diff mbox series

[v10,10/11] tools/libs/guest: add code to restore a v4 libxc stream

Message ID 20201008185735.29875-11-paul@xen.org (mailing list archive)
State New, archived
Headers show
Series domain context infrastructure | expand

Commit Message

Paul Durrant Oct. 8, 2020, 6:57 p.m. UTC 
From: Paul Durrant <pdurrant@amazon.com>

This patch adds the necessary code to accept a v4 stream, and to recognise and
restore a REC_TYPE_DOMAIN_CONTEXT record.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
---
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Ian Jackson <iwj@xenproject.org>
Cc: Wei Liu <wl@xen.org>

v10:
 - New in v10
 - Derived from patch #8 of the v9 series
 - Fix memory leak
---
 tools/libs/guest/xg_sr_common.c          |  1 +
 tools/libs/guest/xg_sr_common.h          |  3 +++
 tools/libs/guest/xg_sr_restore.c         | 24 ++++++++++++++++++++++--
 tools/libs/guest/xg_sr_restore_x86_hvm.c |  9 +++++++++
 tools/libs/guest/xg_sr_restore_x86_pv.c  |  9 +++++++++
 5 files changed, 44 insertions(+), 2 deletions(-)

Comments

Andrew Cooper Jan. 25, 2021, 8:04 p.m. UTC | #1 
On 08/10/2020 19:57, Paul Durrant wrote:
> From: Paul Durrant <pdurrant@amazon.com>
>
> This patch adds the necessary code to accept a v4 stream, and to recognise and
> restore a REC_TYPE_DOMAIN_CONTEXT record.
>
> Signed-off-by: Paul Durrant <pdurrant@amazon.com>

Somewhere within this needs to be logic to reject the forbidden records
in relevant stream versions.

> diff --git a/tools/libs/guest/xg_sr_restore_x86_hvm.c b/tools/libs/guest/xg_sr_restore_x86_hvm.c
> index d6ea6f3012..6bb164b9f0 100644
> --- a/tools/libs/guest/xg_sr_restore_x86_hvm.c
> +++ b/tools/libs/guest/xg_sr_restore_x86_hvm.c
> @@ -225,6 +225,15 @@ static int x86_hvm_stream_complete(struct xc_sr_context *ctx)
>          return rc;
>      }
>  
> +    rc = xc_domain_set_context(xch, ctx->domid,
> +                               ctx->restore.dom_ctx.ptr,
> +                               ctx->restore.dom_ctx.size);
> +    if ( rc )
> +    {
> +        PERROR("Unable to restore Domain context");
> +        return rc;
> +    }

This doesn't match where you specified the record to live in the stream,
and in particular is reordered WRT HVMCONTEXT restoration.

Also, it appears to be in the middle of a block of code which needs to
become `if ( guest-aware )`.

> +
>      rc = xc_dom_gnttab_seed(xch, ctx->domid, true,
>                              ctx->restore.console_gfn,
>                              ctx->restore.xenstore_gfn,
> diff --git a/tools/libs/guest/xg_sr_restore_x86_pv.c b/tools/libs/guest/xg_sr_restore_x86_pv.c
> index dc50b0f5a8..2dafad7b83 100644
> --- a/tools/libs/guest/xg_sr_restore_x86_pv.c
> +++ b/tools/libs/guest/xg_sr_restore_x86_pv.c
> @@ -1134,6 +1134,15 @@ static int x86_pv_stream_complete(struct xc_sr_context *ctx)
>      if ( rc )
>          return rc;
>  
> +    rc = xc_domain_set_context(xch, ctx->domid,
> +                               ctx->restore.dom_ctx.ptr,
> +                               ctx->restore.dom_ctx.size);
> +    if ( rc )
> +    {
> +        PERROR("Unable to restore Domain context");
> +        return rc;
> +    }

Similar comment as HVM for the reordering.  PV guests in particular tend
to be far more sensitive to the restoration order.

~Andrew
diff mbox series

Patch

diff --git a/tools/libs/guest/xg_sr_common.c b/tools/libs/guest/xg_sr_common.c
index 17567ab133..f813320202 100644
--- a/tools/libs/guest/xg_sr_common.c
+++ b/tools/libs/guest/xg_sr_common.c
@@ -39,6 +39,7 @@  static const char *const mandatory_rec_types[] =
     [REC_TYPE_STATIC_DATA_END]              = "Static data end",
     [REC_TYPE_X86_CPUID_POLICY]             = "x86 CPUID policy",
     [REC_TYPE_X86_MSR_POLICY]               = "x86 MSR policy",
+    [REC_TYPE_DOMAIN_CONTEXT]               = "Domain context",
 };
 
 const char *rec_type_to_str(uint32_t type)
diff --git a/tools/libs/guest/xg_sr_common.h b/tools/libs/guest/xg_sr_common.h
index cc3ad1c394..ba9e5b0a84 100644
--- a/tools/libs/guest/xg_sr_common.h
+++ b/tools/libs/guest/xg_sr_common.h
@@ -297,6 +297,9 @@  struct xc_sr_context
 
             /* Sender has invoked verify mode on the stream. */
             bool verify;
+
+            /* Domain context blob. */
+            struct xc_sr_blob dom_ctx;
         } restore;
     };
 
diff --git a/tools/libs/guest/xg_sr_restore.c b/tools/libs/guest/xg_sr_restore.c
index b57a787519..9d2bbdfaa3 100644
--- a/tools/libs/guest/xg_sr_restore.c
+++ b/tools/libs/guest/xg_sr_restore.c
@@ -35,9 +35,9 @@  static int read_headers(struct xc_sr_context *ctx)
         return -1;
     }
 
-    if ( ihdr.version < 2 || ihdr.version > 3 )
+    if ( ihdr.version < 2 || ihdr.version > 4 )
     {
-        ERROR("Invalid Version: Expected 2 <= ver <= 3, Got %d",
+        ERROR("Invalid Version: Expected 2 <= ver <= 4, Got %d",
               ihdr.version);
         return -1;
     }
@@ -682,6 +682,21 @@  int handle_static_data_end(struct xc_sr_context *ctx)
     return rc;
 }
 
+/*
+ * Process a DOMAIN_CONTEXT record from the stream.
+ */
+static int handle_domain_context(struct xc_sr_context *ctx,
+                                 struct xc_sr_record *rec)
+{
+    xc_interface *xch = ctx->xch;
+    int rc = update_blob(&ctx->restore.dom_ctx, rec->data, rec->length);
+
+    if ( rc )
+        ERROR("Unable to allocate %u bytes for domain context", rec->length);
+
+    return rc;
+}
+
 static int process_record(struct xc_sr_context *ctx, struct xc_sr_record *rec)
 {
     xc_interface *xch = ctx->xch;
@@ -709,6 +724,10 @@  static int process_record(struct xc_sr_context *ctx, struct xc_sr_record *rec)
         rc = handle_static_data_end(ctx);
         break;
 
+    case REC_TYPE_DOMAIN_CONTEXT:
+        rc = handle_domain_context(ctx, rec);
+        break;
+
     default:
         rc = ctx->restore.ops.process_record(ctx, rec);
         break;
@@ -784,6 +803,7 @@  static void cleanup(struct xc_sr_context *ctx)
 
     free(ctx->restore.buffered_records);
     free(ctx->restore.populated_pfns);
+    free(ctx->restore.dom_ctx.ptr);
 
     if ( ctx->restore.ops.cleanup(ctx) )
         PERROR("Failed to clean up");
diff --git a/tools/libs/guest/xg_sr_restore_x86_hvm.c b/tools/libs/guest/xg_sr_restore_x86_hvm.c
index d6ea6f3012..6bb164b9f0 100644
--- a/tools/libs/guest/xg_sr_restore_x86_hvm.c
+++ b/tools/libs/guest/xg_sr_restore_x86_hvm.c
@@ -225,6 +225,15 @@  static int x86_hvm_stream_complete(struct xc_sr_context *ctx)
         return rc;
     }
 
+    rc = xc_domain_set_context(xch, ctx->domid,
+                               ctx->restore.dom_ctx.ptr,
+                               ctx->restore.dom_ctx.size);
+    if ( rc )
+    {
+        PERROR("Unable to restore Domain context");
+        return rc;
+    }
+
     rc = xc_dom_gnttab_seed(xch, ctx->domid, true,
                             ctx->restore.console_gfn,
                             ctx->restore.xenstore_gfn,
diff --git a/tools/libs/guest/xg_sr_restore_x86_pv.c b/tools/libs/guest/xg_sr_restore_x86_pv.c
index dc50b0f5a8..2dafad7b83 100644
--- a/tools/libs/guest/xg_sr_restore_x86_pv.c
+++ b/tools/libs/guest/xg_sr_restore_x86_pv.c
@@ -1134,6 +1134,15 @@  static int x86_pv_stream_complete(struct xc_sr_context *ctx)
     if ( rc )
         return rc;
 
+    rc = xc_domain_set_context(xch, ctx->domid,
+                               ctx->restore.dom_ctx.ptr,
+                               ctx->restore.dom_ctx.size);
+    if ( rc )
+    {
+        PERROR("Unable to restore Domain context");
+        return rc;
+    }
+
     rc = xc_dom_gnttab_seed(xch, ctx->domid, false,
                             ctx->restore.console_gfn,
                             ctx->restore.xenstore_gfn,