linux-kernel - [PATCH v3 06/10] x86/fpu/xstate: Initialize guest perm with fpu_guest

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Message-ID: <20250307164123.1613414-7-chao.gao@intel.com>
Date: Sat,  8 Mar 2025 00:41:19 +0800
From: Chao Gao <chao.gao@...el.com>
To: chao.gao@...el.com,
	tglx@...utronix.de,
	dave.hansen@...el.com,
	x86@...nel.org,
	seanjc@...gle.com,
	pbonzini@...hat.com,
	linux-kernel@...r.kernel.org,
	kvm@...r.kernel.org
Cc: peterz@...radead.org,
	rick.p.edgecombe@...el.com,
	weijiang.yang@...el.com,
	john.allen@....com,
	bp@...en8.de
Subject: [PATCH v3 06/10] x86/fpu/xstate: Initialize guest perm with fpu_guest_cfg

From: Yang Weijiang <weijiang.yang@...el.com>

Use the new fpu_guest_cfg to initialize guest permissions.

Note fpu_guest_cfg and fpu_kernel_cfg remain the same for now. So there
is no functional change.

Signed-off-by: Yang Weijiang <weijiang.yang@...el.com>
[Gao Chao: Extrace this from the previous patch ]
Signed-off-by: Chao Gao <chao.gao@...el.com>
---
 arch/x86/kernel/fpu/core.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index b0c1ef40d105..d7ae684adbad 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -534,8 +534,15 @@ void fpstate_reset(struct fpu *fpu)
 	fpu->perm.__state_perm		= fpu_kernel_cfg.default_features;
 	fpu->perm.__state_size		= fpu_kernel_cfg.default_size;
 	fpu->perm.__user_state_size	= fpu_user_cfg.default_size;
-	/* Same defaults for guests */
-	fpu->guest_perm = fpu->perm;
+
+	/* Guest permission settings */
+	fpu->guest_perm.__state_perm	= fpu_guest_cfg.default_features;
+	fpu->guest_perm.__state_size	= fpu_guest_cfg.default_size;
+	/*
+	 * Set guest's __user_state_size to fpu_user_cfg.default_size so that
+	 * existing uAPIs can still work.
+	 */
+	fpu->guest_perm.__user_state_size = fpu_user_cfg.default_size;
 }
 
 static inline void fpu_inherit_perms(struct fpu *dst_fpu)
-- 
2.46.1