xen: Place vcpu_info structure into per-cpu memory
An experimental patch for Xen allows guests to place their vcpu_info
structs anywhere. We try to use this to place the vcpu_info into the
PDA, which allows direct access.
If this works, then switch to using direct access operations for
irq_enable, disable, save_fl and restore_fl.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Keir Fraser <keir@xensource.com>
diff --git a/include/xen/interface/vcpu.h b/include/xen/interface/vcpu.h
index c6218f1..ff61ea3 100644
--- a/include/xen/interface/vcpu.h
+++ b/include/xen/interface/vcpu.h
@@ -151,4 +151,17 @@
#define _VCPU_SSHOTTMR_future (0)
#define VCPU_SSHOTTMR_future (1U << _VCPU_SSHOTTMR_future)
+/*
+ * Register a memory location in the guest address space for the
+ * vcpu_info structure. This allows the guest to place the vcpu_info
+ * structure in a convenient place, such as in a per-cpu data area.
+ * The pointer need not be page aligned, but the structure must not
+ * cross a page boundary.
+ */
+#define VCPUOP_register_vcpu_info 10 /* arg == struct vcpu_info */
+struct vcpu_register_vcpu_info {
+ uint32_t mfn; /* mfn of page to place vcpu_info */
+ uint32_t offset; /* offset within page */
+};
+
#endif /* __XEN_PUBLIC_VCPU_H__ */