[Crash-utility] [PATCH 5/7] Use the size of the Xen domain VCPU array if available

[Petr Tesarik]

If the size of the vcpu array in struct domain is known, use it
to size the dynamically allocated vcpu array in crash. This enables
crash to initialize domains with a different number of VCPUs than
specified by the XEN_HYPER_MAX_VIRT_CPUS macro.

Signed-off-by: Petr Tesarik <ptesarik at suse.cz>

---
 xen_hyper.c      |   15 +++++++++++----
 xen_hyper_defs.h |    1 +
 2 files changed, 12 insertions(+), 4 deletions(-)

--- a/xen_hyper.c
+++ b/xen_hyper.c
@@ -219,6 +219,7 @@ xen_hyper_domain_init(void)
 	XEN_HYPER_MEMBER_OFFSET_INIT(domain_is_shutting_down, "domain", 
"is_shutting_down");
 	XEN_HYPER_MEMBER_OFFSET_INIT(domain_is_shut_down, "domain", 
"is_shut_down");
 	XEN_HYPER_MEMBER_OFFSET_INIT(domain_vcpu, "domain", "vcpu");
+	XEN_HYPER_MEMBER_SIZE_INIT(domain_vcpu, "domain", "vcpu");
 	XEN_HYPER_MEMBER_OFFSET_INIT(domain_arch, "domain", "arch");
 
 	XEN_HYPER_STRUCT_SIZE_INIT(arch_shared_info, "arch_shared_info");
@@ -1207,7 +1208,8 @@ struct xen_hyper_domain_context *
 xen_hyper_store_domain_context(struct xen_hyper_domain_context *dc,
 	       ulong domain, char *dp)
 {
-	int i;
+	unsigned int max_vcpus;
+	unsigned int i;
 
 	dc->domain = domain;
 	BCOPY((char *)(dp + XEN_HYPER_OFFSET(domain_domain_id)),
@@ -1244,11 +1246,16 @@ xen_hyper_store_domain_context(struct xe
 		dc->domain_flags = XEN_HYPER_DOMF_ERROR;
 	}
 	dc->evtchn = ULONG(dp + XEN_HYPER_OFFSET(domain_evtchn));
-	if (!(dc->vcpu = malloc(sizeof(ulong) * XEN_HYPER_MAX_VIRT_CPUS))) {
+	if (XEN_HYPER_VALID_SIZE(domain_vcpu)) {
+		max_vcpus = XEN_HYPER_SIZE(domain_vcpu) / sizeof(void *);
+	} else {
+		max_vcpus = XEN_HYPER_MAX_VIRT_CPUS;
+	}
+	if (!(dc->vcpu = malloc(sizeof(ulong) * max_vcpus))) {
 		error(FATAL, "cannot malloc vcpu array (%d VCPUs).",
-		      XEN_HYPER_MAX_VIRT_CPUS);
+		      max_vcpus);
 	}
-	for (i = 0; i < XEN_HYPER_MAX_VIRT_CPUS; i++) {
+	for (i = 0; i < max_vcpus; i++) {
 		dc->vcpu[i] = ULONG(dp + XEN_HYPER_OFFSET(domain_vcpu) + 
i*sizeof(void *));
 		if (dc->vcpu[i])	XEN_HYPER_NR_VCPUS_IN_DOM(dc)++;
 	}
--- a/xen_hyper_defs.h
+++ b/xen_hyper_defs.h
@@ -583,6 +583,7 @@ struct xen_hyper_size_table {
 	long crash_xen_core_t;			/* elf note v3,v4 */
 	long crash_xen_info_t;			/* elf note v3,v4 */
 	long domain;
+	long domain_vcpu;
 #ifdef IA64
 	long mm_struct;
 #endif