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authorPeter Maydell <peter.maydell@linaro.org>2019-03-04 11:04:31 +0000
committerPeter Maydell <peter.maydell@linaro.org>2019-03-04 11:04:31 +0000
commit1d31f1872b337e4acac5bf6b3c2a45b66e43b494 (patch)
treeb1c71f789d14aee7d170af69fab5a7a8b817c1a3 /hw/virtio/virtio-balloon.c
parent20b084c4b1401b7f8fbc385649d48c67b6f43d44 (diff)
parent88c869198aa630e0477d653d0abf3f42c7c44d1f (diff)
Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging
pci, pc, virtio: fixes, cleanups, tests Lots of work on tests: BiosTablesTest UEFI app, vhost-user testing for non-Linux hosts. Misc cleanups and fixes all over the place Signed-off-by: Michael S. Tsirkin <mst@redhat.com> # gpg: Signature made Fri 22 Feb 2019 15:51:40 GMT # gpg: using RSA key 281F0DB8D28D5469 # gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>" [full] # gpg: aka "Michael S. Tsirkin <mst@redhat.com>" [full] # Primary key fingerprint: 0270 606B 6F3C DF3D 0B17 0970 C350 3912 AFBE 8E67 # Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA 8A0D 281F 0DB8 D28D 5469 * remotes/mst/tags/for_upstream: (26 commits) pci: Sanity test minimum downstream LNKSTA hw/smbios: fix offset of type 3 sku field pci: Move NVIDIA vendor id to the rest of ids virtio-balloon: Safely handle BALLOON_PAGE_SIZE < host page size virtio-balloon: Use ram_block_discard_range() instead of raw madvise() virtio-balloon: Rework ballon_page() interface virtio-balloon: Corrections to address verification virtio-balloon: Remove unnecessary MADV_WILLNEED on deflate i386/kvm: ignore masked irqs when update msi routes contrib/vhost-user-blk: fix the compilation issue Revert "contrib/vhost-user-blk: fix the compilation issue" pc-dimm: use same mechanism for [get|set]_addr tests/data: introduce "uefi-boot-images" with the "bios-tables-test" ISOs tests/uefi-test-tools: add build scripts tests: introduce "uefi-test-tools" with the BiosTablesTest UEFI app roms: build the EfiRom utility from the roms/edk2 submodule roms: add the edk2 project as a git submodule vhost-user-test: create a temporary directory per TestServer vhost-user-test: small changes to init_hugepagefs vhost-user-test: create a main loop per TestServer ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'hw/virtio/virtio-balloon.c')
-rw-r--r--hw/virtio/virtio-balloon.c102
1 files changed, 86 insertions, 16 deletions
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index a12677d4d5..d3f2913a85 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -33,11 +33,81 @@
#define BALLOON_PAGE_SIZE (1 << VIRTIO_BALLOON_PFN_SHIFT)
-static void balloon_page(void *addr, int deflate)
+struct PartiallyBalloonedPage {
+ RAMBlock *rb;
+ ram_addr_t base;
+ unsigned long bitmap[];
+};
+
+static void balloon_inflate_page(VirtIOBalloon *balloon,
+ MemoryRegion *mr, hwaddr offset)
{
- if (!qemu_balloon_is_inhibited()) {
- qemu_madvise(addr, BALLOON_PAGE_SIZE,
- deflate ? QEMU_MADV_WILLNEED : QEMU_MADV_DONTNEED);
+ void *addr = memory_region_get_ram_ptr(mr) + 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_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);
+ /* We ignore errors from ram_block_discard_range(), because it
+ * has already reported them, and failing to discard a balloon
+ * page is not fatal */
+ return;
+ }
+
+ /* Hard case
+ *
+ * We've put a piece of a larger host page into the balloon - we
+ * need to keep track until we have a whole host page to
+ * discard
+ */
+ warn_report_once(
+"Balloon used with backing page size > 4kiB, this may not be reliable");
+
+ subpages = rb_page_size / BALLOON_PAGE_SIZE;
+
+ if (balloon->pbp
+ && (rb != balloon->pbp->rb
+ || host_page_base != 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 */
+ free(balloon->pbp);
+ balloon->pbp = NULL;
+ }
+
+ if (!balloon->pbp) {
+ /* Starting on a new host page */
+ 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;
+ }
+
+ bitmap_set(balloon->pbp->bitmap,
+ (ram_offset - balloon->pbp->base) / BALLOON_PAGE_SIZE,
+ subpages);
+
+ if (bitmap_full(balloon->pbp->bitmap, subpages)) {
+ /* We've accumulated a full host page, we can actually discard
+ * it now */
+
+ ram_block_discard_range(rb, balloon->pbp->base, 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 */
+
+ free(balloon->pbp);
+ balloon->pbp = NULL;
}
}
@@ -222,17 +292,19 @@ static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
}
while (iov_to_buf(elem->out_sg, elem->out_num, offset, &pfn, 4) == 4) {
- ram_addr_t pa;
- ram_addr_t addr;
+ hwaddr pa;
int p = virtio_ldl_p(vdev, &pfn);
- pa = (ram_addr_t) p << VIRTIO_BALLOON_PFN_SHIFT;
+ pa = (hwaddr) p << VIRTIO_BALLOON_PFN_SHIFT;
offset += 4;
- /* FIXME: remove get_system_memory(), but how? */
- section = memory_region_find(get_system_memory(), pa, 1);
- if (!int128_nz(section.size) ||
- !memory_region_is_ram(section.mr) ||
+ section = memory_region_find(get_system_memory(), pa,
+ BALLOON_PAGE_SIZE);
+ if (!section.mr) {
+ trace_virtio_balloon_bad_addr(pa);
+ continue;
+ }
+ if (!memory_region_is_ram(section.mr) ||
memory_region_is_rom(section.mr) ||
memory_region_is_romd(section.mr)) {
trace_virtio_balloon_bad_addr(pa);
@@ -242,11 +314,9 @@ static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
trace_virtio_balloon_handle_output(memory_region_name(section.mr),
pa);
- /* Using memory_region_get_ram_ptr is bending the rules a bit, but
- should be OK because we only want a single page. */
- addr = section.offset_within_region;
- balloon_page(memory_region_get_ram_ptr(section.mr) + addr,
- !!(vq == s->dvq));
+ if (!qemu_balloon_is_inhibited() && vq != s->dvq) {
+ balloon_inflate_page(s, section.mr, section.offset_within_region);
+ }
memory_region_unref(section.mr);
}