From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C2A77C43458 for ; Tue, 30 Jun 2026 12:11:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=aRc/o1VjEwFZCU0Y8DAAl6OM905HgZY7EiCwsWZh4kw=; b=1deTkVCata8djQu4yoBBepZQZc i4LM7PC0i79txCNp/fx9U/Zt/SMlYH6cZ6B8kz1FOulMmH20mgayqxp0rjwIPn8+2RuUkWPd0sakb 50En6FAUDRIPCSdqU2GsldRjd78BILsZYtCOWUFXx1wQxk+J+Xv63Xksj/cb9vNGYpcAWEoBqcxw/ 5cYoKKKo8Irt+v8GeKpN+rTDGoy7OoLeE3cuiJWS/SMsHNRdVN7k1ypN4o513vT3t7QFT+zvizEBa OBNRMlQ1udUlxVklgiqt1qOtS5QO9gPkBsm050VafdTRhhC7mdyuWj+9lai0WfZi6jrt+nuhZNeE0 D6xrG10g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1weXJS-0000000GwLz-0O37; Tue, 30 Jun 2026 12:11:38 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1weXJH-0000000GwFw-3FVZ for linux-arm-kernel@lists.infradead.org; Tue, 30 Jun 2026 12:11:30 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E0A9B2C46; Tue, 30 Jun 2026 05:11:20 -0700 (PDT) Received: from workstation-e142269.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3540C3F905; Tue, 30 Jun 2026 05:11:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1782821485; bh=E7+qqt2CDSjvyTnRaP+lWOF/gpnYwiJEJNdcRjtcUKw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sro8KjLGS/R/zAIi0/8WJL4HpRRCQmjqytT6OEL9seTHr+/yagTQF1CMgbK27HOSj MR7aUDlsUo0CzeKSm8oqSxilDrm32zg2/6fLdBGoOr1S/JC0eUQ9TIOIvO2p8L4j04 zapQbxi1x2n/kb7GMpyC9m4BNldE60JCGUlOt10E= From: Wei-Lin Chang To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Cc: Marc Zyngier , Oliver Upton , Fuad Tabba , Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Itaru Kitayama , Sebastian Ene , Wei-Lin Chang Subject: [PATCH v2 1/6] KVM: arm64: ptdump: Remove shadow ptdump files Date: Tue, 30 Jun 2026 13:10:00 +0100 Message-ID: <20260630121005.1130996-2-weilin.chang@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260630121005.1130996-1-weilin.chang@arm.com> References: <20260630121005.1130996-1-weilin.chang@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260630_051128_475293_2D8122D1 X-CRM114-Status: GOOD ( 16.80 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Previously we exposed shadow page tables by creating a debugfs ptdump file whenever a nested mmu instance gets bound to a new context, and deleting the debugfs file whose context was getting unbound. This turned out to be buggy, as the instance<->context binding process is done with the mmu_lock held, and debugfs creation/deletion can sleep. Revert most of commit 19e15dc73f0f ("KVM: arm64: nv: Expose shadow page tables in debugfs"), keep the "nested" debugfs directory for use in a later patch where we'll expose the shadow ptdump in another way. Fixes: 19e15dc73f0f ("KVM: arm64: nv: Expose shadow page tables in debugfs") Reported-by: Itaru Kitayama Closes: https://lore.kernel.org/kvmarm/aiuF0KSvvv-ZozI1@sm-arm-grace07/ Signed-off-by: Wei-Lin Chang --- arch/arm64/include/asm/kvm_host.h | 5 +---- arch/arm64/include/asm/kvm_mmu.h | 4 ---- arch/arm64/kvm/nested.c | 6 +----- arch/arm64/kvm/ptdump.c | 23 ----------------------- 4 files changed, 2 insertions(+), 36 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 2faa60df847d..94bced53a323 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -217,10 +217,6 @@ struct kvm_s2_mmu { */ bool nested_stage2_enabled; -#ifdef CONFIG_PTDUMP_STAGE2_DEBUGFS - struct dentry *shadow_pt_debugfs_dentry; -#endif - /* * true when this MMU needs to be unmapped before being used for a new * purpose. @@ -424,6 +420,7 @@ struct kvm_arch { /* Nested virtualization info */ struct dentry *debugfs_nv_dentry; #endif + }; struct kvm_vcpu_fault_info { diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 6eae7e7e2a68..c1e535e3d931 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -392,12 +392,8 @@ static inline bool kvm_supports_cacheable_pfnmap(void) #ifdef CONFIG_PTDUMP_STAGE2_DEBUGFS void kvm_s2_ptdump_create_debugfs(struct kvm *kvm); -void kvm_nested_s2_ptdump_create_debugfs(struct kvm_s2_mmu *mmu); -void kvm_nested_s2_ptdump_remove_debugfs(struct kvm_s2_mmu *mmu); #else static inline void kvm_s2_ptdump_create_debugfs(struct kvm *kvm) {} -static inline void kvm_nested_s2_ptdump_create_debugfs(struct kvm_s2_mmu *mmu) {} -static inline void kvm_nested_s2_ptdump_remove_debugfs(struct kvm_s2_mmu *mmu) {} #endif /* CONFIG_PTDUMP_STAGE2_DEBUGFS */ #endif /* __ASSEMBLER__ */ diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index faa4a48f265d..6435efd65cb5 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -834,10 +834,8 @@ static struct kvm_s2_mmu *get_s2_mmu_nested(struct kvm_vcpu *vcpu) kvm->arch.nested_mmus_next = (i + 1) % kvm->arch.nested_mmus_size; /* Make sure we don't forget to do the laundry */ - if (kvm_s2_mmu_valid(s2_mmu)) { - kvm_nested_s2_ptdump_remove_debugfs(s2_mmu); + if (kvm_s2_mmu_valid(s2_mmu)) s2_mmu->pending_unmap = true; - } /* * The virtual VMID (modulo CnP) will be used as a key when matching @@ -851,8 +849,6 @@ static struct kvm_s2_mmu *get_s2_mmu_nested(struct kvm_vcpu *vcpu) s2_mmu->tlb_vtcr = vcpu_read_sys_reg(vcpu, VTCR_EL2); s2_mmu->nested_stage2_enabled = vcpu_read_sys_reg(vcpu, HCR_EL2) & HCR_VM; - kvm_nested_s2_ptdump_create_debugfs(s2_mmu); - out: atomic_inc(&s2_mmu->refcnt); diff --git a/arch/arm64/kvm/ptdump.c b/arch/arm64/kvm/ptdump.c index c9140e22abcf..7c32f1f7772c 100644 --- a/arch/arm64/kvm/ptdump.c +++ b/arch/arm64/kvm/ptdump.c @@ -17,7 +17,6 @@ #define MARKERS_LEN 2 #define KVM_PGTABLE_MAX_LEVELS (KVM_PGTABLE_LAST_LEVEL + 1) -#define S2FNAMESZ sizeof("0x0123456789abcdef-0x0123456789abcdef-s2-disabled") struct kvm_ptdump_guest_state { struct kvm_s2_mmu *mmu; @@ -273,28 +272,6 @@ static const struct file_operations kvm_pgtable_levels_fops = { .release = kvm_pgtable_debugfs_close, }; -void kvm_nested_s2_ptdump_create_debugfs(struct kvm_s2_mmu *mmu) -{ - struct dentry *dent; - char file_name[S2FNAMESZ]; - - snprintf(file_name, sizeof(file_name), "0x%016llx-0x%016llx-s2-%sabled", - mmu->tlb_vttbr, - mmu->tlb_vtcr, - mmu->nested_stage2_enabled ? "en" : "dis"); - - dent = debugfs_create_file(file_name, 0400, - mmu->arch->debugfs_nv_dentry, mmu, - &kvm_ptdump_guest_fops); - - mmu->shadow_pt_debugfs_dentry = dent; -} - -void kvm_nested_s2_ptdump_remove_debugfs(struct kvm_s2_mmu *mmu) -{ - debugfs_remove(mmu->shadow_pt_debugfs_dentry); -} - void kvm_s2_ptdump_create_debugfs(struct kvm *kvm) { debugfs_create_file("stage2_page_tables", 0400, kvm->debugfs_dentry, -- 2.43.0