On 12/22/21 00:15, Yang Zhong wrote:
This selftest do two test cases, one is to trigger #NM
exception and check MSR XFD_ERR value. Another case is
guest load tile data into tmm0 registers and trap to host
side to check memory data after save/restore.
Signed-off-by: Yang Zhong <yang.zhong@xxxxxxxxx>
This is a great start, mainly I'd add a lot more GUEST_SYNCs.
Basically any instruction after the initial GUEST_ASSERTs are a
potential point for GUEST_SYNC, except right after the call to set_tilecfg:
GUEST_SYNC(1)
+ /* xfd=0, enable amx */
+ wrmsr(MSR_IA32_XFD, 0);
GUEST_SYNC(2)
+ GUEST_ASSERT(rdmsr(MSR_IA32_XFD) == 0);
+ set_tilecfg(amx_cfg);
+ __ldtilecfg(amx_cfg);
GUEST_SYNC(3)
+ /* Check save/restore when trap to userspace */
+ __tileloadd(tiledata);
+ GUEST_SYNC(1);
This would become 4; here add tilerelease+GUEST_SYNC(5)+XSAVEC, and
check that state 18 is not included in XCOMP_BV.
+ /* xfd=0x40000, disable amx tiledata */
+ wrmsr(MSR_IA32_XFD, XFEATURE_MASK_XTILEDATA);
GUEST_SYNC(6)
+ GUEST_ASSERT(rdmsr(MSR_IA32_XFD) == XFEATURE_MASK_XTILEDATA);
+ set_tilecfg(amx_cfg);
+ __ldtilecfg(amx_cfg);
+ /* Trigger #NM exception */
+ __tileloadd(tiledata);
GUEST_SYNC(10); this final GUEST_SYNC should also check TMM0 in the host.
+ GUEST_DONE();
+}
+
+void guest_nm_handler(struct ex_regs *regs)
+{
+ /* Check if #NM is triggered by XFEATURE_MASK_XTILEDATA */
GUEST_SYNC(7)
+ GUEST_ASSERT(rdmsr(MSR_IA32_XFD_ERR) == XFEATURE_MASK_XTILEDATA);
+ /* Clear xfd_err */
Same here, I'd do a GUEST_SYNC(8) and re-read MSR_IA32_XFD_ERR.
+ wrmsr(MSR_IA32_XFD_ERR, 0);
+ GUEST_SYNC(2);
This becomes GUEST_SYNC(9).
+}
+ case UCALL_SYNC:
+ switch (uc.args[1]) {
+ case 1:
+ fprintf(stderr,
+ "Exit VM by GUEST_SYNC(1), check save/restore.\n");
+
+ /* Compacted mode, get amx offset by xsave area
+ * size subtract 8K amx size.
+ */
+ amx_offset = xsave_restore_size - NUM_TILES*TILE_SIZE;
+ state = vcpu_save_state(vm, VCPU_ID);
+ void *amx_start = (void *)state->xsave + amx_offset;
+ void *tiles_data = (void *)addr_gva2hva(vm, tiledata);
+ /* Only check TMM0 register, 1 tile */
+ ret = memcmp(amx_start, tiles_data, TILE_SIZE);
+ TEST_ASSERT(ret == 0, "memcmp failed, ret=%d\n", ret);
+ kvm_x86_state_cleanup(state);
+ break;
All GUEST_SYNCs should do save_state/load_state like state_test.c. Then
of course you can *also* check TMM0 after __tileloadd, which would be
cases 4 and 10.
Thanks,
Paolo
+ case 2:
+ fprintf(stderr,
+ "Exit VM by GUEST_SYNC(2), generate #NM exception.\n");
+ goto done;
+ }
+ break;
+ case UCALL_DONE:
+ goto done;
+ default:
+ TEST_FAIL("Unknown ucall %lu", uc.cmd);
+ }
+ }
+done:
+ kvm_vm_free(vm);
+}
