Hi Paul, On 07/04/2020 18:38, Paul Durrant wrote:
... and update xen-domctx to dump some information describing the record.Signed-off-by: Paul Durrant <pdurr...@amazon.com> --- Cc: Ian Jackson <ian.jack...@eu.citrix.com> Cc: Wei Liu <w...@xen.org> Cc: Andrew Cooper <andrew.coop...@citrix.com> Cc: George Dunlap <george.dun...@citrix.com> Cc: Jan Beulich <jbeul...@suse.com> Cc: Julien Grall <jul...@xen.org> Cc: Stefano Stabellini <sstabell...@kernel.org> v2: - Drop the header change to define a 'Xen' page size and instead use a variable length struct now that the framework makes this is feasible - Guard use of 'has_32bit_shinfo' in common code with CONFIG_COMPAT --- tools/misc/xen-domctx.c | 11 ++++++ xen/common/domain.c | 81 +++++++++++++++++++++++++++++++++++++++ xen/include/public/save.h | 10 ++++- 3 files changed, 101 insertions(+), 1 deletion(-) diff --git a/tools/misc/xen-domctx.c b/tools/misc/xen-domctx.c index d663522a8b..a8d3922321 100644 --- a/tools/misc/xen-domctx.c +++ b/tools/misc/xen-domctx.c @@ -59,6 +59,16 @@ static void dump_header(struct domain_save_descriptor *desc) off += desc->length; }+static void dump_shared_info(struct domain_save_descriptor *desc)+{ + DOMAIN_SAVE_TYPE(SHARED_INFO) s; + READ(s); + printf(" SHARED_INFO: field_width %u buffer size: %lu\n", + s.field_width, desc->length - sizeof(s)); + + off += desc->length; +} + static void dump_end(struct domain_save_descriptor *desc) { DOMAIN_SAVE_TYPE(END) e; @@ -125,6 +135,7 @@ int main(int argc, char **argv) switch (desc.typecode) { case DOMAIN_SAVE_CODE(HEADER): dump_header(&desc); break; + case DOMAIN_SAVE_CODE(SHARED_INFO): dump_shared_info(&desc); break; case DOMAIN_SAVE_CODE(END): dump_end(&desc); return 0; default: printf("Unknown type %u: skipping\n", desc.typecode); diff --git a/xen/common/domain.c b/xen/common/domain.c index 3dcd73f67c..8b72462e07 100644 --- a/xen/common/domain.c +++ b/xen/common/domain.c @@ -33,6 +33,7 @@ #include <xen/xenoprof.h> #include <xen/irq.h> #include <xen/argo.h> +#include <xen/save.h> #include <asm/debugger.h> #include <asm/p2m.h> #include <asm/processor.h> @@ -1646,6 +1647,86 @@ int continue_hypercall_on_cpu( return 0; }+static int save_shared_info(const struct vcpu *v, struct domain_context *c,+ bool dry_run) +{ + struct domain *d = v->domain; + struct domain_shared_info_context ctxt = {}; + size_t hdr_size = offsetof(typeof(ctxt), buffer); + size_t size = hdr_size + PAGE_SIZE; + int rc; + + rc = DOMAIN_SAVE_BEGIN(SHARED_INFO, c, v, size); + if ( rc ) + return rc; + + if ( !dry_run )
NIT: I think the if is not necessary here as you don't skip that much code.
+ ctxt.field_width = +#ifdef CONFIG_COMPAT + has_32bit_shinfo(d) ? 4 : +#endif + 8; + + rc = domain_save_data(c, &ctxt, hdr_size); + if ( rc ) + return rc; + + rc = domain_save_data(c, d->shared_info, PAGE_SIZE); + if ( rc ) + return rc; + + return domain_save_end(c); +} + +static int load_shared_info(struct vcpu *v, struct domain_context *c) +{ + struct domain *d = v->domain; + struct domain_shared_info_context ctxt = {}; + size_t hdr_size = offsetof(typeof(ctxt), buffer); + size_t size = hdr_size + PAGE_SIZE; + unsigned int i; + int rc; + + rc = DOMAIN_LOAD_BEGIN(SHARED_INFO, c, v, size, true); + if ( rc ) + return rc; + + rc = domain_load_data(c, &ctxt, hdr_size); + if ( rc ) + return rc; + + for ( i = 0; i < ARRAY_SIZE(ctxt.pad); i++ ) + if ( ctxt.pad[i] ) + return -EINVAL; + + switch ( ctxt.field_width ) + { +#ifdef CONFIG_COMPAT + case 4: + d->arch.has_32bit_shinfo = 1; + break; +#endif + case 8: +#ifdef CONFIG_COMPAT + d->arch.has_32bit_shinfo = 0; +#endif + break; + + default: + rc = -EINVAL; + break; + } + + rc = domain_load_data(c, d->shared_info, PAGE_SIZE); + if ( rc ) + return rc; + + return domain_load_end(c); +} + +DOMAIN_REGISTER_SAVE_RESTORE(SHARED_INFO, false, save_shared_info, + load_shared_info); + /* * Local variables: * mode: C diff --git a/xen/include/public/save.h b/xen/include/public/save.h index 7e5f8752bd..ed994a8765 100644 --- a/xen/include/public/save.h +++ b/xen/include/public/save.h @@ -79,6 +79,14 @@ struct domain_save_header { }; DECLARE_DOMAIN_SAVE_TYPE(HEADER, 1, struct domain_save_header);-#define DOMAIN_SAVE_CODE_MAX 1+struct domain_shared_info_context { + uint8_t field_width; + uint8_t pad[7]; + uint8_t buffer[]; /* Implementation specific size */
I would recommend to use buffer[XEN_FLEX_ARRAY_DIM]. Cheers, -- Julien Grall
