linux-kernel - [tip: x86/urgent] x86/fpu: Remove redundant XCOMP

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Date:   Thu, 31 Mar 2022 09:01:01 -0000
From:   "tip-bot2 for Thomas Gleixner" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Thomas Gleixner <tglx@...utronix.de>, Borislav Petkov <bp@...e.de>,
        x86@...nel.org, linux-kernel@...r.kernel.org
Subject: [tip: x86/urgent] x86/fpu: Remove redundant XCOMP_BV initialization

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     a9f84fb7158fea60cbcadef5c0166fb22b469091
Gitweb:        https://git.kernel.org/tip/a9f84fb7158fea60cbcadef5c0166fb22b469091
Author:        Thomas Gleixner <tglx@...utronix.de>
AuthorDate:    Thu, 24 Mar 2022 14:47:08 +01:00
Committer:     Borislav Petkov <bp@...e.de>
CommitterDate: Tue, 29 Mar 2022 20:57:18 +02:00

x86/fpu: Remove redundant XCOMP_BV initialization

fpu_copy_uabi_to_guest_fpstate() initializes the XCOMP_BV field in the
XSAVE header. That's a leftover from the old KVM FPU buffer handling code.

Since

  d69c1382e1b7 ("x86/kvm: Convert FPU handling to a single swap buffer")

KVM uses the FPU core allocation code, which initializes the XCOMP_BV
field already.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Borislav Petkov <bp@...e.de>
Link: https://lore.kernel.org/r/20220324134623.408932232@linutronix.de
---
 arch/x86/kernel/fpu/core.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 19821f0..c049561 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -415,9 +415,6 @@ int fpu_copy_uabi_to_guest_fpstate(struct fpu_guest *gfpu, const void *buf,
 		xpkru = get_xsave_addr(&kstate->regs.xsave, XFEATURE_PKRU);
 		*vpkru = xpkru->pkru;
 	}
-
-	/* Ensure that XCOMP_BV is set up for XSAVES */
-	xstate_init_xcomp_bv(&kstate->regs.xsave, kstate->xfeatures);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(fpu_copy_uabi_to_guest_fpstate);