Re: [libvirt] [PATCH 10/15] qemu: Store save cookie in save images and snapshots

The following patches will add an actual content in the cookie and use the data when restoring a domain. Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com&gt; --- docs/formatsnapshot.html.in | 6 +++ docs/schemas/domainsnapshot.rng | 7 ++++ src/qemu/qemu_driver.c | 90 ++++++++++++++++++++++++++++++++++++----- 3 files changed, 93 insertions(+), 10 deletions(-) diff --git a/docs/formatsnapshot.html.in b/docs/formatsnapshot.html.in index c3ab516fa..5e8e21c8a 100644 --- a/docs/formatsnapshot.html.in +++ b/docs/formatsnapshot.html.in @@ -235,6 +235,12 @@ at the time of the snapshot (<span class="since">since 0.9.5</span>). Readonly. </dd> + <dt><code>cookie</code></dt> + <dd>Save image cookie containing additional data libvirt may need to + properly restore a domain from an active snapshot when such data + cannot be stored directly in the <code>domain</code> to maintain + compatibility with older libvirt or hypervisor. Readonly. + </dd> </dl> <h2><a name="example">Examples</a></h2> diff --git a/docs/schemas/domainsnapshot.rng b/docs/schemas/domainsnapshot.rng index 4ab1b828f..268088709 100644 --- a/docs/schemas/domainsnapshot.rng +++ b/docs/schemas/domainsnapshot.rng @@ -90,6 +90,13 @@ </element> </element> </optional> + <optional> + <element name='cookie'> + <zeroOrMore> + <ref name='customElement'/> + </zeroOrMore> + </element> + </optional> </interleave> </element> </define> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 96077df78..10df56e61 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -2808,7 +2808,8 @@ struct _virQEMUSaveHeader { uint32_t data_len; uint32_t was_running; uint32_t compressed; - uint32_t unused[15]; + uint32_t cookie;

+ uint32_t unused[14]; }; typedef struct _virQEMUSaveData virQEMUSaveData; @@ -2816,6 +2817,7 @@ typedef virQEMUSaveData *virQEMUSaveDataPtr; struct _virQEMUSaveData { virQEMUSaveHeader header; char *xml; + char *cookie; }; @@ -2826,6 +2828,7 @@ bswap_header(virQEMUSaveHeaderPtr hdr) hdr->data_len = bswap_32(hdr->data_len); hdr->was_running = bswap_32(hdr->was_running); hdr->compressed = bswap_32(hdr->compressed); + hdr->cookie = bswap_32(hdr->cookie); } @@ -2836,6 +2839,7 @@ virQEMUSaveDataFree(virQEMUSaveDataPtr data) return; VIR_FREE(data->xml); + VIR_FREE(data->cookie); VIR_FREE(data); } @@ -2845,8 +2849,10 @@ virQEMUSaveDataFree(virQEMUSaveDataPtr data) */ static virQEMUSaveDataPtr virQEMUSaveDataNew(char *domXML, + qemuDomainSaveCookiePtr cookie,

bool running, - int compressed) + int compressed, + virDomainXMLOptionPtr xmlopt) { virQEMUSaveDataPtr data = NULL; virQEMUSaveHeaderPtr header; @@ -2856,6 +2862,11 @@ virQEMUSaveDataNew(char *domXML, VIR_STEAL_PTR(data->xml, domXML); + if (cookie && + !(data->cookie = virSaveCookieFormat((virObjectPtr) cookie, + virDomainXMLOptionGetSaveCookie(xmlopt))))

+ goto error; + header = &data->header; memcpy(header->magic, QEMU_SAVE_PARTIAL, sizeof(header->magic)); header->version = QEMU_SAVE_VERSION; @@ -2863,6 +2874,10 @@ virQEMUSaveDataNew(char *domXML, header->compressed = compressed; return data; + + error: + virQEMUSaveDataFree(data); + return NULL; } @@ -2882,9 +2897,15 @@ virQEMUSaveDataWrite(virQEMUSaveDataPtr data, { virQEMUSaveHeaderPtr header = &data->header; size_t len; + size_t xml_len; + size_t cookie_len = 0; int ret = -1; - len = strlen(data->xml) + 1; + xml_len = strlen(data->xml) + 1; + if (data->cookie) + cookie_len = strlen(data->cookie) + 1; + + len = xml_len + cookie_len; if (header->data_len > 0) { if (len > header->data_len) { @@ -2893,12 +2914,15 @@ virQEMUSaveDataWrite(virQEMUSaveDataPtr data, goto cleanup; } - if (VIR_EXPAND_N(data->xml, len, header->data_len - len) < 0) + if (VIR_EXPAND_N(data->xml, xml_len, header->data_len - len) < 0)

goto cleanup; } else { header->data_len = len; } + if (data->cookie) + header->cookie = xml_len;

+ if (safewrite(fd, header, sizeof(*header)) != sizeof(*header)) { virReportSystemError(errno, _("failed to write header to domain save file '%s'"), @@ -2906,13 +2930,21 @@ virQEMUSaveDataWrite(virQEMUSaveDataPtr data, goto cleanup; } - if (safewrite(fd, data->xml, header->data_len) != header->data_len) { + if (safewrite(fd, data->xml, xml_len) != xml_len) { virReportSystemError(errno, _("failed to write domain xml to '%s'"), path); goto cleanup;

} + if (data->cookie && + safewrite(fd, data->cookie, cookie_len) != cookie_len) { + virReportSystemError(errno, + _("failed to write cookie to '%s'"), + path); + goto cleanup; + } +