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[Xen-devel] [PATCH v6 02/16] libxc/save: Adjust stream-position callbacks for checkpointed streams

From: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> There are some records which should only be sent once in the stream, and not repeated for each checkpoint. {start,end}_of_stream() become per-checkpoint, and a new start_of_stream() is introduced. There is no resulting change record order, but the X86_PV_INFO record is identified as once per stream. Currently the X86_PV_P2M_FRAMES record is as well, but this is because of an implementation bug and can move back to being on an as-needed basis when fixed. In addition, a few minor adjustments of comments and layout. Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CC: Ian Campbell <Ian.Campbell@xxxxxxxxxx> CC: Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx> CC: Wei Liu <wei.liu2@xxxxxxxxxx> CC: Yang Hongyang <yanghy@xxxxxxxxxxxxxx> --- tools/libxc/xc_sr_common.h | 21 +++++++++++++-------- tools/libxc/xc_sr_save.c | 10 +++++++--- tools/libxc/xc_sr_save_x86_hvm.c | 23 +++++++++++++++-------- tools/libxc/xc_sr_save_x86_pv.c | 29 +++++++++++++++++++---------- 4 files changed, 54 insertions(+), 29 deletions(-) diff --git a/tools/libxc/xc_sr_common.h b/tools/libxc/xc_sr_common.h index ef42412..c4fe92c 100644 --- a/tools/libxc/xc_sr_common.h +++ b/tools/libxc/xc_sr_common.h @@ -61,19 +61,24 @@ struct xc_sr_save_ops int (*setup)(struct xc_sr_context *ctx); /** - * Write records which need to be at the start of the stream. This is - * called after the Image and Domain headers are written. (Any records - * which need to be ahead of the memory.) + * Send records which need to be at the start of the stream. This is + * called once, after the Image and Domain headers are written. */ int (*start_of_stream)(struct xc_sr_context *ctx); /** - * Write records which need to be at the end of the stream, following the - * complete memory contents. The caller shall handle writing the END - * record into the stream. (Any records which need to be after the memory - * is complete.) + * Send records which need to be at the start of a checkpoint. This is + * called once, or once per checkpoint in a checkpointed stream, and is + * ahead of memory data. */ - int (*end_of_stream)(struct xc_sr_context *ctx); + int (*start_of_checkpoint)(struct xc_sr_context *ctx); + + /** + * Send records which need to be at the end of the checkpoint. This is + * called once, or once per checkpoint in a checkpointed stream, and is + * after the memory data. + */ + int (*end_of_checkpoint)(struct xc_sr_context *ctx); /** * Clean up the local environment. Will be called exactly once, either diff --git a/tools/libxc/xc_sr_save.c b/tools/libxc/xc_sr_save.c index 83f0591..66fcd3e 100644 --- a/tools/libxc/xc_sr_save.c +++ b/tools/libxc/xc_sr_save.c @@ -662,6 +662,10 @@ static int save(struct xc_sr_context *ctx, uint16_t guest_type) if ( rc ) goto err; + rc = ctx->save.ops.start_of_checkpoint(ctx); + if ( rc ) + goto err; + if ( ctx->save.live ) rc = send_domain_memory_live(ctx); else @@ -678,12 +682,12 @@ static int save(struct xc_sr_context *ctx, uint16_t guest_type) goto err; } - xc_report_progress_single(xch, "End of stream"); - - rc = ctx->save.ops.end_of_stream(ctx); + rc = ctx->save.ops.end_of_checkpoint(ctx); if ( rc ) goto err; + xc_report_progress_single(xch, "End of stream"); + rc = write_end_record(ctx); if ( rc ) goto err; diff --git a/tools/libxc/xc_sr_save_x86_hvm.c b/tools/libxc/xc_sr_save_x86_hvm.c index 58efdb9..f4604db 100644 --- a/tools/libxc/xc_sr_save_x86_hvm.c +++ b/tools/libxc/xc_sr_save_x86_hvm.c @@ -184,7 +184,13 @@ static int x86_hvm_start_of_stream(struct xc_sr_context *ctx) return 0; } -static int x86_hvm_end_of_stream(struct xc_sr_context *ctx) +static int x86_hvm_start_of_checkpoint(struct xc_sr_context *ctx) +{ + /* no-op */ + return 0; +} + +static int x86_hvm_end_of_checkpoint(struct xc_sr_context *ctx) { int rc; @@ -209,7 +215,7 @@ static int x86_hvm_end_of_stream(struct xc_sr_context *ctx) if ( rc ) return rc; - return rc; + return 0; } static int x86_hvm_cleanup(struct xc_sr_context *ctx) @@ -230,12 +236,13 @@ static int x86_hvm_cleanup(struct xc_sr_context *ctx) struct xc_sr_save_ops save_ops_x86_hvm = { - .pfn_to_gfn = x86_hvm_pfn_to_gfn, - .normalise_page = x86_hvm_normalise_page, - .setup = x86_hvm_setup, - .start_of_stream = x86_hvm_start_of_stream, - .end_of_stream = x86_hvm_end_of_stream, - .cleanup = x86_hvm_cleanup, + .pfn_to_gfn = x86_hvm_pfn_to_gfn, + .normalise_page = x86_hvm_normalise_page, + .setup = x86_hvm_setup, + .start_of_stream = x86_hvm_start_of_stream, + .start_of_checkpoint = x86_hvm_start_of_checkpoint, + .end_of_checkpoint = x86_hvm_end_of_checkpoint, + .cleanup = x86_hvm_cleanup, }; /* diff --git a/tools/libxc/xc_sr_save_x86_pv.c b/tools/libxc/xc_sr_save_x86_pv.c index a668221..f63f40b 100644 --- a/tools/libxc/xc_sr_save_x86_pv.c +++ b/tools/libxc/xc_sr_save_x86_pv.c @@ -816,6 +816,12 @@ static int x86_pv_start_of_stream(struct xc_sr_context *ctx) if ( rc ) return rc; + /* + * Ideally should be able to change during migration. Currently + * corruption will occur if the contents or location of the P2M changes + * during the live migration loop. If one is very lucky, the breakage + * will not be subtle. + */ rc = write_x86_pv_p2m_frames(ctx); if ( rc ) return rc; @@ -823,10 +829,12 @@ static int x86_pv_start_of_stream(struct xc_sr_context *ctx) return 0; } -/* - * save_ops function. Writes tail records information into the stream. - */ -static int x86_pv_end_of_stream(struct xc_sr_context *ctx) +static int x86_pv_start_of_checkpoint(struct xc_sr_context *ctx) +{ + return 0; +} + +static int x86_pv_end_of_checkpoint(struct xc_sr_context *ctx) { int rc; @@ -866,12 +874,13 @@ static int x86_pv_cleanup(struct xc_sr_context *ctx) struct xc_sr_save_ops save_ops_x86_pv = { - .pfn_to_gfn = x86_pv_pfn_to_gfn, - .normalise_page = x86_pv_normalise_page, - .setup = x86_pv_setup, - .start_of_stream = x86_pv_start_of_stream, - .end_of_stream = x86_pv_end_of_stream, - .cleanup = x86_pv_cleanup, + .pfn_to_gfn = x86_pv_pfn_to_gfn, + .normalise_page = x86_pv_normalise_page, + .setup = x86_pv_setup, + .start_of_stream = x86_pv_start_of_stream, + .start_of_checkpoint = x86_pv_start_of_checkpoint, + .end_of_checkpoint = x86_pv_end_of_checkpoint, + .cleanup = x86_pv_cleanup, }; /* -- 1.9.1 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel

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