From patchwork Mon Mar 3 13:30:10 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikita Kalyazin X-Patchwork-Id: 13998844 Received: from smtp-fw-80008.amazon.com (smtp-fw-80008.amazon.com [99.78.197.219]) (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 50F80211491; Mon, 3 Mar 2025 13:31:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=99.78.197.219 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741008681; cv=none; b=aHwnm1gniDT1hjGzk3Ok4FTjM0dGw/lqvkNqcU3kMKjw2KvDdnQug1XP42Vs2vNzojBDB2Ck+oprSmMjxSlUyVDEJDII63Hx6wxH5hCZ5s+BGtSDbAkVrbT0wgodqAxgZBP/0dmdngKDb4//aa0QN7wTcrfU1URI2PhX4vPzVIk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741008681; c=relaxed/simple; bh=OkqqRo0IbFH81I+Mj1ghNzX9j1deQ4VMO3aCHBD6vkw=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=gF83RWIIKsu1H/USxzkgCeVlB/aZqDGz+qFKSkqtx1OFbqCKb8cswpW/zp6t0RwZXfa5arZbu/CBi2wR3qmlDzNbMyUPOrT6R1VNgBjub47a8aziqDL9mJsiECVOiGBrEzzMlwuIYFl9VuEkLnevUiTXa/FCGbtd1dhkMtRT2lk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.co.uk; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b=rXnVLjtr; arc=none smtp.client-ip=99.78.197.219 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.co.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="rXnVLjtr" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1741008680; x=1772544680; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=JIXEK8fZmfp3pTHcHhhnyrOSlMvjIkeSF6WjbQ+OQL4=; b=rXnVLjtrQ3ZiAxemifjuboxOG4rjR6dO0H5uwAlhAHHHfod337Hvf1mJ gzCBNlgNp0pF2AmFL8MmXW3iGYXyhKUFq0Lw/PeTpMbLxzhxk3ZWL8ltf 2eg54ktUP5tWb8bF5dQbnyMWlQFvbFiTKXub00RYpAnMA5AFQp5633ql2 g=; X-IronPort-AV: E=Sophos;i="6.13,329,1732579200"; d="scan'208";a="174959912" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO smtpout.prod.us-east-1.prod.farcaster.email.amazon.dev) ([10.25.36.214]) by smtp-border-fw-80008.pdx80.corp.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Mar 2025 13:31:17 +0000 Received: from EX19MTAUWA001.ant.amazon.com [10.0.7.35:29532] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.9.61:2525] with esmtp (Farcaster) id 1338de01-a28d-410f-a789-9dc43131ae5f; Mon, 3 Mar 2025 13:31:16 +0000 (UTC) X-Farcaster-Flow-ID: 1338de01-a28d-410f-a789-9dc43131ae5f Received: from EX19D003UWB004.ant.amazon.com (10.13.138.24) by EX19MTAUWA001.ant.amazon.com (10.250.64.204) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1544.14; Mon, 3 Mar 2025 13:31:08 +0000 Received: from EX19MTAUWC002.ant.amazon.com (10.250.64.143) by EX19D003UWB004.ant.amazon.com (10.13.138.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1544.14; Mon, 3 Mar 2025 13:31:07 +0000 Received: from email-imr-corp-prod-pdx-all-2c-785684ef.us-west-2.amazon.com (10.25.36.210) by mail-relay.amazon.com (10.250.64.149) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1544.14 via Frontend Transport; Mon, 3 Mar 2025 13:31:07 +0000 Received: from dev-dsk-kalyazin-1a-a12e27e2.eu-west-1.amazon.com (dev-dsk-kalyazin-1a-a12e27e2.eu-west-1.amazon.com [172.19.103.116]) by email-imr-corp-prod-pdx-all-2c-785684ef.us-west-2.amazon.com (Postfix) with ESMTPS id 27701A1025; Mon, 3 Mar 2025 13:31:05 +0000 (UTC) From: Nikita Kalyazin To: , , CC: , , , , , , , , , , , , , , , , Subject: [RFC PATCH 4/5] mm: userfaultfd: support continue for guest_memfd Date: Mon, 3 Mar 2025 13:30:10 +0000 Message-ID: <20250303133011.44095-5-kalyazin@amazon.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250303133011.44095-1-kalyazin@amazon.com> References: <20250303133011.44095-1-kalyazin@amazon.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 When userspace receives a page missing event, it is supposed to populate the missing page in guest_memfd pagecache via the write syscall and unblock the faulting process via UFFDIO_CONTINUE. Signed-off-by: Nikita Kalyazin --- mm/userfaultfd.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index af3dfc3633db..aaff66a7f15b 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -19,6 +19,10 @@ #include #include "internal.h" +#ifdef CONFIG_KVM_PRIVATE_MEM +bool kvm_gmem_vma_is_gmem(struct vm_area_struct *vma); +#endif + static __always_inline bool validate_dst_vma(struct vm_area_struct *dst_vma, unsigned long dst_end) { @@ -391,6 +395,16 @@ static int mfill_atomic_pte_continue(pmd_t *dst_pmd, struct page *page; int ret; +#ifdef CONFIG_KVM_PRIVATE_MEM + if (kvm_gmem_vma_is_gmem(dst_vma)) { + ret = 0; + folio = filemap_get_entry(inode->i_mapping, pgoff); + if (IS_ERR(folio)) + ret = PTR_ERR(folio); + else + folio_lock(folio); + } else +#endif ret = shmem_get_folio(inode, pgoff, 0, &folio, SGP_NOALLOC); /* Our caller expects us to return -EFAULT if we failed to find folio */ if (ret == -ENOENT) @@ -769,9 +783,16 @@ static __always_inline ssize_t mfill_atomic(struct userfaultfd_ctx *ctx, return mfill_atomic_hugetlb(ctx, dst_vma, dst_start, src_start, len, flags); - if (!vma_is_anonymous(dst_vma) && !vma_is_shmem(dst_vma)) + if (!vma_is_anonymous(dst_vma) && !vma_is_shmem(dst_vma) +#ifdef CONFIG_KVM_PRIVATE_MEM + && !kvm_gmem_vma_is_gmem(dst_vma) +#endif + ) goto out_unlock; if (!vma_is_shmem(dst_vma) && +#ifdef CONFIG_KVM_PRIVATE_MEM + !kvm_gmem_vma_is_gmem(dst_vma) && +#endif uffd_flags_mode_is(flags, MFILL_ATOMIC_CONTINUE)) goto out_unlock;