On 8/3/22 11:46, Claudio Imbrenda wrote:
On Mon, 25 Jul 2022 13:08:59 +0000 Janosch Frank <frankja@xxxxxxxxxxxxx> wrote:Let's check if the UV really protected all the memory we donated. Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx> --- s390x/uv-host.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/s390x/uv-host.c b/s390x/uv-host.c index dfcebe10..ba6c9008 100644 --- a/s390x/uv-host.c +++ b/s390x/uv-host.c @@ -45,6 +45,32 @@ static void cpu_loop(void) for (;;) {} }+/*+ * Checks if a memory area is protected as secure memory. + * Will return true if all pages are protected, false otherwise. + */ +static bool access_check_3d(uint64_t *access_ptr, uint64_t len) +{ + assert(!(len & ~PAGE_MASK)); + assert(!((uint64_t)access_ptr & ~PAGE_MASK)); + + while (len) { + expect_pgm_int(); + READ_ONCE(*access_ptr); + if (clear_pgm_int() != PGM_INT_CODE_SECURE_STOR_ACCESS) + return false; + expect_pgm_int(); + WRITE_ONCE(*access_ptr, 42); + if (clear_pgm_int() != PGM_INT_CODE_SECURE_STOR_ACCESS) + return false; + + access_ptr += PAGE_SIZE / sizeof(access_ptr);this looks ugly, although in principle the correct way to handle a pointer. In this specific case it's techically wrong though (you actually want sizeof(*access_ptr) ) what about making access_ptr a char*? then you can do just access_ptr += PAGE_SIZE; and you can keep the READ_ONCE and WRITE_ONCE as they are
Sure
+ len -= PAGE_SIZE; + } + + return true; +} + static struct cmd_list cmds[] = { { "init", UVC_CMD_INIT_UV, sizeof(struct uv_cb_init), BIT_UVC_CMD_INIT_UV }, { "create conf", UVC_CMD_CREATE_SEC_CONF, sizeof(struct uv_cb_cgc), BIT_UVC_CMD_CREATE_SEC_CONF }, @@ -332,6 +358,10 @@ static void test_cpu_create(void) report(rc == 0 && uvcb_csc.header.rc == UVC_RC_EXECUTED && uvcb_csc.cpu_handle, "success");+ rc = access_check_3d((uint64_t *)uvcb_csc.stor_origin,+ uvcb_qui.cpu_stor_len); + report(rc, "Storage protection"); + tmp = uvcb_csc.stor_origin; uvcb_csc.stor_origin = (unsigned long)memalign(PAGE_SIZE, uvcb_qui.cpu_stor_len); rc = uv_call(0, (uint64_t)&uvcb_csc); @@ -430,6 +460,13 @@ static void test_config_create(void) rc = uv_call(0, (uint64_t)&uvcb_cgc); report(rc == 0 && uvcb_cgc.header.rc == UVC_RC_EXECUTED, "successful");+ rc = access_check_3d((uint64_t *)uvcb_cgc.conf_var_stor_origin, vsize);+ report(rc, "Base storage protection"); + + rc = access_check_3d((uint64_t *)uvcb_cgc.conf_base_stor_origin, + uvcb_qui.conf_base_phys_stor_len); + report(rc, "Variable storage protection"); + uvcb_cgc.header.rc = 0; uvcb_cgc.header.rrc = 0; tmp = uvcb_cgc.guest_handle;
