mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Rik van Riel <riel@surriel.com>
To: Juergen Gross <jgross@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Arnd Bergmann <arnd@arndb.de>,
	linux-kernel@vger.kernel.org, x86@kernel.org,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	kernel-team@meta.com
Subject: [PATCH] x86,spinlock: make disabling virt_spin_lock_key contingent on CONFIG_PARAVIRT
Date: Mon, 15 Jul 2024 13:18:53 -0400	[thread overview]
Message-ID: <20240715131853.313c3bae@imladris.surriel.com> (raw)

The existence of virt_spin_lock_key is contingent only on CONFIG_PARAVIRT, not 
on CONFIG_PARAVIRT_SPINLOCKS.

As a result, a kernel with CONFIG_PARAVIRT enabled, but CONFIG_PARAVIRT_SPINLOCKS
disabled will end up disabling queued spinlocks when running on bare metal.

Making the disabling of virt_spin_lock_key contingent on CONFIG_PARAVIRT, which 
controls whether the key exists, results in queued spinlocks being enabled on
bare metal again.

Signed-off-by: Rik van Riel <riel@surriel.com>
Cc: stable@vger.kernel.org
Fixes: ce0a1b608bfc ("x86/paravirt: Silence unused native_pv_lock_init() function warning")
---
 arch/x86/kernel/paravirt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 5358d43886ad..dd542a9c6667 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -55,7 +55,7 @@ DEFINE_STATIC_KEY_TRUE(virt_spin_lock_key);
 
 void __init native_pv_lock_init(void)
 {
-	if (IS_ENABLED(CONFIG_PARAVIRT_SPINLOCKS) &&
+	if (IS_ENABLED(CONFIG_PARAVIRT) &&
 	    !boot_cpu_has(X86_FEATURE_HYPERVISOR))
 		static_branch_disable(&virt_spin_lock_key);
 }
-- 
2.45.2


             reply	other threads:[~2024-07-15 17:19 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-07-15 17:18 Rik van Riel [this message]
2024-07-16  9:41 ` Jürgen Groß

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20240715131853.313c3bae@imladris.surriel.com \
    --to=riel@surriel.com \
    --cc=arnd@arndb.de \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=jgross@suse.com \
    --cc=kernel-team@meta.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®