From 8d9a62a5fa89001266352a929c5d40b28c0dda85 Mon Sep 17 00:00:00 2001
From: Matt Weber <matthew.weber@rockwellcollins.com>
Date: Fri, 12 Jan 2018 19:07:27 -0600
Subject: [PATCH] kvm-unit-tests: test for rdseed/rdrand

The build fails when the host binutils isn't at least 2.23
(2.22.x introduced RDSEED).

Fixes:
http://autobuild.buildroot.net/results/c39/c3987a3cbd2960b0ff50f872636bdfd8d1a9c820/

Upstream:
https://marc.info/?l=kvm&m=151580743523259&w=2

Signed-off-by: Matthew Weber <matthew.weber@rockwellcollins.com>
---
 Makefile        |  2 +-
 configure       | 18 ++++++++++++++++++
 x86/vmx_tests.c |  6 ++++++
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index d9ad42b..799e9b5 100644
--- a/Makefile
+++ b/Makefile
@@ -50,7 +50,7 @@ include $(SRCDIR)/$(TEST_DIR)/Makefile
 cc-option = $(shell if $(CC) $(1) -S -o /dev/null -xc /dev/null \
               > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)
 
-COMMON_CFLAGS += -g $(autodepend-flags)
+COMMON_CFLAGS += -g $(autodepend-flags) $(EXTRA_CFLAGS)
 COMMON_CFLAGS += -Wall -Wwrite-strings -Wclobbered -Wempty-body -Wuninitialized
 COMMON_CFLAGS += -Wignored-qualifiers -Wunused-but-set-parameter
 frame-pointer-flag=-f$(if $(KEEP_FRAME_POINTER),no-,)omit-frame-pointer
diff --git a/configure b/configure
index dd9d361..21c0219 100755
--- a/configure
+++ b/configure
@@ -171,6 +171,23 @@ mkdir -p lib
 ln -sf "$asm" lib/asm
 
 
+cat > rd_test.c <<EOF
+#include <stdint.h>
+int main() {
+   uint16_t seed=0;
+   unsigned char ok;
+   asm volatile ("rdseed %0; setc %1"
+                 : "=r" (seed), "=qm" (ok));
+   return ok;
+}
+EOF
+if $cross_prefix$cc -o /dev/null rd_test.c &> /dev/null; then
+  echo "Checking for rdseed/rdrand... Yes."
+else
+  echo "Checking for rdseed/rdrand... No."
+  extra_cflags="-DNO_RDSEEDRAND"
+fi
+
 # create the config
 cat <<EOF > config.mak
 SRCDIR=$srcdir
@@ -181,6 +198,7 @@ ARCH_NAME=$arch_name
 PROCESSOR=$processor
 CC=$cross_prefix$cc
 CXX=$cross_prefix$cxx
+EXTRA_CFLAGS=$extra_cflags
 LD=$cross_prefix$ld
 OBJCOPY=$cross_prefix$objcopy
 OBJDUMP=$cross_prefix$objdump
diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
index 4a3e94b..2cbe3eb 100644
--- a/x86/vmx_tests.c
+++ b/x86/vmx_tests.c
@@ -770,8 +770,10 @@ asm(
 	"insn_sldt: sldt %ax;ret\n\t"
 	"insn_lldt: xor %eax, %eax; lldt %ax;ret\n\t"
 	"insn_str: str %ax;ret\n\t"
+#ifndef NO_RDSEEDRAND
 	"insn_rdrand: rdrand %rax;ret\n\t"
 	"insn_rdseed: rdseed %rax;ret\n\t"
+#endif
 );
 extern void insn_hlt();
 extern void insn_invlpg();
@@ -796,8 +798,10 @@ extern void insn_lldt();
 extern void insn_str();
 extern void insn_cpuid();
 extern void insn_invd();
+#ifndef NO_RDSEEDRAND
 extern void insn_rdrand();
 extern void insn_rdseed();
+#endif
 
 u32 cur_insn;
 u64 cr3;
@@ -853,8 +857,10 @@ static struct insn_table insn_table[] = {
 	{"DESC_TABLE (LLDT)", CPU_DESC_TABLE, insn_lldt, INSN_CPU1, 47, 0, 0, 0},
 	{"DESC_TABLE (STR)", CPU_DESC_TABLE, insn_str, INSN_CPU1, 47, 0, 0, 0},
 	/* LTR causes a #GP if done with a busy selector, so it is not tested.  */
+#ifndef NO_RDSEEDRAND
 	{"RDRAND", CPU_RDRAND, insn_rdrand, INSN_CPU1, VMX_RDRAND, 0, 0, 0},
 	{"RDSEED", CPU_RDSEED, insn_rdseed, INSN_CPU1, VMX_RDSEED, 0, 0, 0},
+#endif
 	// Instructions always trap
 	{"CPUID", 0, insn_cpuid, INSN_ALWAYS_TRAP, 10, 0, 0, 0},
 	{"INVD", 0, insn_invd, INSN_ALWAYS_TRAP, 13, 0, 0, 0},
-- 
1.9.1