linux-kernel - [PATCH] x86, microcode: Remove unnecessary paravirt

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Date:	Thu, 11 Feb 2016 10:13:18 -0500
From:	Boris Ostrovsky <boris.ostrovsky@...cle.com>
To:	bp@...en8.de, tglx@...utronix.de, mingo@...hat.com, hpa@...or.com
Cc:	x86@...nel.org, linux-kernel@...r.kernel.org,
	david.vrabel@...rix.com, konrad.wilk@...cle.com,
	xen-devel@...ts.xenproject.org,
	Boris Ostrovsky <boris.ostrovsky@...cle.com>
Subject: [PATCH] x86, microcode: Remove unnecessary paravirt_enabled check

Commit a18a0f6850d4 ("x86, microcode: Don't initialize microcode code on
paravirt") added a paravirt test in microcode_init(), primarily to avoid
making mc_bp_resume()->load_ucode_ap()->check_loader_disabled_ap() calls
On 32-bit kernels this callchain ends up using __pa_nodebug() macro
which is invalid for Xen PV guests.

A subsequent commit, fbae4ba8c4a3 ("x86, microcode: Reload microcode on
resume"), eliminated this callchain thus making a18a0f6850d4
unnecessary.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@...cle.com>
---
 arch/x86/kernel/cpu/microcode/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index cea8552..ac360bf 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -623,7 +623,7 @@ int __init microcode_init(void)
 	struct cpuinfo_x86 *c = &boot_cpu_data;
 	int error;

-	if (paravirt_enabled() || dis_ucode_ldr)
+	if (dis_ucode_ldr)
 		return -EINVAL;

 	if (c->x86_vendor == X86_VENDOR_INTEL)
-- 
2.1.0