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From: Thomas Gleixner <tglx@linutronix.de>
To: Usama Arif <usama.arif@bytedance.com>,
	dwmw2@infradead.org, kim.phillips@amd.com, brgerst@gmail.com
Cc: piotrgorski@cachyos.org, oleksandr@natalenko.name,
	arjan@linux.intel.com, mingo@redhat.com, bp@alien8.de,
	dave.hansen@linux.intel.com, hpa@zytor.com, x86@kernel.org,
	pbonzini@redhat.com, paulmck@kernel.org,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	rcu@vger.kernel.org, mimoja@mimoja.de, hewenliang4@huawei.com,
	thomas.lendacky@amd.com, seanjc@google.com,
	pmenzel@molgen.mpg.de, fam.zheng@bytedance.com,
	punit.agrawal@bytedance.com, simon.evans@bytedance.com,
	liangma@liangbit.com, David Woodhouse <dwmw@amazon.co.uk>,
	Usama Arif <usama.arif@bytedance.com>,
	"Guilherme G . Piccoli" <gpiccoli@igalia.com>
Subject: Re: [PATCH v14 10/12] x86/smpboot: Send INIT/SIPI/SIPI to secondary CPUs in parallel
Date: Sat, 11 Mar 2023 10:54:58 +0200	[thread overview]
Message-ID: <87y1o3acrh.ffs@tglx> (raw)
In-Reply-To: <20230308171328.1562857-11-usama.arif@bytedance.com>

On Wed, Mar 08 2023 at 17:13, Usama Arif wrote:
>  
> +/* Bringup step one: Send INIT/SIPI to the target AP */
> +static int native_cpu_kick(unsigned int cpu)
> +{
> +	return do_cpu_up(cpu, idle_thread_get(cpu));

This idle_thread_get() is not sufficient. bringup_cpu() does:

	struct task_struct *idle = idle_thread_get(cpu);

	/*
	 * Reset stale stack state from the last time this CPU was online.
	 */
	scs_task_reset(idle);
	kasan_unpoison_task_stack(idle);

But with this new model neither the shadow stack gets reset nor the
kasan unpoisoning happens _before_ the to be kicked CPU starts
executing.

That needs a new function which does the get() and the above.

Thanks,

        tglx

  reply	other threads:[~2023-03-11  8:55 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-08 17:13 [PATCH v14 00/12] Parallel CPU bringup for x86_64 Usama Arif
2023-03-08 17:13 ` [PATCH v14 01/12] x86/apic/x2apic: Allow CPU cluster_mask to be populated in parallel Usama Arif
2023-03-08 17:13 ` [PATCH v14 02/12] cpu/hotplug: Move idle_thread_get() to <linux/smpboot.h> Usama Arif
2023-03-08 17:13 ` [PATCH v14 03/12] cpu/hotplug: Add dynamic parallel bringup states before CPUHP_BRINGUP_CPU Usama Arif
2023-03-08 17:13 ` [PATCH v14 04/12] x86/smpboot: Reference count on smpboot_setup_warm_reset_vector() Usama Arif
2023-03-08 17:13 ` [PATCH v14 05/12] x86/smpboot: Split up native_cpu_up into separate phases and document them Usama Arif
2023-03-11  9:19   ` Thomas Gleixner
2023-03-11 10:21     ` David Woodhouse
2023-03-08 17:13 ` [PATCH v14 06/12] x86/smpboot: Remove initial_stack on 64-bit Usama Arif
2023-03-08 17:13 ` [PATCH v14 07/12] x86/smpboot: Remove early_gdt_descr " Usama Arif
2023-03-08 17:13 ` [PATCH v14 08/12] x86/smpboot: Remove initial_gs Usama Arif
2023-03-08 17:13 ` [PATCH v14 09/12] x86/smpboot: Support parallel startup of secondary CPUs Usama Arif
2023-03-13 22:21   ` Brian Gerst
2023-03-08 17:13 ` [PATCH v14 10/12] x86/smpboot: Send INIT/SIPI/SIPI to secondary CPUs in parallel Usama Arif
2023-03-11  8:54   ` Thomas Gleixner [this message]
2023-03-11  9:55     ` David Woodhouse
2023-03-11 14:14       ` Thomas Gleixner
2023-03-11 14:25         ` David Woodhouse
2023-03-11 10:17     ` David Woodhouse
2023-03-08 17:13 ` [PATCH v14 11/12] x86/smpboot: Serialize topology updates for secondary bringup Usama Arif
2023-03-08 17:13 ` [PATCH v14 12/12] x86/smpboot: Allow parallel bringup for SEV-ES Usama Arif
2023-03-10 19:20 ` [PATCH v14 00/12] Parallel CPU bringup for x86_64 Tor Vic
2023-03-10 20:18   ` Paul Menzel
2023-03-11 19:23     ` Tor Vic

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