From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-170.mta1.migadu.com (out-170.mta1.migadu.com [95.215.58.170]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 17D7F645 for ; Tue, 1 Oct 2024 00:17:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.170 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727741847; cv=none; b=dWotfW2zmbChXdOZs+rHwCkAlGn6oCeV8b6Q5TxVGpRXCXa3D0g5I1Hul4ZF0uTUnG8z1SY+vXVwVBqI/E5Gv2yRFI8rmV/hB2Onb7wTqAKc05lRfAXJzY7VVoXcteAYMapfBQtSMQ8igys05MisyW6vpl8srG8TZ3my+fjzIQc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727741847; c=relaxed/simple; bh=4g8aUb0ZK29koBByoyOmIBKY7jmLr/W2F/f26J/2wTM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mv5FNDFDBINwwdC+CUU5tRO9ZcjXYZvVan4sRAaIXqchNyav3umrtgKXHHBEsQz21LfvC4GIibpshFhpou9+N2IQz1P2NGLlYHKs6MOP5AzMXkjVWt5q2yrlM8peG7zsS8r98r2MVeHpx7DIMC6/5vR3vG5eXS7vZoPcPI8YGmw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=rD2QzsKr; arc=none smtp.client-ip=95.215.58.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="rD2QzsKr" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1727741843; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/OOv/+kWYut5sQwvgbK8l1vqAQOaV6gnpjjgOneG8EE=; b=rD2QzsKr10s/wROL9mh3Lk+nZclyJES6VfrNJnoKl74dg8EzBKvTjTLAe1FuTfl20+tbSX Ryz02yvDYQtE5fyMXWE95TciCq7I64UBH2YwGBZAQxMBBd5t2pzjNMbqimsJEFVJbQU6QM ixH4cyUsqlyqveBzqyNZnzgRNCDqUl4= From: Oliver Upton To: kvmarm@lists.linux.dev Cc: Marc Zyngier , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Oliver Upton Subject: [PATCH 2/3] KVM: arm64: nv: Do not block when unmapping stage-2 if disallowed Date: Tue, 1 Oct 2024 00:17:08 +0000 Message-ID: <20241001001709.1303668-3-oliver.upton@linux.dev> In-Reply-To: <20241001001709.1303668-1-oliver.upton@linux.dev> References: <20241001001709.1303668-1-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Right now the nested code allows unmap operations on a shadow stage-2 to block unconditionally. This is wrong in a couple places, such as a non-blocking MMU notifier or on the back of a sched_in() notifier as part of shadow MMU recycling. Carry through whether or not blocking is allowed to kvm_pgtable_stage2_unmap(). This 'fixes' an issue where stage-2 MMU reclaim would precipitate a stack overflow from a pile of vcpu_load() calls, all trying to recycle a stage-2 MMU. Signed-off-by: Oliver Upton --- arch/arm64/include/asm/kvm_mmu.h | 3 ++- arch/arm64/include/asm/kvm_nested.h | 2 +- arch/arm64/kvm/mmu.c | 15 ++++++++------- arch/arm64/kvm/nested.c | 6 +++--- arch/arm64/kvm/sys_regs.c | 6 +++--- 5 files changed, 17 insertions(+), 15 deletions(-) diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index a6379ca1b0d7..a9a3225c9f75 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -166,7 +166,8 @@ int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size, int create_hyp_stack(phys_addr_t phys_addr, unsigned long *haddr); void __init free_hyp_pgds(void); -void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size); +void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start, + u64 size, bool may_block); void kvm_stage2_flush_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end); void kvm_stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end); diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index e8bc6d67aba2..e74b90dcfac4 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -124,7 +124,7 @@ extern int kvm_s2_handle_perm_fault(struct kvm_vcpu *vcpu, struct kvm_s2_trans *trans); extern int kvm_inject_s2_fault(struct kvm_vcpu *vcpu, u64 esr_el2); extern void kvm_nested_s2_wp(struct kvm *kvm); -extern void kvm_nested_s2_unmap(struct kvm *kvm); +extern void kvm_nested_s2_unmap(struct kvm *kvm, bool may_block); extern void kvm_nested_s2_flush(struct kvm *kvm); unsigned long compute_tlb_inval_range(struct kvm_s2_mmu *mmu, u64 val); diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 800cf3e7ecae..02275854c288 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -328,9 +328,10 @@ static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 may_block)); } -void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size) +void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start, + u64 size, bool may_block) { - __unmap_stage2_range(mmu, start, size, true); + __unmap_stage2_range(mmu, start, size, may_block); } void kvm_stage2_flush_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end) @@ -1015,7 +1016,7 @@ static void stage2_unmap_memslot(struct kvm *kvm, if (!(vma->vm_flags & VM_PFNMAP)) { gpa_t gpa = addr + (vm_start - memslot->userspace_addr); - kvm_stage2_unmap_range(&kvm->arch.mmu, gpa, vm_end - vm_start); + kvm_stage2_unmap_range(&kvm->arch.mmu, gpa, vm_end - vm_start, true); } hva = vm_end; } while (hva < reg_end); @@ -1042,7 +1043,7 @@ void stage2_unmap_vm(struct kvm *kvm) kvm_for_each_memslot(memslot, bkt, slots) stage2_unmap_memslot(kvm, memslot); - kvm_nested_s2_unmap(kvm); + kvm_nested_s2_unmap(kvm, true); write_unlock(&kvm->mmu_lock); mmap_read_unlock(current->mm); @@ -1915,7 +1916,7 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) (range->end - range->start) << PAGE_SHIFT, range->may_block); - kvm_nested_s2_unmap(kvm); + kvm_nested_s2_unmap(kvm, range->may_block); return false; } @@ -2182,8 +2183,8 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm, phys_addr_t size = slot->npages << PAGE_SHIFT; write_lock(&kvm->mmu_lock); - kvm_stage2_unmap_range(&kvm->arch.mmu, gpa, size); - kvm_nested_s2_unmap(kvm); + kvm_stage2_unmap_range(&kvm->arch.mmu, gpa, size, true); + kvm_nested_s2_unmap(kvm, true); write_unlock(&kvm->mmu_lock); } diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index c5b61415b852..1ba211541290 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -634,7 +634,7 @@ static struct kvm_s2_mmu *get_s2_mmu_nested(struct kvm_vcpu *vcpu) /* Clear the old state */ if (kvm_s2_mmu_valid(s2_mmu)) - kvm_stage2_unmap_range(s2_mmu, 0, kvm_phys_size(s2_mmu)); + kvm_stage2_unmap_range(s2_mmu, 0, kvm_phys_size(s2_mmu), false); /* * The virtual VMID (modulo CnP) will be used as a key when matching @@ -732,7 +732,7 @@ void kvm_nested_s2_wp(struct kvm *kvm) } } -void kvm_nested_s2_unmap(struct kvm *kvm) +void kvm_nested_s2_unmap(struct kvm *kvm, bool may_block) { int i; @@ -742,7 +742,7 @@ void kvm_nested_s2_unmap(struct kvm *kvm) struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i]; if (kvm_s2_mmu_valid(mmu)) - kvm_stage2_unmap_range(mmu, 0, kvm_phys_size(mmu)); + kvm_stage2_unmap_range(mmu, 0, kvm_phys_size(mmu), may_block); } } diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index dad88e31f953..e0c7cc16466e 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2903,7 +2903,7 @@ static bool handle_alle1is(struct kvm_vcpu *vcpu, struct sys_reg_params *p, * Drop all shadow S2s, resulting in S1/S2 TLBIs for each of the * corresponding VMIDs. */ - kvm_nested_s2_unmap(vcpu->kvm); + kvm_nested_s2_unmap(vcpu->kvm, true); write_unlock(&vcpu->kvm->mmu_lock); @@ -2955,7 +2955,7 @@ union tlbi_info { static void s2_mmu_unmap_range(struct kvm_s2_mmu *mmu, const union tlbi_info *info) { - kvm_stage2_unmap_range(mmu, info->range.start, info->range.size); + kvm_stage2_unmap_range(mmu, info->range.start, info->range.size, true); } static bool handle_vmalls12e1is(struct kvm_vcpu *vcpu, struct sys_reg_params *p, @@ -3050,7 +3050,7 @@ static void s2_mmu_unmap_ipa(struct kvm_s2_mmu *mmu, max_size = compute_tlb_inval_range(mmu, info->ipa.addr); base_addr &= ~(max_size - 1); - kvm_stage2_unmap_range(mmu, base_addr, max_size); + kvm_stage2_unmap_range(mmu, base_addr, max_size, true); } static bool handle_ipas2e1is(struct kvm_vcpu *vcpu, struct sys_reg_params *p, -- 2.46.1.824.gd892dcdcdd-goog