Did a few things to make the code easier to fllow:
* named I/O operands
* removed pointless LOAD_RFLAGS
* replaced global host_rflags with local
* only save rflags when they're meaningful (i.e., after early failure)
* got rid of unecessary %rsi scratch register
Signed-off-by: Peter Feiner <pfeiner@xxxxxxxxxx>
---
x86/vmx.c | 23 +++++++++++------------
x86/vmx.h | 8 --------
2 files changed, 11 insertions(+), 20 deletions(-)
diff --git a/x86/vmx.c b/x86/vmx.c
index 27e85eb..67f8650 100644
--- a/x86/vmx.c
+++ b/x86/vmx.c
@@ -46,7 +46,6 @@ struct regs regs;
struct vmx_test *current;
u64 hypercall_field;
bool launched;
-u64 host_rflags;
union vmx_basic basic;
union vmx_ctrl_msr ctrl_pin_rev;
@@ -909,33 +908,33 @@ static int exit_handler()
static int vmx_run()
{
u32 ret = 0, fail = 0;
+ unsigned long host_rflags;
while (1) {
asm volatile (
- "mov %%rsp, %%rsi\n\t"
- "mov %2, %%rdi\n\t"
- "vmwrite %%rsi, %%rdi\n\t"
-
+ "mov %[HOST_RSP], %%rdi\n\t"
+ "vmwrite %%rsp, %%rdi\n\t"
LOAD_GPR_C
- "cmpl $0, %1\n\t"
+ "cmpl $0, %[launched]\n\t"
"jne 1f\n\t"
- LOAD_RFLAGS
"vmlaunch\n\t"
"jmp 2f\n\t"
"1: "
"vmresume\n\t"
"2: "
SAVE_GPR_C
- "movl $1, %0\n\t"
+ "pushf\n\t"
+ "pop %%rdi\n\t"
+ "mov %%rdi, %[host_rflags]\n\t"
+ "movl $1, %[fail]\n\t"
"jmp 3f\n\t"
"vmx_return:\n\t"
SAVE_GPR_C
"3: \n\t"
- SAVE_RFLAGS
- : "+m"(fail)
- : "m"(launched), "i"(HOST_RSP)
- : "rdi", "rsi", "memory", "cc"
+ : [fail]"+m"(fail), [host_rflags]"=m"(host_rflags)
+ : [launched]"m"(launched), [HOST_RSP]"i"(HOST_RSP)
+ : "rdi", "memory", "cc"
);
if (fail)
diff --git a/x86/vmx.h b/x86/vmx.h
index 34e9be4..aba5642 100644
--- a/x86/vmx.h
+++ b/x86/vmx.h
@@ -396,14 +396,6 @@ enum Ctrl1 {
#define LOAD_GPR_C SAVE_GPR_C
-#define SAVE_RFLAGS \
- "pushf\n\t" \
- "pop host_rflags\n\t"
-
-#define LOAD_RFLAGS \
- "push host_rflags\n\t" \
- "popf\n\t"
-
#define VMX_IO_SIZE_MASK 0x7
#define _VMX_IO_BYTE 0
#define _VMX_IO_WORD 1
--
2.8.0.rc3.226.g39d4020
--
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