On 2026/6/9 下午5:23, Huacai Chen wrote:
On Tue, Jun 9, 2026 at 5:02 PM Bibo Mao <[email protected]> wrote:



On 2026/6/9 下午4:40, Huacai Chen wrote:
Hi, Bibo,

On Tue, Jun 9, 2026 at 3:27 PM Bibo Mao <[email protected]> wrote:

Add FPU test case and verify FPU register get and set APIs, the
FPU width supports 64/128/256 bits.

Signed-off-by: Bibo Mao <[email protected]>
---
   tools/testing/selftests/kvm/Makefile.kvm      |   1 +
   .../kvm/include/loongarch/processor.h         |   8 +
   .../selftests/kvm/loongarch/fpu_test.c        | 145 ++++++++++++++++++
   3 files changed, 154 insertions(+)
   create mode 100644 tools/testing/selftests/kvm/loongarch/fpu_test.c

diff --git a/tools/testing/selftests/kvm/Makefile.kvm 
b/tools/testing/selftests/kvm/Makefile.kvm
index 9118a5a51b89..7d11592b3759 100644
--- a/tools/testing/selftests/kvm/Makefile.kvm
+++ b/tools/testing/selftests/kvm/Makefile.kvm
@@ -224,6 +224,7 @@ TEST_GEN_PROGS_riscv += rseq_test
   TEST_GEN_PROGS_riscv += steal_time

   TEST_GEN_PROGS_loongarch = loongarch/pmu_test
+TEST_GEN_PROGS_loongarch += loongarch/fpu_test
   TEST_GEN_PROGS_loongarch += arch_timer
   TEST_GEN_PROGS_loongarch += coalesced_io_test
   TEST_GEN_PROGS_loongarch += demand_paging_test
diff --git a/tools/testing/selftests/kvm/include/loongarch/processor.h 
b/tools/testing/selftests/kvm/include/loongarch/processor.h
index 2324e311180f..981ae7078354 100644
--- a/tools/testing/selftests/kvm/include/loongarch/processor.h
+++ b/tools/testing/selftests/kvm/include/loongarch/processor.h
@@ -82,6 +82,14 @@
   #define  PLV_MASK                      0x3
   #define LOONGARCH_CSR_PRMD             0x1
   #define LOONGARCH_CSR_EUEN             0x2
+#define  CSR_EUEN_LBTEN_SHIFT          3
+#define  CSR_EUEN_LBTEN                        BIT_ULL(CSR_EUEN_LBTEN_SHIFT)
+#define  CSR_EUEN_LASXEN_SHIFT         2
+#define  CSR_EUEN_LASXEN               BIT_ULL(CSR_EUEN_LASXEN_SHIFT)
+#define  CSR_EUEN_LSXEN_SHIFT          1
+#define  CSR_EUEN_LSXEN                        BIT_ULL(CSR_EUEN_LSXEN_SHIFT)
+#define  CSR_EUEN_FPEN_SHIFT           0
+#define  CSR_EUEN_FPEN                 BIT_ULL(CSR_EUEN_FPEN_SHIFT)
   #define LOONGARCH_CSR_ECFG             0x4
   #define  ECFGB_PMU                     10
   #define  ECFGF_PMU                     (BIT_ULL(ECFGB_PMU))
diff --git a/tools/testing/selftests/kvm/loongarch/fpu_test.c 
b/tools/testing/selftests/kvm/loongarch/fpu_test.c
new file mode 100644
index 000000000000..5bccce9db5d0
--- /dev/null
+++ b/tools/testing/selftests/kvm/loongarch/fpu_test.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdio.h>
+#include <string.h>
+#include "kvm_util.h"
+#include "processor.h"
+#include "loongarch/processor.h"
+
+struct kvm_fpureg __aligned(64) vector = {{1, 2, 3, 4 }};
+
+static void guest_code(void)
+{
+       unsigned long val;
+       struct kvm_fpureg *fp = &vector;
+
+       val = csr_read(LOONGARCH_CSR_EUEN);
+       val |= CSR_EUEN_FPEN | CSR_EUEN_LSXEN | CSR_EUEN_LASXEN;
+       csr_write(val, LOONGARCH_CSR_EUEN);
+
+       __asm__ __volatile__("fld.d $f0, %0, 0\n" : : "r"(fp) : "$f0");
+       GUEST_SYNC(0);
+
+       __asm__ __volatile__("vld $vr0, %0, 0\n" : : "r"(fp) : "$vr0");
+       GUEST_SYNC(1);
+
+       __asm__ __volatile__("xvld $xr0, %0, 0\n" : : "r"(fp) : "$xr0");
+       GUEST_SYNC(2);
+
+       __asm__ __volatile__("fst.d $f0, %0, 0\n" : : "r"(fp) : "memory");
+       GUEST_SYNC(3);
+
+       __asm__ __volatile__("vst $vr0, %0, 0\n" : : "r"(fp) : "memory");
+       GUEST_SYNC(4);
+
+       __asm__ __volatile__("xvst $xr0, %0, 0\n" : : "r"(fp) : "memory");
+       GUEST_SYNC(5);
+
+       GUEST_DONE();
+}
+
+static void run_vcpu(struct kvm_vcpu *vcpu)
+{
+       struct ucall uc;
+       int cont;
+
+       cont = 1;
+       while (cont) {
+               vcpu_run(vcpu);
+
+               switch (get_ucall(vcpu, &uc)) {
+               case UCALL_PRINTF:
+                       printf("%s", (const char *)uc.buffer);
+                       break;
+               case UCALL_DONE:
+                       printf("FPU test PASSED\n");
+                       fallthrough;
+               case UCALL_SYNC:
+                       cont = 0;
+                       break;
+               case UCALL_ABORT:
+                       REPORT_GUEST_ASSERT(uc);
+               default:
+                       TEST_ASSERT(false, "Unexpected exit: %s",
+                               exit_reason_str(vcpu->run->exit_reason));
+               }
+       }
+}
+
+static bool __vm_has_feature(struct kvm_vm *vm, int feature)
+{
+       int ret;
+
+       ret = __kvm_has_device_attr(vm->fd, KVM_LOONGARCH_VM_FEAT_CTRL, 
feature);
+       return !ret;
+}
+
+
+int main(void)
+{
+       struct kvm_vcpu *vcpu;
+       struct kvm_vm *vm;
+       struct kvm_fpu fpu;
+       struct kvm_fpureg *fp = &vector;
+
+       vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+       __TEST_REQUIRE(__vm_has_feature(vm, KVM_LOONGARCH_VM_FEAT_LSX),
+                       "LSX not available, skipping test\n");
+       __TEST_REQUIRE(__vm_has_feature(vm, KVM_LOONGARCH_VM_FEAT_LASX),
+                       "LASX not available, skipping test\n");
Directly use __kvm_has_device_attr() as the first patch, or use
__vm_has_feature() in the first patch?
do you mean something like this?
         ret = __kvm_has_device_attr(vm->fd, KVM_LOONGARCH_VM_FEAT_CTRL,
KVM_LOONGARCH_VM_FEAT_LSX);
         __TEST_REQUIRE(!ret, "LSX not available, skipping test\n");
         ret = __kvm_has_device_attr(vm->fd, KVM_LOONGARCH_VM_FEAT_CTRL,
KVM_LOONGARCH_VM_FEAT_LASX);
         __TEST_REQUIRE(!ret, "LASX not available, skipping test\n");
Yes, I think this is a little better, it removes the inconsistency
between two patch.
ok, will do in this way in the next version.

Regards
Bibo Mao

Huacai


I am ok with both.

BTW, I don't think the __ prefix is necessary.
There seem no unified rules with kvm selftest cases, I have no idea
about this actually. There are __kvm_has_device_attr/__TEST_REQUIRE
public APIs and real usages.

Regards
Bibo Mao

Huacai

+
+       run_vcpu(vcpu);
+       vcpu_fpu_get(vcpu, &fpu);
+       TEST_ASSERT(!memcmp(fpu.fpr, fp, 8), "Wanted 0x%llx from f0, got 
0x%llx",
+                       fp->val64[0], fpu.fpr[0].val64[0]);
+
+       run_vcpu(vcpu);
+       vcpu_fpu_get(vcpu, &fpu);
+       TEST_ASSERT(!memcmp(fpu.fpr, fp, 16), "Wanted 0x%llx %llx from vr0, got 
0x%llx %llx",
+                       fp->val64[0], fp->val64[1],
+                       fpu.fpr[0].val64[0], fpu.fpr[0].val64[1]);
+
+       run_vcpu(vcpu);
+       vcpu_fpu_get(vcpu, &fpu);
+       TEST_ASSERT(!memcmp(fpu.fpr, fp, 32),
+                       "Wanted 0x%llx %llx %llx %llx from xr0, got 0x%llx %llx %llx 
%llx",
+                       fp->val64[0], fp->val64[1], fp->val64[2], fp->val64[3],
+                       fpu.fpr[0].val64[0], fpu.fpr[0].val64[1],
+                       fpu.fpr[0].val64[2], fpu.fpr[0].val64[3]);
+
+       fpu.fpr[0].val64[0] += random();
+       vcpu_fpu_set(vcpu, &fpu);
+       run_vcpu(vcpu);
+       vcpu_fpu_get(vcpu, &fpu);
+       sync_global_from_guest(vm, *fp);
+       TEST_ASSERT(!memcmp(fpu.fpr, fp, 8), "Wanted 0x%llx from f0, got 
0x%llx",
+                       fp->val64[0], fpu.fpr[0].val64[0]);
+
+       fpu.fpr[0].val64[0] += random();
+       fpu.fpr[0].val64[1] += random();
+       vcpu_fpu_set(vcpu, &fpu);
+       run_vcpu(vcpu);
+       vcpu_fpu_get(vcpu, &fpu);
+       sync_global_from_guest(vm, *fp);
+       TEST_ASSERT(!memcmp(fpu.fpr, fp, 16), "Wanted 0x%llx %llx from vr0, got 
0x%llx %llx",
+                       fp->val64[0], fp->val64[1],
+                       fpu.fpr[0].val64[0], fpu.fpr[0].val64[1]);
+
+       fpu.fpr[0].val64[0] += random();
+       fpu.fpr[0].val64[1] += random();
+       fpu.fpr[0].val64[2] += random();
+       fpu.fpr[0].val64[3] += random();
+       vcpu_fpu_set(vcpu, &fpu);
+       run_vcpu(vcpu);
+       vcpu_fpu_get(vcpu, &fpu);
+       sync_global_from_guest(vm, *fp);
+       TEST_ASSERT(!memcmp(fpu.fpr, fp, 32),
+                       "Wanted 0x%llx %llx %llx %llx from xr0, got 0x%llx %llx %llx 
%llx",
+                       fp->val64[0], fp->val64[1], fp->val64[2], fp->val64[3],
+                       fpu.fpr[0].val64[0], fpu.fpr[0].val64[1],
+                       fpu.fpr[0].val64[2], fpu.fpr[0].val64[3]);
+
+       run_vcpu(vcpu);
+       kvm_vm_free(vm);
+       return 0;
+}
--
2.39.3




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