From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 CB63D391E46; Fri, 27 Mar 2026 11:36:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774611390; cv=none; b=Zqd35Xg2gS61KYCZqP3Gogqz27c49XdX9UvSR/MvGWR59bpDsevdA51748jkMSBDwHqvBsLjjO3Pn8SZUEFn8EjIo0Xu5IYDJMkCbuWSmiwKc7GCEBJkVpEh0NSBzUhy+v2ODasiJYJ8N09MxItfatmjzdDpn3NbAkGlXkzuAAY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774611390; c=relaxed/simple; bh=tqFovywmBvcvEZzUbRpB8s3MtVGzdsQRy1BeOyGDLjY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kMJ5/SEIR8OjzbUtDidj2G6gP1fD0iZ6BMiuolD9aQ/h0D4WYC8VF8/DR0Mf1+o+dQbRy3ZJCCY7ZNTFW1qEgUMn1cMV3/5A44r00ZaQGjfT8XFNhd5u71pXLsK/tVW9O9Be5dtRN2rnk+k5NQ5VI4rpf2gTxADuSB6iRp1ZtvY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QbJ4iZPl; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QbJ4iZPl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8CA94C2BCB6; Fri, 27 Mar 2026 11:36:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774611390; bh=tqFovywmBvcvEZzUbRpB8s3MtVGzdsQRy1BeOyGDLjY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QbJ4iZPlpBPayPoKRnIv+D4m5rE/zKdcvYTJ0mlfvCv7ManGeASG5cxNuXkAQWd0H i7vV2h5i73vyhtBjsLuy8oH8B7WOnOCkE2S+1Y7stsJQucfjfkAgy4oYI7q8i9rqMC USWZh8Tcww+ddXMauNmr3IAnDEI3n4C3JLmOZGtpHxxc/KgitTnWDmozignhhK9XZa vAi4FLoohQ3vXFHx+gNv6Xz01Ylqk/U5MAfAJYA48rXmgqlgpyUxV+56szrXgWk+K4 xG+ewIkLPSK2TdraRpwMsOqFICAvX+6nEYYNCFr1rlKi9kk9jNM9JUFNEUYutkdTmz gMgaPfM/UXzJw== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1w65UK-00000006K4a-2o0H; Fri, 27 Mar 2026 11:36:28 +0000 From: Marc Zyngier To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org Cc: Joey Gouly , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Fuad Tabba , Will Deacon , Quentin Perret Subject: [PATCH v2 27/30] KVM: arm64: Move device mapping management into kvm_s2_fault_pin_pfn() Date: Fri, 27 Mar 2026 11:36:15 +0000 Message-ID: <20260327113618.4051534-28-maz@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260327113618.4051534-1-maz@kernel.org> References: <20260327113618.4051534-1-maz@kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, oupton@kernel.org, yuzenghui@huawei.com, tabba@google.com, will@kernel.org, qperret@google.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Attributes computed for devices are computed very late in the fault handling process, meanning they are mutable for that long. Introduce both 'device' and 'map_non_cacheable' attributes to the vma_info structure, allowing that information to be set in stone earlier, in kvm_s2_fault_pin_pfn(). Tested-by: Fuad Tabba Reviewed-by: Fuad Tabba Reviewed-by: Suzuki K Poulose Signed-off-by: Marc Zyngier --- arch/arm64/kvm/mmu.c | 52 ++++++++++++++++++++++++-------------------- 1 file changed, 29 insertions(+), 23 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 61b979365c6ee..23245ee7b1ec2 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1656,9 +1656,11 @@ struct kvm_s2_fault_vma_info { struct page *page; kvm_pfn_t pfn; gfn_t gfn; + bool device; bool mte_allowed; bool is_vma_cacheable; bool map_writable; + bool map_non_cacheable; }; static short kvm_s2_resolve_vma_size(const struct kvm_s2_fault_desc *s2fd, @@ -1728,7 +1730,6 @@ static short kvm_s2_resolve_vma_size(const struct kvm_s2_fault_desc *s2fd, } struct kvm_s2_fault { - bool s2_force_noncacheable; enum kvm_pgtable_prot prot; }; @@ -1738,7 +1739,6 @@ static bool kvm_s2_fault_is_perm(const struct kvm_s2_fault_desc *s2fd) } static int kvm_s2_fault_get_vma_info(const struct kvm_s2_fault_desc *s2fd, - struct kvm_s2_fault *fault, struct kvm_s2_fault_vma_info *s2vi) { struct vm_area_struct *vma; @@ -1794,12 +1794,11 @@ static gfn_t get_canonical_gfn(const struct kvm_s2_fault_desc *s2fd, } static int kvm_s2_fault_pin_pfn(const struct kvm_s2_fault_desc *s2fd, - struct kvm_s2_fault *fault, struct kvm_s2_fault_vma_info *s2vi) { int ret; - ret = kvm_s2_fault_get_vma_info(s2fd, fault, s2vi); + ret = kvm_s2_fault_get_vma_info(s2fd, s2vi); if (ret) return ret; @@ -1814,16 +1813,6 @@ static int kvm_s2_fault_pin_pfn(const struct kvm_s2_fault_desc *s2fd, return -EFAULT; } - return 1; -} - -static int kvm_s2_fault_compute_prot(const struct kvm_s2_fault_desc *s2fd, - struct kvm_s2_fault *fault, - const struct kvm_s2_fault_vma_info *s2vi) -{ - struct kvm *kvm = s2fd->vcpu->kvm; - bool writable = s2vi->map_writable; - /* * Check if this is non-struct page memory PFN, and cannot support * CMOs. It could potentially be unsafe to access as cacheable. @@ -1842,8 +1831,10 @@ static int kvm_s2_fault_compute_prot(const struct kvm_s2_fault_desc *s2fd, * S2FWB and CACHE DIC are mandatory to avoid the need for * cache maintenance. */ - if (!kvm_supports_cacheable_pfnmap()) + if (!kvm_supports_cacheable_pfnmap()) { + kvm_release_faultin_page(s2fd->vcpu->kvm, s2vi->page, true, false); return -EFAULT; + } } else { /* * If the page was identified as device early by looking at @@ -1855,9 +1846,24 @@ static int kvm_s2_fault_compute_prot(const struct kvm_s2_fault_desc *s2fd, * In both cases, we don't let transparent_hugepage_adjust() * change things at the last minute. */ - fault->s2_force_noncacheable = true; + s2vi->map_non_cacheable = true; } - } else if (memslot_is_logging(s2fd->memslot) && !kvm_is_write_fault(s2fd->vcpu)) { + + s2vi->device = true; + } + + return 1; +} + +static int kvm_s2_fault_compute_prot(const struct kvm_s2_fault_desc *s2fd, + struct kvm_s2_fault *fault, + const struct kvm_s2_fault_vma_info *s2vi) +{ + struct kvm *kvm = s2fd->vcpu->kvm; + bool writable = s2vi->map_writable; + + if (!s2vi->device && memslot_is_logging(s2fd->memslot) && + !kvm_is_write_fault(s2fd->vcpu)) { /* * Only actually map the page as writable if this was a write * fault. @@ -1865,7 +1871,7 @@ static int kvm_s2_fault_compute_prot(const struct kvm_s2_fault_desc *s2fd, writable = false; } - if (kvm_vcpu_trap_is_exec_fault(s2fd->vcpu) && fault->s2_force_noncacheable) + if (kvm_vcpu_trap_is_exec_fault(s2fd->vcpu) && s2vi->map_non_cacheable) return -ENOEXEC; /* @@ -1888,7 +1894,7 @@ static int kvm_s2_fault_compute_prot(const struct kvm_s2_fault_desc *s2fd, if (kvm_vcpu_trap_is_exec_fault(s2fd->vcpu)) fault->prot |= KVM_PGTABLE_PROT_X; - if (fault->s2_force_noncacheable) + if (s2vi->map_non_cacheable) fault->prot |= (s2vi->vm_flags & VM_ALLOW_ANY_UNCACHED) ? KVM_PGTABLE_PROT_NORMAL_NC : KVM_PGTABLE_PROT_DEVICE; else if (cpus_have_final_cap(ARM64_HAS_CACHE_DIC)) @@ -1897,7 +1903,7 @@ static int kvm_s2_fault_compute_prot(const struct kvm_s2_fault_desc *s2fd, if (s2fd->nested) adjust_nested_exec_perms(kvm, s2fd->nested, &fault->prot); - if (!kvm_s2_fault_is_perm(s2fd) && !fault->s2_force_noncacheable && kvm_has_mte(kvm)) { + if (!kvm_s2_fault_is_perm(s2fd) && !s2vi->map_non_cacheable && kvm_has_mte(kvm)) { /* Check the VMM hasn't introduced a new disallowed VMA */ if (!s2vi->mte_allowed) return -EFAULT; @@ -1937,7 +1943,7 @@ static int kvm_s2_fault_map(const struct kvm_s2_fault_desc *s2fd, * backed by a THP and thus use block mapping if possible. */ if (mapping_size == PAGE_SIZE && - !(s2vi->max_map_size == PAGE_SIZE || fault->s2_force_noncacheable)) { + !(s2vi->max_map_size == PAGE_SIZE || s2vi->map_non_cacheable)) { if (perm_fault_granule > PAGE_SIZE) { mapping_size = perm_fault_granule; } else { @@ -1951,7 +1957,7 @@ static int kvm_s2_fault_map(const struct kvm_s2_fault_desc *s2fd, } } - if (!perm_fault_granule && !fault->s2_force_noncacheable && kvm_has_mte(kvm)) + if (!perm_fault_granule && !s2vi->map_non_cacheable && kvm_has_mte(kvm)) sanitise_mte_tags(kvm, pfn, mapping_size); /* @@ -2020,7 +2026,7 @@ static int user_mem_abort(const struct kvm_s2_fault_desc *s2fd) * Let's check if we will get back a huge page backed by hugetlbfs, or * get block mapping for device MMIO region. */ - ret = kvm_s2_fault_pin_pfn(s2fd, &fault, &s2vi); + ret = kvm_s2_fault_pin_pfn(s2fd, &s2vi); if (ret != 1) return ret; -- 2.47.3