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.
