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Re: [Qemu-devel] [RFC PATCH v2 15/16] Wire in BER visitors
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [RFC PATCH v2 15/16] Wire in BER visitors |
Date: |
Wed, 7 May 2014 13:02:26 +0300 |
On Wed, Apr 23, 2014 at 05:37:48PM +0100, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <address@hidden>
>
> BER output visitor to be selected with env
> BER input visitor recognized by file header
>
> Signed-off-by: Dr. David Alan Gilbert <address@hidden>
> ---
> include/migration/migration.h | 2 +
> savevm.c | 105
> +++++++++++++++++++++++++++++++-----------
> 2 files changed, 80 insertions(+), 27 deletions(-)
>
> diff --git a/include/migration/migration.h b/include/migration/migration.h
> index 8111125..5d500ec 100644
> --- a/include/migration/migration.h
> +++ b/include/migration/migration.h
> @@ -27,6 +27,8 @@
> #define QEMU_VM_FILE_VERSION_COMPAT 0x00000002
> #define QEMU_VM_FILE_VERSION 0x00000003
>
> +#define QEMU_VM_BER_FILE_MAGIC 0x7fcdc551
> +
Where does this come from? I presume this matches
something in BER format?
> #define QEMU_VM_EOF 0x00
> #define QEMU_VM_SECTION_START 0x01
> #define QEMU_VM_SECTION_PART 0x02
> diff --git a/savevm.c b/savevm.c
> index 515dd77..2bbbcdc 100644
> --- a/savevm.c
> +++ b/savevm.c
> @@ -24,6 +24,8 @@
>
> #include "config-host.h"
> #include "qemu-common.h"
> +#include "qapi/qemu-file-ber-output-visitor.h"
> +#include "qapi/qemu-file-ber-input-visitor.h"
> #include "qapi/qemu-file-binary-input-visitor.h"
> #include "qapi/qemu-file-binary-output-visitor.h"
> #include "hw/hw.h"
> @@ -527,6 +529,34 @@ bool qemu_savevm_state_blocked(Error **errp)
> return false;
> }
>
> +/* Return a visitor for use on the QEMUFile; visit_destroy should be
> + * called on it to clean it up.
> + */
> +static Visitor *qemu_savevm_get_visitor(QEMUFile *f)
> +{
> + char *formatvar = getenv("QEMUMIGFORMAT");
> +
> + if (formatvar && (!strcmp(formatvar, "BER"))) {
> + QemuFileBEROutputVisitor *qfberov =
> qemu_file_ber_output_visitor_new(f);
> + Visitor *v = qemu_file_ber_output_get_visitor(qfberov);
> +
> + qemu_file_set_tmp_visitor(f, v);
> + return v;
> + }
> +
> + if (formatvar) {
> + error_report("QEMUMIGFORMAT set to unknown value '%s'", formatvar);
> + assert(0);
> + }
> +
> + QemuFileBinOutputVisitor *qfbov = qemu_file_bin_output_visitor_new(f);
> + Visitor *v = qemu_file_bin_output_get_visitor(qfbov);
> +
> + qemu_file_set_tmp_visitor(f, v);
> +
> + return v;
> +}
> +
> void qemu_savevm_state_begin(QEMUFile *f,
> const MigrationParams *params)
> {
> @@ -534,10 +564,7 @@ void qemu_savevm_state_begin(QEMUFile *f,
> int ret;
> Error *local_err = NULL;
> SectionHeader sh;
> -
> - QemuFileBinOutputVisitor *qfbov = qemu_file_bin_output_visitor_new(f);
> - Visitor *v = qemu_file_bin_output_get_visitor(qfbov);
> - qemu_file_set_tmp_visitor(f, v);
> + Visitor *v = qemu_savevm_get_visitor(f);
>
> trace_savevm_state_begin();
> QTAILQ_FOREACH(se, &savevm_handlers, entry) {
> @@ -789,13 +816,11 @@ static int qemu_savevm_state(QEMUFile *f)
>
> static int qemu_save_device_state(QEMUFile *f)
> {
> + Visitor *v = qemu_savevm_get_visitor(f);
> SaveStateEntry *se;
> Error *local_err;
> SectionHeader sh;
>
> - QemuFileBinOutputVisitor *qfbov = qemu_file_bin_output_visitor_new(f);
> - qemu_file_set_tmp_visitor(f, qemu_file_bin_output_get_visitor(qfbov));
> - Visitor *v = qemu_file_bin_output_get_visitor(qfbov);
> int32_t section_type;
>
> cpu_synchronize_all_states();
> @@ -861,41 +886,65 @@ typedef struct LoadStateEntry {
> int version_id;
> } LoadStateEntry;
>
> +/* Given a just opened input QEMUFile, peak at the header and figure
> + * out which visitor should be used for it.
> + * Return the visitor ready for use.
> + */
> +static Visitor *pick_input_visitor(QEMUFile *f)
> +{
> + uint32_t tmp32;
> +
> + if (qemu_peek_buffer(f, (uint8_t *)&tmp32, 4, 0) != 4) {
> + fprintf(stderr, "Failed to read SaveVM header word\n");
> + return NULL;
> + }
> +
> + tmp32 = be32_to_cpu(tmp32);
> +
> + switch (tmp32) {
> + case QEMU_VM_FILE_MAGIC: {
> + QemuFileBinInputVisitor *qfbiv = qemu_file_bin_input_visitor_new(f);
> + Visitor *v = qemu_file_bin_input_get_visitor(qfbiv);
> + qemu_file_set_tmp_visitor(f, v);
> +
> + return v;
> + }
> +
> + case QEMU_VM_BER_FILE_MAGIC: {
> + QemuFileBERInputVisitor *qfberiv =
> qemu_file_ber_input_visitor_new(f);
> + Visitor *v = qemu_file_ber_input_get_visitor(qfberiv);
> + qemu_file_set_tmp_visitor(f, v);
> +
> + return v;
> + }
> +
> + default:
> + fprintf(stderr, "Invalid SaveVM header (0x%x)\n", tmp32);
> + return NULL;
> + }
> +}
> +
> int qemu_loadvm_state(QEMUFile *f)
> {
> QLIST_HEAD(, LoadStateEntry) loadvm_handlers =
> QLIST_HEAD_INITIALIZER(loadvm_handlers);
> LoadStateEntry *le, *new_le;
> + Visitor *v;
> Error *local_err = NULL;
> int32_t section_type;
> - unsigned int tmp;
> int ret;
>
> if (qemu_savevm_state_blocked(NULL)) {
> return -EINVAL;
> }
>
> - tmp = qemu_get_be32(f);
> - if (tmp != QEMU_VM_FILE_MAGIC) {
> - return -EINVAL;
> - }
> -
> - tmp = qemu_get_be32(f);
> - if (tmp == QEMU_VM_FILE_VERSION_COMPAT) {
> - error_report("SaveVM v2 format is obsolete and don't work anymore");
> + v = pick_input_visitor(f);
> + if (!v) {
> return -ENOTSUP;
> }
> - if (tmp != QEMU_VM_FILE_VERSION) {
> - return -ENOTSUP;
> - }
> -
> - /* TODO: Here we should be able to figure out if it's a binary file
> - * or what and open the right type of visitor
> - */
> - QemuFileBinInputVisitor *qfbiv = qemu_file_bin_input_visitor_new(f);
> - Visitor *v = qemu_file_bin_input_get_visitor(qfbiv);
> - qemu_file_set_tmp_visitor(f, v);
>
> + visit_start_sequence_compat(v, "file", VISIT_SEQ_COMPAT_FILE, NULL,
> + &local_err);
> visit_start_sequence_compat(v, "top", VISIT_SEQ_COMPAT_BYTE0TERM,
> NULL, &local_err);
> while (visit_get_next_type(v, §ion_type, NULL, "section",
> &local_err),
> @@ -912,6 +961,7 @@ int qemu_loadvm_state(QEMUFile *f)
> "secstart" : "secfull",
> VISIT_SEQ_COMPAT_SECTION_HEADER, &sh, &local_err);
> if (local_err) {
> + error_report("%s", error_get_pretty(local_err));
> ret = -EINVAL;
> goto out;
> }
> @@ -1001,6 +1051,7 @@ out:
> }
>
> visit_end_sequence_compat(v, "top", VISIT_SEQ_COMPAT_BYTE0TERM,
> &local_err);
> + visit_end_sequence_compat(v, "file", VISIT_SEQ_COMPAT_FILE, &local_err);
> if (local_err) {
> error_report("%s", error_get_pretty(local_err));
> ret = -EINVAL;
> @@ -1010,7 +1061,7 @@ out:
> ret = qemu_file_get_error(f);
> }
>
> - qemu_file_bin_input_visitor_cleanup(qfbiv);
> + visit_destroy(v, &local_err);
> return ret;
> }
>
> --
> 1.9.0
- Re: [Qemu-devel] [RFC PATCH v2 15/16] Wire in BER visitors,
Michael S. Tsirkin <=