[PATCH RFC 06/31] xen/x86: Infrastructure to calculate guest featuresets

[Andrew Cooper <andrew.cooper3@citrix.com>]

Guest featuresets are seeded from the host featureset, and the host featureset
has calculated in the front of boot_cpu_data.x86_capability.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
---
 xen/arch/x86/Makefile       |  1 +
 xen/arch/x86/cpuid.c        | 23 +++++++++++++++++++++++
 xen/arch/x86/setup.c        |  3 +++
 xen/include/asm-x86/cpuid.h | 22 ++++++++++++++++++++++
 4 files changed, 49 insertions(+)
 create mode 100644 xen/arch/x86/cpuid.c
 create mode 100644 xen/include/asm-x86/cpuid.h

diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
index 122cbe9..c1f6f73 100644
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -15,6 +15,7 @@ obj-bin-y += bzimage.init.o
 obj-bin-y += clear_page.o
 obj-bin-y += copy_page.o
 obj-y += compat.o
+obj-y += cpuid.o
 obj-y += debug.o
 obj-y += delay.o
 obj-bin-y += dmi_scan.init.o
diff --git a/xen/arch/x86/cpuid.c b/xen/arch/x86/cpuid.c
new file mode 100644
index 0000000..099e145
--- /dev/null
+++ b/xen/arch/x86/cpuid.c
@@ -0,0 +1,23 @@
+#include <xen/lib.h>
+#include <xen/init.h>
+#include <asm/processor.h>
+#include <asm/cpuid.h>
+
+uint32_t __read_mostly host_featureset[XEN_NR_FEATURESET_ENTRIES];
+
+void __init calculate_featuresets(void)
+{
+    /* Host featureset. */
+    memcpy(host_featureset, boot_cpu_data.x86_capability,
+           sizeof(host_featureset));
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 54995ed..d91c2fb 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -50,6 +50,7 @@
 #include <asm/nmi.h>
 #include <asm/alternative.h>
 #include <asm/mc146818rtc.h>
+#include <asm/cpuid.h>
 
 /* opt_nosmp: If true, secondary processors are ignored. */
 static bool_t __initdata opt_nosmp;
@@ -1434,6 +1435,8 @@ void __init noreturn __start_xen(unsigned long mbi_p)
                "Multiple initrd candidates, picking module #%u\n",
                initrdidx);
 
+    calculate_featuresets();
+
     /*
      * Temporarily clear SMAP in CR4 to allow user-accesses in construct_dom0().
      * This saves a large number of corner cases interactions with
diff --git a/xen/include/asm-x86/cpuid.h b/xen/include/asm-x86/cpuid.h
new file mode 100644
index 0000000..c303c74
--- /dev/null
+++ b/xen/include/asm-x86/cpuid.h
@@ -0,0 +1,22 @@
+#ifndef __X86_CPUID_H__
+#define __X86_CPUID_H__
+
+#include <xen/types.h>
+#include <asm/cpufeature.h>
+#include <public/sysctl.h>
+
+extern uint32_t host_featureset[XEN_NR_FEATURESET_ENTRIES];
+
+void calculate_featuresets(void);
+
+#endif /* !__X86_CPUID_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
2.1.4