|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v4 11/16] PoC: libs/guest: use foreign copy during migration
From: Edwin Török <edwin.torok@xxxxxxxxxx>
ministat confirms the improvement:
```
x baseline
+ foreigncopy
N Min Max Median Avg Stddev
x 20 1.1306997 1.1447931 1.1356569 1.1365742 0.003242175
+ 20 0.4311504 0.44180303 0.43616705 0.43600089 0.0031094689
Difference at 95.0% confidence
-0.700573 +/- 0.00203311
-61.639% +/- 0.133355%
(Student's t, pooled s = 0.00317652)
```
The tests pass too, which means that it has correctly migrated all guest
memory.
Frediano: This PoC was adapted to be included in a final series.
Signed-off-by: Edwin Török <edwin.torok@xxxxxxxxxx>
Signed-off-by: Frediano Ziglio <frediano.ziglio@xxxxxxxxxx>
---
tools/libs/guest/xg_sr_common.h | 1 +
tools/libs/guest/xg_sr_restore.c | 42 +++--------------
tools/libs/guest/xg_sr_save.c | 81 +++++++++-----------------------
3 files changed, 30 insertions(+), 94 deletions(-)
diff --git a/tools/libs/guest/xg_sr_common.h b/tools/libs/guest/xg_sr_common.h
index 72c9511f38..0e0e279ae1 100644
--- a/tools/libs/guest/xg_sr_common.h
+++ b/tools/libs/guest/xg_sr_common.h
@@ -256,6 +256,7 @@ struct xc_sr_context
unsigned long nr_deferred_pages;
xc_hypercall_buffer_t dirty_bitmap_hbuf;
struct xc_sr_context_save_buffers *buffers;
+ void *dest_buf;
} save;
struct /* Restore data. */
diff --git a/tools/libs/guest/xg_sr_restore.c b/tools/libs/guest/xg_sr_restore.c
index fb46142d87..b589f0397d 100644
--- a/tools/libs/guest/xg_sr_restore.c
+++ b/tools/libs/guest/xg_sr_restore.c
@@ -259,7 +259,6 @@ static int process_page_data(struct xc_sr_context *ctx,
unsigned int count,
xen_pfn_t *mfns = malloc(count * sizeof(*mfns));
int *map_errs = malloc(count * sizeof(*map_errs));
int rc;
- void *mapping = NULL, *guest_page = NULL;
unsigned nr_pages;
if ( !mfns || !map_errs )
@@ -295,27 +294,8 @@ static int process_page_data(struct xc_sr_context *ctx,
unsigned int count,
if ( nr_pages == 0 )
goto done;
- mapping = guest_page = xenforeignmemory_map(
- xch->fmem, ctx->domid, PROT_READ | PROT_WRITE,
- nr_pages, mfns, map_errs);
- if ( !mapping )
- {
- rc = -1;
- PERROR("Unable to map %u mfns for %u pages of data",
- nr_pages, count);
- goto err;
- }
-
for ( unsigned i = 0; i < nr_pages; ++i )
{
- if ( map_errs[i] )
- {
- rc = -1;
- ERROR("Mapping pfn %#"PRIpfn" (mfn %#"PRIpfn", type %#"PRIx32")
failed with %d",
- pfns[i], mfns[i], types[i], map_errs[i]);
- goto err;
- }
-
/* Undo page normalisation done by the saver. */
rc = ctx->restore.ops.localise_page(ctx, types[i], page_data);
if ( rc )
@@ -325,29 +305,19 @@ static int process_page_data(struct xc_sr_context *ctx,
unsigned int count,
goto err;
}
- if ( ctx->restore.verify )
- {
- /* Verify mode - compare incoming data to what we already have. */
- if ( memcmp(guest_page, page_data, PAGE_SIZE) )
- ERROR("verify pfn %#"PRIpfn" failed (type %#"PRIx32")",
- pfns[i], types[i] >> XEN_DOMCTL_PFINFO_LTAB_SHIFT);
- }
- else
- {
- /* Regular mode - copy incoming data into place. */
- memcpy(guest_page, page_data, PAGE_SIZE);
- }
-
- guest_page += PAGE_SIZE;
page_data += PAGE_SIZE;
}
+ if ( !ctx->restore.verify )
+ {
+ rc = xg_foreignmemory_copy_to(xch, ctx->domid, nr_pages, mfns,
page_data);
+ if ( rc < 0 )
+ goto err;
+ }
done:
rc = 0;
err:
- if ( mapping )
- xenforeignmemory_unmap(xch->fmem, mapping, nr_pages);
free(map_errs);
free(mfns);
diff --git a/tools/libs/guest/xg_sr_save.c b/tools/libs/guest/xg_sr_save.c
index 593268f176..ae61f97a47 100644
--- a/tools/libs/guest/xg_sr_save.c
+++ b/tools/libs/guest/xg_sr_save.c
@@ -87,12 +87,10 @@ static int write_batch(struct xc_sr_context *ctx)
{
xc_interface *xch = ctx->xch;
xen_pfn_t *mfns, *types;
- void *guest_mapping = NULL;
void **local_pages;
int *errors, rc = -1;
- unsigned int i, p, nr_pages = 0, nr_pages_mapped = 0;
+ unsigned int i, nr_pages = 0;
unsigned int nr_pfns = ctx->save.nr_batch_pfns;
- void *page, *orig_page;
uint64_t *rec_pfns;
struct iovec *iov; int iovcnt = 0;
struct {
@@ -168,61 +166,18 @@ static int write_batch(struct xc_sr_context *ctx)
iovcnt = 2;
- if ( nr_pages > 0 )
+ rc = xg_foreignmemory_copy_from(xch, ctx->domid, nr_pages,
ctx->save.dest_buf, mfns);
+ if ( rc < 0 )
{
- guest_mapping = xenforeignmemory_map(
- xch->fmem, ctx->domid, PROT_READ, nr_pages, mfns, errors);
- if ( !guest_mapping )
- {
- PERROR("Failed to map guest pages");
- goto err;
- }
- nr_pages_mapped = nr_pages;
-
- for ( i = 0, p = 0; i < nr_pfns; ++i )
- {
- if ( !page_type_has_stream_data(types[i]) )
- continue;
-
- if ( errors[p] )
- {
- ERROR("Mapping of pfn %#"PRIpfn" (mfn %#"PRIpfn") failed %d",
- ctx->save.batch_pfns[i], mfns[p], errors[p]);
- goto err;
- }
-
- orig_page = page = guest_mapping + (p * PAGE_SIZE);
- rc = ctx->save.ops.normalise_page(ctx, types[i], &page);
-
- if ( orig_page != page )
- local_pages[i] = page;
-
- if ( rc )
- {
- if ( rc == -1 && errno == EAGAIN )
- {
- set_bit(ctx->save.batch_pfns[i], ctx->save.deferred_pages);
- ++ctx->save.nr_deferred_pages;
- types[i] = XEN_DOMCTL_PFINFO_XTAB;
- --nr_pages;
- }
- else
- goto err;
- }
- else if ( iov[iovcnt-1].iov_base + iov[iovcnt-1].iov_len != page )
- {
- iov[iovcnt].iov_base = page;
- iov[iovcnt].iov_len = PAGE_SIZE;
- iovcnt++;
- }
- else
- {
- iov[iovcnt-1].iov_len += PAGE_SIZE;
- }
+ ERROR("xg_foreignmemory_copy_from failed");
+ goto err;
+ }
- rc = -1;
- ++p;
- }
+ if ( nr_pages )
+ {
+ iov[iovcnt].iov_base = ctx->save.dest_buf;
+ iov[iovcnt].iov_len = nr_pages << XC_PAGE_SHIFT;
+ iovcnt++;
}
hdrs.rec.length += nr_pages * PAGE_SIZE;
@@ -239,8 +194,6 @@ static int write_batch(struct xc_sr_context *ctx)
rc = ctx->save.nr_batch_pfns = 0;
err:
- if ( guest_mapping )
- xenforeignmemory_unmap(xch->fmem, guest_mapping, nr_pages_mapped);
for ( i = 0; local_pages && i < nr_pfns; ++i )
{
free(local_pages[i]);
@@ -764,6 +717,7 @@ static int setup(struct xc_sr_context *ctx)
{
xc_interface *xch = ctx->xch;
int rc;
+ const unsigned dest_buf_len = MAX_BATCH_SIZE * XC_PAGE_SIZE;
DECLARE_HYPERCALL_BUFFER_SHADOW(unsigned long, dirty_bitmap,
&ctx->save.dirty_bitmap_hbuf);
@@ -775,6 +729,16 @@ static int setup(struct xc_sr_context *ctx)
xch, dirty_bitmap, NRPAGES(bitmap_size(ctx->save.p2m_size)));
ctx->save.deferred_pages = bitmap_alloc(ctx->save.p2m_size);
ctx->save.buffers = calloc(1, sizeof(*ctx->save.buffers));
+ ctx->save.dest_buf = NULL;
+
+ rc = posix_memalign(&ctx->save.dest_buf, XC_PAGE_SIZE, dest_buf_len);
+ if ( rc )
+ {
+ ERROR("Unable to allocate %u bytes of buffer", dest_buf_len);
+ errno = rc;
+ rc = -1;
+ goto err;
+ }
if ( !dirty_bitmap || !ctx->save.deferred_pages || !ctx->save.buffers)
{
@@ -809,6 +773,7 @@ static void cleanup(struct xc_sr_context *ctx)
NRPAGES(bitmap_size(ctx->save.p2m_size)));
free(ctx->save.deferred_pages);
free(ctx->save.buffers);
+ free(ctx->save.dest_buf);
}
/*
--
2.54.0
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |