On 11/12/19 21:22, Jim Mattson wrote:
> On Wed, Feb 20, 2019 at 12:25 PM Peter Shier <pshier@xxxxxxxxxx> wrote:
>>
>> The GNU assembler (gas) allows omitting operands where there is only a
>> single choice e.g. "VMRUN rAX".The LLVM assembler requires those operands
>> even though they are the default and only choice.
>>
>> In addition, LLVM does not allow a CLGI instruction with a terminating
>> \n\t. Adding a ; separator after the instruction is a workaround.
>>
>> Signed-off-by: Peter Shier <pshier@xxxxxxxxxx>
>> Reviewed-by: Marc Orr <marcorr@xxxxxxxxxx>
>> Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>
>> ---
>> x86/svm.c | 16 ++++++++--------
>> 1 file changed, 8 insertions(+), 8 deletions(-)
>>
>> diff --git a/x86/svm.c b/x86/svm.c
>> index bc74e7c690a8..e5cb730b08cb 100644
>> --- a/x86/svm.c
>> +++ b/x86/svm.c
>> @@ -154,7 +154,7 @@ static void vmcb_ident(struct vmcb *vmcb)
>> struct descriptor_table_ptr desc_table_ptr;
>>
>> memset(vmcb, 0, sizeof(*vmcb));
>> - asm volatile ("vmsave" : : "a"(vmcb_phys) : "memory");
>> + asm volatile ("vmsave %0" : : "a"(vmcb_phys) : "memory");
>> vmcb_set_seg(&save->es, read_es(), 0, -1U, data_seg_attr);
>> vmcb_set_seg(&save->cs, read_cs(), 0, -1U, code_seg_attr);
>> vmcb_set_seg(&save->ss, read_ss(), 0, -1U, data_seg_attr);
>> @@ -262,20 +262,20 @@ static void test_run(struct test *test, struct vmcb *vmcb)
>> do {
>> tsc_start = rdtsc();
>> asm volatile (
>> - "clgi \n\t"
>> - "vmload \n\t"
>> + "clgi;\n\t" // semi-colon needed for LLVM compatibility
>> + "vmload %0\n\t"
>> "mov regs+0x80, %%r15\n\t" // rflags
>> "mov %%r15, 0x170(%0)\n\t"
>> "mov regs, %%r15\n\t" // rax
>> "mov %%r15, 0x1f8(%0)\n\t"
>> LOAD_GPR_C
>> - "vmrun \n\t"
>> + "vmrun %0\n\t"
>> SAVE_GPR_C
>> "mov 0x170(%0), %%r15\n\t" // rflags
>> "mov %%r15, regs+0x80\n\t"
>> "mov 0x1f8(%0), %%r15\n\t" // rax
>> "mov %%r15, regs\n\t"
>> - "vmsave \n\t"
>> + "vmsave %0\n\t"
>> "stgi"
>> : : "a"(vmcb_phys)
>> : "rbx", "rcx", "rdx", "rsi",
>> @@ -330,7 +330,7 @@ static bool check_no_vmrun_int(struct test *test)
>>
>> static void test_vmrun(struct test *test)
>> {
>> - asm volatile ("vmrun" : : "a"(virt_to_phys(test->vmcb)));
>> + asm volatile ("vmrun %0" : : "a"(virt_to_phys(test->vmcb)));
>> }
>>
>> static bool check_vmrun(struct test *test)
>> @@ -1241,7 +1241,7 @@ static bool lat_svm_insn_finished(struct test *test)
>>
>> for ( ; runs != 0; runs--) {
>> tsc_start = rdtsc();
>> - asm volatile("vmload\n\t" : : "a"(vmcb_phys) : "memory");
>> + asm volatile("vmload %0\n\t" : : "a"(vmcb_phys) : "memory");
>> cycles = rdtsc() - tsc_start;
>> if (cycles > latvmload_max)
>> latvmload_max = cycles;
>> @@ -1250,7 +1250,7 @@ static bool lat_svm_insn_finished(struct test *test)
>> vmload_sum += cycles;
>>
>> tsc_start = rdtsc();
>> - asm volatile("vmsave\n\t" : : "a"(vmcb_phys) : "memory");
>> + asm volatile("vmsave %0\n\t" : : "a"(vmcb_phys) : "memory");
>> cycles = rdtsc() - tsc_start;
>> if (cycles > latvmsave_max)
>> latvmsave_max = cycles;
>
> Ping.
>
I am applying it, but I'm seriously puzzled by the clgi one. Can you
open a bug on LLVM?
Paolo
