From patchwork Fri Jul 12 09:39:40 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ravi Bangoria X-Patchwork-Id: 13731533 Received: from NAM11-CO1-obe.outbound.protection.outlook.com (mail-co1nam11on2045.outbound.protection.outlook.com [40.107.220.45]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AEC6213D51E; Fri, 12 Jul 2024 09:41:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.220.45 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720777271; cv=fail; b=lBPxVlSqQqZERXd/W3yyVS/AdrNiHNlpUJe2gBJwtVEYZK2X0eg3vSaHG79ytxhKELBTVxz1AslW9+TvdbhyVyLyP1eMmc911/Hfz721gZAilAHpPGq0pVD8seKY7s+LhjzzZWX1FaIQpIH2zLP0WHK6pHzcmzOO5vDPip9vEuw= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720777271; c=relaxed/simple; bh=FdDutJ0Nr/zgUys2vq1EZNADolPDSMCq7giKnFYf+/o=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=MGsTU2FO8UCVsNvZsh9vh+woSge3PRq6RJbMN6xHhAq0JPKiSnjd1CYODFxTEmHDJuDVEXvVCT6kftiQTpYNo03ab0JBwYhLwqjfC/TQtwlh/rxMZ0FvjhvJhJIbMIq4hbv4HQyY5r5FS80+Llm2Lgzfpc9KWRe1PNMXTe0WF1o= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=R1+cJht4; arc=fail smtp.client-ip=40.107.220.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="R1+cJht4" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=yEL6+V0J/GrN3UJlJR+UFlPETiN28QiYo2Ld7nVUfo7HZdrY/yRMG4KzrJ7GZndcEj0yGIaeWENhxlSa9WhYL0FurIxuxj/CAinByDUftxE/1CF2ZEEAMvVm3/xjt9i7piFRV4YJN/5QktUlmGMx6eZ4bPClqYuCR5Z/SOVCIy7TtLrVoyzfKdhlIA+2Mydg1GywsKkdvdXCMPXdWOdVhxlT48Mdeck9X0hPUPlHCi9gz8NYwNLzvkhoqHfEkgXpI/Wy2i4unAckBbRcycMN1hCHQ9lxNRa0jbwlYKgooJ1evNyxejjRtpjlWK8QDGf215Po0yXwbRbTK4Yl5fYlKg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=G/CdgHy5BLgCrA/MN/TzXfZLXB0KjHLg36W+spRGkPY=; b=DQ3biCe1H7GvMnef5Mrmi5qimtIfy9Kokbxd4jwuNbX00f5rc7CjBh9kD2utybpQMphADGtbtwztGjlEFYnukfVz8E/c2tklGZPtaodTJPOYhVrdHQNnkTIWPmMiDxWowtlMhkXOJ8loUUAYwtvE3hdWY3RdO7VZVHSKDG05y/MupdgylTILIDWf/96pefM3awvAwHaZv7zgyTIIhP+d6aDkpNwyb8JrEmAAYLZKO99k3J3yKdyIU+V3cCnTDi9hBUsi3gjPECLdmVoIjjFiSuh18vfYsLW+Az0oyQhiCzCQZnlWH4WfiBOv89r2kP1LQgf6TPvCUXvlKqPEqllMKw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=linutronix.de smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=G/CdgHy5BLgCrA/MN/TzXfZLXB0KjHLg36W+spRGkPY=; b=R1+cJht4yPPhzq7vHkJ6O2RBHHhXcCkpr1ev4gEbcgQ3m8SyqjWvIkz+HR2Ksj50dW2MW1cneEfzrinvOIsl/Jfulns6LY2irRgoKEi92Zr+ael3KYi+6ooLhIgxdEFu2U8HczhisZD/yrtsd1atKnE9F9c5qfzummUr7L0TRJU= Received: from DS7PR03CA0098.namprd03.prod.outlook.com (2603:10b6:5:3b7::13) by PH8PR12MB7375.namprd12.prod.outlook.com (2603:10b6:510:215::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7741.36; Fri, 12 Jul 2024 09:41:04 +0000 Received: from DS3PEPF0000C37F.namprd04.prod.outlook.com (2603:10b6:5:3b7:cafe::d8) by DS7PR03CA0098.outlook.office365.com (2603:10b6:5:3b7::13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7762.23 via Frontend Transport; Fri, 12 Jul 2024 09:41:04 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C Received: from SATLEXMB04.amd.com (165.204.84.17) by DS3PEPF0000C37F.mail.protection.outlook.com (10.167.23.9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.7762.17 via Frontend Transport; Fri, 12 Jul 2024 09:41:04 +0000 Received: from BLR-L-RBANGORI.amd.com (10.180.168.240) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Fri, 12 Jul 2024 04:40:55 -0500 From: Ravi Bangoria To: , , , , , , CC: , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v2 1/4] x86/split_lock: Move Split and Bus lock code to a dedicated file Date: Fri, 12 Jul 2024 09:39:40 +0000 Message-ID: <20240712093943.1288-2-ravi.bangoria@amd.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240712093943.1288-1-ravi.bangoria@amd.com> References: <20240712093943.1288-1-ravi.bangoria@amd.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: SATLEXMB04.amd.com (10.181.40.145) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS3PEPF0000C37F:EE_|PH8PR12MB7375:EE_ X-MS-Office365-Filtering-Correlation-Id: 74168020-336e-4913-9ae8-08dca256bf93 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|82310400026|1800799024|36860700013; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:SATLEXMB04.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(7416014)(376014)(82310400026)(1800799024)(36860700013);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Jul 2024 09:41:04.3370 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 74168020-336e-4913-9ae8-08dca256bf93 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: DS3PEPF0000C37F.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH8PR12MB7375 Upcoming AMD uarch will support Bus Lock Detect, which functionally works identical to Intel. Move split_lock and bus_lock specific code from intel.c to a dedicated file so that it can be compiled and supported on non-Intel platforms. Signed-off-by: Ravi Bangoria --- arch/x86/include/asm/cpu.h | 4 + arch/x86/kernel/cpu/Makefile | 1 + arch/x86/kernel/cpu/bus_lock.c | 406 +++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/intel.c | 406 --------------------------------- 4 files changed, 411 insertions(+), 406 deletions(-) create mode 100644 arch/x86/kernel/cpu/bus_lock.c diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index aa30fd8cad7f..4b5c31dc8112 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -51,6 +51,10 @@ static inline u8 get_this_hybrid_cpu_type(void) return 0; } #endif + +void split_lock_init(void); +void bus_lock_init(void); + #ifdef CONFIG_IA32_FEAT_CTL void init_ia32_feat_ctl(struct cpuinfo_x86 *c); #else diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index 5857a0f5d514..9f74e0011f01 100644 --- a/arch/x86/kernel/cpu/Makefile +++ b/arch/x86/kernel/cpu/Makefile @@ -27,6 +27,7 @@ obj-y += aperfmperf.o obj-y += cpuid-deps.o obj-y += umwait.o obj-y += capflags.o powerflags.o +obj-y += bus_lock.o obj-$(CONFIG_X86_LOCAL_APIC) += topology.o diff --git a/arch/x86/kernel/cpu/bus_lock.c b/arch/x86/kernel/cpu/bus_lock.c new file mode 100644 index 000000000000..704e9241b964 --- /dev/null +++ b/arch/x86/kernel/cpu/bus_lock.c @@ -0,0 +1,406 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define pr_fmt(fmt) "x86/split lock detection: " fmt + +#include +#include +#include +#include +#include +#include +#include +#include + +enum split_lock_detect_state { + sld_off = 0, + sld_warn, + sld_fatal, + sld_ratelimit, +}; + +/* + * Default to sld_off because most systems do not support split lock detection. + * sld_state_setup() will switch this to sld_warn on systems that support + * split lock/bus lock detect, unless there is a command line override. + */ +static enum split_lock_detect_state sld_state __ro_after_init = sld_off; +static u64 msr_test_ctrl_cache __ro_after_init; + +/* + * With a name like MSR_TEST_CTL it should go without saying, but don't touch + * MSR_TEST_CTL unless the CPU is one of the whitelisted models. Writing it + * on CPUs that do not support SLD can cause fireworks, even when writing '0'. + */ +static bool cpu_model_supports_sld __ro_after_init; + +static const struct { + const char *option; + enum split_lock_detect_state state; +} sld_options[] __initconst = { + { "off", sld_off }, + { "warn", sld_warn }, + { "fatal", sld_fatal }, + { "ratelimit:", sld_ratelimit }, +}; + +static struct ratelimit_state bld_ratelimit; + +static unsigned int sysctl_sld_mitigate = 1; +static DEFINE_SEMAPHORE(buslock_sem, 1); + +#ifdef CONFIG_PROC_SYSCTL +static struct ctl_table sld_sysctls[] = { + { + .procname = "split_lock_mitigate", + .data = &sysctl_sld_mitigate, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_douintvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, +}; + +static int __init sld_mitigate_sysctl_init(void) +{ + register_sysctl_init("kernel", sld_sysctls); + return 0; +} + +late_initcall(sld_mitigate_sysctl_init); +#endif + +static inline bool match_option(const char *arg, int arglen, const char *opt) +{ + int len = strlen(opt), ratelimit; + + if (strncmp(arg, opt, len)) + return false; + + /* + * Min ratelimit is 1 bus lock/sec. + * Max ratelimit is 1000 bus locks/sec. + */ + if (sscanf(arg, "ratelimit:%d", &ratelimit) == 1 && + ratelimit > 0 && ratelimit <= 1000) { + ratelimit_state_init(&bld_ratelimit, HZ, ratelimit); + ratelimit_set_flags(&bld_ratelimit, RATELIMIT_MSG_ON_RELEASE); + return true; + } + + return len == arglen; +} + +static bool split_lock_verify_msr(bool on) +{ + u64 ctrl, tmp; + + if (rdmsrl_safe(MSR_TEST_CTRL, &ctrl)) + return false; + if (on) + ctrl |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT; + else + ctrl &= ~MSR_TEST_CTRL_SPLIT_LOCK_DETECT; + if (wrmsrl_safe(MSR_TEST_CTRL, ctrl)) + return false; + rdmsrl(MSR_TEST_CTRL, tmp); + return ctrl == tmp; +} + +static void __init sld_state_setup(void) +{ + enum split_lock_detect_state state = sld_warn; + char arg[20]; + int i, ret; + + if (!boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) && + !boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) + return; + + ret = cmdline_find_option(boot_command_line, "split_lock_detect", + arg, sizeof(arg)); + if (ret >= 0) { + for (i = 0; i < ARRAY_SIZE(sld_options); i++) { + if (match_option(arg, ret, sld_options[i].option)) { + state = sld_options[i].state; + break; + } + } + } + sld_state = state; +} + +static void __init __split_lock_setup(void) +{ + if (!split_lock_verify_msr(false)) { + pr_info("MSR access failed: Disabled\n"); + return; + } + + rdmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache); + + if (!split_lock_verify_msr(true)) { + pr_info("MSR access failed: Disabled\n"); + return; + } + + /* Restore the MSR to its cached value. */ + wrmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache); + + setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT); +} + +/* + * MSR_TEST_CTRL is per core, but we treat it like a per CPU MSR. Locking + * is not implemented as one thread could undo the setting of the other + * thread immediately after dropping the lock anyway. + */ +static void sld_update_msr(bool on) +{ + u64 test_ctrl_val = msr_test_ctrl_cache; + + if (on) + test_ctrl_val |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT; + + wrmsrl(MSR_TEST_CTRL, test_ctrl_val); +} + +void split_lock_init(void) +{ + /* + * #DB for bus lock handles ratelimit and #AC for split lock is + * disabled. + */ + if (sld_state == sld_ratelimit) { + split_lock_verify_msr(false); + return; + } + + if (cpu_model_supports_sld) + split_lock_verify_msr(sld_state != sld_off); +} + +static void __split_lock_reenable_unlock(struct work_struct *work) +{ + sld_update_msr(true); + up(&buslock_sem); +} + +static DECLARE_DELAYED_WORK(sl_reenable_unlock, __split_lock_reenable_unlock); + +static void __split_lock_reenable(struct work_struct *work) +{ + sld_update_msr(true); +} +static DECLARE_DELAYED_WORK(sl_reenable, __split_lock_reenable); + +/* + * If a CPU goes offline with pending delayed work to re-enable split lock + * detection then the delayed work will be executed on some other CPU. That + * handles releasing the buslock_sem, but because it executes on a + * different CPU probably won't re-enable split lock detection. This is a + * problem on HT systems since the sibling CPU on the same core may then be + * left running with split lock detection disabled. + * + * Unconditionally re-enable detection here. + */ +static int splitlock_cpu_offline(unsigned int cpu) +{ + sld_update_msr(true); + + return 0; +} + +static void split_lock_warn(unsigned long ip) +{ + struct delayed_work *work; + int cpu; + + if (!current->reported_split_lock) + pr_warn_ratelimited("#AC: %s/%d took a split_lock trap at address: 0x%lx\n", + current->comm, current->pid, ip); + current->reported_split_lock = 1; + + if (sysctl_sld_mitigate) { + /* + * misery factor #1: + * sleep 10ms before trying to execute split lock. + */ + if (msleep_interruptible(10) > 0) + return; + /* + * Misery factor #2: + * only allow one buslocked disabled core at a time. + */ + if (down_interruptible(&buslock_sem) == -EINTR) + return; + work = &sl_reenable_unlock; + } else { + work = &sl_reenable; + } + + cpu = get_cpu(); + schedule_delayed_work_on(cpu, work, 2); + + /* Disable split lock detection on this CPU to make progress */ + sld_update_msr(false); + put_cpu(); +} + +bool handle_guest_split_lock(unsigned long ip) +{ + if (sld_state == sld_warn) { + split_lock_warn(ip); + return true; + } + + pr_warn_once("#AC: %s/%d %s split_lock trap at address: 0x%lx\n", + current->comm, current->pid, + sld_state == sld_fatal ? "fatal" : "bogus", ip); + + current->thread.error_code = 0; + current->thread.trap_nr = X86_TRAP_AC; + force_sig_fault(SIGBUS, BUS_ADRALN, NULL); + return false; +} +EXPORT_SYMBOL_GPL(handle_guest_split_lock); + +void bus_lock_init(void) +{ + u64 val; + + if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) + return; + + rdmsrl(MSR_IA32_DEBUGCTLMSR, val); + + if ((boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) && + (sld_state == sld_warn || sld_state == sld_fatal)) || + sld_state == sld_off) { + /* + * Warn and fatal are handled by #AC for split lock if #AC for + * split lock is supported. + */ + val &= ~DEBUGCTLMSR_BUS_LOCK_DETECT; + } else { + val |= DEBUGCTLMSR_BUS_LOCK_DETECT; + } + + wrmsrl(MSR_IA32_DEBUGCTLMSR, val); +} + +bool handle_user_split_lock(struct pt_regs *regs, long error_code) +{ + if ((regs->flags & X86_EFLAGS_AC) || sld_state == sld_fatal) + return false; + split_lock_warn(regs->ip); + return true; +} + +void handle_bus_lock(struct pt_regs *regs) +{ + switch (sld_state) { + case sld_off: + break; + case sld_ratelimit: + /* Enforce no more than bld_ratelimit bus locks/sec. */ + while (!__ratelimit(&bld_ratelimit)) + msleep(20); + /* Warn on the bus lock. */ + fallthrough; + case sld_warn: + pr_warn_ratelimited("#DB: %s/%d took a bus_lock trap at address: 0x%lx\n", + current->comm, current->pid, regs->ip); + break; + case sld_fatal: + force_sig_fault(SIGBUS, BUS_ADRALN, NULL); + break; + } +} + +/* + * CPU models that are known to have the per-core split-lock detection + * feature even though they do not enumerate IA32_CORE_CAPABILITIES. + */ +static const struct x86_cpu_id split_lock_cpu_ids[] __initconst = { + X86_MATCH_VFM(INTEL_ICELAKE_X, 0), + X86_MATCH_VFM(INTEL_ICELAKE_L, 0), + X86_MATCH_VFM(INTEL_ICELAKE_D, 0), + {} +}; + +static void __init split_lock_setup(struct cpuinfo_x86 *c) +{ + const struct x86_cpu_id *m; + u64 ia32_core_caps; + + if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) + return; + + /* Check for CPUs that have support but do not enumerate it: */ + m = x86_match_cpu(split_lock_cpu_ids); + if (m) + goto supported; + + if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES)) + return; + + /* + * Not all bits in MSR_IA32_CORE_CAPS are architectural, but + * MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT is. All CPUs that set + * it have split lock detection. + */ + rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps); + if (ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT) + goto supported; + + /* CPU is not in the model list and does not have the MSR bit: */ + return; + +supported: + cpu_model_supports_sld = true; + __split_lock_setup(); +} + +static void sld_state_show(void) +{ + if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT) && + !boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) + return; + + switch (sld_state) { + case sld_off: + pr_info("disabled\n"); + break; + case sld_warn: + if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) { + pr_info("#AC: crashing the kernel on kernel split_locks and warning on user-space split_locks\n"); + if (cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, + "x86/splitlock", NULL, splitlock_cpu_offline) < 0) + pr_warn("No splitlock CPU offline handler\n"); + } else if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) { + pr_info("#DB: warning on user-space bus_locks\n"); + } + break; + case sld_fatal: + if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) { + pr_info("#AC: crashing the kernel on kernel split_locks and sending SIGBUS on user-space split_locks\n"); + } else if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) { + pr_info("#DB: sending SIGBUS on user-space bus_locks%s\n", + boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) ? + " from non-WB" : ""); + } + break; + case sld_ratelimit: + if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) + pr_info("#DB: setting system wide bus lock rate limit to %u/sec\n", bld_ratelimit.burst); + break; + } +} + +void __init sld_setup(struct cpuinfo_x86 *c) +{ + split_lock_setup(c); + sld_state_setup(); + sld_state_show(); +} diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 08b95a35b5cb..8a483f4ad026 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -7,13 +7,9 @@ #include #include #include -#include #include #include #include -#include -#include -#include #include #include @@ -24,8 +20,6 @@ #include #include #include -#include -#include #include #include #include @@ -41,28 +35,6 @@ #include #endif -enum split_lock_detect_state { - sld_off = 0, - sld_warn, - sld_fatal, - sld_ratelimit, -}; - -/* - * Default to sld_off because most systems do not support split lock detection. - * sld_state_setup() will switch this to sld_warn on systems that support - * split lock/bus lock detect, unless there is a command line override. - */ -static enum split_lock_detect_state sld_state __ro_after_init = sld_off; -static u64 msr_test_ctrl_cache __ro_after_init; - -/* - * With a name like MSR_TEST_CTL it should go without saying, but don't touch - * MSR_TEST_CTL unless the CPU is one of the whitelisted models. Writing it - * on CPUs that do not support SLD can cause fireworks, even when writing '0'. - */ -static bool cpu_model_supports_sld __ro_after_init; - /* * Processors which have self-snooping capability can handle conflicting * memory type across CPUs by snooping its own cache. However, there exists @@ -547,9 +519,6 @@ static void init_intel_misc_features(struct cpuinfo_x86 *c) wrmsrl(MSR_MISC_FEATURES_ENABLES, msr); } -static void split_lock_init(void); -static void bus_lock_init(void); - static void init_intel(struct cpuinfo_x86 *c) { early_init_intel(c); @@ -907,381 +876,6 @@ static const struct cpu_dev intel_cpu_dev = { cpu_dev_register(intel_cpu_dev); -#undef pr_fmt -#define pr_fmt(fmt) "x86/split lock detection: " fmt - -static const struct { - const char *option; - enum split_lock_detect_state state; -} sld_options[] __initconst = { - { "off", sld_off }, - { "warn", sld_warn }, - { "fatal", sld_fatal }, - { "ratelimit:", sld_ratelimit }, -}; - -static struct ratelimit_state bld_ratelimit; - -static unsigned int sysctl_sld_mitigate = 1; -static DEFINE_SEMAPHORE(buslock_sem, 1); - -#ifdef CONFIG_PROC_SYSCTL -static struct ctl_table sld_sysctls[] = { - { - .procname = "split_lock_mitigate", - .data = &sysctl_sld_mitigate, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = proc_douintvec_minmax, - .extra1 = SYSCTL_ZERO, - .extra2 = SYSCTL_ONE, - }, -}; - -static int __init sld_mitigate_sysctl_init(void) -{ - register_sysctl_init("kernel", sld_sysctls); - return 0; -} - -late_initcall(sld_mitigate_sysctl_init); -#endif - -static inline bool match_option(const char *arg, int arglen, const char *opt) -{ - int len = strlen(opt), ratelimit; - - if (strncmp(arg, opt, len)) - return false; - - /* - * Min ratelimit is 1 bus lock/sec. - * Max ratelimit is 1000 bus locks/sec. - */ - if (sscanf(arg, "ratelimit:%d", &ratelimit) == 1 && - ratelimit > 0 && ratelimit <= 1000) { - ratelimit_state_init(&bld_ratelimit, HZ, ratelimit); - ratelimit_set_flags(&bld_ratelimit, RATELIMIT_MSG_ON_RELEASE); - return true; - } - - return len == arglen; -} - -static bool split_lock_verify_msr(bool on) -{ - u64 ctrl, tmp; - - if (rdmsrl_safe(MSR_TEST_CTRL, &ctrl)) - return false; - if (on) - ctrl |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT; - else - ctrl &= ~MSR_TEST_CTRL_SPLIT_LOCK_DETECT; - if (wrmsrl_safe(MSR_TEST_CTRL, ctrl)) - return false; - rdmsrl(MSR_TEST_CTRL, tmp); - return ctrl == tmp; -} - -static void __init sld_state_setup(void) -{ - enum split_lock_detect_state state = sld_warn; - char arg[20]; - int i, ret; - - if (!boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) && - !boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) - return; - - ret = cmdline_find_option(boot_command_line, "split_lock_detect", - arg, sizeof(arg)); - if (ret >= 0) { - for (i = 0; i < ARRAY_SIZE(sld_options); i++) { - if (match_option(arg, ret, sld_options[i].option)) { - state = sld_options[i].state; - break; - } - } - } - sld_state = state; -} - -static void __init __split_lock_setup(void) -{ - if (!split_lock_verify_msr(false)) { - pr_info("MSR access failed: Disabled\n"); - return; - } - - rdmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache); - - if (!split_lock_verify_msr(true)) { - pr_info("MSR access failed: Disabled\n"); - return; - } - - /* Restore the MSR to its cached value. */ - wrmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache); - - setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT); -} - -/* - * MSR_TEST_CTRL is per core, but we treat it like a per CPU MSR. Locking - * is not implemented as one thread could undo the setting of the other - * thread immediately after dropping the lock anyway. - */ -static void sld_update_msr(bool on) -{ - u64 test_ctrl_val = msr_test_ctrl_cache; - - if (on) - test_ctrl_val |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT; - - wrmsrl(MSR_TEST_CTRL, test_ctrl_val); -} - -static void split_lock_init(void) -{ - /* - * #DB for bus lock handles ratelimit and #AC for split lock is - * disabled. - */ - if (sld_state == sld_ratelimit) { - split_lock_verify_msr(false); - return; - } - - if (cpu_model_supports_sld) - split_lock_verify_msr(sld_state != sld_off); -} - -static void __split_lock_reenable_unlock(struct work_struct *work) -{ - sld_update_msr(true); - up(&buslock_sem); -} - -static DECLARE_DELAYED_WORK(sl_reenable_unlock, __split_lock_reenable_unlock); - -static void __split_lock_reenable(struct work_struct *work) -{ - sld_update_msr(true); -} -static DECLARE_DELAYED_WORK(sl_reenable, __split_lock_reenable); - -/* - * If a CPU goes offline with pending delayed work to re-enable split lock - * detection then the delayed work will be executed on some other CPU. That - * handles releasing the buslock_sem, but because it executes on a - * different CPU probably won't re-enable split lock detection. This is a - * problem on HT systems since the sibling CPU on the same core may then be - * left running with split lock detection disabled. - * - * Unconditionally re-enable detection here. - */ -static int splitlock_cpu_offline(unsigned int cpu) -{ - sld_update_msr(true); - - return 0; -} - -static void split_lock_warn(unsigned long ip) -{ - struct delayed_work *work; - int cpu; - - if (!current->reported_split_lock) - pr_warn_ratelimited("#AC: %s/%d took a split_lock trap at address: 0x%lx\n", - current->comm, current->pid, ip); - current->reported_split_lock = 1; - - if (sysctl_sld_mitigate) { - /* - * misery factor #1: - * sleep 10ms before trying to execute split lock. - */ - if (msleep_interruptible(10) > 0) - return; - /* - * Misery factor #2: - * only allow one buslocked disabled core at a time. - */ - if (down_interruptible(&buslock_sem) == -EINTR) - return; - work = &sl_reenable_unlock; - } else { - work = &sl_reenable; - } - - cpu = get_cpu(); - schedule_delayed_work_on(cpu, work, 2); - - /* Disable split lock detection on this CPU to make progress */ - sld_update_msr(false); - put_cpu(); -} - -bool handle_guest_split_lock(unsigned long ip) -{ - if (sld_state == sld_warn) { - split_lock_warn(ip); - return true; - } - - pr_warn_once("#AC: %s/%d %s split_lock trap at address: 0x%lx\n", - current->comm, current->pid, - sld_state == sld_fatal ? "fatal" : "bogus", ip); - - current->thread.error_code = 0; - current->thread.trap_nr = X86_TRAP_AC; - force_sig_fault(SIGBUS, BUS_ADRALN, NULL); - return false; -} -EXPORT_SYMBOL_GPL(handle_guest_split_lock); - -static void bus_lock_init(void) -{ - u64 val; - - if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) - return; - - rdmsrl(MSR_IA32_DEBUGCTLMSR, val); - - if ((boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) && - (sld_state == sld_warn || sld_state == sld_fatal)) || - sld_state == sld_off) { - /* - * Warn and fatal are handled by #AC for split lock if #AC for - * split lock is supported. - */ - val &= ~DEBUGCTLMSR_BUS_LOCK_DETECT; - } else { - val |= DEBUGCTLMSR_BUS_LOCK_DETECT; - } - - wrmsrl(MSR_IA32_DEBUGCTLMSR, val); -} - -bool handle_user_split_lock(struct pt_regs *regs, long error_code) -{ - if ((regs->flags & X86_EFLAGS_AC) || sld_state == sld_fatal) - return false; - split_lock_warn(regs->ip); - return true; -} - -void handle_bus_lock(struct pt_regs *regs) -{ - switch (sld_state) { - case sld_off: - break; - case sld_ratelimit: - /* Enforce no more than bld_ratelimit bus locks/sec. */ - while (!__ratelimit(&bld_ratelimit)) - msleep(20); - /* Warn on the bus lock. */ - fallthrough; - case sld_warn: - pr_warn_ratelimited("#DB: %s/%d took a bus_lock trap at address: 0x%lx\n", - current->comm, current->pid, regs->ip); - break; - case sld_fatal: - force_sig_fault(SIGBUS, BUS_ADRALN, NULL); - break; - } -} - -/* - * CPU models that are known to have the per-core split-lock detection - * feature even though they do not enumerate IA32_CORE_CAPABILITIES. - */ -static const struct x86_cpu_id split_lock_cpu_ids[] __initconst = { - X86_MATCH_VFM(INTEL_ICELAKE_X, 0), - X86_MATCH_VFM(INTEL_ICELAKE_L, 0), - X86_MATCH_VFM(INTEL_ICELAKE_D, 0), - {} -}; - -static void __init split_lock_setup(struct cpuinfo_x86 *c) -{ - const struct x86_cpu_id *m; - u64 ia32_core_caps; - - if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) - return; - - /* Check for CPUs that have support but do not enumerate it: */ - m = x86_match_cpu(split_lock_cpu_ids); - if (m) - goto supported; - - if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES)) - return; - - /* - * Not all bits in MSR_IA32_CORE_CAPS are architectural, but - * MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT is. All CPUs that set - * it have split lock detection. - */ - rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps); - if (ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT) - goto supported; - - /* CPU is not in the model list and does not have the MSR bit: */ - return; - -supported: - cpu_model_supports_sld = true; - __split_lock_setup(); -} - -static void sld_state_show(void) -{ - if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT) && - !boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) - return; - - switch (sld_state) { - case sld_off: - pr_info("disabled\n"); - break; - case sld_warn: - if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) { - pr_info("#AC: crashing the kernel on kernel split_locks and warning on user-space split_locks\n"); - if (cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, - "x86/splitlock", NULL, splitlock_cpu_offline) < 0) - pr_warn("No splitlock CPU offline handler\n"); - } else if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) { - pr_info("#DB: warning on user-space bus_locks\n"); - } - break; - case sld_fatal: - if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) { - pr_info("#AC: crashing the kernel on kernel split_locks and sending SIGBUS on user-space split_locks\n"); - } else if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) { - pr_info("#DB: sending SIGBUS on user-space bus_locks%s\n", - boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) ? - " from non-WB" : ""); - } - break; - case sld_ratelimit: - if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) - pr_info("#DB: setting system wide bus lock rate limit to %u/sec\n", bld_ratelimit.burst); - break; - } -} - -void __init sld_setup(struct cpuinfo_x86 *c) -{ - split_lock_setup(c); - sld_state_setup(); - sld_state_show(); -} - #define X86_HYBRID_CPU_TYPE_ID_SHIFT 24 /** From patchwork Fri Jul 12 09:39:41 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ravi Bangoria X-Patchwork-Id: 13731534 Received: from NAM10-BN7-obe.outbound.protection.outlook.com (mail-bn7nam10on2056.outbound.protection.outlook.com [40.107.92.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6333314E2E9; Fri, 12 Jul 2024 09:41:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.92.56 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720777277; cv=fail; b=syQpDtoVbXcBvYM/i00Nu3/kMI04zYXKo6IZEZgxSDcKNCskJ6YhdMk1ExKzPMbF645RmIcOzs/xKjjqIrIrToTzIRa+tPPV22cUIKIryekoYcl6wMn9mvjrXyZqXSqR0VecD4tMHOQIxq3Xy6yZVP6RGU+lnNOH0Kb4uh1ZO2c= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720777277; c=relaxed/simple; bh=ZJeYgHoE2heWABlyYrKq8jcm4ycRim7/NlsjXAcQkRI=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Hu81DS7hTkt6wT0hlIncTGMUhGCP73Q5sO/nPLa7qK5/8ZpjUxUkj7j5k62n1mxUmmhD3OcEvN16N7HatHsX8eZk61b8iuIcytl6fY53CyR+Grr56BytgMmkn0GWxKMyLIHaLhk/sW3bl7JwwL0K9OZQBLGbkIRMk+7GUHlmAqs= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=D+a7phdk; arc=fail smtp.client-ip=40.107.92.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="D+a7phdk" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=qTfsoj5TM1tZ0PLymBuAcsdzpwawZOmqbGL33sfKB9sLUu/9jid3dHD9cmFhBLi6BJJiekw8M4BKQDpwo7PPi0s3GUs+NDi3mJw45K+420Nh9rfXfy5qP8D982U3zJkGB2oLIKPIVUy4SFnz/wTNcB92TSuAoXoeVY+hGAGT3MLw376tF0UXXBpiJoinzTEHzNJs/pO82wiEIDnC7d390FWsvTYkbtJYn+VTpTxt2WgjkNaYS25KCZxL0rS5MUYkbg0B6mnwVcfVQ2CavRfv5zXY+Gwd1TsC8/acIJYV3ktnTSrmGufx2WwbrhNFvMInymSQWgPEQqFdchEjMF3AUg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=2VRfcUMaTK1uUwOjU23QxEqD/e9C7IWLvN7ZICcxKec=; b=fWO5A7ZVy1E88sfb5Er/8FaHU5i8HStqlLYNYWI/1lnO7+XORAw4FLtL186WqWUOJtLK3nGg2UTf1bXh6Fl2mn9qoaaMicHj50UerGbVftSnY951yR8PQ4QY/sXVZ+KP3kuSXqfO5ScHIO9DuyWFc6AjbINJDHxrBu214jkb4W8IsdXVMWq938gKXbP3Zo3ZppisxxSpuqghY7Y3W6rSfJauUMf7a2knj3x5n9763XflHSeeU3tVp63j+QepXRf9d50xY/Kfaz78+7v//hYrIfT7Xb8t9gJbyLjQqH9Mm5DTEZm2hQowxMY0BlUc785s+xBNkd5d2h83SDnGnPor2g== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=linutronix.de smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=2VRfcUMaTK1uUwOjU23QxEqD/e9C7IWLvN7ZICcxKec=; b=D+a7phdkLoehmIIyeLjlOQLa5zJB2ir6IRthfy5ERad9DYldjHvf14fW+Sw2Iy6SeP2KzVC86GRv/aNut8Lcz3QKUM+mFVHFq3o5rfDPZe+rsITQbDkw4/Pe5sup9IDd05VaHYi8hl4Joo1h1s8ysfUaaSkEDHQ0doa6Yt8olaE= Received: from CH0PR03CA0442.namprd03.prod.outlook.com (2603:10b6:610:10e::32) by DM4PR12MB7669.namprd12.prod.outlook.com (2603:10b6:8:106::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7762.20; Fri, 12 Jul 2024 09:41:12 +0000 Received: from DS3PEPF0000C37A.namprd04.prod.outlook.com (2603:10b6:610:10e:cafe::87) by CH0PR03CA0442.outlook.office365.com (2603:10b6:610:10e::32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7762.23 via Frontend Transport; Fri, 12 Jul 2024 09:41:11 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C Received: from SATLEXMB04.amd.com (165.204.84.17) by DS3PEPF0000C37A.mail.protection.outlook.com (10.167.23.4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.7762.17 via Frontend Transport; Fri, 12 Jul 2024 09:41:11 +0000 Received: from BLR-L-RBANGORI.amd.com (10.180.168.240) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Fri, 12 Jul 2024 04:41:03 -0500 From: Ravi Bangoria To: , , , , , , CC: , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v2 2/4] x86/bus_lock: Add support for AMD Date: Fri, 12 Jul 2024 09:39:41 +0000 Message-ID: <20240712093943.1288-3-ravi.bangoria@amd.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240712093943.1288-1-ravi.bangoria@amd.com> References: <20240712093943.1288-1-ravi.bangoria@amd.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: SATLEXMB04.amd.com (10.181.40.145) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS3PEPF0000C37A:EE_|DM4PR12MB7669:EE_ X-MS-Office365-Filtering-Correlation-Id: b57664f6-0712-452b-0037-08dca256c3ec X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|82310400026|36860700013|1800799024; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:SATLEXMB04.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(376014)(7416014)(82310400026)(36860700013)(1800799024);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Jul 2024 09:41:11.6584 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: b57664f6-0712-452b-0037-08dca256c3ec X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: DS3PEPF0000C37A.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR12MB7669 Upcoming AMD uarch will support Bus Lock Detect (called Bus Lock Trap in AMD docs). Add support for the same in Linux. Bus Lock Detect is enumerated with cpuid CPUID Fn0000_0007_ECX_x0 bit [24 / BUSLOCKTRAP]. It can be enabled through MSR_IA32_DEBUGCTLMSR. When enabled, hardware clears DR6[11] and raises a #DB exception on occurrence of Bus Lock if CPL > 0. More detail about the feature can be found in AMD APM[1]. [1]: AMD64 Architecture Programmer's Manual Pub. 40332, Rev. 4.07 - June 2023, Vol 2, 13.1.3.6 Bus Lock Trap https://bugzilla.kernel.org/attachment.cgi?id=304653 Signed-off-by: Ravi Bangoria --- arch/x86/kernel/cpu/common.c | 2 ++ arch/x86/kernel/cpu/intel.c | 1 - 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index d4e539d4e158..a37670e1ab4d 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1832,6 +1832,8 @@ static void identify_cpu(struct cpuinfo_x86 *c) if (this_cpu->c_init) this_cpu->c_init(c); + bus_lock_init(); + /* Disable the PN if appropriate */ squash_the_stupid_serial_number(c); diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 8a483f4ad026..799f18545c6e 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -610,7 +610,6 @@ static void init_intel(struct cpuinfo_x86 *c) init_intel_misc_features(c); split_lock_init(); - bus_lock_init(); intel_init_thermal(c); } From patchwork Fri Jul 12 09:39:42 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ravi Bangoria X-Patchwork-Id: 13731535 Received: from NAM11-CO1-obe.outbound.protection.outlook.com (mail-co1nam11on2055.outbound.protection.outlook.com [40.107.220.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7939814F9ED; Fri, 12 Jul 2024 09:41:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.220.55 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720777284; cv=fail; b=W6t08N+txQgAJ3rCVxGEKYPAq4Ux/hots6NtJgfsUTtpWbvW/eLx0mxaEykiV1mcd2GFWoHLSOCUVRDXIUjZBnxEj9j6xa0p0Q7Djv+iVnj86oTYqCMPDOTZEnuz38CpEIKB4JPs++ILTJPikWbfmSVXvXSiTm0AGM7cVVm93VY= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720777284; c=relaxed/simple; bh=IoVvaE3xZ9R5+M+fDsytf4UsGiS2efyI9wsyZjQMncc=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=RtC0alSOKCyjHvg3rDFSItHTt/aJZDJVcYBbsZXk/T4kl7oINTmti7OD0mLbPeWLe3UCnv1Mz7rV/UNsdmPZ2jYDKT2qtVxJhf8Ok/gVte0pAYEZ/kkT/PWe79GxHM6b+fAUitEfZjbG+9+i1FMpoSCxWjZDlXv5gORQ9BIb+2g= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=VAAqt6Fd; arc=fail smtp.client-ip=40.107.220.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="VAAqt6Fd" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=Krrf+ZqsMwEiPy5ANt1EtHO/jwIOlTgjXMz3WckwGBHMPNT8+IumcM+bjtPhcUpEj2nraQxamUW8AZ7HQ7hG5SszKajO34YHc1Tpf8YbX7Uk1f4OyWI+AbHaQd1WyzS4pRer9Uz7XVq91AIOhz0X4Nw1QxHUn2o9VAgIpxB7OTXrdjSUkS0gSzw+EvVokC8DSHfcL8jD4BEsaNhlYr/s3HLYAGMyTB+9rZiqe2JVS4/bGSGiCs7JqIrY8uF6MJOSzjn6i1accPX6LLn18MuiLkZsQFXB7WOFmJBLzkaRuvVCITpy1jMB3nAS0sG/UxI4dTYgPInvAwTNdFikDMlVAQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=mrVvy5wSsYvWEH/zMIUOCM18ZLpeaOVIvu30TvxsVbA=; b=oUIRJBlw7QAJtkm6p4SYwk5VbCY3mgrRdMiN9raVcBHT1DBveHVzTSnbGIKsG/ew5lKM4kbLT2KltStC4VB4w3NB9cAgGF9eOvb4/ZbwznodFsZm7Pue6oA8eM/xswKwmaUo423Vz8lLQxxX/cOrLx4k5nc6XV/3cuH3iwQbGKIukrym7p+1Wp0W5f4J2MpqGVsaMsDWrB1tvH41KwC6hdyJIUxlnldUOsr5CEZ12G2KA4wc/gGGScqc8qF6qi4b5Uryng+wak1SHdHw3hbzIHOwBvCGjdzQmFnk033CRLyO6iWEuVO+L2xsGl2HXcSzIj/kAtcCG/yEtJ0vigvpQg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=linutronix.de smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=mrVvy5wSsYvWEH/zMIUOCM18ZLpeaOVIvu30TvxsVbA=; b=VAAqt6FdbSLiSLHl6fwS/ry7XPUq9jNRNW7/kGF0YbfkuadSvYJXoJ3TXJ28+KodwLGvzkGN3K9rAz0bMPbtOGhvImv/b4w/A+a2mb1gmxHtc/motw1LTCkHFSOdneT7dDp14BkgDNwK7QU406/lwRNuaJljdVnq0v4iI8bm9eY= Received: from DM6PR13CA0066.namprd13.prod.outlook.com (2603:10b6:5:134::43) by LV3PR12MB9412.namprd12.prod.outlook.com (2603:10b6:408:211::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7762.22; Fri, 12 Jul 2024 09:41:19 +0000 Received: from DS3PEPF0000C37D.namprd04.prod.outlook.com (2603:10b6:5:134:cafe::b5) by DM6PR13CA0066.outlook.office365.com (2603:10b6:5:134::43) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7762.20 via Frontend Transport; Fri, 12 Jul 2024 09:41:19 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C Received: from SATLEXMB04.amd.com (165.204.84.17) by DS3PEPF0000C37D.mail.protection.outlook.com (10.167.23.7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.7762.17 via Frontend Transport; Fri, 12 Jul 2024 09:41:19 +0000 Received: from BLR-L-RBANGORI.amd.com (10.180.168.240) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Fri, 12 Jul 2024 04:41:11 -0500 From: Ravi Bangoria To: , , , , , , CC: , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v2 3/4] KVM: SVM: Don't advertise Bus Lock Detect to guest if SVM support is missing Date: Fri, 12 Jul 2024 09:39:42 +0000 Message-ID: <20240712093943.1288-4-ravi.bangoria@amd.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240712093943.1288-1-ravi.bangoria@amd.com> References: <20240712093943.1288-1-ravi.bangoria@amd.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: SATLEXMB04.amd.com (10.181.40.145) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS3PEPF0000C37D:EE_|LV3PR12MB9412:EE_ X-MS-Office365-Filtering-Correlation-Id: 8f9915ff-1382-4908-5be1-08dca256c85d X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|82310400026|1800799024|36860700013; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:SATLEXMB04.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(376014)(7416014)(82310400026)(1800799024)(36860700013);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Jul 2024 09:41:19.1279 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 8f9915ff-1382-4908-5be1-08dca256c85d X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: DS3PEPF0000C37D.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV3PR12MB9412 If host supports Bus Lock Detect, KVM advertises it to guests even if SVM support is absent. Additionally, guest wouldn't be able to use it despite guest CPUID bit being set. Fix it by unconditionally clearing the feature bit in KVM cpu capability. Reported-by: Jim Mattson Closes: https://lore.kernel.org/r/CALMp9eRet6+v8Y1Q-i6mqPm4hUow_kJNhmVHfOV8tMfuSS=tVg@mail.gmail.com Fixes: 76ea438b4afc ("KVM: X86: Expose bus lock debug exception to guest") Cc: stable@vger.kernel.org Signed-off-by: Ravi Bangoria Reviewed-by: Jim Mattson --- arch/x86/kvm/svm/svm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index c95d3900fe56..4a1d0a8478a5 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -5211,6 +5211,9 @@ static __init void svm_set_cpu_caps(void) /* CPUID 0x8000001F (SME/SEV features) */ sev_set_cpu_caps(); + + /* Don't advertise Bus Lock Detect to guest if SVM support is absent */ + kvm_cpu_cap_clear(X86_FEATURE_BUS_LOCK_DETECT); } static __init int svm_hardware_setup(void) From patchwork Fri Jul 12 09:39:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ravi Bangoria X-Patchwork-Id: 13731536 Received: from NAM11-CO1-obe.outbound.protection.outlook.com (mail-co1nam11on2052.outbound.protection.outlook.com [40.107.220.52]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B79E814B95A; Fri, 12 Jul 2024 09:41:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.220.52 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720777293; cv=fail; b=BlMs5fPidjr7A63TzFHVHINlWxa+UeeoK1GqWpL9y05dN/B/zQPJDsa2bf3Hnf/w3BRoYWWVgRQ/JRs/x/B0L6agTm1NphbyttzlfMJOLzlPZxuL4R1yhtzllm/iC8KzoErjBpRDBWBhDNVrt7ORux57NnCotLO6CGzi6sNX98M= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720777293; c=relaxed/simple; bh=5rtVdFPU5cEI4KrUx229jRVQzguTWV25lhXzYyQIT6k=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=HdYU3gUMKJC4mvTDv4djm1otda5/qwuwxYuA4kOitAPv0DqTQ9K6A1yEwN8/V/VSxtxZcoTTGoBy8l6xdk4vC5zZjNqxI9G+B+NbuwKzEaPcVvqfo4cKDo/0DgGdKRlNJ4k0aXC6TOUcu1XjuKtmmUHSZymnVWCDmjR1MZa0Fnw= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=usiOEBqX; arc=fail smtp.client-ip=40.107.220.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="usiOEBqX" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=Kgqm5fJeCEN0jFZW5k8TqpOzrUxkjFqbneBZGKtSJbGDFBbHwpZMjhrfWLkqyGEl9iG9C+pQ373TJnFNO2ebcZlXZCcU318EWHd5eQAxvouqulT9pD5WAdH4FCOP1P0Q3DqlRwveykenuhjolP3TY2va/q3qE7l/SckBzEW8svMBhr8zCg8mKEOoyTa5tYILu4xI8t/bM0eYrmVrbZW/L7/F5GrptNpFQ7A8aVofHEkY8eJ91tuuuF2VOIRZ/iEGkp4qoFMBvTeY0fy4VINNggrF67TAJTW1TOHAH4GL+Kd1hEXhMz/kaa8QbzLWozvtWSPMsJ0Dd+ObSEo3733/dA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=0FJc+LLEm3A2DN67vA8hUOqchnflGEqrPUfUrqOJaBA=; b=yVozrWuYF89DeTFupgDW8dPmUHUClfBR3r9b8QCIRuQJb4t4bN2vguj7IaicJHyEmK7mZBSssNjgp+VUBeFuw2+mJKMV1rQfJgdk6b3Kh2KwbxwwssCr7tWrFIdwEp22R8qf/VRfmwV9SjhaQ6lpsLi/TzkDSU6TbLXRHCZbdmYREXphhPVbDLKcM5Dqd3KBJTSAdhzSNE70V4uEZNQmIplxpbLeaoNR6iklHBjBRA8Y7I9YIZYJjgaLoYej8wnqre2EmK1+E7C18sM1ECpADn3oOn1AoF9hHVprpzMrosKISeMardpQW8rHFfx1SjZWR+a2Pft1nfhotaQK/et9xw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=linutronix.de smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=0FJc+LLEm3A2DN67vA8hUOqchnflGEqrPUfUrqOJaBA=; b=usiOEBqXNs80G4hSmO/ZTZaCuJxd3ddg9czaYrUUKy8XSRJbEwbxShkxsQw3XBTqLjopzoJC1lgf1hIhiTrNuba9BIIwYGbq/2p9YsWTNmkNss9vOaDrfOddSMrbWfRzIXw9sBcW1isaUiIuUGieS/WHVmxaLEn2WC6tjQe2rU8= Received: from DM6PR14CA0047.namprd14.prod.outlook.com (2603:10b6:5:18f::24) by DM6PR12MB4353.namprd12.prod.outlook.com (2603:10b6:5:2a6::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7762.23; Fri, 12 Jul 2024 09:41:26 +0000 Received: from DS3PEPF0000C37B.namprd04.prod.outlook.com (2603:10b6:5:18f:cafe::4) by DM6PR14CA0047.outlook.office365.com (2603:10b6:5:18f::24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7762.23 via Frontend Transport; Fri, 12 Jul 2024 09:41:26 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C Received: from SATLEXMB04.amd.com (165.204.84.17) by DS3PEPF0000C37B.mail.protection.outlook.com (10.167.23.5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.7762.17 via Frontend Transport; Fri, 12 Jul 2024 09:41:26 +0000 Received: from BLR-L-RBANGORI.amd.com (10.180.168.240) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Fri, 12 Jul 2024 04:41:18 -0500 From: Ravi Bangoria To: , , , , , , CC: , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v2 4/4] KVM: SVM: Add Bus Lock Detect support Date: Fri, 12 Jul 2024 09:39:43 +0000 Message-ID: <20240712093943.1288-5-ravi.bangoria@amd.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240712093943.1288-1-ravi.bangoria@amd.com> References: <20240712093943.1288-1-ravi.bangoria@amd.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: SATLEXMB04.amd.com (10.181.40.145) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS3PEPF0000C37B:EE_|DM6PR12MB4353:EE_ X-MS-Office365-Filtering-Correlation-Id: 730c80cb-7f36-4dae-a784-08dca256ccdd X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|36860700013|82310400026|1800799024|7416014|376014; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:SATLEXMB04.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(36860700013)(82310400026)(1800799024)(7416014)(376014);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Jul 2024 09:41:26.6170 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 730c80cb-7f36-4dae-a784-08dca256ccdd X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: DS3PEPF0000C37B.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB4353 Upcoming AMD uarch will support Bus Lock Detect. Add support for it in KVM. Bus Lock Detect is enabled through MSR_IA32_DEBUGCTLMSR and MSR_IA32_DEBUGCTLMSR is virtualized only if LBR Virtualization is enabled. Add this dependency in the KVM. Signed-off-by: Ravi Bangoria --- arch/x86/kvm/svm/nested.c | 3 ++- arch/x86/kvm/svm/svm.c | 17 ++++++++++++++--- 2 files changed, 16 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 55b9a6d96bcf..6e93c2d9e7df 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -586,7 +586,8 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm *svm, struct vmcb *vmcb12 /* These bits will be set properly on the first execution when new_vmc12 is true */ if (unlikely(new_vmcb12 || vmcb_is_dirty(vmcb12, VMCB_DR))) { vmcb02->save.dr7 = svm->nested.save.dr7 | DR7_FIXED_1; - svm->vcpu.arch.dr6 = svm->nested.save.dr6 | DR6_ACTIVE_LOW; + /* DR6_RTM is not supported on AMD as of now. */ + svm->vcpu.arch.dr6 = svm->nested.save.dr6 | DR6_FIXED_1 | DR6_RTM; vmcb_mark_dirty(vmcb02, VMCB_DR); } diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 4a1d0a8478a5..e00e1e2a0b78 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1044,7 +1044,8 @@ void svm_update_lbrv(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); bool current_enable_lbrv = svm->vmcb->control.virt_ext & LBR_CTL_ENABLE_MASK; - bool enable_lbrv = (svm_get_lbr_vmcb(svm)->save.dbgctl & DEBUGCTLMSR_LBR) || + u64 dbgctl_buslock_lbr = DEBUGCTLMSR_BUS_LOCK_DETECT | DEBUGCTLMSR_LBR; + bool enable_lbrv = (svm_get_lbr_vmcb(svm)->save.dbgctl & dbgctl_buslock_lbr) || (is_guest_mode(vcpu) && guest_can_use(vcpu, X86_FEATURE_LBRV) && (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK)); @@ -3145,6 +3146,10 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) if (data & DEBUGCTL_RESERVED_BITS) return 1; + if ((data & DEBUGCTLMSR_BUS_LOCK_DETECT) && + !guest_cpuid_has(vcpu, X86_FEATURE_BUS_LOCK_DETECT)) + return 1; + svm_get_lbr_vmcb(svm)->save.dbgctl = data; svm_update_lbrv(vcpu); break; @@ -5212,8 +5217,14 @@ static __init void svm_set_cpu_caps(void) /* CPUID 0x8000001F (SME/SEV features) */ sev_set_cpu_caps(); - /* Don't advertise Bus Lock Detect to guest if SVM support is absent */ - kvm_cpu_cap_clear(X86_FEATURE_BUS_LOCK_DETECT); + /* + * LBR Virtualization must be enabled to support BusLockTrap inside the + * guest, since BusLockTrap is enabled through MSR_IA32_DEBUGCTLMSR and + * MSR_IA32_DEBUGCTLMSR is virtualized only if LBR Virtualization is + * enabled. + */ + if (!lbrv) + kvm_cpu_cap_clear(X86_FEATURE_BUS_LOCK_DETECT); } static __init int svm_hardware_setup(void)