From: Alex Williamson <alex.williamson@hp.com>
Date: Tue, 20 Nov 2007 16:11:15 +0000 (-0700)
Subject: [IA64] vti save-restore: fix opt_feature hypercall
X-Git-Tag: 3.2.0-rc1~116
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=68d8221103c2e6886cfceddb0f80f49fdf976622;p=xen.git

[IA64] vti save-restore: fix opt_feature hypercall

- Fix XEN_IA64_OPTF_IDENT_MAP_REG[457] definitions.
- SMP fix. writing to domain->arch.opt_feature is racy.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
---

diff --git a/xen/arch/ia64/xen/domain.c b/xen/arch/ia64/xen/domain.c
index 47924a54e0..d951cca218 100644
--- a/xen/arch/ia64/xen/domain.c
+++ b/xen/arch/ia64/xen/domain.c
@@ -2285,13 +2285,23 @@ optf_set_identity_mapping(unsigned long* mask, struct identity_mapping* im,
 	}
 }
 
-/* Switch a optimization feature on/off. */
+/*
+ * Switch an optimization feature on/off.
+ * The vcpu must be paused to avoid racy access to opt_feature.
+ */
 int
 domain_opt_feature(struct xen_ia64_opt_feature* f)
 {
-	struct opt_feature* optf = &(current->domain->arch.opt_feature);
+	struct domain *d = current->domain;
+	struct opt_feature* optf = &d->arch.opt_feature;
+	struct vcpu *v;
 	long rc = 0;
 
+	for_each_vcpu(d, v) {
+		if (v != current)
+			vcpu_pause(v);
+	}
+
 	switch (f->cmd) {
 	case XEN_IA64_OPTF_IDENT_MAP_REG4:
 		optf_set_identity_mapping(&optf->mask, &optf->im_reg4, f);
@@ -2307,6 +2317,12 @@ domain_opt_feature(struct xen_ia64_opt_feature* f)
 		rc = -ENOSYS;
 		break;
 	}
+
+	for_each_vcpu(d, v) {
+		if (v != current)
+			vcpu_unpause(v);
+	}
+
 	return rc;
 }
 
diff --git a/xen/include/asm-ia64/domain.h b/xen/include/asm-ia64/domain.h
index 91d4d9f709..486696d679 100644
--- a/xen/include/asm-ia64/domain.h
+++ b/xen/include/asm-ia64/domain.h
@@ -105,9 +105,15 @@ struct opt_feature {
  * The base XEN_IA64_OPTF_IDENT_MAP_REG7 is defined in public/arch-ia64.h.
  * Identity mapping of region 4 addresses in HVM.
  */
-#define XEN_IA64_OPTF_IDENT_MAP_REG4	(XEN_IA64_OPTF_IDENT_MAP_REG7 + 1)
+#define XEN_IA64_OPTF_IDENT_MAP_REG4_BIT        \
+    (XEN_IA64_OPTF_IDENT_MAP_REG7_BIT + 1)
+#define XEN_IA64_OPTF_IDENT_MAP_REG4            \
+    (1UL << XEN_IA64_OPTF_IDENT_MAP_REG4_BIT)
 /* Identity mapping of region 5 addresses in HVM. */
-#define XEN_IA64_OPTF_IDENT_MAP_REG5	(XEN_IA64_OPTF_IDENT_MAP_REG4 + 1)
+#define XEN_IA64_OPTF_IDENT_MAP_REG5_BIT        \
+    (XEN_IA64_OPTF_IDENT_MAP_REG7_BIT + 2)
+#define XEN_IA64_OPTF_IDENT_MAP_REG5            \
+    (1UL << XEN_IA64_OPTF_IDENT_MAP_REG5_BIT)
 
 /* Set an optimization feature in the struct arch_domain. */
 extern int domain_opt_feature(struct xen_ia64_opt_feature*);
diff --git a/xen/include/public/arch-ia64.h b/xen/include/public/arch-ia64.h
index d197a79bfa..0895dd0eff 100644
--- a/xen/include/public/arch-ia64.h
+++ b/xen/include/public/arch-ia64.h
@@ -674,7 +674,9 @@ DEFINE_XEN_GUEST_HANDLE(xen_ia64_debug_op_t);
  * This is useful in guests using region 7 for identity mapping
  * like the linux kernel does.
  */
-#define XEN_IA64_OPTF_IDENT_MAP_REG7	0x1UL
+#define XEN_IA64_OPTF_IDENT_MAP_REG7_BIT	0
+#define XEN_IA64_OPTF_IDENT_MAP_REG7		\
+	(1UL << XEN_IA64_OPTF_IDENT_MAP_REG7_BIT)
 
 struct xen_ia64_opt_feature {
 	unsigned long cmd;		/* Which feature */