From patchwork Wed Aug 10 01:59:37 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suraj Jitindar Singh X-Patchwork-Id: 9272501 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id DF33660231 for ; Wed, 10 Aug 2016 02:01:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A629628358 for ; Wed, 10 Aug 2016 02:01:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 95D8F28375; Wed, 10 Aug 2016 02:01:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F211A28358 for ; Wed, 10 Aug 2016 02:01:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932654AbcHJCBG (ORCPT ); Tue, 9 Aug 2016 22:01:06 -0400 Received: from mail-pa0-f67.google.com ([209.85.220.67]:34793 "EHLO mail-pa0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932540AbcHJCBD (ORCPT ); Tue, 9 Aug 2016 22:01:03 -0400 Received: by mail-pa0-f67.google.com with SMTP id hh10so1888035pac.1; Tue, 09 Aug 2016 19:00:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=xuwM5ig5JlV0GctnYviTmGhGDa8pq1EGhhO7zL2esZs=; b=BQEqRh2/7ZAsj7fpwE6yON0RZVvF7qyj6gUuF8+NeSteD0SHzulHpvuB8w8UaOkU6N Vb6LAkpb6QRHrU2Jl4EvVjvoQ4YciR9xl0yifPMXC2c9qjfWv73l0qA5t1Q6kt1XiGAY yKV+4t/HPhZeEcdQ62N79YYO0OoEljzQgaaLCBB1n16b9kHy4gssABK/MSTUQSuVMv0m XM5faRu0p5F671iuxWiZtj4xMSBuN+lLlPuFOXWQlle7IAYT9COMGna7oUA+FyiZ0Zuq 7EnmRX9sr33cbTJ2uQOxKa2EaLm0/7mO0J+uwYwKCMGhCM6EAuKE93tCNqzEXLdHO/gH NWmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=xuwM5ig5JlV0GctnYviTmGhGDa8pq1EGhhO7zL2esZs=; b=bG6SLxk5Yie4jYOzdRc8mWaPv7sdxnQBy6HBEqY/OtmkKDY8X/qmgpENp7PwJ5kUxO UlY5x7QkdS7sXFKe9E+Ay/98kaUcNmTk+ODSNn7MZNwR0MRN6mi31bb15zSuNyyPXq29 X9AE+bvSXvab89858QKciPu1a5HQCTu1fT2sWK3SMWjyZoCywIg9XORxJd++/lfL3ZAu VN/DwyaOfBB/HmkW6nEeEjeWunN7wFvjz+VPyou4yw+GvKB/UExIhJxTXGWDtE19bl+G VOyyPbpXNBuezOxQxOho/KWJ/xEyiBYR5aPbecMdnmSFkQhdSiFj/eyoGiHZiQfH98Dx TzuA== X-Gm-Message-State: AEkoouscLLX7ikpGulmqeD3rcNI6GmGXEEJ0nv/HVcHqPp35RXF493Qs9MuZmHvRJKP45A== X-Received: by 10.66.76.132 with SMTP id k4mr2617621paw.22.1470794406239; Tue, 09 Aug 2016 19:00:06 -0700 (PDT) Received: from dyn253.ozlabs.ibm.com ([122.99.82.10]) by smtp.gmail.com with ESMTPSA id n69sm58888633pfa.77.2016.08.09.19.00.01 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 09 Aug 2016 19:00:05 -0700 (PDT) From: Suraj Jitindar Singh To: kvm@vger.kernel.org Cc: sjitindarsingh@gmail.com, pbonzini@redhat.com, rkrcmar@redhat.com, kvm-ppc@vger.kernel.org, lvivier@redhat.com, thuth@redhat.com, drjones@redhat.com Subject: [kvm-unit-tests PATCH V2 4/4] powerpc/tm: Add a test for H_CEDE while tm suspended Date: Wed, 10 Aug 2016 11:59:37 +1000 Message-Id: <1470794377-14427-4-git-send-email-sjitindarsingh@gmail.com> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1470794377-14427-1-git-send-email-sjitindarsingh@gmail.com> References: <1470794377-14427-1-git-send-email-sjitindarsingh@gmail.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Power machines if a guest cedes while a tm transaction is in the suspended state then the checkpointed state of the vcpu may be lost and we lose the cpu in the host. Add a file for tm tests "powerpc/tm.c" and add a test to check if the fix has been applied to the host kernel. If this fix hasn't been applied then the test will never complete and the cpu will be lost. Otherwise the test should succeed. Since this has the ability to mess things up in the host mark this test as don't run by default. Based on initial work done by: Cyril Bur Signed-off-by: Suraj Jitindar Singh --- lib/powerpc/asm/hcall.h | 1 + powerpc/Makefile.common | 3 +- powerpc/tm.c | 176 ++++++++++++++++++++++++++++++++++++++++++++++++ powerpc/unittests.cfg | 6 ++ 4 files changed, 185 insertions(+), 1 deletion(-) create mode 100644 powerpc/tm.c diff --git a/lib/powerpc/asm/hcall.h b/lib/powerpc/asm/hcall.h index 99bce79..80aa3e3 100644 --- a/lib/powerpc/asm/hcall.h +++ b/lib/powerpc/asm/hcall.h @@ -18,6 +18,7 @@ #define H_SET_SPRG0 0x24 #define H_SET_DABR 0x28 #define H_PAGE_INIT 0x2c +#define H_CEDE 0xE0 #define H_PUT_TERM_CHAR 0x58 #define H_RANDOM 0x300 #define H_SET_MODE 0x31C diff --git a/powerpc/Makefile.common b/powerpc/Makefile.common index 677030a..93e4f66 100644 --- a/powerpc/Makefile.common +++ b/powerpc/Makefile.common @@ -8,7 +8,8 @@ tests-common = \ $(TEST_DIR)/selftest.elf \ $(TEST_DIR)/spapr_hcall.elf \ $(TEST_DIR)/rtas.elf \ - $(TEST_DIR)/emulator.elf + $(TEST_DIR)/emulator.elf \ + $(TEST_DIR)/tm.elf all: $(TEST_DIR)/boot_rom.bin test_cases diff --git a/powerpc/tm.c b/powerpc/tm.c new file mode 100644 index 0000000..7f675ff --- /dev/null +++ b/powerpc/tm.c @@ -0,0 +1,176 @@ +/* + * Transactional Memory Unit Tests + * + * Copyright 2016 Suraj Jitindar Singh, IBM. + * + * This work is licensed under the terms of the GNU LGPL, version 2. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define US_TO_CYCLES(us) (us << 9) + +/* + * Get decrementer value + */ +static uint64_t get_dec(void) +{ + uint64_t dec = 0; + + asm volatile ( "mfdec %[dec]" : [dec] "+r" (dec) + : + : + ); + + return dec; +} + +/* + * Sleep for micro-seconds (must be less than 4 seconds) + */ +static void sleep(uint64_t us) +{ + uint64_t expire_time, dec, cycles = US_TO_CYCLES(us); + + if (cycles > 0x7FFFFFFF) + cycles = 0x7FFFFFFF; + + if (cycles > (dec = get_dec())) { + expire_time = 0x7FFFFFFF + dec - cycles; + while (get_dec() < dec) + ; + } else { + expire_time = dec - cycles; + } + + while (get_dec() > expire_time) + ; +} + +static int h_cede(void) +{ + register uint64_t r3 asm("r3") = H_CEDE; + + asm volatile ( "sc 1" : "+r"(r3) + : + : "r0", "r4", "r5", "r6", "r7", "r8", "r9", + "r10", "r11", "r12", "xer", "ctr", "cc" + ); + + return r3; +} + +/* + * Enable transactional memory + * Returns: 0 - Failure + * 1 - Success + */ +static bool enable_tm(void) +{ + uint64_t msr = 0; + + asm volatile ( "mfmsr %[msr]" : [msr] "+r" (msr) + : + : + ); + + msr |= (((uint64_t) 1) << 32); + + asm volatile ( "mtmsrd %1\n\t" + "mfmsr %0" : "+r" (msr) + : "r" (msr) + : + ); + + return !!(msr & (((uint64_t) 1) << 32)); +} + +/* + * Test H_CEDE call while transactional memory transaction is suspended + * + * WARNING: This tests for a known vulnerability in which the host may go down. + * Probably best not to run this if your host going down is going to cause + * problems. + * + * If the test passes then your kernel probably has the necessary patch. + * If the test fails then the H_CEDE call was unsuccessful and the + * vulnerability wasn't tested. + * If the test hits the vulnerability then it will never complete or report and + * the qemu process will block indefinately. RCU stalls will be detected on the + * cpu and any process scheduled on the lost cpu will also block indefinitely. + */ +static void test_h_cede_tm(int argc, char **argv) +{ + bool pass = true; + int i; + + if (argc > 2) + report_abort("Unsupported argument: '%s'", argv[2]); + + handle_exception(0x900, &dec_except_handler, NULL); + + if (!start_all_cpus(&halt, 0)) + report_abort("Failed to start secondary cpus"); + + if (!enable_tm()) + report_abort("Failed to enable tm"); + + /* + * Begin a transaction and guarantee we are in the suspend state + * before continuing + */ + asm volatile ( "1: tbegin.\n\t" + "beq 2f\n\t" + "tsuspend.\n\t" + "2: tcheck cr0\n\t" + "bf 2,1b" : + : + : "cr0" + ); + + for (i = 0; i < 500 && pass; i++) { + uint64_t rval = h_cede(); + + if (rval != H_SUCCESS) + pass = false; + sleep(5000); + } + + report("H_CEDE TM", pass); +} + +struct { + const char *name; + void (*func)(int argc, char **argv); +} hctests[] = { + { "h_cede_tm", test_h_cede_tm }, + { NULL, NULL } +}; + +int main(int argc, char **argv) +{ + bool all = false; + int i; + + report_prefix_push("tm"); + + all = (argc == 1 || (argc == 2 && !strcmp(argv[1], "all"))); + + for (i = 0; hctests[i].name != NULL; i++) { + if (all || strcmp(argv[1], hctests[i].name) == 0) { + report_prefix_push(hctests[i].name); + hctests[i].func(argc, argv); + report_prefix_pop(); + } + } + + return report_summary(); +} diff --git a/powerpc/unittests.cfg b/powerpc/unittests.cfg index 0098cb6..20dbde6 100644 --- a/powerpc/unittests.cfg +++ b/powerpc/unittests.cfg @@ -53,3 +53,9 @@ groups = rtas [emulator] file = emulator.elf + +[h_cede_tm] +file = tm.elf +smp = 2,threads=2 +extra_params = -append "h_cede_tm" +groups = nodefault,h_cede_tm