From patchwork Fri Dec 8 08:39:45 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Quan Xu X-Patchwork-Id: 10101799 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id DABCC60325 for ; Fri, 8 Dec 2017 08:42:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C9F8C28B30 for ; Fri, 8 Dec 2017 08:42:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BE80E28B3B; Fri, 8 Dec 2017 08:42:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6D79D28B30 for ; Fri, 8 Dec 2017 08:42:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752564AbdLHIkn (ORCPT ); Fri, 8 Dec 2017 03:40:43 -0500 Received: from mail-ot0-f193.google.com ([74.125.82.193]:46039 "EHLO mail-ot0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752522AbdLHIkk (ORCPT ); Fri, 8 Dec 2017 03:40:40 -0500 Received: by mail-ot0-f193.google.com with SMTP id 103so8632918otj.12; Fri, 08 Dec 2017 00:40:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=D5KYkNGIT0WsopZYkHZRoTwIKr32DmpsXyH/+r1Bh1Y=; b=eNdgS1C0kLXTmbee8sZLtFBlaYXzTgHBWRqg29/1PpFekIkcFsWLfr2F+Uc7zTuYtr 7I0zJflHO5lVTVRCShXxdRFtIVWhsPZpHG3olv4siHfeYZfIEBQt5psvv8aT84c8wHAQ hOQJqJbm8nNMV2v+AsHD+moXhBU+mx2r3j/n6CjP+edgXWWYHBtD1Rj5EBxLhPv3v9Qi NUp2pHqxa90HEE0VgQv8E7bXuj3LVwqrYrZMT7h67E3iHnpvMJ4EOnQHiR0R5IUNnF3x 5KbybbpEqytuMHXkirLXKZIOnq7veKXN+ISdVTQU97Akr6jUbYnbqnDa/AySKH4ye44/ h+bQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=D5KYkNGIT0WsopZYkHZRoTwIKr32DmpsXyH/+r1Bh1Y=; b=uc+K55Fmil1ptpG/TSyyV/VaDrZm0SfeOqtvCJ8QE0OagWtNdufbCFP/TQCLeHxrIp xkULcG0qaxOYQ57aQuLzjigE7dkqmqouUC55zmFHu+7RwVcUIteb8aUGMQ2GYcPSB6PS 8ts8DKVgEL3oNFAcT0UGtfEuSKRZqazIPJOq5SCfYH0e6+5Mbpb42GLkF3ojdND4hETU fr7CIzhRA+EYRfiqng37tRu6RzzEw9MdFIHeyomS+T9TE9SfWIni2yi1STSabqPkCLSz oUT6c0kCwgTzxBqYmn5Meri2ahCkqMlEjTNRO3fhVn9PLfq6ADT25AVoI3nW32B35CGS t8CQ== X-Gm-Message-State: AJaThX5dWzIWJe3cJYgd2HDA2dwoHNtUmNyxPNi9M+O/wHtC7vijzyzK APqrPw505gVKMBNsIoxEsNU= X-Google-Smtp-Source: AGs4zMYI6dfBzLUGXtKEeEWRt5K6w2bR5BE3aB/0Vstfa7ljW9Z1XQi1/2j7zh6hCwZlGGaxWl1HtA== X-Received: by 10.157.50.166 with SMTP id u35mr27460736otb.123.1512722439992; Fri, 08 Dec 2017 00:40:39 -0800 (PST) Received: from localhost.localdomain ([121.0.29.66]) by smtp.googlemail.com with ESMTPSA id p24sm3046407oie.54.2017.12.08.00.40.30 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 08 Dec 2017 00:40:39 -0800 (PST) From: Quan Xu X-Google-Original-From: Quan Xu To: pbonzini@redhat.com, rkrcmar@redhat.com Cc: yang.zhang.wz@gmail.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Ben Luo , Quan Xu Subject: [PATCH RFC 2/7] kvm: x86: add a function to exchange value Date: Fri, 8 Dec 2017 16:39:45 +0800 Message-Id: <1512722390-3654-3-git-send-email-quan.xu0@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1512722390-3654-1-git-send-email-quan.xu0@gmail.com> References: <1512722390-3654-1-git-send-email-quan.xu0@gmail.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Ben Luo Introduce kvm_xchg_guest_cached to exchange value with guest page atomically. Signed-off-by: Yang Zhang Signed-off-by: Quan Xu Signed-off-by: Ben Luo --- include/linux/kvm_host.h | 3 +++ virt/kvm/kvm_main.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 45 insertions(+), 0 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 6882538..32949ed 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -688,6 +688,9 @@ int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, void *data, int offset, unsigned long len); int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc, gpa_t gpa, unsigned long len); +unsigned long kvm_xchg_guest_cached(struct kvm *kvm, + struct gfn_to_hva_cache *ghc, unsigned long offset, + unsigned long new, int size); int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len); int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len); struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 9deb5a2..3149e17 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2010,6 +2010,48 @@ int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, } EXPORT_SYMBOL_GPL(kvm_read_guest_cached); +unsigned long kvm_xchg_guest_cached(struct kvm *kvm, + struct gfn_to_hva_cache *ghc, unsigned long offset, + unsigned long new, int size) +{ + unsigned long r; + void *kva; + struct page *page; + kvm_pfn_t pfn; + + WARN_ON(offset > ghc->len); + + pfn = gfn_to_pfn_atomic(kvm, ghc->gpa >> PAGE_SHIFT); + page = kvm_pfn_to_page(pfn); + + if (is_error_page(page)) + return -EFAULT; + + kva = kmap_atomic(page) + offset_in_page(ghc->gpa) + offset; + switch (size) { + case 1: + r = xchg((char *)kva, new); + break; + case 2: + r = xchg((short *)kva, new); + break; + case 4: + r = xchg((int *)kva, new); + break; + case 8: + r = xchg((long *)kva, new); + break; + default: + kunmap_atomic(kva); + return -EFAULT; + } + + kunmap_atomic(kva); + mark_page_dirty_in_slot(ghc->memslot, ghc->gpa >> PAGE_SHIFT); + + return r; +} + int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len) { const void *zero_page = (const void *) __va(page_to_phys(ZERO_PAGE(0)));