SHA256
2
0
forked from SLFO-pool/xen
xen/libxc-sr-save-mfns.patch

133 lines
4.8 KiB
Diff

From: Olaf Hering <olaf@aepfle.de>
Date: Fri, 23 Oct 2020 11:20:36 +0200
Subject: libxc sr save mfns
tools: save: preallocate mfns array
Remove repeated allocation from migration loop. There will never be
more than MAX_BATCH_SIZE pages to process in a batch, see add_to_batch.
Allocate the space once.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
---
tools/libs/guest/xg_sr_common.h | 1 +
tools/libs/guest/xg_sr_save.c | 25 +++++++++++++------------
2 files changed, 14 insertions(+), 12 deletions(-)
--- a/tools/libs/guest/xg_sr_common.h
+++ b/tools/libs/guest/xg_sr_common.h
@@ -244,6 +244,7 @@ struct xc_sr_context
struct precopy_stats stats;
xen_pfn_t *batch_pfns;
+ xen_pfn_t *mfns;
unsigned int nr_batch_pfns;
unsigned long *deferred_pages;
unsigned long nr_deferred_pages;
--- a/tools/libs/guest/xg_sr_save.c
+++ b/tools/libs/guest/xg_sr_save.c
@@ -88,7 +88,7 @@ static int write_checkpoint_record(struc
static int write_batch(struct xc_sr_context *ctx)
{
xc_interface *xch = ctx->xch;
- xen_pfn_t *mfns = NULL, *types = NULL;
+ xen_pfn_t *types = NULL;
void *guest_mapping = NULL;
void **guest_data = NULL;
void **local_pages = NULL;
@@ -105,8 +105,6 @@ static int write_batch(struct xc_sr_cont
assert(nr_pfns != 0);
- /* Mfns of the batch pfns. */
- mfns = malloc(nr_pfns * sizeof(*mfns));
/* Types of the batch pfns. */
types = malloc(nr_pfns * sizeof(*types));
/* Errors from attempting to map the gfns. */
@@ -118,7 +116,7 @@ static int write_batch(struct xc_sr_cont
/* iovec[] for writev(). */
iov = malloc((nr_pfns + 4) * sizeof(*iov));
- if ( !mfns || !types || !errors || !guest_data || !local_pages || !iov )
+ if ( !types || !errors || !guest_data || !local_pages || !iov )
{
ERROR("Unable to allocate arrays for a batch of %u pages",
nr_pfns);
@@ -127,11 +125,11 @@ static int write_batch(struct xc_sr_cont
for ( i = 0; i < nr_pfns; ++i )
{
- types[i] = mfns[i] = ctx->save.ops.pfn_to_gfn(ctx,
+ types[i] = ctx->save.mfns[i] = ctx->save.ops.pfn_to_gfn(ctx,
ctx->save.batch_pfns[i]);
/* Likely a ballooned page. */
- if ( mfns[i] == INVALID_MFN )
+ if ( ctx->save.mfns[i] == INVALID_MFN )
{
set_bit(ctx->save.batch_pfns[i], ctx->save.deferred_pages);
++ctx->save.nr_deferred_pages;
@@ -150,20 +148,21 @@ static int write_batch(struct xc_sr_cont
{
if ( !is_known_page_type(types[i]) )
{
- ERROR("Unknown type %#"PRIpfn" for pfn %#"PRIpfn, types[i], mfns[i]);
+ ERROR("Unknown type %#"PRIpfn" for pfn %#"PRIpfn,
+ types[i], ctx->save.mfns[i]);
goto err;
}
if ( !page_type_has_stream_data(types[i]) )
continue;
- mfns[nr_pages++] = mfns[i];
+ ctx->save.mfns[nr_pages++] = ctx->save.mfns[i];
}
if ( nr_pages > 0 )
{
guest_mapping = xenforeignmemory_map(
- xch->fmem, ctx->domid, PROT_READ, nr_pages, mfns, errors);
+ xch->fmem, ctx->domid, PROT_READ, nr_pages, ctx->save.mfns, errors);
if ( !guest_mapping )
{
PERROR("Failed to map guest pages");
@@ -179,7 +178,7 @@ static int write_batch(struct xc_sr_cont
if ( errors[p] )
{
ERROR("Mapping of pfn %#"PRIpfn" (mfn %#"PRIpfn") failed %d",
- ctx->save.batch_pfns[i], mfns[p], errors[p]);
+ ctx->save.batch_pfns[i], ctx->save.mfns[p], errors[p]);
goto err;
}
@@ -277,7 +276,6 @@ static int write_batch(struct xc_sr_cont
free(guest_data);
free(errors);
free(types);
- free(mfns);
return rc;
}
@@ -850,9 +848,11 @@ static int setup(struct xc_sr_context *c
xch, dirty_bitmap, NRPAGES(bitmap_size(ctx->save.p2m_size)));
ctx->save.batch_pfns = malloc(MAX_BATCH_SIZE *
sizeof(*ctx->save.batch_pfns));
+ ctx->save.mfns = malloc(MAX_BATCH_SIZE * sizeof(*ctx->save.mfns));
ctx->save.deferred_pages = bitmap_alloc(ctx->save.p2m_size);
- if ( !ctx->save.batch_pfns || !dirty_bitmap || !ctx->save.deferred_pages )
+ if ( !ctx->save.batch_pfns || !ctx->save.mfns ||
+ !dirty_bitmap || !ctx->save.deferred_pages )
{
ERROR("Unable to allocate memory for dirty bitmaps, batch pfns and"
" deferred pages");
@@ -883,6 +883,7 @@ static void cleanup(struct xc_sr_context
xc_hypercall_buffer_free_pages(xch, dirty_bitmap,
NRPAGES(bitmap_size(ctx->save.p2m_size)));
free(ctx->save.deferred_pages);
+ free(ctx->save.mfns);
free(ctx->save.batch_pfns);
}