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[PATCH v7 5/9] docs / tools: specific migration v4 to include DOMAIN_CONTEXT

From: Paul Durrant <paul@xxxxxxx>

Date: Tue, 18 Aug 2020 11:30:28 +0100

Cc: Paul Durrant <pdurrant@xxxxxxxxxx>, Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, George Dunlap <george.dunlap@xxxxxxxxxx>, Ian Jackson <ian.jackson@xxxxxxxxxxxxx>, Jan Beulich <jbeulich@xxxxxxxx>, Julien Grall <julien@xxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Wei Liu <wl@xxxxxxx>, Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>

Delivery-date: Tue, 18 Aug 2020 10:30:46 +0000

List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

From: Paul Durrant <pdurrant@xxxxxxxxxx> A new 'domain context' framework was recently introduced to facilitate transfer of state for both PV and HVM guests. Hence this patch mandates the presence of a new DOMAIN_CONTEXT record in version 4 of the libxc migration stream. This record will incorprate the content of the domain's 'shared_info' page and the TSC informaiton so the SHARED_INFO and TSC_INFO records are deprecated. It is intended that, in future, this record will contain state currently present in the HVM_CONTEXT record. However, for compatibility with earlier migration streams, the version 4 stream format continues to specify an HVM_CONTEXT record and XEN_DOMCTL_sethvmcontext will continue to accept all content of that record that may be present in a version 3 stream. Signed-off-by: Paul Durrant <pdurrant@xxxxxxxxxx> --- Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Cc: George Dunlap <george.dunlap@xxxxxxxxxx> Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx> Cc: Jan Beulich <jbeulich@xxxxxxxx> Cc: Julien Grall <julien@xxxxxxx> Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx> Cc: Wei Liu <wl@xxxxxxx> Cc: "Marek Marczykowski-Górecki" <marmarek@xxxxxxxxxxxxxxxxxxxxxx> v7: - New in v7 --- docs/specs/libxc-migration-stream.pandoc | 62 ++++++++++++++++++------ tools/libxc/xc_sr_common.c | 1 + tools/libxc/xc_sr_stream_format.h | 1 + tools/python/xen/migration/libxc.py | 2 + 4 files changed, 52 insertions(+), 14 deletions(-) diff --git a/docs/specs/libxc-migration-stream.pandoc b/docs/specs/libxc-migration-stream.pandoc index 8aeab3b11b..989f2a0cb6 100644 --- a/docs/specs/libxc-migration-stream.pandoc +++ b/docs/specs/libxc-migration-stream.pandoc @@ -3,7 +3,7 @@ Andrew Cooper <<andrew.cooper3@xxxxxxxxxx>> Wen Congyang <<wency@xxxxxxxxxxxxxx>> Yang Hongyang <<hongyang.yang@xxxxxxxxxxxx>> -% Revision 3 +% Revision 4 Introduction ============ @@ -127,7 +127,7 @@ marker 0xFFFFFFFFFFFFFFFF. id 0x58454E46 ("XENF" in ASCII). -version 0x00000003. The version of this specification. +version 0x00000004. The version of this specification. options bit 0: Endianness. 0 = little-endian, 1 = big-endian. @@ -209,9 +209,9 @@ type 0x00000000: END 0x00000006: X86_PV_VCPU_XSAVE - 0x00000007: SHARED_INFO + 0x00000007: SHARED_INFO (deprecated) - 0x00000008: X86_TSC_INFO + 0x00000008: X86_TSC_INFO (deprecated) 0x00000009: HVM_CONTEXT @@ -233,7 +233,9 @@ type 0x00000000: END 0x00000012: X86_MSR_POLICY - 0x00000013 - 0x7FFFFFFF: Reserved for future _mandatory_ + 0x00000013: DOMAIN_CONTEXT + + 0x00000014 - 0x7FFFFFFF: Reserved for future _mandatory_ records. 0x80000000 - 0xFFFFFFFF: Reserved for future _optional_ @@ -442,10 +444,11 @@ X86_PV_VCPU_MSRS XEN_DOMCTL_{get,set}\_vcpu_msrs \clearpage -SHARED_INFO ------------ +SHARED_INFO (deprecated) +------------------------ -The content of the Shared Info page. +The content of the Shared Info page. This is incorporated into the +DOMAIN_CONTEXT record as of specification version 4. 0 1 2 3 4 5 6 7 octet +-------------------------------------------------+ @@ -462,11 +465,12 @@ shared_info Contents of the shared info page. This record \clearpage -X86_TSC_INFO ------------- +X86_TSC_INFO (deprecated) +------------------------- Domain TSC information, as accessed by the -XEN_DOMCTL_{get,set}tscinfo hypercall sub-ops. +XEN_DOMCTL_{get,set}tscinfo hypercall sub-ops. This is incorporated into the +DOMAIN_CONTEXT record as of specification version 4. 0 1 2 3 4 5 6 7 octet +------------------------+------------------------+ @@ -680,6 +684,25 @@ MSR_policy Array of xen_msr_entry_t[]'s \clearpage +DOMAIN_CONTEXT +-------------- + +Domain context, as accessed by the +XEN_DOMCTL_{get,set}domaincontext hypercall sub-ops. + + 0 1 2 3 4 5 6 7 octet + +-------------------------------------------------+ + | dom_ctx | + ... + +-------------------------------------------------+ + +-------------------------------------------------------------------- +Field Description +----------- --------------------------------------------------- +dom_ctx The Domain Context blob from Xen. +-------------------------------------------------------------------- + +\clearpage Layout ====== @@ -706,8 +729,7 @@ A typical save record for an x86 PV guest image would look like: * STATIC_DATA_END * X86_PV_P2M_FRAMES record * Many PAGE_DATA records -* X86_TSC_INFO -* SHARED_INFO record +* DOMAIN_CONTEXT * VCPU context records for each online VCPU * X86_PV_VCPU_BASIC record * X86_PV_VCPU_EXTENDED record @@ -735,7 +757,7 @@ A typical save record for an x86 HVM guest image would look like: * X86_{CPUID,MSR}_POLICY * STATIC_DATA_END * Many PAGE_DATA records -* X86_TSC_INFO +* DOMAIN_CONTEXT * HVM_PARAMS * HVM_CONTEXT * END record @@ -746,6 +768,18 @@ the validity of architectural state in the context. Compatibility with older versions ================================= +v4 compat with v3 +----------------- + +A v4 stream is compatible with a v3 stream, but mandates the presence of a +DOMAIN_CONTEXT record. This incorporates context such as the content of +the domain's Shared Info page and the TSC information, hence the SHARED_INFO +and TSC_INFO records are deprecated. +It also supercedes HVM_CONTEXT and, over time, data that is currently part of +the HVM_CONTEXT blob will move to the DOMAIN_CONTEXT blob. Xen, however, will +continue to accept all defined HVM_CONTEXT records so a v4-compatible +receiver can still accept an unmodified v3 stream. + v3 compat with v2 ----------------- diff --git a/tools/libxc/xc_sr_common.c b/tools/libxc/xc_sr_common.c index 7c54b03414..2fdb6e6634 100644 --- a/tools/libxc/xc_sr_common.c +++ b/tools/libxc/xc_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/libxc/xc_sr_stream_format.h b/tools/libxc/xc_sr_stream_format.h index 8a0da26f75..bc538bc192 100644 --- a/tools/libxc/xc_sr_stream_format.h +++ b/tools/libxc/xc_sr_stream_format.h @@ -76,6 +76,7 @@ struct xc_sr_rhdr #define REC_TYPE_STATIC_DATA_END 0x00000010U #define REC_TYPE_X86_CPUID_POLICY 0x00000011U #define REC_TYPE_X86_MSR_POLICY 0x00000012U +#define REC_TYPE_DOMAIN_CONTEXT 0x00000013U #define REC_TYPE_OPTIONAL 0x80000000U diff --git a/tools/python/xen/migration/libxc.py b/tools/python/xen/migration/libxc.py index 9881f5ced4..08ac81344f 100644 --- a/tools/python/xen/migration/libxc.py +++ b/tools/python/xen/migration/libxc.py @@ -59,6 +59,7 @@ REC_TYPE_checkpoint_dirty_pfn_list = 0x0000000f REC_TYPE_static_data_end = 0x00000010 REC_TYPE_x86_cpuid_policy = 0x00000011 REC_TYPE_x86_msr_policy = 0x00000012 +REC_TYPE_domain_context = 0x00000013 rec_type_to_str = { REC_TYPE_end : "End", @@ -80,6 +81,7 @@ rec_type_to_str = { 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", } # page_data -- 2.20.1

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