[PATCH v4 23/37] KVM: selftests: Better XMM read/write helpers

Vitaly Kuznetsov
2022-05-25T09:13:30Z

set_xmm()/get_xmm() helpers are fairly useless as they only read 64 bits
from 128-bit registers. Moreover, these helpers are not used. Borrow
_kvm_read_sse_reg()/_kvm_write_sse_reg() from KVM limiting them to
XMM0-XMM8 for now.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
.../selftests/kvm/include/x86_64/processor.h | 70 ++++++++++---------
1 file changed, 36 insertions(+), 34 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 37db341d4cc5..9ad7602a257b 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -296,71 +296,73 @@ static inline void cpuid(uint32_t *eax, uint32_t *ebx,
: "memory");
}

-#define SET_XMM(__var, __xmm) \
- asm volatile("movq %0, %%"#__xmm : : "r"(__var) : #__xmm)
+typedef u32 __attribute__((vector_size(16))) sse128_t;
+#define __sse128_u union { sse128_t vec; u64 as_u64[2]; u32 as_u32[4]; }
+#define sse128_lo(x) ({ __sse128_u t; t.vec = x; t.as_u64[0]; })
+#define sse128_hi(x) ({ __sse128_u t; t.vec = x; t.as_u64[1]; })

-static inline void set_xmm(int n, unsigned long val)
+static inline void read_sse_reg(int reg, sse128_t *data)
{
- switch (n) {
+ switch (reg) {
case 0:
- SET_XMM(val, xmm0);
+ asm("movdqa %%xmm0, %0" : "=m"(*data));
break;
case 1:
- SET_XMM(val, xmm1);
+ asm("movdqa %%xmm1, %0" : "=m"(*data));
break;
case 2:
- SET_XMM(val, xmm2);
+ asm("movdqa %%xmm2, %0" : "=m"(*data));
break;
case 3:
- SET_XMM(val, xmm3);
+ asm("movdqa %%xmm3, %0" : "=m"(*data));
break;
case 4:
- SET_XMM(val, xmm4);
+ asm("movdqa %%xmm4, %0" : "=m"(*data));
break;
case 5:
- SET_XMM(val, xmm5);
+ asm("movdqa %%xmm5, %0" : "=m"(*data));
break;
case 6:
- SET_XMM(val, xmm6);
+ asm("movdqa %%xmm6, %0" : "=m"(*data));
break;
case 7:
- SET_XMM(val, xmm7);
+ asm("movdqa %%xmm7, %0" : "=m"(*data));
break;
+ default:
+ BUG();
}
}

-#define GET_XMM(__xmm) \
-({ \
- unsigned long __val; \
- asm volatile("movq %%"#__xmm", %0" : "=r"(__val)); \
- __val; \
-})
-
-static inline unsigned long get_xmm(int n)
+static inline void write_sse_reg(int reg, const sse128_t *data)
{
- assert(n >= 0 && n <= 7);
-
- switch (n) {
+ switch (reg) {
case 0:
- return GET_XMM(xmm0);
+ asm("movdqa %0, %%xmm0" : : "m"(*data));
+ break;
case 1:
- return GET_XMM(xmm1);
+ asm("movdqa %0, %%xmm1" : : "m"(*data));
+ break;
case 2:
- return GET_XMM(xmm2);
+ asm("movdqa %0, %%xmm2" : : "m"(*data));
+ break;
case 3:
- return GET_XMM(xmm3);
+ asm("movdqa %0, %%xmm3" : : "m"(*data));
+ break;
case 4:
- return GET_XMM(xmm4);
+ asm("movdqa %0, %%xmm4" : : "m"(*data));
+ break;
case 5:
- return GET_XMM(xmm5);
+ asm("movdqa %0, %%xmm5" : : "m"(*data));
+ break;
case 6:
- return GET_XMM(xmm6);
+ asm("movdqa %0, %%xmm6" : : "m"(*data));
+ break;
case 7:
- return GET_XMM(xmm7);
+ asm("movdqa %0, %%xmm7" : : "m"(*data));
+ break;
+ default:
+ BUG();
}
-
- /* never reached */
- return 0;
}

static inline void cpu_relax(void)
--
2.35.3