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From: Juergen Gross <jgross@suse.com>
To: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org,
	x86@kernel.org
Cc: Juergen Gross <jgross@suse.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH v2 3/5] x86: drop 32-bit Xen PV guest code in update_task_stack()
Date: Fri,  4 Nov 2022 08:26:59 +0100	[thread overview]
Message-ID: <20221104072701.20283-4-jgross@suse.com> (raw)
In-Reply-To: <20221104072701.20283-1-jgross@suse.com>

Testing for Xen PV guest mode in a 32-bit only code section can be
dropped, as Xen PV guests are supported in 64-bit mode only.

While at it switch from boot_cpu_has() to cpu_feature_enabled() in the
64-bit part of the code.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 arch/x86/include/asm/switch_to.h | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h
index c08eb0fdd11f..5c91305d09d2 100644
--- a/arch/x86/include/asm/switch_to.h
+++ b/arch/x86/include/asm/switch_to.h
@@ -66,13 +66,10 @@ static inline void update_task_stack(struct task_struct *task)
 {
 	/* sp0 always points to the entry trampoline stack, which is constant: */
 #ifdef CONFIG_X86_32
-	if (static_cpu_has(X86_FEATURE_XENPV))
-		load_sp0(task->thread.sp0);
-	else
-		this_cpu_write(cpu_tss_rw.x86_tss.sp1, task->thread.sp0);
+	this_cpu_write(cpu_tss_rw.x86_tss.sp1, task->thread.sp0);
 #else
 	/* Xen PV enters the kernel on the thread stack. */
-	if (static_cpu_has(X86_FEATURE_XENPV))
+	if (cpu_feature_enabled(X86_FEATURE_XENPV))
 		load_sp0(task_top_of_stack(task));
 #endif
 }
-- 
2.35.3


  parent reply	other threads:[~2022-11-04  7:27 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-04  7:26 [PATCH v2 0/5] x86: Switch X86_FEATURE_XENPV to cpu_feature_enabled() use Juergen Gross
2022-11-04  7:26 ` [PATCH v2 1/5] x86: add X86_FEATURE_XENPV to disabled-features.h Juergen Gross
2022-11-04 14:56   ` Dave Hansen
2022-11-22 18:04   ` [tip: x86/cpu] x86/cpufeatures: Add " tip-bot2 for Juergen Gross
2022-11-04  7:26 ` [PATCH v2 2/5] x86: remove unneeded 64-bit dependency in arch_enter_from_user_mode() Juergen Gross
2022-11-04 14:58   ` Dave Hansen
2022-11-22 18:04   ` [tip: x86/cpu] x86/cpu: Remove " tip-bot2 for Juergen Gross
2022-11-04  7:26 ` Juergen Gross [this message]
2022-11-04 15:04   ` [PATCH v2 3/5] x86: drop 32-bit Xen PV guest code in update_task_stack() Dave Hansen
2022-11-22 18:04   ` [tip: x86/cpu] x86/cpu: Drop " tip-bot2 for Juergen Gross
2022-11-04  7:27 ` [PATCH v2 4/5] x86: remove X86_FEATURE_XENPV usage in setup_cpu_entry_area() Juergen Gross
2022-11-04 15:04   ` Dave Hansen
2022-11-22 18:04   ` [tip: x86/cpu] x86/cpu: Remove " tip-bot2 for Juergen Gross
2022-11-04  7:27 ` [PATCH v2 5/5] x86: switch to cpu_feature_enabled() for X86_FEATURE_XENPV Juergen Gross
2022-11-04 17:32   ` Dave Hansen
2022-11-22 18:04   ` [tip: x86/cpu] x86/cpu: Switch " tip-bot2 for Juergen Gross
2022-11-22 12:47 ` [PATCH v2 0/5] x86: Switch X86_FEATURE_XENPV to cpu_feature_enabled() use Juergen Gross

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