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virtio-balloon: Better names for offset variables in inflate/deflate code 

"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.

Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20190722134108.22151-5-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
stable-4.1
David Hildenbrand 2019-07-22 15:41:06 +02:00 committed by Michael S. Tsirkin
parent 2ffc49eea1
commit e6129b271b
1 changed files with 13 additions and 13 deletions
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26
hw/virtio/virtio-balloon.c
View File

@ -41,24 +41,23 @@ struct PartiallyBalloonedPage {
};
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 */
@ -74,11 +73,12 @@ 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 */
@ -91,10 +91,10 @@ 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)) {
@ -112,18 +112,18 @@ 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) {