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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v20210601 36/38] tools: use superpages during restore of HVM guest
During creating of a HVM domU meminit_hvm() tries to map superpages.
After save/restore or migration this mapping is lost, everything is
allocated in single pages. This causes a performance degradation after
migration.
Add neccessary code to preallocate a superpage for an incoming chunk of
pfns. In case a pfn was not populated on the sending side, it must be
freed on the receiving side to avoid over-allocation.
The existing code for x86_pv is moved unmodified into its own file.
Signed-off-by: Olaf Hering <olaf@xxxxxxxxx>
---
tools/libs/guest/xg_dom_x86.c | 5 -
tools/libs/guest/xg_private.h | 5 +
tools/libs/saverestore/common.c | 2 -
tools/libs/saverestore/common.h | 29 +-
tools/libs/saverestore/restore.c | 62 +---
tools/libs/saverestore/restore_x86_hvm.c | 369 ++++++++++++++++++++++-
tools/libs/saverestore/restore_x86_pv.c | 61 +++-
7 files changed, 455 insertions(+), 78 deletions(-)
diff --git a/tools/libs/guest/xg_dom_x86.c b/tools/libs/guest/xg_dom_x86.c
index d2eb89ce01..ec0d18fd60 100644
--- a/tools/libs/guest/xg_dom_x86.c
+++ b/tools/libs/guest/xg_dom_x86.c
@@ -44,11 +44,6 @@
#define SUPERPAGE_BATCH_SIZE 512
-#define SUPERPAGE_2MB_SHIFT 9
-#define SUPERPAGE_2MB_NR_PFNS (1UL << SUPERPAGE_2MB_SHIFT)
-#define SUPERPAGE_1GB_SHIFT 18
-#define SUPERPAGE_1GB_NR_PFNS (1UL << SUPERPAGE_1GB_SHIFT)
-
#define X86_CR0_PE 0x01
#define X86_CR0_ET 0x10
diff --git a/tools/libs/guest/xg_private.h b/tools/libs/guest/xg_private.h
index 25e46d7ce1..ad3d108c14 100644
--- a/tools/libs/guest/xg_private.h
+++ b/tools/libs/guest/xg_private.h
@@ -154,4 +154,9 @@ int pin_table(xc_interface *xch, unsigned int type,
unsigned long mfn,
#define M2P_SIZE(_m) ROUNDUP(((_m) * sizeof(xen_pfn_t)), M2P_SHIFT)
#define M2P_CHUNKS(_m) (M2P_SIZE((_m)) >> M2P_SHIFT)
+#define SUPERPAGE_2MB_SHIFT 9
+#define SUPERPAGE_2MB_NR_PFNS (1UL << SUPERPAGE_2MB_SHIFT)
+#define SUPERPAGE_1GB_SHIFT 18
+#define SUPERPAGE_1GB_NR_PFNS (1UL << SUPERPAGE_1GB_SHIFT)
+
#endif /* XG_PRIVATE_H */
diff --git a/tools/libs/saverestore/common.c b/tools/libs/saverestore/common.c
index 9f1af4e671..09b2983898 100644
--- a/tools/libs/saverestore/common.c
+++ b/tools/libs/saverestore/common.c
@@ -1,5 +1,3 @@
-#include <assert.h>
-
#include "common.h"
#include <xen-tools/libs.h>
diff --git a/tools/libs/saverestore/common.h b/tools/libs/saverestore/common.h
index f3ee619844..b323c1b71a 100644
--- a/tools/libs/saverestore/common.h
+++ b/tools/libs/saverestore/common.h
@@ -3,6 +3,7 @@
#include <unistd.h>
#include <errno.h>
+#include <assert.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
@@ -219,6 +220,16 @@ struct xc_sr_restore_ops
*/
int (*setup)(struct xc_sr_context *ctx);
+ /**
+ * Populate PFNs
+ *
+ * Given a set of pfns, obtain memory from Xen to fill the physmap for the
+ * unpopulated subset.
+ */
+ int (*populate_pfns)(struct xc_sr_context *ctx, unsigned count,
+ const xen_pfn_t *original_pfns, const uint32_t
*types);
+
+
/**
* Process an individual record from the stream. The caller shall take
* care of processing common records (e.g. END, PAGE_DATA).
@@ -366,6 +377,8 @@ struct xc_sr_context
int send_back_fd;
unsigned long p2m_size;
+ unsigned long max_pages;
+ unsigned long tot_pages;
xc_hypercall_buffer_t dirty_bitmap_hbuf;
/* From Image Header. */
@@ -503,6 +516,14 @@ struct xc_sr_context
{
/* HVM context blob. */
struct xc_sr_blob context;
+
+ /* Bitmap of currently allocated PFNs during restore.
*/
+ struct xg_sr_bitmap attempted_1g;
+ struct xg_sr_bitmap attempted_2m;
+ struct xg_sr_bitmap allocated_pfns;
+ xen_pfn_t prev_populated_pfn;
+ xen_pfn_t iteration_tracker_pfn;
+ unsigned long iteration;
} restore;
};
} hvm;
@@ -567,14 +588,6 @@ int read_record_header(struct xc_sr_context *ctx, int fd,
struct xc_sr_rhdr *rhd
int read_record_data(struct xc_sr_context *ctx, int fd, struct xc_sr_rhdr
*rhdr,
struct xc_sr_record *rec);
-/*
- * This would ideally be private in restore.c, but is needed by
- * x86_pv_localise_page() if we receive pagetables frames ahead of the
- * contents of the frames they point at.
- */
-int populate_pfns(struct xc_sr_context *ctx, unsigned int count,
- const xen_pfn_t *original_pfns, const uint32_t *types);
-
/* Handle a STATIC_DATA_END record. */
int handle_static_data_end(struct xc_sr_context *ctx);
diff --git a/tools/libs/saverestore/restore.c b/tools/libs/saverestore/restore.c
index 0682616f16..d4657e8e57 100644
--- a/tools/libs/saverestore/restore.c
+++ b/tools/libs/saverestore/restore.c
@@ -71,63 +71,6 @@ static int read_headers(struct xc_sr_context *ctx)
return 0;
}
-/*
- * Given a set of pfns, obtain memory from Xen to fill the physmap for the
- * unpopulated subset. If types is NULL, no page type checking is performed
- * and all unpopulated pfns are populated.
- */
-int populate_pfns(struct xc_sr_context *ctx, unsigned int count,
- const xen_pfn_t *original_pfns, const uint32_t *types)
-{
- xc_interface *xch = ctx->xch;
- xen_pfn_t *mfns = ctx->restore.m->pp_mfns,
- *pfns = ctx->restore.m->pp_pfns;
- unsigned int i, nr_pfns = 0;
- int rc = -1;
-
- for ( i = 0; i < count; ++i )
- {
- if ( (!types ||
- (types && page_type_has_stream_data(types[i]) == true)) &&
- !pfn_is_populated(ctx, original_pfns[i]) )
- {
- rc = pfn_set_populated(ctx, original_pfns[i]);
- if ( rc )
- goto err;
- pfns[nr_pfns] = mfns[nr_pfns] = original_pfns[i];
- ++nr_pfns;
- }
- }
-
- if ( nr_pfns )
- {
- rc = xc_domain_populate_physmap_exact(
- xch, ctx->domid, nr_pfns, 0, 0, mfns);
- if ( rc )
- {
- PERROR("Failed to populate physmap");
- goto err;
- }
-
- for ( i = 0; i < nr_pfns; ++i )
- {
- if ( mfns[i] == INVALID_MFN )
- {
- ERROR("Populate physmap failed for pfn %u", i);
- rc = -1;
- goto err;
- }
-
- ctx->restore.ops.set_gfn(ctx, pfns[i], mfns[i]);
- }
- }
-
- rc = 0;
-
- err:
- return rc;
-}
-
static int handle_static_data_end_v2(struct xc_sr_context *ctx)
{
int rc = 0;
@@ -270,7 +213,7 @@ static int map_guest_pages(struct xc_sr_context *ctx,
uint32_t i, p;
int rc;
- rc = populate_pfns(ctx, pages->count, m->pfns, m->types);
+ rc = ctx->restore.ops.populate_pfns(ctx, pages->count, m->pfns, m->types);
if ( rc )
{
ERROR("Failed to populate pfns for batch of %u pages", pages->count);
@@ -1077,6 +1020,9 @@ int xc_domain_restore(xc_interface *xch, int io_fd,
uint32_t dom,
return -1;
}
+ /* See xc_domain_getinfo */
+ ctx.restore.max_pages = ctx.dominfo.max_memkb >> (PAGE_SHIFT-10);
+ ctx.restore.tot_pages = ctx.dominfo.nr_pages;
ctx.restore.p2m_size = nr_pfns;
ctx.restore.ops = ctx.dominfo.hvm
? restore_ops_x86_hvm : restore_ops_x86_pv;
diff --git a/tools/libs/saverestore/restore_x86_hvm.c
b/tools/libs/saverestore/restore_x86_hvm.c
index 73f17b7fcb..79bcf07e04 100644
--- a/tools/libs/saverestore/restore_x86_hvm.c
+++ b/tools/libs/saverestore/restore_x86_hvm.c
@@ -130,6 +130,25 @@ static int x86_hvm_localise_page(struct xc_sr_context *ctx,
return 0;
}
+static bool x86_hvm_expand_sp_bitmaps(struct xc_sr_context *ctx, unsigned long
max_pfn)
+{
+ struct xg_sr_bitmap *bm;
+
+ bm = &ctx->x86.hvm.restore.attempted_1g;
+ if ( !xg_sr_bitmap_expand(bm, max_pfn >> SUPERPAGE_1GB_SHIFT) )
+ return false;
+
+ bm = &ctx->x86.hvm.restore.attempted_2m;
+ if ( !xg_sr_bitmap_expand(bm, max_pfn >> SUPERPAGE_2MB_SHIFT) )
+ return false;
+
+ bm = &ctx->x86.hvm.restore.allocated_pfns;
+ if ( !xg_sr_bitmap_expand(bm, max_pfn) )
+ return false;
+
+ return true;
+}
+
/*
* restore_ops function. Confirms the stream matches the domain.
*/
@@ -164,12 +183,20 @@ static int x86_hvm_setup(struct xc_sr_context *ctx)
max_pfn = max(ctx->restore.p2m_size, ctx->dominfo.max_memkb >>
(PAGE_SHIFT-10));
if ( !xg_sr_bitmap_expand(&ctx->restore.populated_pfns, max_pfn) )
- {
- PERROR("Unable to allocate memory for populated_pfns bitmap");
- return -1;
- }
+ goto out;
+
+ if ( !x86_hvm_expand_sp_bitmaps(ctx, max_pfn) )
+ goto out;
+
+ /* No superpage in 1st 2MB due to VGA hole */
+ xg_sr_set_bit(0, &ctx->x86.hvm.restore.attempted_1g);
+ xg_sr_set_bit(0, &ctx->x86.hvm.restore.attempted_2m);
return 0;
+
+out:
+ PERROR("Unable to allocate memory for pfn bitmaps");
+ return -1;
}
/*
@@ -250,6 +277,9 @@ static int x86_hvm_stream_complete(struct xc_sr_context
*ctx)
static int x86_hvm_cleanup(struct xc_sr_context *ctx)
{
xg_sr_bitmap_free(&ctx->restore.populated_pfns);
+ xg_sr_bitmap_free(&ctx->x86.hvm.restore.attempted_1g);
+ xg_sr_bitmap_free(&ctx->x86.hvm.restore.attempted_2m);
+ xg_sr_bitmap_free(&ctx->x86.hvm.restore.allocated_pfns);
free(ctx->x86.hvm.restore.context.ptr);
free(ctx->x86.restore.cpuid.ptr);
@@ -258,6 +288,336 @@ static int x86_hvm_cleanup(struct xc_sr_context *ctx)
return 0;
}
+/*
+ * Set a range of pfns as allocated
+ */
+static void pfn_set_long_allocated(struct xc_sr_context *ctx, xen_pfn_t
base_pfn)
+{
+ xg_sr_set_long_bit(base_pfn, &ctx->x86.hvm.restore.allocated_pfns);
+}
+
+static void pfn_set_allocated(struct xc_sr_context *ctx, xen_pfn_t pfn)
+{
+ xg_sr_set_bit(pfn, &ctx->x86.hvm.restore.allocated_pfns);
+}
+
+struct x86_hvm_sp {
+ xen_pfn_t pfn;
+ xen_pfn_t base_pfn;
+ unsigned long index;
+ unsigned long count;
+};
+
+/*
+ * Try to allocate a 1GB page for this pfn, but avoid Over-allocation.
+ * If this succeeds, mark the range of 2MB pages as busy.
+ */
+static bool x86_hvm_alloc_1g(struct xc_sr_context *ctx, struct x86_hvm_sp *sp)
+{
+ xc_interface *xch = ctx->xch;
+ unsigned int order;
+ int i, done;
+ xen_pfn_t extent;
+
+ /* Only one attempt to avoid overlapping allocation */
+ if ( xg_sr_test_and_set_bit(sp->index, &ctx->x86.hvm.restore.attempted_1g)
)
+ return false;
+
+ order = SUPERPAGE_1GB_SHIFT;
+ sp->count = SUPERPAGE_1GB_NR_PFNS;
+
+ /* Allocate only if there is room for another superpage */
+ if ( ctx->restore.tot_pages + sp->count > ctx->restore.max_pages )
+ return false;
+
+ extent = sp->base_pfn = (sp->pfn >> order) << order;
+ done = xc_domain_populate_physmap(xch, ctx->domid, 1, order, 0, &extent);
+ if ( done < 0 ) {
+ PERROR("populate_physmap failed.");
+ return false;
+ }
+ if ( done == 0 )
+ return false;
+
+ DPRINTF("1G %" PRI_xen_pfn "\n", sp->base_pfn);
+
+ /* Mark all 2MB pages as done to avoid overlapping allocation */
+ for ( i = 0; i < (SUPERPAGE_1GB_NR_PFNS/SUPERPAGE_2MB_NR_PFNS); i++ )
+ xg_sr_set_bit((sp->base_pfn >> SUPERPAGE_2MB_SHIFT) + i,
&ctx->x86.hvm.restore.attempted_2m);
+
+ return true;
+}
+
+/* Allocate a 2MB page if x86_hvm_alloc_1g failed, avoid Over-allocation. */
+static bool x86_hvm_alloc_2m(struct xc_sr_context *ctx, struct x86_hvm_sp *sp)
+{
+ xc_interface *xch = ctx->xch;
+ unsigned int order;
+ int done;
+ xen_pfn_t extent;
+
+ /* Only one attempt to avoid overlapping allocation */
+ if ( xg_sr_test_and_set_bit(sp->index, &ctx->x86.hvm.restore.attempted_2m)
)
+ return false;
+
+ order = SUPERPAGE_2MB_SHIFT;
+ sp->count = SUPERPAGE_2MB_NR_PFNS;
+
+ /* Allocate only if there is room for another superpage */
+ if ( ctx->restore.tot_pages + sp->count > ctx->restore.max_pages )
+ return false;
+
+ extent = sp->base_pfn = (sp->pfn >> order) << order;
+ done = xc_domain_populate_physmap(xch, ctx->domid, 1, order, 0, &extent);
+ if ( done < 0 ) {
+ PERROR("populate_physmap failed.");
+ return false;
+ }
+ if ( done == 0 )
+ return false;
+
+ DPRINTF("2M %" PRI_xen_pfn "\n", sp->base_pfn);
+ return true;
+}
+
+/* Allocate a single page if x86_hvm_alloc_2m failed. */
+static bool x86_hvm_alloc_4k(struct xc_sr_context *ctx, struct x86_hvm_sp *sp)
+{
+ xc_interface *xch = ctx->xch;
+ unsigned int order;
+ int done;
+ xen_pfn_t extent;
+
+ order = 0;
+ sp->count = 1UL;
+
+ /* Allocate only if there is room for another page */
+ if ( ctx->restore.tot_pages + sp->count > ctx->restore.max_pages ) {
+ errno = E2BIG;
+ return false;
+ }
+
+ extent = sp->base_pfn = (sp->pfn >> order) << order;
+ done = xc_domain_populate_physmap(xch, ctx->domid, 1, order, 0, &extent);
+ if ( done < 0 ) {
+ PERROR("populate_physmap failed.");
+ return false;
+ }
+ if ( done == 0 ) {
+ errno = ENOMEM;
+ return false;
+ }
+
+ DPRINTF("4K %" PRI_xen_pfn "\n", sp->base_pfn);
+ return true;
+}
+/*
+ * Attempt to allocate a superpage where the pfn resides.
+ */
+static int x86_hvm_allocate_pfn(struct xc_sr_context *ctx, xen_pfn_t pfn)
+{
+ bool success;
+ unsigned long idx_1g, idx_2m;
+ struct x86_hvm_sp sp = {
+ .pfn = pfn
+ };
+
+ if ( xg_sr_test_bit(pfn, &ctx->x86.hvm.restore.allocated_pfns) )
+ return 0;
+
+ idx_1g = pfn >> SUPERPAGE_1GB_SHIFT;
+ idx_2m = pfn >> SUPERPAGE_2MB_SHIFT;
+
+ sp.index = idx_1g;
+ success = x86_hvm_alloc_1g(ctx, &sp);
+
+ if ( success == false ) {
+ sp.index = idx_2m;
+ success = x86_hvm_alloc_2m(ctx, &sp);
+ }
+
+ if ( success == false ) {
+ sp.index = 0;
+ success = x86_hvm_alloc_4k(ctx, &sp);
+ }
+
+ if ( success == false )
+ return -1;
+
+ do {
+ if ( sp.count >= BITS_PER_LONG ) {
+ sp.count -= BITS_PER_LONG;
+ ctx->restore.tot_pages += BITS_PER_LONG;
+ pfn_set_long_allocated(ctx, sp.base_pfn + sp.count);
+ } else {
+ sp.count--;
+ ctx->restore.tot_pages++;
+ pfn_set_allocated(ctx, sp.base_pfn + sp.count);
+ }
+ } while ( sp.count );
+
+ return 0;
+}
+
+/*
+ * Deallocate memory.
+ * There was likely an optimistic superpage allocation.
+ * This means more pages may have been allocated past gap_end.
+ * This range is not freed now. Incoming higher pfns will release it.
+ */
+static int x86_hvm_punch_hole(struct xc_sr_context *ctx,
+ xen_pfn_t gap_start, xen_pfn_t gap_end)
+{
+ xc_interface *xch = ctx->xch;
+ xen_pfn_t _pfn, pfn;
+ uint32_t domid, freed = 0;
+ int rc;
+
+ pfn = gap_start >> SUPERPAGE_1GB_SHIFT;
+ do
+ {
+ xg_sr_set_bit(pfn, &ctx->x86.hvm.restore.attempted_1g);
+ } while (++pfn <= gap_end >> SUPERPAGE_1GB_SHIFT);
+
+ pfn = gap_start >> SUPERPAGE_2MB_SHIFT;
+ do
+ {
+ xg_sr_set_bit(pfn, &ctx->x86.hvm.restore.attempted_2m);
+ } while (++pfn <= gap_end >> SUPERPAGE_2MB_SHIFT);
+
+ pfn = gap_start;
+
+ while ( pfn <= gap_end )
+ {
+ if ( xg_sr_test_and_clear_bit(pfn,
&ctx->x86.hvm.restore.allocated_pfns) )
+ {
+ domid = ctx->domid;
+ _pfn = pfn;
+ rc = xc_domain_decrease_reservation_exact(xch, domid, 1, 0, &_pfn);
+ if ( rc )
+ {
+ PERROR("Failed to release pfn %" PRI_xen_pfn, pfn);
+ return -1;
+ }
+ ctx->restore.tot_pages--;
+ freed++;
+ }
+ pfn++;
+ }
+ if ( freed )
+ DPRINTF("freed %u between %" PRI_xen_pfn " %" PRI_xen_pfn "\n",
+ freed, gap_start, gap_end);
+ return 0;
+}
+
+static int x86_hvm_unpopulate_page(struct xc_sr_context *ctx, xen_pfn_t pfn)
+{
+ xg_sr_clear_bit(pfn, &ctx->restore.populated_pfns);
+ return x86_hvm_punch_hole(ctx, pfn, pfn);
+}
+
+static int x86_hvm_populate_page(struct xc_sr_context *ctx, xen_pfn_t pfn)
+{
+ xen_pfn_t gap_start, gap_end;
+ bool has_gap, first_iteration;
+ int rc;
+
+ /*
+ * Check for a gap between the previous populated pfn and this pfn.
+ * In case a gap exists, it is required to punch a hole to release memory,
+ * starting after the previous pfn and before this pfn.
+ *
+ * But: this can be done only during the first iteration, which is the
+ * only place there superpage allocations are attempted. All following
+ * iterations lack the info to properly maintain prev_populated_pfn.
+ */
+ has_gap = ctx->x86.hvm.restore.prev_populated_pfn + 1 < pfn;
+ first_iteration = ctx->x86.hvm.restore.iteration == 0;
+ if ( has_gap && first_iteration )
+ {
+ gap_start = ctx->x86.hvm.restore.prev_populated_pfn + 1;
+ gap_end = pfn - 1;
+
+ rc = x86_hvm_punch_hole(ctx, gap_start, gap_end);
+ if ( rc )
+ goto err;
+ }
+
+ rc = x86_hvm_allocate_pfn(ctx, pfn);
+ if ( rc )
+ goto err;
+ pfn_set_populated(ctx, pfn);
+ ctx->x86.hvm.restore.prev_populated_pfn = pfn;
+
+ rc = 0;
+err:
+ return rc;
+}
+
+/*
+ * Try to allocate superpages.
+ * This works without memory map because the pfns arrive in incremental order.
+ * All pfn numbers and their type are submitted.
+ * Only pfns with data will have also pfn content transmitted.
+ */
+static int x86_hvm_populate_pfns(struct xc_sr_context *ctx, unsigned count,
+ const xen_pfn_t *original_pfns,
+ const uint32_t *types)
+{
+ xc_interface *xch = ctx->xch;
+ xen_pfn_t pfn, min_pfn, max_pfn;
+ bool has_data, populated;
+ unsigned i = count;
+ int rc = 0;
+
+ min_pfn = count ? original_pfns[0] : 0;
+ max_pfn = count ? original_pfns[count - 1] : 0;
+ DPRINTF("batch of %u pfns between %" PRI_xen_pfn " %" PRI_xen_pfn "\n",
+ count, min_pfn, max_pfn);
+
+ if ( !x86_hvm_expand_sp_bitmaps(ctx, max_pfn) )
+ {
+ ERROR("Unable to allocate memory for pfn bitmaps");
+ return -1;
+ }
+
+ /*
+ * There is no indicator for a new iteration.
+ * Simulate it by checking if a lower pfn is coming in.
+ * In the end it matters only to know if this iteration is the first one.
+ */
+ if ( min_pfn < ctx->x86.hvm.restore.iteration_tracker_pfn )
+ ctx->x86.hvm.restore.iteration++;
+ ctx->x86.hvm.restore.iteration_tracker_pfn = min_pfn;
+
+ for ( i = 0; i < count; ++i )
+ {
+ pfn = original_pfns[i];
+
+ has_data = page_type_has_stream_data(types[i]);
+ populated = pfn_is_populated(ctx, pfn);
+
+ /*
+ * page has data, pfn populated: nothing to do
+ * page has data, pfn not populated: likely never seen before
+ * page has no data, pfn populated: likely ballooned out during
migration
+ * page has no data, pfn not populated: nothing to do
+ */
+ if ( has_data && !populated )
+ {
+ rc = x86_hvm_populate_page(ctx, pfn);
+ } else if ( !has_data && populated )
+ {
+ rc = x86_hvm_unpopulate_page(ctx, pfn);
+ }
+ if ( rc )
+ break;
+ }
+
+ return rc;
+}
+
+
struct xc_sr_restore_ops restore_ops_x86_hvm =
{
.pfn_is_valid = x86_hvm_pfn_is_valid,
@@ -266,6 +626,7 @@ struct xc_sr_restore_ops restore_ops_x86_hvm =
.set_page_type = x86_hvm_set_page_type,
.localise_page = x86_hvm_localise_page,
.setup = x86_hvm_setup,
+ .populate_pfns = x86_hvm_populate_pfns,
.process_record = x86_hvm_process_record,
.static_data_complete = x86_static_data_complete,
.stream_complete = x86_hvm_stream_complete,
diff --git a/tools/libs/saverestore/restore_x86_pv.c
b/tools/libs/saverestore/restore_x86_pv.c
index bdaa0c0e76..f4f0f49dee 100644
--- a/tools/libs/saverestore/restore_x86_pv.c
+++ b/tools/libs/saverestore/restore_x86_pv.c
@@ -959,6 +959,64 @@ static void x86_pv_set_gfn(struct xc_sr_context *ctx,
xen_pfn_t pfn,
((uint32_t *)ctx->x86.pv.p2m)[pfn] = mfn;
}
+/*
+ * Given a set of pfns, obtain memory from Xen to fill the physmap for the
+ * unpopulated subset. If types is NULL, no page type checking is performed
+ * and all unpopulated pfns are populated.
+ */
+static int x86_pv_populate_pfns(struct xc_sr_context *ctx, unsigned count,
+ const xen_pfn_t *original_pfns,
+ const uint32_t *types)
+{
+ xc_interface *xch = ctx->xch;
+ xen_pfn_t *mfns = ctx->restore.m->pp_mfns,
+ *pfns = ctx->restore.m->pp_pfns;
+ unsigned int i, nr_pfns = 0;
+ int rc = -1;
+
+ for ( i = 0; i < count; ++i )
+ {
+ if ( (!types ||
+ (types && page_type_has_stream_data(types[i]) == true)) &&
+ !pfn_is_populated(ctx, original_pfns[i]) )
+ {
+ rc = pfn_set_populated(ctx, original_pfns[i]);
+ if ( rc )
+ goto err;
+ pfns[nr_pfns] = mfns[nr_pfns] = original_pfns[i];
+ ++nr_pfns;
+ }
+ }
+
+ if ( nr_pfns )
+ {
+ rc = xc_domain_populate_physmap_exact(
+ xch, ctx->domid, nr_pfns, 0, 0, mfns);
+ if ( rc )
+ {
+ PERROR("Failed to populate physmap");
+ goto err;
+ }
+
+ for ( i = 0; i < nr_pfns; ++i )
+ {
+ if ( mfns[i] == INVALID_MFN )
+ {
+ ERROR("Populate physmap failed for pfn %u", i);
+ rc = -1;
+ goto err;
+ }
+
+ ctx->restore.ops.set_gfn(ctx, pfns[i], mfns[i]);
+ }
+ }
+
+ rc = 0;
+
+ err:
+ return rc;
+}
+
/*
* restore_ops function. Convert pfns back to mfns in pagetables. Possibly
* needs to populate new frames if a PTE is found referring to a frame which
@@ -1003,7 +1061,7 @@ static int x86_pv_localise_page(struct xc_sr_context *ctx,
}
}
- if ( to_populate && populate_pfns(ctx, to_populate, pfns, NULL) )
+ if ( to_populate && x86_pv_populate_pfns(ctx, to_populate, pfns, NULL) )
return -1;
for ( i = 0; i < (PAGE_SIZE / sizeof(uint64_t)); ++i )
@@ -1200,6 +1258,7 @@ struct xc_sr_restore_ops restore_ops_x86_pv =
.set_gfn = x86_pv_set_gfn,
.localise_page = x86_pv_localise_page,
.setup = x86_pv_setup,
+ .populate_pfns = x86_pv_populate_pfns,
.process_record = x86_pv_process_record,
.static_data_complete = x86_static_data_complete,
.stream_complete = x86_pv_stream_complete,
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