalloon *balloon, > - MemoryRegion *mr, hwaddr offset) > + MemoryRegion *mr, hwaddr mr_offset) > { > - void *addr = memory_region_get_ram_ptr(mr) + offset; > + void *addr = memory_region_get_ram_ptr(mr) + mr_offset; > + ram_addr_t rb_offset; > RAMBlock *rb; > size_t rb_page_size; > - ram_addr_t ram_offset; > void *host_addr; > int ret; > > /* XXX is there a better way to get to the RAMBlock than via a > * host address? */ > - rb = qemu_ram_block_from_host(addr, false, &ram_offset); > + rb = qemu_ram_block_from_host(addr, false, &rb_offset); > rb_page_size = qemu_ram_pagesize(rb); > > if (balloon->pbp) {
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index 287d5d4c97..29cee344b2 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -47,24 +47,23 @@ static void virtio_balloon_reset_pbp(VirtIOBalloon *balloon) } static void balloon_inflate_page(VirtIOBalloon *balloon, - MemoryRegion *mr, hwaddr offset) + MemoryRegion *mr, hwaddr mr_offset) { - void *addr = memory_region_get_ram_ptr(mr) + offset; + void *addr = memory_region_get_ram_ptr(mr) + mr_offset; + ram_addr_t rb_offset, rb_aligned_offset; RAMBlock *rb; size_t rb_page_size; int subpages; - ram_addr_t ram_offset, host_page_base; /* XXX is there a better way to get to the RAMBlock than via a * host address? */ - rb = qemu_ram_block_from_host(addr, false, &ram_offset); + rb = qemu_ram_block_from_host(addr, false, &rb_offset); rb_page_size = qemu_ram_pagesize(rb); - host_page_base = ram_offset & ~(rb_page_size - 1); if (rb_page_size == BALLOON_PAGE_SIZE) { /* Easy case */ - ram_block_discard_range(rb, ram_offset, rb_page_size); + ram_block_discard_range(rb, rb_offset, rb_page_size); /* We ignore errors from ram_block_discard_range(), because it * has already reported them, and failing to discard a balloon * page is not fatal */ @@ -80,11 +79,12 @@ static void balloon_inflate_page(VirtIOBalloon *balloon, warn_report_once( "Balloon used with backing page size > 4kiB, this may not be reliable"); + rb_aligned_offset = QEMU_ALIGN_DOWN(rb_offset, rb_page_size); subpages = rb_page_size / BALLOON_PAGE_SIZE; if (balloon->pbp && (rb != balloon->pbp->rb - || host_page_base != balloon->pbp->base)) { + || rb_aligned_offset != balloon->pbp->base)) { /* We've partially ballooned part of a host page, but now * we're trying to balloon part of a different one. Too hard, * give up on the old partial page */ @@ -96,10 +96,10 @@ static void balloon_inflate_page(VirtIOBalloon *balloon, size_t bitlen = BITS_TO_LONGS(subpages) * sizeof(unsigned long); balloon->pbp = g_malloc0(sizeof(PartiallyBalloonedPage) + bitlen); balloon->pbp->rb = rb; - balloon->pbp->base = host_page_base; + balloon->pbp->base = rb_aligned_offset; } - set_bit((ram_offset - balloon->pbp->base) / BALLOON_PAGE_SIZE, + set_bit((rb_offset - balloon->pbp->base) / BALLOON_PAGE_SIZE, balloon->pbp->bitmap); if (bitmap_full(balloon->pbp->bitmap, subpages)) { @@ -116,18 +116,18 @@ static void balloon_inflate_page(VirtIOBalloon *balloon, } static void balloon_deflate_page(VirtIOBalloon *balloon, - MemoryRegion *mr, hwaddr offset) + MemoryRegion *mr, hwaddr mr_offset) { - void *addr = memory_region_get_ram_ptr(mr) + offset; + void *addr = memory_region_get_ram_ptr(mr) + mr_offset; + ram_addr_t rb_offset; RAMBlock *rb; size_t rb_page_size; - ram_addr_t ram_offset; void *host_addr; int ret; /* XXX is there a better way to get to the RAMBlock than via a * host address? */ - rb = qemu_ram_block_from_host(addr, false, &ram_offset); + rb = qemu_ram_block_from_host(addr, false, &rb_offset); rb_page_size = qemu_ram_pagesize(rb); if (balloon->pbp) {
"host_page_base" is really confusing, let's make this clearer, also rename the other offsets to indicate to which base they apply. offset -> mr_offset ram_offset -> rb_offset host_page_base -> rb_aligned_offset While at it, use QEMU_ALIGN_DOWN() instead of a handcrafted computation and move the computation to the place where it is needed. Signed-off-by: David Hildenbrand <david@redhat.com> --- hw/virtio/virtio-balloon.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-)