From patchwork Fri Jun 17 01:41:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 12885023 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5AE41C433EF for ; Fri, 17 Jun 2022 01:41:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E3BFC6B0073; Thu, 16 Jun 2022 21:41:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DC5036B0074; Thu, 16 Jun 2022 21:41:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BCB7C6B0075; Thu, 16 Jun 2022 21:41:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id A852A6B0073 for ; Thu, 16 Jun 2022 21:41:55 -0400 (EDT) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay12.hostedemail.com (Postfix) with ESMTP id 83BA91210BA for ; Fri, 17 Jun 2022 01:41:55 +0000 (UTC) X-FDA: 79586026590.30.8649F69 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf30.hostedemail.com (Postfix) with ESMTP id 287798008E for ; Fri, 17 Jun 2022 01:41:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1655430114; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=gOKc2ikh4vL40/zpc4P3kwwtd9Sh2ixHRUheDMcVbAY=; b=Re9DLprTMLucwg/CeomytiZGwA6+Cszo9q6YubTrIOGU+HSxht3tn7atElt5Zflk5xMlmN TM+gIhSeoWsJd29BiRPlmxlGGh1ayUqReGrzfOmPUOjH5Ig6JBzQEBGiJjfP3Bpyfrq9gO mU+5hp8Ah9ZsiH/N/y4EKq7nUKVgiKI= Received: from mail-io1-f70.google.com (mail-io1-f70.google.com [209.85.166.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-258-7lpW9Jm7Pf659ByUDMMQkg-1; Thu, 16 Jun 2022 21:41:53 -0400 X-MC-Unique: 7lpW9Jm7Pf659ByUDMMQkg-1 Received: by mail-io1-f70.google.com with SMTP id z19-20020a05660200d300b0066583f8cf2eso1769591ioe.2 for ; Thu, 16 Jun 2022 18:41:53 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=gOKc2ikh4vL40/zpc4P3kwwtd9Sh2ixHRUheDMcVbAY=; b=zYADVw7X3yxUFhEH8RuYZaV1rB0O+GZEGsu68VqfHcungFb63Xsw2p4usiu/VRfW3g gPx/Z0Yt0XgdoHMFdUHKG3QicRwlgeacj5c7nskou+JSpEYdVYvwneWgLFKPEzWpn4cJ cdp6RNTg5Dy61ABZuVh6ab9koqUZ0uu+fIcZOTJ6pZWkynwU7cngcUO+qBx2VSjil7wM Nwgg6uvYl6imJRLZQXVKuLaOHoA1lUONB/MKS3PiN1FzSUQ5nAKe6g2G8GPOJZXnQJgP t7Zlo77+fqRfFpyghBAszkKJz9lDVc0rpzZQzVFQMzfhrWG806KYbacEaFXly2vRC0U9 +GaA== X-Gm-Message-State: AJIora/TPKIUr1qTjg2OHZHc91CeHhZhOT/HYDGG3171Sxx9Zw1crVZi BPHSRrr7k7SM9luX4L9HxR0s9Iyp++ZauJzYB8X9OfTJf2Dv64a0mdSybPmPCxK1dtdYwjrkOlz oZNAdAZqAupM= X-Received: by 2002:a05:6602:2e8c:b0:66a:4455:f47f with SMTP id m12-20020a0566022e8c00b0066a4455f47fmr3885643iow.117.1655430112627; Thu, 16 Jun 2022 18:41:52 -0700 (PDT) X-Google-Smtp-Source: AGRyM1s04pAPsDFQ2EsphsSIxc0HRk8pePN/EeNdFJuRy8R4vdX4O6YoQejClCtVPRC2WoSkD63FbA== X-Received: by 2002:a05:6602:2e8c:b0:66a:4455:f47f with SMTP id m12-20020a0566022e8c00b0066a4455f47fmr3885638iow.117.1655430112362; Thu, 16 Jun 2022 18:41:52 -0700 (PDT) Received: from localhost.localdomain (cpec09435e3e0ee-cmc09435e3e0ec.cpe.net.cable.rogers.com. [99.241.198.116]) by smtp.gmail.com with ESMTPSA id n4-20020a056e02140400b002d522958fb4sm1726538ilo.2.2022.06.16.18.41.51 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Thu, 16 Jun 2022 18:41:51 -0700 (PDT) From: Peter Xu To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: "Dr . David Alan Gilbert" , Linux MM Mailing List , Sean Christopherson , Paolo Bonzini , Andrea Arcangeli , Andrew Morton , peterx@redhat.com Subject: [PATCH RFC 1/4] mm/gup: Add FOLL_INTERRUPTIBLE Date: Thu, 16 Jun 2022 21:41:44 -0400 Message-Id: <20220617014147.7299-2-peterx@redhat.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220617014147.7299-1-peterx@redhat.com> References: <20220617014147.7299-1-peterx@redhat.com> MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-type: text/plain ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1655430115; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=gOKc2ikh4vL40/zpc4P3kwwtd9Sh2ixHRUheDMcVbAY=; b=ceqqVQVntBm87Yl0YI5Zv7S5IrYOAkY6cvHHDPSKlxJOd2cajIsUu/P+bXmiRX/Xy0/62U +U98EV3SecMsiB2dIyR7qa2rmyS62QG7p9eyBHTuBrblt7Olbkqxe533m/9Ak10VwE1+AV 19Skg1E03O78ZfIbaQbtBvXGklzUQlg= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=Re9DLprT; spf=none (imf30.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=peterx@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1655430115; a=rsa-sha256; cv=none; b=UkS65nU0spddxebsYFNsV9SEXYkHj0hV6fsIZ4N393Mcp5hJdGfQL6+O4lmdyWa9T1XWQ1 dH50Pyxl4bZk+awyjaBlQzpFBe/AlMC/Kdv8ibeiQ1VuIX7w3a57odgNeWoGMgMvfz9lKT NP+8oEYZgbYxuct0YpPHr27sVLOD7c8= X-Stat-Signature: ca9jzoxwt6x53giq7nqctmjhoepwrwuf X-Rspamd-Queue-Id: 287798008E X-Rspamd-Server: rspam11 X-Rspam-User: Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=Re9DLprT; spf=none (imf30.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=peterx@redhat.com; dmarc=pass (policy=none) header.from=redhat.com X-HE-Tag: 1655430114-610706 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: We have had FAULT_FLAG_INTERRUPTIBLE but it was never applied to GUPs. One issue with it is that not all GUP paths are able to handle signal delivers besides SIGKILL. That's not ideal for the GUP users who are actually able to handle these cases, like KVM. KVM uses GUP extensively on faulting guest pages, during which we've got existing infrastructures to retry a page fault at a later time. Allowing the GUP to be interrupted by generic signals can make KVM related threads to be more responsive. For examples: (1) SIGUSR1: which QEMU/KVM uses to deliver an inter-process IPI, e.g. when the admin issues a vm_stop QMP command, SIGUSR1 can be generated to kick the vcpus out of kernel context immediately, (2) SIGINT: which can be used with interactive hypervisor users to stop a virtual machine with Ctrl-C without any delays/hangs, (3) SIGTRAP: which grants GDB capability even during page faults that are stuck for a long time. Normally hypervisor will be able to receive these signals properly, but not if we're stuck in a GUP for a long time for whatever reason. It happens easily with a stucked postcopy migration when e.g. a network temp failure happens, then some vcpu threads can hang death waiting for the pages. With the new FOLL_INTERRUPTIBLE, we can allow GUP users like KVM to selectively enable the ability to trap these signals. Signed-off-by: Peter Xu --- include/linux/mm.h | 1 + mm/gup.c | 33 +++++++++++++++++++++++++++++---- 2 files changed, 30 insertions(+), 4 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index bc8f326be0ce..ebdf8a6b86c1 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2941,6 +2941,7 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, #define FOLL_SPLIT_PMD 0x20000 /* split huge pmd before returning */ #define FOLL_PIN 0x40000 /* pages must be released via unpin_user_page */ #define FOLL_FAST_ONLY 0x80000 /* gup_fast: prevent fall-back to slow gup */ +#define FOLL_INTERRUPTIBLE 0x100000 /* allow interrupts from generic signals */ /* * FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each diff --git a/mm/gup.c b/mm/gup.c index 551264407624..ad74b137d363 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -933,8 +933,17 @@ static int faultin_page(struct vm_area_struct *vma, fault_flags |= FAULT_FLAG_WRITE; if (*flags & FOLL_REMOTE) fault_flags |= FAULT_FLAG_REMOTE; - if (locked) + if (locked) { fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; + /* + * We should only grant FAULT_FLAG_INTERRUPTIBLE when we're + * (at least) killable. It also mostly means we're not + * with NOWAIT. Otherwise ignore FOLL_INTERRUPTIBLE since + * it won't make a lot of sense to be used alone. + */ + if (*flags & FOLL_INTERRUPTIBLE) + fault_flags |= FAULT_FLAG_INTERRUPTIBLE; + } if (*flags & FOLL_NOWAIT) fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT; if (*flags & FOLL_TRIED) { @@ -1322,6 +1331,22 @@ int fixup_user_fault(struct mm_struct *mm, } EXPORT_SYMBOL_GPL(fixup_user_fault); +/* + * GUP always responds to fatal signals. When FOLL_INTERRUPTIBLE is + * specified, it'll also respond to generic signals. The caller of GUP + * that has FOLL_INTERRUPTIBLE should take care of the GUP interruption. + */ +static bool gup_signal_pending(unsigned int flags) +{ + if (fatal_signal_pending(current)) + return true; + + if (!(flags & FOLL_INTERRUPTIBLE)) + return false; + + return signal_pending(current); +} + /* * Please note that this function, unlike __get_user_pages will not * return 0 for nr_pages > 0 without FOLL_NOWAIT @@ -1403,11 +1428,11 @@ static __always_inline long __get_user_pages_locked(struct mm_struct *mm, * Repeat on the address that fired VM_FAULT_RETRY * with both FAULT_FLAG_ALLOW_RETRY and * FAULT_FLAG_TRIED. Note that GUP can be interrupted - * by fatal signals, so we need to check it before we + * by fatal signals of even common signals, depending on + * the caller's request. So we need to check it before we * start trying again otherwise it can loop forever. */ - - if (fatal_signal_pending(current)) { + if (gup_signal_pending(flags)) { if (!pages_done) pages_done = -EINTR; break; From patchwork Fri Jun 17 01:41:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 12885025 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97887C43334 for ; Fri, 17 Jun 2022 01:42:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E3C776B0075; Thu, 16 Jun 2022 21:42:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DEB9F6B0078; Thu, 16 Jun 2022 21:42:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C3F4A6B007B; Thu, 16 Jun 2022 21:42:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id B2A2A6B0075 for ; Thu, 16 Jun 2022 21:42:05 -0400 (EDT) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 8CE2C34CC5 for ; Fri, 17 Jun 2022 01:42:05 +0000 (UTC) X-FDA: 79586027010.07.DC4F813 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf10.hostedemail.com (Postfix) with ESMTP id 25589C0032 for ; Fri, 17 Jun 2022 01:42:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1655430124; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bR8MuwpznI9qRUj89FotcZKYXyQ5fO5vJmhSv17cXWQ=; b=YgZrLF1BrhOBWudN+0Oyy2LxWE/RvW2Tg9R/D67o6HmRLcPhysVXYA20w7jLZVpLoEyTgV erYFqx/C8mFDXByXbAyn7xefzKxu/Zw96LhJUnEdKg7v326JYEuwyhT2nd8wBx3VG8thIh QDxcBu3JK0fQCp7JhGp/N50Urysyypw= Received: from mail-il1-f199.google.com (mail-il1-f199.google.com [209.85.166.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-446-pWBidUNeN5KkLCpGLVvPyw-1; Thu, 16 Jun 2022 21:41:55 -0400 X-MC-Unique: pWBidUNeN5KkLCpGLVvPyw-1 Received: by mail-il1-f199.google.com with SMTP id y18-20020a927d12000000b002d3dd2a5d53so1857965ilc.0 for ; Thu, 16 Jun 2022 18:41:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=bR8MuwpznI9qRUj89FotcZKYXyQ5fO5vJmhSv17cXWQ=; b=3VncJzeQ9XXm3yWDingdDGzdl2+2m8XzpI1s/f6/UhAUYe9LBDCI7VNQOEFHuDEE7I qIwy8u+CpgJSD/o8XYyn52WowFOIPu+5Hc7EYZs8p/HQMTLyp+xEc7v0sFgf28yH0ATK 3i4usiGuNRdY836Wzk90AOA1iECr0Gh80iHhVSxCUQZPj0A3Q+EM38ZqR12PC9tMVBPN M+oCeK+8uoCNbL49z3hhlXr/+qY1J+UeHIg3LX6S08v6MslDBxVT7PW8PRkS1X/3YucA gN2oc9J6IkxeujkcAYG75H3qHYZr8f6GC+Ug1EJenfuKLBOjaPPtyEMFRdawXSKx2Cvd Hq3Q== X-Gm-Message-State: AJIora/X+BlOJ3kDKprA+LHwlMaNddg3tsmmMBeKOGdFYfnCU2YOM8rg OP3R5r4CpS9XykdVRw6PFrVqdIxqtThR7yc+gZ0csuCG/RWhp+Z4ThRg+aPamgFxI00rfCgN5WQ V+XqrMvqKWoY= X-Received: by 2002:a92:ca0b:0:b0:2d1:ed7a:a1fc with SMTP id j11-20020a92ca0b000000b002d1ed7aa1fcmr4338223ils.282.1655430114481; Thu, 16 Jun 2022 18:41:54 -0700 (PDT) X-Google-Smtp-Source: AGRyM1spYww9dWZVjK4wNwAz3pACZhgd3fjV/WAPqh1xL4lB2Vo7rp9WsWx7H9mGd00hnV7NGDXT3A== X-Received: by 2002:a92:ca0b:0:b0:2d1:ed7a:a1fc with SMTP id j11-20020a92ca0b000000b002d1ed7aa1fcmr4338213ils.282.1655430114178; Thu, 16 Jun 2022 18:41:54 -0700 (PDT) Received: from localhost.localdomain (cpec09435e3e0ee-cmc09435e3e0ec.cpe.net.cable.rogers.com. [99.241.198.116]) by smtp.gmail.com with ESMTPSA id n4-20020a056e02140400b002d522958fb4sm1726538ilo.2.2022.06.16.18.41.52 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Thu, 16 Jun 2022 18:41:53 -0700 (PDT) From: Peter Xu To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: "Dr . David Alan Gilbert" , Linux MM Mailing List , Sean Christopherson , Paolo Bonzini , Andrea Arcangeli , Andrew Morton , peterx@redhat.com Subject: [PATCH RFC 2/4] kvm: Merge "atomic" and "write" in __gfn_to_pfn_memslot() Date: Thu, 16 Jun 2022 21:41:45 -0400 Message-Id: <20220617014147.7299-3-peterx@redhat.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220617014147.7299-1-peterx@redhat.com> References: <20220617014147.7299-1-peterx@redhat.com> MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-type: text/plain ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1655430125; a=rsa-sha256; cv=none; b=sbHysVFARedNoLg7/QqbSxNXrO3a+FAqfvovWtQb8UXfx+t1Ig9O780cQ3I8Ct9j54Jbf7 2TOmyggOsnFhMndqgy6v6RGHIVMO5bYMREBy9Rq3YnTagLSO+Xgrmk+TCbzLRNvQ+WBhr4 d/Afdh6MRuwgH/ynzSr5mT9c9sSDrOA= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=YgZrLF1B; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf10.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=peterx@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1655430125; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=bR8MuwpznI9qRUj89FotcZKYXyQ5fO5vJmhSv17cXWQ=; b=oBZIsrqfkBEGMUTWD8pJpHlqFIBX0BYxdcgYqU7Ly3Hyk9DFbjFoAZLLkfG2PR1EJWmkQb eVv5nRfEPqNLOfsclrpdujoNG8uJk4xXUHZZ/AD4DWIpfAuWdnuxMi2KwGbQR/cVZxUeEQ klg7xRko2KY8N4IzRSIL3kkKtJOiiA8= X-Rspamd-Queue-Id: 25589C0032 X-Rspam-User: Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=YgZrLF1B; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf10.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=peterx@redhat.com X-Rspamd-Server: rspam06 X-Stat-Signature: qu5o49zeug9mkijg41ym8frd9i9fq7fe X-HE-Tag: 1655430124-647779 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Merge two boolean parameters into a bitmask flag called kvm_gtp_flag_t for __gfn_to_pfn_memslot(). This cleans the parameter lists, and also prepare for new boolean to be added to __gfn_to_pfn_memslot(). Signed-off-by: Peter Xu --- arch/arm64/kvm/mmu.c | 5 ++-- arch/powerpc/kvm/book3s_64_mmu_hv.c | 5 ++-- arch/powerpc/kvm/book3s_64_mmu_radix.c | 5 ++-- arch/x86/kvm/mmu/mmu.c | 10 +++---- include/linux/kvm_host.h | 9 ++++++- virt/kvm/kvm_main.c | 37 +++++++++++++++----------- virt/kvm/kvm_mm.h | 6 +++-- virt/kvm/pfncache.c | 2 +- 8 files changed, 49 insertions(+), 30 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index f5651a05b6a8..ce8066ded15b 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1204,8 +1204,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, */ smp_rmb(); - pfn = __gfn_to_pfn_memslot(memslot, gfn, false, NULL, - write_fault, &writable, NULL); + pfn = __gfn_to_pfn_memslot(memslot, gfn, + write_fault ? KVM_GTP_WRITE : 0, + false, NULL, &writable, NULL); if (pfn == KVM_PFN_ERR_HWPOISON) { kvm_send_hwpoison_signal(hva, vma_shift); return 0; diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index 514fd45c1994..2f5fad2e1b7f 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -598,8 +598,9 @@ int kvmppc_book3s_hv_page_fault(struct kvm_vcpu *vcpu, write_ok = true; } else { /* Call KVM generic code to do the slow-path check */ - pfn = __gfn_to_pfn_memslot(memslot, gfn, false, NULL, - writing, &write_ok, NULL); + pfn = __gfn_to_pfn_memslot(memslot, gfn, + writing ? KVM_GTP_WRITE : 0, + false, NULL, &write_ok, NULL); if (is_error_noslot_pfn(pfn)) return -EFAULT; page = NULL; diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c index 42851c32ff3b..232b17c75b83 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c @@ -845,8 +845,9 @@ int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu, unsigned long pfn; /* Call KVM generic code to do the slow-path check */ - pfn = __gfn_to_pfn_memslot(memslot, gfn, false, NULL, - writing, upgrade_p, NULL); + pfn = __gfn_to_pfn_memslot(memslot, gfn, + writing ? KVM_GTP_WRITE : 0, + NULL, upgrade_p, NULL); if (is_error_noslot_pfn(pfn)) return -EFAULT; page = NULL; diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index f4653688fa6d..e92f1ab63d6a 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3968,6 +3968,7 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) { + kvm_gtp_flag_t flags = fault->write ? KVM_GTP_WRITE : 0; struct kvm_memory_slot *slot = fault->slot; bool async; @@ -3999,8 +4000,8 @@ static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) } async = false; - fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, &async, - fault->write, &fault->map_writable, + fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, flags, + &async, &fault->map_writable, &fault->hva); if (!async) return RET_PF_CONTINUE; /* *pfn has correct page already */ @@ -4016,9 +4017,8 @@ static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) } } - fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, NULL, - fault->write, &fault->map_writable, - &fault->hva); + fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, flags, NULL, + &fault->map_writable, &fault->hva); return RET_PF_CONTINUE; } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index c20f2d55840c..b646b6fcaec6 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1146,8 +1146,15 @@ kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault, bool *writable); kvm_pfn_t gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn); kvm_pfn_t gfn_to_pfn_memslot_atomic(const struct kvm_memory_slot *slot, gfn_t gfn); + +/* gfn_to_pfn (gtp) flags */ +typedef unsigned int __bitwise kvm_gtp_flag_t; + +#define KVM_GTP_WRITE ((__force kvm_gtp_flag_t) BIT(0)) +#define KVM_GTP_ATOMIC ((__force kvm_gtp_flag_t) BIT(1)) + kvm_pfn_t __gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn, - bool atomic, bool *async, bool write_fault, + kvm_gtp_flag_t gtp_flags, bool *async, bool *writable, hva_t *hva); void kvm_release_pfn_clean(kvm_pfn_t pfn); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 64ec2222a196..952400b42ee9 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2444,9 +2444,11 @@ static bool hva_to_pfn_fast(unsigned long addr, bool write_fault, * The slow path to get the pfn of the specified host virtual address, * 1 indicates success, -errno is returned if error is detected. */ -static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault, +static int hva_to_pfn_slow(unsigned long addr, bool *async, + kvm_gtp_flag_t gtp_flags, bool *writable, kvm_pfn_t *pfn) { + bool write_fault = gtp_flags & KVM_GTP_WRITE; unsigned int flags = FOLL_HWPOISON; struct page *page; int npages = 0; @@ -2565,20 +2567,22 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma, /* * Pin guest page in memory and return its pfn. * @addr: host virtual address which maps memory to the guest - * @atomic: whether this function can sleep + * @gtp_flags: kvm_gtp_flag_t flags (atomic, write, ..) * @async: whether this function need to wait IO complete if the * host page is not in the memory - * @write_fault: whether we should get a writable host page * @writable: whether it allows to map a writable host page for !@write_fault * - * The function will map a writable host page for these two cases: + * The function will map a writable (KVM_GTP_WRITE set) host page for these + * two cases: * 1): @write_fault = true * 2): @write_fault = false && @writable, @writable will tell the caller * whether the mapping is writable. */ -kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, - bool write_fault, bool *writable) +kvm_pfn_t hva_to_pfn(unsigned long addr, kvm_gtp_flag_t gtp_flags, bool *async, + bool *writable) { + bool write_fault = gtp_flags & KVM_GTP_WRITE; + bool atomic = gtp_flags & KVM_GTP_ATOMIC; struct vm_area_struct *vma; kvm_pfn_t pfn = 0; int npages, r; @@ -2592,7 +2596,7 @@ kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, if (atomic) return KVM_PFN_ERR_FAULT; - npages = hva_to_pfn_slow(addr, async, write_fault, writable, &pfn); + npages = hva_to_pfn_slow(addr, async, gtp_flags, writable, &pfn); if (npages == 1) return pfn; @@ -2625,10 +2629,11 @@ kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, } kvm_pfn_t __gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn, - bool atomic, bool *async, bool write_fault, + kvm_gtp_flag_t gtp_flags, bool *async, bool *writable, hva_t *hva) { - unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault); + unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, + gtp_flags & KVM_GTP_WRITE); if (hva) *hva = addr; @@ -2651,28 +2656,30 @@ kvm_pfn_t __gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn, writable = NULL; } - return hva_to_pfn(addr, atomic, async, write_fault, - writable); + return hva_to_pfn(addr, gtp_flags, async, writable); } EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot); kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault, bool *writable) { - return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, NULL, - write_fault, writable, NULL); + return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, + write_fault ? KVM_GTP_WRITE : 0, + NULL, writable, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_prot); kvm_pfn_t gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn) { - return __gfn_to_pfn_memslot(slot, gfn, false, NULL, true, NULL, NULL); + return __gfn_to_pfn_memslot(slot, gfn, KVM_GTP_WRITE, + NULL, NULL, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot); kvm_pfn_t gfn_to_pfn_memslot_atomic(const struct kvm_memory_slot *slot, gfn_t gfn) { - return __gfn_to_pfn_memslot(slot, gfn, true, NULL, true, NULL, NULL); + return __gfn_to_pfn_memslot(slot, gfn, KVM_GTP_WRITE | KVM_GTP_ATOMIC, + NULL, NULL, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic); diff --git a/virt/kvm/kvm_mm.h b/virt/kvm/kvm_mm.h index 41da467d99c9..1c870911eb48 100644 --- a/virt/kvm/kvm_mm.h +++ b/virt/kvm/kvm_mm.h @@ -3,6 +3,8 @@ #ifndef __KVM_MM_H__ #define __KVM_MM_H__ 1 +#include + /* * Architectures can choose whether to use an rwlock or spinlock * for the mmu_lock. These macros, for use in common code @@ -24,8 +26,8 @@ #define KVM_MMU_READ_UNLOCK(kvm) spin_unlock(&(kvm)->mmu_lock) #endif /* KVM_HAVE_MMU_RWLOCK */ -kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, - bool write_fault, bool *writable); +kvm_pfn_t hva_to_pfn(unsigned long addr, kvm_gtp_flag_t gtp_flags, bool *async, + bool *writable); #ifdef CONFIG_HAVE_KVM_PFNCACHE void gfn_to_pfn_cache_invalidate_start(struct kvm *kvm, diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c index dd84676615f1..0f9f6b5d2fbb 100644 --- a/virt/kvm/pfncache.c +++ b/virt/kvm/pfncache.c @@ -123,7 +123,7 @@ static kvm_pfn_t hva_to_pfn_retry(struct kvm *kvm, unsigned long uhva) smp_rmb(); /* We always request a writeable mapping */ - new_pfn = hva_to_pfn(uhva, false, NULL, true, NULL); + new_pfn = hva_to_pfn(uhva, KVM_GTP_WRITE, NULL, NULL); if (is_error_noslot_pfn(new_pfn)) break; From patchwork Fri Jun 17 01:41:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 12885024 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30FADC43334 for ; Fri, 17 Jun 2022 01:42:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 562E46B0074; Thu, 16 Jun 2022 21:42:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 512006B0075; Thu, 16 Jun 2022 21:42:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 38BF76B0078; Thu, 16 Jun 2022 21:42:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 2848D6B0074 for ; Thu, 16 Jun 2022 21:42:00 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 046B93512F for ; Fri, 17 Jun 2022 01:41:59 +0000 (UTC) X-FDA: 79586026800.21.F1B5922 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf11.hostedemail.com (Postfix) with ESMTP id 8812640086 for ; Fri, 17 Jun 2022 01:41:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1655430118; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ghHac7UV1N6vPGfjk7ojRXZFbMUyEtSeJQo5S/wAoOg=; b=NrOv7d3XvSDGb0fYfbi7wP1PoaH7k/6zz5b27rM4b4vBGKehgt+FutkOsW5Xm3jwREuXMO kl4pb6WiiCLKesYQkwfEqy09WwPDc3Mh//J5Q6LTbZO/LLhC0TICRncdzNLLTEv6Oa8Mlq xx4D9Bw6WCvmb5vUpa4VSjHaH7e9Ej4= Received: from mail-il1-f198.google.com (mail-il1-f198.google.com [209.85.166.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-641-rRgf8BrBP2qvLTsUUtyolA-1; Thu, 16 Jun 2022 21:41:57 -0400 X-MC-Unique: rRgf8BrBP2qvLTsUUtyolA-1 Received: by mail-il1-f198.google.com with SMTP id a3-20020a924443000000b002d1bc79da14so1819922ilm.15 for ; Thu, 16 Jun 2022 18:41:57 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ghHac7UV1N6vPGfjk7ojRXZFbMUyEtSeJQo5S/wAoOg=; b=m+diBoW2HSP3dKQJOLNKWn+wC7rKbA/axuf6SXsM568Zl1vupQH+swFyEPfnj7d45e MoB6J8W8rBPsWafqjxFiW417V4IWp5f6EOFWpjcy3xXfQm4Hb6qAEJF90b1D+eMWc4ti lAcQbqeDEXO6DiY93z4G7raQcSU+immWFgJkXlZzp2exzTXLCW5OC1LrZOG0/avCK3q+ JXTLtrYb7oIvnQ4RxXKhwSh17ZlJOUI4/PHlKzMs257391zLq7L2mGVqcVgEbfWJircW vfKGgHN1fW0wB759JaZBbghtz88k6dKjHDpmwscbkQpvUbV+C5f6KXAXkkjF3OFVz6ze +U4g== X-Gm-Message-State: AJIora80KTxT1hus7CNHkDjK3VeQ/OhhBurAe/Rz4YY5NA10rufSigp1 TkuNTANb5BTPx5h78L8A2UMgnjgSKy6+3AomeqShnvqTNkAORJms840Lju5xC7T1BxXDoA2Hmwq COI4WcLqEOPM= X-Received: by 2002:a05:6e02:811:b0:2d5:2294:ff37 with SMTP id u17-20020a056e02081100b002d52294ff37mr4319993ilm.249.1655430116764; Thu, 16 Jun 2022 18:41:56 -0700 (PDT) X-Google-Smtp-Source: AGRyM1vkkfMz7cqp5MF8GJOCZIECqzgeFNO0MvlQHMdn1ovMhxzPuVoVfsfN47FOLsLaed4L90CO1w== X-Received: by 2002:a05:6e02:811:b0:2d5:2294:ff37 with SMTP id u17-20020a056e02081100b002d52294ff37mr4319979ilm.249.1655430116477; Thu, 16 Jun 2022 18:41:56 -0700 (PDT) Received: from localhost.localdomain (cpec09435e3e0ee-cmc09435e3e0ec.cpe.net.cable.rogers.com. [99.241.198.116]) by smtp.gmail.com with ESMTPSA id n4-20020a056e02140400b002d522958fb4sm1726538ilo.2.2022.06.16.18.41.54 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Thu, 16 Jun 2022 18:41:56 -0700 (PDT) From: Peter Xu To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: "Dr . David Alan Gilbert" , Linux MM Mailing List , Sean Christopherson , Paolo Bonzini , Andrea Arcangeli , Andrew Morton , peterx@redhat.com Subject: [PATCH RFC 3/4] kvm: Add new pfn error KVM_PFN_ERR_INTR Date: Thu, 16 Jun 2022 21:41:46 -0400 Message-Id: <20220617014147.7299-4-peterx@redhat.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220617014147.7299-1-peterx@redhat.com> References: <20220617014147.7299-1-peterx@redhat.com> MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-type: text/plain ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=NrOv7d3X; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf11.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.129.124) smtp.mailfrom=peterx@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1655430119; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ghHac7UV1N6vPGfjk7ojRXZFbMUyEtSeJQo5S/wAoOg=; b=TnE7VYTdVoVtKLEaeW97iFX3fCZ/7sxzrBTQbSF2/+B1DllDPFHeFEuusZhGez2YS0GdFe sZoID00+2xycmVHQ7jvqLZl6HqKjxc2pucFt1DXHzi2dVhtlw7nj9fE9l2yln4q/i6Dlcz nwRF+I/Z5rp0+WfHer02oiVsRge+3gk= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1655430119; a=rsa-sha256; cv=none; b=j3woExolU31kc1I/XfSzI17bv+LoMV1hkaFjozSSTeR9ZbdQWhck/la6K319k6jD3edV6A 3BS2YRMOCWt+x3lqEjXdDQKdQPTG0b6sC15V7xEOKxRmnfQ4hLs6f7lszdaL2CKkDtXEf4 VitP9vQT3Hxb0rcDrQzzxCBdaW0NATA= X-Stat-Signature: 7yr1g3q9rfudogxrrebtp1gyootxaa3c X-Rspamd-Queue-Id: 8812640086 X-Rspam-User: Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=NrOv7d3X; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf11.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.129.124) smtp.mailfrom=peterx@redhat.com X-Rspamd-Server: rspam10 X-HE-Tag: 1655430119-374699 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Add one new PFN error type to show when we cannot finish fetching the PFN due to interruptions. For example, by receiving a generic signal. This prepares KVM to be able to respond to SIGUSR1 (for QEMU that's the SIGIPI) even during e.g. handling an userfaultfd page fault. Signed-off-by: Peter Xu --- include/linux/kvm_host.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index b646b6fcaec6..4f84a442f67f 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -96,6 +96,7 @@ #define KVM_PFN_ERR_FAULT (KVM_PFN_ERR_MASK) #define KVM_PFN_ERR_HWPOISON (KVM_PFN_ERR_MASK + 1) #define KVM_PFN_ERR_RO_FAULT (KVM_PFN_ERR_MASK + 2) +#define KVM_PFN_ERR_INTR (KVM_PFN_ERR_MASK + 3) /* * error pfns indicate that the gfn is in slot but faild to @@ -106,6 +107,16 @@ static inline bool is_error_pfn(kvm_pfn_t pfn) return !!(pfn & KVM_PFN_ERR_MASK); } +/* + * When KVM_PFN_ERR_INTR is returned, it means we're interrupted during + * fetching the PFN (e.g. a signal might have arrived), so we may want to + * retry at some later point and kick the userspace to handle the signal. + */ +static inline bool is_intr_pfn(kvm_pfn_t pfn) +{ + return pfn == KVM_PFN_ERR_INTR; +} + /* * error_noslot pfns indicate that the gfn can not be * translated to pfn - it is not in slot or failed to From patchwork Fri Jun 17 01:41:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 12885026 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 932F3CCA47A for ; Fri, 17 Jun 2022 01:42:07 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CDE2D6B0078; Thu, 16 Jun 2022 21:42:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C66066B007B; Thu, 16 Jun 2022 21:42:06 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A6A746B007D; Thu, 16 Jun 2022 21:42:06 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 928F06B0078 for ; Thu, 16 Jun 2022 21:42:06 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 6BA7920888 for ; Fri, 17 Jun 2022 01:42:06 +0000 (UTC) X-FDA: 79586027052.27.4C28B1B Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf24.hostedemail.com (Postfix) with ESMTP id 81942180087 for ; Fri, 17 Jun 2022 01:42:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1655430124; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+Bc6oiDMKyczPP3MnRg+YG2Ibpmu1/F27D1fgoc2Uo0=; b=TV6DXJjY1kXgx3weTVnI3QEAXEKKgojclb8llBf9yXc6d8TMbKatV0JrYOZZssOrr4cLNk V7hNdtFB7JSh5H4EbE8a2IN0RZG48LXE5lKpGNgThX+Pa9s3GgHL74QKQ0cfA5BxiFGXnf AkfrLKwdTFENpTAhTN9e80aC2z4gmio= Received: from mail-io1-f70.google.com (mail-io1-f70.google.com [209.85.166.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-331-P3Sl5d1AMSGXugtCEWDiFw-1; Thu, 16 Jun 2022 21:42:01 -0400 X-MC-Unique: P3Sl5d1AMSGXugtCEWDiFw-1 Received: by mail-io1-f70.google.com with SMTP id h4-20020a056602008400b0066a011ac3d6so1752083iob.14 for ; Thu, 16 Jun 2022 18:42:00 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=+Bc6oiDMKyczPP3MnRg+YG2Ibpmu1/F27D1fgoc2Uo0=; b=UC4YlQEmk6zA+7yHIhPLBCy1GfqTU4Pqm10LYjZEPfAzNrAo4XBGs9BiucYqb9yPG+ PoaNc118n9emTHSkLgWWvctJb/IWuA+dJfLY8j2ShQVZep22wdsTLzwvTVLTQYgVxn9A FhJR+7JEagX4raT8Z1IZqsuGiYmOg5rzEOKdETgVD00G3FiEE0OAempa1pLAvxxw+rWM ZpWANhig/579uB4nxgRJmDepGU5sO3CTpbq/U369VxhE3azqAMhAoFRQXKQBwtJGWa8J inPc2Sz8tnt8NkZ74ivDyySgAkKYrjdx8qJomTp2FJf0Bh+Vds9BNH9SsmTeuZcyirpN 5YVA== X-Gm-Message-State: AJIora8EhiFbCo8DDQxFHu8zVJsyxn4UlNbg3R3VC90Q8a6OzDTqvcoq Pr4TdDeb5EH8D4n4cSOgGe5ooEqXYfU2+lSTCcyWNjQVg+ZqRWJobefzq5YCfiGrV/7qF2S4pNG rxQdDmGKhtnA= X-Received: by 2002:a92:da4e:0:b0:2d6:6554:a33b with SMTP id p14-20020a92da4e000000b002d66554a33bmr4355223ilq.10.1655430118246; Thu, 16 Jun 2022 18:41:58 -0700 (PDT) X-Google-Smtp-Source: AGRyM1vLhgSniNb4wQ9rsYIx2n9iJ0unph2M/HKN3cx1HhnNV8Tgz+efjRctqDyhOiUvQlicAOOc3w== X-Received: by 2002:a92:da4e:0:b0:2d6:6554:a33b with SMTP id p14-20020a92da4e000000b002d66554a33bmr4355213ilq.10.1655430117980; Thu, 16 Jun 2022 18:41:57 -0700 (PDT) Received: from localhost.localdomain (cpec09435e3e0ee-cmc09435e3e0ec.cpe.net.cable.rogers.com. [99.241.198.116]) by smtp.gmail.com with ESMTPSA id n4-20020a056e02140400b002d522958fb4sm1726538ilo.2.2022.06.16.18.41.56 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Thu, 16 Jun 2022 18:41:57 -0700 (PDT) From: Peter Xu To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: "Dr . David Alan Gilbert" , Linux MM Mailing List , Sean Christopherson , Paolo Bonzini , Andrea Arcangeli , Andrew Morton , peterx@redhat.com Subject: [PATCH RFC 4/4] kvm/x86: Allow to respond to generic signals during slow page faults Date: Thu, 16 Jun 2022 21:41:47 -0400 Message-Id: <20220617014147.7299-5-peterx@redhat.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220617014147.7299-1-peterx@redhat.com> References: <20220617014147.7299-1-peterx@redhat.com> MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-type: text/plain ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=TV6DXJjY; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf24.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.129.124) smtp.mailfrom=peterx@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1655430126; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=+Bc6oiDMKyczPP3MnRg+YG2Ibpmu1/F27D1fgoc2Uo0=; b=51onhB7YBnGOj0UvmAUDbfrXnF2Ineviz2FJej9Cg/avPufbdbvlIWiRQifHOyH4R1kKuF 7WuI2pxTv6isnXK/2d/OFcA+Zk3vjSuBnLyqYSkqrPKQc7gSuIvlBJzB596c/BBjbtDeLl EF6fViB/Ee5UyrIwACELSCONSnRkOFc= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1655430126; a=rsa-sha256; cv=none; b=wg/Th4tNK8nFX0jRC5/1zXznqQst3HJMsTT9+pmpRB+Z9QC/j4w2qlstZe8U41E4akuGbH TY/PGhGdSfYXW+Mu3j0sOJUwdh1p29vgTht2SJLkfbfGK8Qhey26aR8dlh4zBiibo9TfGP v/9Y6BN3ZJGB/azrBpRNbORa2BvyTug= X-Rspam-User: X-Stat-Signature: j4437szq5qyb3s7fwr1fihn43q7oucaz X-Rspamd-Queue-Id: 81942180087 Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=TV6DXJjY; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf24.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.129.124) smtp.mailfrom=peterx@redhat.com X-Rspamd-Server: rspam05 X-HE-Tag: 1655430125-439202 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: All the facilities should be ready for this, what we need to do is to add a new KVM_GTP_INTERRUPTIBLE flag showing that we're willing to be interrupted by common signals during the __gfn_to_pfn_memslot() request, and wire it up with a FOLL_INTERRUPTIBLE flag that we've just introduced. Note that only x86 slow page fault routine will set this new bit. The new bit is not used in non-x86 arch or on other gup paths even for x86. However it can actually be used elsewhere too but not yet covered. When we see the PFN fetching was interrupted, do early exit to userspace with an KVM_EXIT_INTR exit reason. Signed-off-by: Peter Xu --- arch/x86/kvm/mmu/mmu.c | 9 +++++++++ include/linux/kvm_host.h | 1 + virt/kvm/kvm_main.c | 4 ++++ 3 files changed, 14 insertions(+) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index e92f1ab63d6a..b39acb7cb16d 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3012,6 +3012,13 @@ static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn) static int handle_abnormal_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, unsigned int access) { + /* NOTE: not all error pfn is fatal; handle intr before the other ones */ + if (unlikely(is_intr_pfn(fault->pfn))) { + vcpu->run->exit_reason = KVM_EXIT_INTR; + ++vcpu->stat.signal_exits; + return -EINTR; + } + /* The pfn is invalid, report the error! */ if (unlikely(is_error_pfn(fault->pfn))) return kvm_handle_bad_page(vcpu, fault->gfn, fault->pfn); @@ -4017,6 +4024,8 @@ static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) } } + /* Allow to respond to generic signals in slow page faults */ + flags |= KVM_GTP_INTERRUPTIBLE; fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, flags, NULL, &fault->map_writable, &fault->hva); return RET_PF_CONTINUE; diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 4f84a442f67f..c8d98e435537 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1163,6 +1163,7 @@ typedef unsigned int __bitwise kvm_gtp_flag_t; #define KVM_GTP_WRITE ((__force kvm_gtp_flag_t) BIT(0)) #define KVM_GTP_ATOMIC ((__force kvm_gtp_flag_t) BIT(1)) +#define KVM_GTP_INTERRUPTIBLE ((__force kvm_gtp_flag_t) BIT(2)) kvm_pfn_t __gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn, kvm_gtp_flag_t gtp_flags, bool *async, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 952400b42ee9..b3873cac5672 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2462,6 +2462,8 @@ static int hva_to_pfn_slow(unsigned long addr, bool *async, flags |= FOLL_WRITE; if (async) flags |= FOLL_NOWAIT; + if (gtp_flags & KVM_GTP_INTERRUPTIBLE) + flags |= FOLL_INTERRUPTIBLE; npages = get_user_pages_unlocked(addr, 1, &page, flags); if (npages != 1) @@ -2599,6 +2601,8 @@ kvm_pfn_t hva_to_pfn(unsigned long addr, kvm_gtp_flag_t gtp_flags, bool *async, npages = hva_to_pfn_slow(addr, async, gtp_flags, writable, &pfn); if (npages == 1) return pfn; + if (npages == -EINTR) + return KVM_PFN_ERR_INTR; mmap_read_lock(current->mm); if (npages == -EHWPOISON ||