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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v6 5/5] tools/libxc: make use of domain context SHARED_INFO record...
... in the save/restore code.
This patch replaces direct mapping of the shared_info_frame (retrieved
using XEN_DOMCTL_getdomaininfo) with save/load of the domain context
SHARED_INFO record.
No modifications are made to the definition of the migration stream at
this point. Subsequent patches will define a record in the libxc domain
image format for passing domain context and convert the save/restore code
to use that.
Signed-off-by: Paul Durrant <pdurrant@xxxxxxxxxx>
---
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Wei Liu <wl@xxxxxxx>
NOTE: Ian requested ack from Andrew
v5:
- Added BUILD_BUG_ON() in write_shared_info() to ensure copied data is not
bigger than the record buffer
v4:
- write_shared_info() now needs to allocate the record data since the
shared info buffer is smaller than PAGE_SIZE
v3:
- Moved basic get/set domain context functions to common code
v2:
- Re-based (now making use of DOMAIN_SAVE_FLAG_IGNORE)
---
tools/libxc/xc_sr_common.c | 67 +++++++++++++++++++++++++++
tools/libxc/xc_sr_common.h | 11 ++++-
tools/libxc/xc_sr_common_x86_pv.c | 74 ++++++++++++++++++++++++++++++
tools/libxc/xc_sr_common_x86_pv.h | 3 ++
tools/libxc/xc_sr_restore_x86_pv.c | 26 ++++-------
tools/libxc/xc_sr_save_x86_pv.c | 44 ++++++++----------
tools/libxc/xg_save_restore.h | 1 +
7 files changed, 182 insertions(+), 44 deletions(-)
diff --git a/tools/libxc/xc_sr_common.c b/tools/libxc/xc_sr_common.c
index dd9a11b4b5..1acb3765aa 100644
--- a/tools/libxc/xc_sr_common.c
+++ b/tools/libxc/xc_sr_common.c
@@ -138,6 +138,73 @@ int read_record(struct xc_sr_context *ctx, int fd, struct
xc_sr_record *rec)
return 0;
};
+int get_domain_context(struct xc_sr_context *ctx)
+{
+ xc_interface *xch = ctx->xch;
+ size_t len = 0;
+ int rc;
+
+ if ( ctx->domain_context.buffer )
+ {
+ ERROR("Domain context already present");
+ return -1;
+ }
+
+ rc = xc_domain_getcontext(xch, ctx->domid, NULL, &len);
+ if ( rc < 0 )
+ {
+ PERROR("Unable to get size of domain context");
+ return -1;
+ }
+
+ ctx->domain_context.buffer = malloc(len);
+ if ( !ctx->domain_context.buffer )
+ {
+ PERROR("Unable to allocate memory for domain context");
+ return -1;
+ }
+
+ rc = xc_domain_getcontext(xch, ctx->domid, ctx->domain_context.buffer,
+ &len);
+ if ( rc < 0 )
+ {
+ PERROR("Unable to get domain context");
+ return -1;
+ }
+
+ ctx->domain_context.len = len;
+
+ return 0;
+}
+
+int set_domain_context(struct xc_sr_context *ctx)
+{
+ xc_interface *xch = ctx->xch;
+ int rc;
+
+ if ( !ctx->domain_context.buffer )
+ {
+ ERROR("Domain context not present");
+ return -1;
+ }
+
+ rc = xc_domain_setcontext(xch, ctx->domid, ctx->domain_context.buffer,
+ ctx->domain_context.len);
+
+ if ( rc < 0 )
+ {
+ PERROR("Unable to set domain context");
+ return -1;
+ }
+
+ return 0;
+}
+
+void common_cleanup(struct xc_sr_context *ctx)
+{
+ free(ctx->domain_context.buffer);
+}
+
static void __attribute__((unused)) build_assertions(void)
{
BUILD_BUG_ON(sizeof(struct xc_sr_ihdr) != 24);
diff --git a/tools/libxc/xc_sr_common.h b/tools/libxc/xc_sr_common.h
index 5dd51ccb15..0d61978b08 100644
--- a/tools/libxc/xc_sr_common.h
+++ b/tools/libxc/xc_sr_common.h
@@ -208,6 +208,11 @@ struct xc_sr_context
xc_dominfo_t dominfo;
+ struct {
+ void *buffer;
+ unsigned int len;
+ } domain_context;
+
union /* Common save or restore data. */
{
struct /* Save data. */
@@ -314,7 +319,7 @@ struct xc_sr_context
/* The guest pfns containing the p2m leaves */
xen_pfn_t *p2m_pfns;
- /* Read-only mapping of guests shared info page */
+ /* Pointer to shared_info (located in context buffer) */
shared_info_any_t *shinfo;
/* p2m generation count for verifying validity of local p2m. */
@@ -425,6 +430,10 @@ int read_record(struct xc_sr_context *ctx, int fd, struct
xc_sr_record *rec);
int populate_pfns(struct xc_sr_context *ctx, unsigned int count,
const xen_pfn_t *original_pfns, const uint32_t *types);
+int get_domain_context(struct xc_sr_context *ctx);
+int set_domain_context(struct xc_sr_context *ctx);
+void common_cleanup(struct xc_sr_context *ctx);
+
#endif
/*
* Local variables:
diff --git a/tools/libxc/xc_sr_common_x86_pv.c
b/tools/libxc/xc_sr_common_x86_pv.c
index d3d425cb82..69d9b142b8 100644
--- a/tools/libxc/xc_sr_common_x86_pv.c
+++ b/tools/libxc/xc_sr_common_x86_pv.c
@@ -182,6 +182,80 @@ int x86_pv_map_m2p(struct xc_sr_context *ctx)
return rc;
}
+int x86_pv_get_shinfo(struct xc_sr_context *ctx)
+{
+ xc_interface *xch = ctx->xch;
+ unsigned int off = 0;
+ int rc;
+
+#define GET_PTR(_x) \
+ do { \
+ if ( ctx->domain_context.len - off < sizeof(*(_x)) ) \
+ { \
+ ERROR("Need another %lu bytes of context, only %u available\n", \
+ sizeof(*(_x)), ctx->domain_context.len - off); \
+ return -1; \
+ } \
+ (_x) = ctx->domain_context.buffer + off; \
+ } while (false);
+
+ rc = get_domain_context(ctx);
+ if ( rc )
+ return rc;
+
+ for ( ; ; )
+ {
+ struct domain_save_descriptor *desc;
+
+ GET_PTR(desc);
+
+ off += sizeof(*desc);
+
+ switch (desc->typecode)
+ {
+ case DOMAIN_SAVE_CODE(SHARED_INFO):
+ {
+ DOMAIN_SAVE_TYPE(SHARED_INFO) *s;
+
+ GET_PTR(s);
+
+ ctx->x86.pv.shinfo = (shared_info_any_t *)s->buffer;
+ break;
+ }
+ default:
+ break;
+ }
+
+ if ( desc->typecode == DOMAIN_SAVE_CODE(END) )
+ break;
+
+ off += desc->length;
+ }
+
+ if ( !ctx->x86.pv.shinfo )
+ {
+ ERROR("Failed to get SHARED_INFO\n");
+ return -1;
+ }
+
+ return 0;
+
+#undef GET_PTR
+}
+
+int x86_pv_set_shinfo(struct xc_sr_context *ctx)
+{
+ xc_interface *xch = ctx->xch;
+
+ if ( !ctx->x86.pv.shinfo )
+ {
+ ERROR("SHARED_INFO buffer not present\n");
+ return -1;
+ }
+
+ return set_domain_context(ctx);
+}
+
/*
* Local variables:
* mode: C
diff --git a/tools/libxc/xc_sr_common_x86_pv.h
b/tools/libxc/xc_sr_common_x86_pv.h
index 2ed03309af..01442f48fb 100644
--- a/tools/libxc/xc_sr_common_x86_pv.h
+++ b/tools/libxc/xc_sr_common_x86_pv.h
@@ -97,6 +97,9 @@ int x86_pv_domain_info(struct xc_sr_context *ctx);
*/
int x86_pv_map_m2p(struct xc_sr_context *ctx);
+int x86_pv_get_shinfo(struct xc_sr_context *ctx);
+int x86_pv_set_shinfo(struct xc_sr_context *ctx);
+
#endif
/*
* Local variables:
diff --git a/tools/libxc/xc_sr_restore_x86_pv.c
b/tools/libxc/xc_sr_restore_x86_pv.c
index 904ccc462a..21982a38ad 100644
--- a/tools/libxc/xc_sr_restore_x86_pv.c
+++ b/tools/libxc/xc_sr_restore_x86_pv.c
@@ -865,7 +865,7 @@ static int handle_shared_info(struct xc_sr_context *ctx,
xc_interface *xch = ctx->xch;
unsigned int i;
int rc = -1;
- shared_info_any_t *guest_shinfo = NULL;
+ shared_info_any_t *guest_shinfo;
const shared_info_any_t *old_shinfo = rec->data;
if ( !ctx->x86.pv.restore.seen_pv_info )
@@ -878,18 +878,14 @@ static int handle_shared_info(struct xc_sr_context *ctx,
{
ERROR("X86_PV_SHARED_INFO record wrong size: length %u"
", expected 4096", rec->length);
- goto err;
+ return -1;
}
- guest_shinfo = xc_map_foreign_range(
- xch, ctx->domid, PAGE_SIZE, PROT_READ | PROT_WRITE,
- ctx->dominfo.shared_info_frame);
- if ( !guest_shinfo )
- {
- PERROR("Failed to map Shared Info at mfn %#lx",
- ctx->dominfo.shared_info_frame);
- goto err;
- }
+ rc = x86_pv_get_shinfo(ctx);
+ if ( rc )
+ return rc;
+
+ guest_shinfo = ctx->x86.pv.shinfo;
MEMCPY_FIELD(guest_shinfo, old_shinfo, vcpu_info, ctx->x86.pv.width);
MEMCPY_FIELD(guest_shinfo, old_shinfo, arch, ctx->x86.pv.width);
@@ -904,13 +900,7 @@ static int handle_shared_info(struct xc_sr_context *ctx,
MEMSET_ARRAY_FIELD(guest_shinfo, evtchn_mask, 0xff, ctx->x86.pv.width);
- rc = 0;
-
- err:
- if ( guest_shinfo )
- munmap(guest_shinfo, PAGE_SIZE);
-
- return rc;
+ return x86_pv_set_shinfo(ctx);
}
/* restore_ops function. */
diff --git a/tools/libxc/xc_sr_save_x86_pv.c b/tools/libxc/xc_sr_save_x86_pv.c
index f3ccf5bb4b..fdd172b639 100644
--- a/tools/libxc/xc_sr_save_x86_pv.c
+++ b/tools/libxc/xc_sr_save_x86_pv.c
@@ -9,25 +9,6 @@ static inline bool is_canonical_address(xen_vaddr_t vaddr)
return ((int64_t)vaddr >> 47) == ((int64_t)vaddr >> 63);
}
-/*
- * Maps the guests shared info page.
- */
-static int map_shinfo(struct xc_sr_context *ctx)
-{
- xc_interface *xch = ctx->xch;
-
- ctx->x86.pv.shinfo = xc_map_foreign_range(
- xch, ctx->domid, PAGE_SIZE, PROT_READ, ctx->dominfo.shared_info_frame);
- if ( !ctx->x86.pv.shinfo )
- {
- PERROR("Failed to map shared info frame at mfn %#lx",
- ctx->dominfo.shared_info_frame);
- return -1;
- }
-
- return 0;
-}
-
/*
* Copy a list of mfns from a guest, accounting for differences between guest
* and toolstack width. Can fail if truncation would occur.
@@ -854,13 +835,27 @@ static int write_x86_pv_p2m_frames(struct xc_sr_context
*ctx)
*/
static int write_shared_info(struct xc_sr_context *ctx)
{
+ xc_interface *xch = ctx->xch;
struct xc_sr_record rec = {
.type = REC_TYPE_SHARED_INFO,
.length = PAGE_SIZE,
- .data = ctx->x86.pv.shinfo,
};
+ int rc;
- return write_record(ctx, &rec);
+ if ( !(rec.data = calloc(1, PAGE_SIZE)) )
+ {
+ ERROR("Cannot allocate buffer for SHARED_INFO data");
+ return -1;
+ }
+
+ BUILD_BUG_ON(sizeof(*ctx->x86.pv.shinfo) > PAGE_SIZE);
+ memcpy(rec.data, ctx->x86.pv.shinfo, sizeof(*ctx->x86.pv.shinfo));
+
+ rc = write_record(ctx, &rec);
+
+ free(rec.data);
+
+ return rc;
}
/*
@@ -1041,7 +1036,7 @@ static int x86_pv_setup(struct xc_sr_context *ctx)
if ( rc )
return rc;
- rc = map_shinfo(ctx);
+ rc = x86_pv_get_shinfo(ctx);
if ( rc )
return rc;
@@ -1112,12 +1107,11 @@ static int x86_pv_cleanup(struct xc_sr_context *ctx)
if ( ctx->x86.pv.p2m )
munmap(ctx->x86.pv.p2m, ctx->x86.pv.p2m_frames * PAGE_SIZE);
- if ( ctx->x86.pv.shinfo )
- munmap(ctx->x86.pv.shinfo, PAGE_SIZE);
-
if ( ctx->x86.pv.m2p )
munmap(ctx->x86.pv.m2p, ctx->x86.pv.nr_m2p_frames * PAGE_SIZE);
+ common_cleanup(ctx);
+
return 0;
}
diff --git a/tools/libxc/xg_save_restore.h b/tools/libxc/xg_save_restore.h
index 303081df0d..296b523963 100644
--- a/tools/libxc/xg_save_restore.h
+++ b/tools/libxc/xg_save_restore.h
@@ -19,6 +19,7 @@
#include <xen/foreign/x86_32.h>
#include <xen/foreign/x86_64.h>
+#include <xen/save.h>
/*
** We process save/restore/migrate in batches of pages; the below
--
2.20.1
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