linux-kernel - [PATCH v2 2/3] xen: assume XENFEAT_mmu_pt_update_preserve

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Message-Id: <20210730071804.4302-3-jgross@suse.com>
Date:   Fri, 30 Jul 2021 09:18:03 +0200
From:   Juergen Gross <jgross@...e.com>
To:     xen-devel@...ts.xenproject.org, x86@...nel.org,
        linux-kernel@...r.kernel.org
Cc:     Juergen Gross <jgross@...e.com>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Stefano Stabellini <sstabellini@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        Peter Zijlstra <peterz@...radead.org>
Subject: [PATCH v2 2/3] xen: assume XENFEAT_mmu_pt_update_preserve_ad being set for pv guests

XENFEAT_mmu_pt_update_preserve_ad is always set in Xen 4.0 and newer.
Remove coding assuming it might be zero.

Signed-off-by: Juergen Gross <jgross@...e.com>
Acked-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 arch/x86/xen/enlighten_pv.c | 12 ++----------
 arch/x86/xen/mmu_pv.c       |  4 ++--
 2 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 03149422dce2..753f63734c13 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -116,9 +116,8 @@ static void __init xen_banner(void)
 	HYPERVISOR_xen_version(XENVER_extraversion, &extra);
 
 	pr_info("Booting paravirtualized kernel on %s\n", pv_info.name);
-	printk(KERN_INFO "Xen version: %d.%d%s%s\n",
-	       version >> 16, version & 0xffff, extra.extraversion,
-	       xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
+	pr_info("Xen version: %d.%d%s (preserve-AD)\n",
+		version >> 16, version & 0xffff, extra.extraversion);
 }
 
 static void __init xen_pv_init_platform(void)
@@ -1302,13 +1301,6 @@ asmlinkage __visible void __init xen_start_kernel(void)
 	xen_init_apic();
 #endif
 
-	if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
-		pv_ops.mmu.ptep_modify_prot_start =
-			xen_ptep_modify_prot_start;
-		pv_ops.mmu.ptep_modify_prot_commit =
-			xen_ptep_modify_prot_commit;
-	}
-
 	machine_ops = xen_machine_ops;
 
 	/*
diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
index ade789e73ee4..1df5f01529e5 100644
--- a/arch/x86/xen/mmu_pv.c
+++ b/arch/x86/xen/mmu_pv.c
@@ -2099,8 +2099,8 @@ static const struct pv_mmu_ops xen_mmu_ops __initconst = {
 	.set_pte = xen_set_pte_init,
 	.set_pmd = xen_set_pmd_hyper,
 
-	.ptep_modify_prot_start = __ptep_modify_prot_start,
-	.ptep_modify_prot_commit = __ptep_modify_prot_commit,
+	.ptep_modify_prot_start = xen_ptep_modify_prot_start,
+	.ptep_modify_prot_commit = xen_ptep_modify_prot_commit,
 
 	.pte_val = PV_CALLEE_SAVE(xen_pte_val),
 	.pgd_val = PV_CALLEE_SAVE(xen_pgd_val),
-- 
2.26.2