selftests: kvm: try getting XFD and XSAVE state out of sync

The host is allowed to set FPU state that includes a disabled
xstate component.  Check that this does not cause bad effects.

Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/tools/testing/selftests/kvm/x86/amx_test.c b/tools/testing/selftests/kvm/x86/amx_test.c
index 3de4402ac17dee113dc1f13baf8477de20a061c2..bee56c1f783399fde31b1636d17f5d8c7f7da074 100644 (file)
--- a/tools/testing/selftests/kvm/x86/amx_test.c
+++ b/tools/testing/selftests/kvm/x86/amx_test.c
@@ -125,11 +125,17 @@ static void set_tilecfg(struct tile_config *cfg)
 }
 
 enum {
+       /* Retrieve TMM0 from guest, stash it for TEST_RESTORE_TILEDATA */
+       TEST_SAVE_TILEDATA = 1,
+
        /* Check TMM0 against tiledata */
-       TEST_COMPARE_TILEDATA = 1,
+       TEST_COMPARE_TILEDATA = 2,
+
+       /* Restore TMM0 from earlier save */
+       TEST_RESTORE_TILEDATA = 4,
 
        /* Full VM save/restore */
-       TEST_SAVE_RESTORE = 2,
+       TEST_SAVE_RESTORE = 8,
 };
 
 static void __attribute__((__flatten__)) guest_code(struct tile_config *amx_cfg,
@@ -150,7 +156,16 @@ static void __attribute__((__flatten__)) guest_code(struct tile_config *amx_cfg,
        GUEST_SYNC(TEST_SAVE_RESTORE);
        /* Check save/restore when trap to userspace */
        __tileloadd(tiledata);
-       GUEST_SYNC(TEST_COMPARE_TILEDATA | TEST_SAVE_RESTORE);
+       GUEST_SYNC(TEST_SAVE_TILEDATA | TEST_COMPARE_TILEDATA | TEST_SAVE_RESTORE);
+
+       /* xfd=0x40000, disable amx tiledata */
+       wrmsr(MSR_IA32_XFD, XFEATURE_MASK_XTILE_DATA);
+
+       /* host tries setting tiledata while guest XFD is set */
+       GUEST_SYNC(TEST_RESTORE_TILEDATA);
+       GUEST_SYNC(TEST_SAVE_RESTORE);
+
+       wrmsr(MSR_IA32_XFD, 0);
        __tilerelease();
        GUEST_SYNC(TEST_SAVE_RESTORE);
        /*
@@ -210,10 +225,10 @@ int main(int argc, char *argv[])
        struct kvm_vcpu *vcpu;
        struct kvm_vm *vm;
        struct kvm_x86_state *state;
+       struct kvm_x86_state *tile_state = NULL;
        int xsave_restore_size;
        vm_vaddr_t amx_cfg, tiledata, xstate;
        struct ucall uc;
-       u32 amx_offset;
        int ret;
 
        /*
@@ -265,20 +280,27 @@ int main(int argc, char *argv[])
                        /* NOT REACHED */
                case UCALL_SYNC:
                        ++iter;
+                       if (uc.args[1] & TEST_SAVE_TILEDATA) {
+                               fprintf(stderr, "GUEST_SYNC #%d, save tiledata\n", iter);
+                               tile_state = vcpu_save_state(vcpu);
+                       }
                        if (uc.args[1] & TEST_COMPARE_TILEDATA) {
                                fprintf(stderr, "GUEST_SYNC #%d, check TMM0 contents\n", iter);
 
                                /* 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(vcpu);
-                               void *amx_start = (void *)state->xsave + amx_offset;
+                               u32 amx_offset = xsave_restore_size - NUM_TILES*TILE_SIZE;
+                               void *amx_start = (void *)tile_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", ret);
-                               kvm_x86_state_cleanup(state);
+                       }
+                       if (uc.args[1] & TEST_RESTORE_TILEDATA) {
+                               fprintf(stderr, "GUEST_SYNC #%d, before KVM_SET_XSAVE\n", iter);
+                               vcpu_xsave_set(vcpu, tile_state->xsave);
+                               fprintf(stderr, "GUEST_SYNC #%d, after KVM_SET_XSAVE\n", iter);
                        }
                        if (uc.args[1] & TEST_SAVE_RESTORE) {
                                fprintf(stderr, "GUEST_SYNC #%d, save/restore VM state\n", iter);