SMSW instruction on long-mode is performed according to the operand size, if
the destination operand is a register. This patch tests whether it is
performed correctly instead of always using two-bytes operands (as KVM
previously did). Note that when a dword destination operand is used, the
result is zero-extended to qword on long-mode.
Signed-off-by: Nadav Amit <na...@cs.technion.ac.il>
---
x86/emulator.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/x86/emulator.c b/x86/emulator.c
index 033f246..f653127 100644
--- a/x86/emulator.c
+++ b/x86/emulator.c
@@ -825,6 +825,26 @@ static void test_movabs(uint64_t *mem, uint8_t *insn_page,
report("64-bit mov imm2", outregs.rcx == 0x9090909090909090);
}
+static void test_smsw_reg(uint64_t *mem, uint8_t *insn_page,
+ uint8_t *alt_insn_page, void *insn_ram)
+{
+ unsigned long cr0 = read_cr0();
+ inregs = (struct regs){ .rax = 0x1234567890abcdeful };
+
+ MK_INSN(smsww, "smsww %ax\n\t");
+ trap_emulator(mem, alt_insn_page, &insn_smsww);
+ report("16-bit smsw reg", (u16)outregs.rax == (u16)cr0 &&
+ outregs.rax >> 16 == inregs.rax >> 16);
+
+ MK_INSN(smswl, "smswl %eax\n\t");
+ trap_emulator(mem, alt_insn_page, &insn_smswl);
+ report("32-bit smsw reg", outregs.rax == (u32)cr0);
+
+ MK_INSN(smswq, "smswq %rax\n\t");
+ trap_emulator(mem, alt_insn_page, &insn_smswq);
+ report("64-bit smsw reg", outregs.rax == cr0);
+}
+
static void test_crosspage_mmio(volatile uint8_t *mem)
{
volatile uint16_t w, *pw;
@@ -1024,6 +1044,7 @@ int main()
test_mmx_movq_mf(mem, insn_page, alt_insn_page, insn_ram);
test_movabs(mem, insn_page, alt_insn_page, insn_ram);
+ test_smsw_reg(mem, insn_page, alt_insn_page, insn_ram);
test_crosspage_mmio(mem);
--
1.9.1
--
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