commit 2616ad934e29dbc3e5995bfd25b3372014983423
author Roman Bolshakov <r.bolshakov@yadro.com> Thu Sep 24 15:05:17 2020 +0300
committer Paolo Bonzini <pbonzini@redhat.com> Thu Sep 24 14:09:19 2020 +0200
tree cc6b5244ba65349ea8c2d6fcf1a5af45f3a3b42b
parent f01561d3d12c05fc3d952c28e538cc5797670aef

x86: realmode: Workaround clang issues

clang doesn't properly support .code16gcc and generates wrong machine
code [1][2][3][4]. But the test works if object file is compiled with -m16 and
explicit suffixes are added for instructions.

1. https://lore.kernel.org/kvm/4d20fbce-d247-abf4-3ceb-da2c0d48fc50@redhat.com/
2. https://lore.kernel.org/kvm/20200915155959.GF52559@SPB-NB-133.local/
3. https://lore.kernel.org/kvm/788b7191-6987-9399-f352-2e661255157e@redhat.com/
4. https://lore.kernel.org/kvm/20200922212507.GA11460@SPB-NB-133.local/

Suggested-by: Thomas Huth <thuth@redhat.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200924120516.77299-1-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

.travis.yml

diff --git a/.travis.yml b/.travis.yml
index 2e5ae41..bd62190 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -24,7 +24,7 @@
       - BUILD_DIR="."
       - TESTS="access asyncpf debug emulator ept hypercall hyperv_stimer
                hyperv_synic idt_test intel_iommu ioapic ioapic-split
-               kvmclock_test msr pcid rdpru rmap_chain s3 setjmp umip"
+               kvmclock_test msr pcid rdpru realmode rmap_chain s3 setjmp umip"
       - ACCEL="kvm"
 
     - addons:

x86/Makefile.common

diff --git a/x86/Makefile.common b/x86/Makefile.common
index 090ce22..5567d66 100644
--- a/x86/Makefile.common
+++ b/x86/Makefile.common
@@ -72,7 +72,7 @@
 	$(CC) -m32 -nostdlib -o $@ -Wl,-m,elf_i386 \
 	      -Wl,-T,$(SRCDIR)/$(TEST_DIR)/realmode.lds $^
 
-$(TEST_DIR)/realmode.o: bits = 32
+$(TEST_DIR)/realmode.o: bits = 16
 
 $(TEST_DIR)/kvmclock_test.elf: $(TEST_DIR)/kvmclock.o
 

x86/realmode.c

diff --git a/x86/realmode.c b/x86/realmode.c
index 7c2d776..c8a6ae0 100644
--- a/x86/realmode.c
+++ b/x86/realmode.c
@@ -639,7 +639,7 @@
 
 static void test_long_jmp(void)
 {
-	MK_INSN(long_jmp, "call 1f\n\t"
+	MK_INSN(long_jmp, "calll 1f\n\t"
 			  "jmp 2f\n\t"
 			  "1: jmp $0, $test_function\n\t"
 		          "2:\n\t");
@@ -728,26 +728,26 @@
 
 static void test_pusha_popa(void)
 {
-	MK_INSN(pusha, "pusha\n\t"
-		       "pop %edi\n\t"
-		       "pop %esi\n\t"
-		       "pop %ebp\n\t"
-		       "add $4, %esp\n\t"
-		       "pop %ebx\n\t"
-		       "pop %edx\n\t"
-		       "pop %ecx\n\t"
-		       "pop %eax\n\t"
+	MK_INSN(pusha, "pushal\n\t"
+		       "popl %edi\n\t"
+		       "popl %esi\n\t"
+		       "popl %ebp\n\t"
+		       "addl $4, %esp\n\t"
+		       "popl %ebx\n\t"
+		       "popl %edx\n\t"
+		       "popl %ecx\n\t"
+		       "popl %eax\n\t"
 		       );
 
-	MK_INSN(popa, "push %eax\n\t"
-		      "push %ecx\n\t"
-		      "push %edx\n\t"
-		      "push %ebx\n\t"
-		      "push %esp\n\t"
-		      "push %ebp\n\t"
-		      "push %esi\n\t"
-		      "push %edi\n\t"
-		      "popa\n\t"
+	MK_INSN(popa, "pushl %eax\n\t"
+		      "pushl %ecx\n\t"
+		      "pushl %edx\n\t"
+		      "pushl %ebx\n\t"
+		      "pushl %esp\n\t"
+		      "pushl %ebp\n\t"
+		      "pushl %esi\n\t"
+		      "pushl %edi\n\t"
+		      "popal\n\t"
 		      );
 
 	init_inregs(&(struct regs){ .eax = 0, .ebx = 1, .ecx = 2, .edx = 3, .esi = 4, .edi = 5, .ebp = 6 });
@@ -761,9 +761,9 @@
 
 static void test_iret(void)
 {
-	MK_INSN(iret32, "pushf\n\t"
+	MK_INSN(iret32, "pushfl\n\t"
 			"pushl %cs\n\t"
-			"call 1f\n\t" /* a near call will push eip onto the stack */
+			"calll 1f\n\t" /* a near call will push eip onto the stack */
 			"jmp 2f\n\t"
 			"1: iretl\n\t"
 			"2:\n\t"
@@ -782,7 +782,7 @@
 			      "orl $0xffc18028, %eax\n\t"
 			      "pushl %eax\n\t"
 			      "pushl %cs\n\t"
-			      "call 1f\n\t"
+			      "calll 1f\n\t"
 			      "jmp 2f\n\t"
 			      "1: iretl\n\t"
 			      "2:\n\t");