From: Dave Hansen <dave.hansen@intel.com>
To: Valentin Schneider <vschneid@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>
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Subject: Re: [PATCH v5 00/25] context_tracking,x86: Defer some IPIs until a user->kernel transition
Date: Fri, 2 May 2025 06:53:17 -0700 [thread overview]
Message-ID: <34535b8c-35c8-4a7f-8363-f5a9c5a69023@intel.com> (raw)
In-Reply-To: <xhsmhr0179w1i.mognet@vschneid-thinkpadt14sgen2i.remote.csb>
On 5/2/25 02:55, Valentin Schneider wrote:
> My gripe with that was having two separate mechanisms
> - super early entry around SWITCH_TO_KERNEL_CR3)
> - later entry at context tracking
What do you mean by "later entry"?
All of the paths to enter the kernel from userspace have some
SWITCH_TO_KERNEL_CR3 variant. If they didn't, the userspace that they
entered from could have attacked the kernel with Meltdown.
I'm theorizing that if this is _just_ about avoiding TLB flush IPIs that
you can get away with a single mechanism.
next prev parent reply other threads:[~2025-05-02 13:53 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-29 11:32 [PATCH v5 00/25] context_tracking,x86: Defer some IPIs until a user->kernel transition Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 01/25] objtool: Make validate_call() recognize indirect calls to pv_ops[] Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 02/25] objtool: Flesh out warning related to pv_ops[] calls Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 03/25] rcu: Add a small-width RCU watching counter debug option Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 04/25] rcutorture: Make TREE04 use CONFIG_RCU_DYNTICKS_TORTURE Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 05/25] jump_label: Add annotations for validating noinstr usage Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 06/25] static_call: Add read-only-after-init static calls Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 07/25] x86/paravirt: Mark pv_sched_clock static call as __ro_after_init Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 08/25] x86/idle: Mark x86_idle " Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 09/25] x86/paravirt: Mark pv_steal_clock " Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 10/25] riscv/paravirt: " Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 11/25] loongarch/paravirt: " Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 12/25] arm64/paravirt: " Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 13/25] arm/paravirt: " Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 14/25] perf/x86/amd: Mark perf_lopwr_cb " Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 15/25] sched/clock: Mark sched_clock_running key " Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 16/25] KVM: VMX: Mark __kvm_is_using_evmcs static " Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 17/25] x86/speculation/mds: Mark mds_idle_clear key as allowed in .noinstr Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 18/25] sched/clock, x86: Mark __sched_clock_stable " Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 19/25] KVM: VMX: Mark vmx_l1d_should flush and vmx_l1d_flush_cond keys " Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 20/25] stackleack: Mark stack_erasing_bypass key " Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 21/25] objtool: Add noinstr validation for static branches/calls Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 22/25] module: Remove outdated comment about text_size Valentin Schneider
2025-05-05 14:27 ` Petr Pavlu
2025-04-29 11:32 ` [PATCH v5 23/25] module: Add MOD_NOINSTR_TEXT mem_type Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 24/25] context-tracking: Introduce work deferral infrastructure Valentin Schneider
2025-04-29 11:32 ` [PATCH v5 25/25] context_tracking,x86: Defer kernel text patching IPIs Valentin Schneider
2025-04-29 16:11 ` [PATCH v5 00/25] context_tracking,x86: Defer some IPIs until a user->kernel transition Dave Hansen
2025-04-30 17:20 ` Steven Rostedt
2025-04-30 18:07 ` Dave Hansen
2025-04-30 19:42 ` Steven Rostedt
2025-04-30 20:00 ` Dave Hansen
2025-05-02 9:55 ` Valentin Schneider
2025-05-02 13:53 ` Dave Hansen [this message]
2025-05-02 16:38 ` Valentin Schneider
2025-05-02 17:57 ` Dave Hansen
2025-05-05 15:45 ` Valentin Schneider
2025-05-02 11:22 ` Peter Zijlstra
2025-05-02 14:33 ` Dave Hansen
2025-05-02 15:20 ` Peter Zijlstra
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