Building the KVM selftests with LLVM's integrated assembler fails with:
$ CFLAGS=-fintegrated-as make -C tools/testing/selftests/kvm CC=clang
lib/x86_64/svm.c:77:16: error: too few operands for instruction
asm volatile ("vmsave\n\t" : : "a" (vmcb_gpa) : "memory");
^
<inline asm>:1:2: note: instantiated into assembly here
vmsave
^
lib/x86_64/svm.c:134:3: error: too few operands for instruction
"vmload\n\t"
^
<inline asm>:1:2: note: instantiated into assembly here
vmload
^
This is because LLVM IAS does not currently support calling vmsave,
vmload, or vmload without an explicit %rax operand.
Add an explicit operand to vmsave, vmload, and vmrum in svm.c. Fixing
this was suggested by Sean Christopherson.
Tested: building without this error in clang 11. The following patch
(not queued yet) needs to be applied to solve the other remaining error:
"selftests: kvm: remove reassignment of non-absolute variables".
Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Link: https://lore.kernel.org/kvm/X+Df2oQczVBmwEzi@xxxxxxxxxx/
Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>
Signed-off-by: Ricardo Koller <ricarkol@xxxxxxxxxx>
---
tools/testing/selftests/kvm/lib/x86_64/svm.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/x86_64/svm.c b/tools/testing/selftests/kvm/lib/x86_64/svm.c
index 3a5c72ed2b79..827fe6028dd4 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/svm.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/svm.c
@@ -74,7 +74,7 @@ void generic_svm_setup(struct svm_test_data *svm, void *guest_rip, void *guest_r
wrmsr(MSR_VM_HSAVE_PA, svm->save_area_gpa);
memset(vmcb, 0, sizeof(*vmcb));
- asm volatile ("vmsave\n\t" : : "a" (vmcb_gpa) : "memory");
+ asm volatile ("vmsave %0\n\t" : : "a" (vmcb_gpa) : "memory");
vmcb_set_seg(&save->es, get_es(), 0, -1U, data_seg_attr);
vmcb_set_seg(&save->cs, get_cs(), 0, -1U, code_seg_attr);
vmcb_set_seg(&save->ss, get_ss(), 0, -1U, data_seg_attr);
@@ -131,19 +131,19 @@ void generic_svm_setup(struct svm_test_data *svm, void *guest_rip, void *guest_r
void run_guest(struct vmcb *vmcb, uint64_t vmcb_gpa)
{
asm volatile (
- "vmload\n\t"
+ "vmload %[vmcb_gpa]\n\t"
"mov rflags, %%r15\n\t" // rflags
"mov %%r15, 0x170(%[vmcb])\n\t"
"mov guest_regs, %%r15\n\t" // rax
"mov %%r15, 0x1f8(%[vmcb])\n\t"
LOAD_GPR_C
- "vmrun\n\t"
+ "vmrun %[vmcb_gpa]\n\t"
SAVE_GPR_C
"mov 0x170(%[vmcb]), %%r15\n\t" // rflags
"mov %%r15, rflags\n\t"
"mov 0x1f8(%[vmcb]), %%r15\n\t" // rax
"mov %%r15, guest_regs\n\t"
- "vmsave\n\t"
+ "vmsave %[vmcb_gpa]\n\t"
: : [vmcb] "r" (vmcb), [vmcb_gpa] "a" (vmcb_gpa)
: "r15", "memory");
}
--
2.30.0.478.g8a0d178c01-goog
