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Tue, 25 May 2021 10:28:40 -0400 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-597-1hsdM-hQMT-4_MYERSrUxw-1; Tue, 25 May 2021 10:28:32 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9C50319253D3 for ; Tue, 25 May 2021 14:28:31 +0000 (UTC) Received: from localhost (ovpn-115-80.ams2.redhat.com [10.36.115.80]) by smtp.corp.redhat.com (Postfix) with ESMTP id 32EDC5C1C2; Tue, 25 May 2021 14:28:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621952916; 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=nUnwbG2LTVhPpxM8WRSWhFamkuOkPnk96+tXIzDWUtY=; b=GwLU3S/HfgooPnFTLt6SCkk3ESsOzVAgJs/ksmDKDCrok6nYN7QE4IzEinK/uTuH0kHCAr /mZMaqJ+qYdS6hh4bcSP24yYiRgsZY12g6FSgwR5Oub5QuX/dmqujEVBBqY0HIRYA1x5JH zoceROQPhtxB8ZssONy7cY3SpKJD+y8= X-MC-Unique: 1hsdM-hQMT-4_MYERSrUxw-1 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Subject: [PATCH v2 1/3] tests/qtest/vhost-user-test: use share=on with memfd Date: Tue, 25 May 2021 15:28:01 +0100 Message-Id: <20210525142803.125401-2-stefanha@redhat.com> In-Reply-To: <20210525142803.125401-1-stefanha@redhat.com> References: <20210525142803.125401-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=stefanha@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=216.205.24.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.371, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, Laurent Vivier , Thomas Huth , "Michael S. Tsirkin" , Stefan Hajnoczi , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Paolo Bonzini Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" Add share=3Don for consistency and to prevent future bugs in the test. Note that share=3Don is the default for memory-backend-memfd so existing tests work. Reviewed-by: Marc-Andr=C3=A9 Lureau Acked-by: Thomas Huth Signed-off-by: Stefan Hajnoczi --- tests/qtest/vhost-user-test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tests/qtest/vhost-user-test.c b/tests/qtest/vhost-user-test.c index 3d6337fb5c..6c0891d429 100644 --- a/tests/qtest/vhost-user-test.c +++ b/tests/qtest/vhost-user-test.c @@ -40,7 +40,7 @@ #define QEMU_CMD_MEM " -m %d -object memory-backend-file,id=3Dmem,size= =3D%dM," \ "mem-path=3D%s,share=3Don -numa node,memdev=3Dmem" #define QEMU_CMD_MEMFD " -m %d -object memory-backend-memfd,id=3Dmem,size= =3D%dM," \ - " -numa node,memdev=3Dmem" + "share=3Don -numa node,memdev=3Dmem" #define QEMU_CMD_CHR " -chardev socket,id=3D%s,path=3D%s%s" #define QEMU_CMD_NETDEV " -netdev vhost-user,id=3Dhs0,chardev=3D%s,vhostfo= rce" =20 --=20 2.31.1 From nobody Mon Feb 9 11:15:38 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; 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Tue, 25 May 2021 10:28:35 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5246B107ACCD for ; Tue, 25 May 2021 14:28:33 +0000 (UTC) Received: from localhost (ovpn-115-80.ams2.redhat.com [10.36.115.80]) by smtp.corp.redhat.com (Postfix) with ESMTP id E0FEF5C1A1; Tue, 25 May 2021 14:28:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621952916; 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=23O4rxiDH011Z16W0VTAiloRe5pkfPjYB7RF1gKOyJ0=; b=fgbQmZXjfsS/EMsRDoLZf5jhKHmynPPlFNKBaHUtsIy/y5zTWFrwluDAAyw/PLssnSMJyv 2sADR18DDNRljdG8MZsk5QoYJzCckjvWdHiZySPd7UgRTNjuEtP+o9Rg8YMDQWHlSuNZH3 f+agT4adbCnNrR16hpAk545910eqJWA= X-MC-Unique: dZBWk2wUPlm-uJAi1RPkIQ-1 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Subject: [PATCH v2 2/3] memory: add memory_region_is_mapped_shared() Date: Tue, 25 May 2021 15:28:02 +0100 Message-Id: <20210525142803.125401-3-stefanha@redhat.com> In-Reply-To: <20210525142803.125401-1-stefanha@redhat.com> References: <20210525142803.125401-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=stefanha@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=216.205.24.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -13 X-Spam_score: -1.4 X-Spam_bar: - X-Spam_report: (-1.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.371, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, MIME_BASE64_TEXT=1.741, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, Laurent Vivier , Thomas Huth , "Michael S. Tsirkin" , Stefan Hajnoczi , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Paolo Bonzini Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" Add a function to query whether a memory region is mmap(MAP_SHARED). This will be used to check that vhost-user memory regions can be shared with the device backend process in the next patch. An inline function in "exec/memory.h" would have been nice but RAMBlock fields are only accessible from memory.c (see "exec/ramblock.h"). Signed-off-by: Stefan Hajnoczi --- include/exec/memory.h | 11 +++++++++++ softmmu/memory.c | 6 ++++++ 2 files changed, 17 insertions(+) diff --git a/include/exec/memory.h b/include/exec/memory.h index c8b9088924..88dbcb69c4 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -2483,6 +2483,17 @@ static inline bool memory_access_is_direct(MemoryReg= ion *mr, bool is_write) } } =20 +/** + * memory_region_is_mapped_shared: check whether a memory region is + * mmap(MAP_SHARED) + * + * Returns %true is a memory region is mmap(MAP_SHARED). This is always fa= lse + * on memory regions that do not support memory_region_get_ram_ptr(). + * + * @mr: the memory region being queried + */ +bool memory_region_is_mapped_shared(MemoryRegion *mr); + /** * address_space_read: read from an address space. * diff --git a/softmmu/memory.c b/softmmu/memory.c index 3bb533c0bc..7379d44d18 100644 --- a/softmmu/memory.c +++ b/softmmu/memory.c @@ -1808,6 +1808,12 @@ bool memory_region_is_ram_device(MemoryRegion *mr) return mr->ram_device; } =20 +bool memory_region_is_mapped_shared(MemoryRegion *mr) +{ + return memory_access_is_direct(mr, false) && + (mr->ram_block->flags & RAM_SHARED); +} + uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr) { uint8_t mask =3D mr->dirty_log_mask; --=20 2.31.1 From nobody Mon Feb 9 11:15:38 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; 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Tue, 25 May 2021 10:28:35 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B48B219253C6 for ; Tue, 25 May 2021 14:28:34 +0000 (UTC) Received: from localhost (ovpn-115-80.ams2.redhat.com [10.36.115.80]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5AB615C1A1; Tue, 25 May 2021 14:28:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621952919; 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=dZJpRdzUg+uzEOwmii3gIqvtPsdARGPqDcEANL3u4sw=; b=dolxSw1377kQdOmHvB1j8D1fWxSTr3jOAvFLNkBxE9CDjPojtutLeu1t2UKlmbfpJCJIbD Dckhi0f1F/02jqyG/y+UxvVsyoEsxvgQqtLgkW/PHUbzf1m6F++xgYzkuNRtr6X6osLb/h RWO4YBCn+j05v5R1iaGA/g53UXqPrlA= X-MC-Unique: UOyFyd3UOE2B_ZZFZp4k9g-1 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Subject: [PATCH v2 3/3] vhost-user: warn when guest RAM is not shared Date: Tue, 25 May 2021 15:28:03 +0100 Message-Id: <20210525142803.125401-4-stefanha@redhat.com> In-Reply-To: <20210525142803.125401-1-stefanha@redhat.com> References: <20210525142803.125401-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=stefanha@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=216.205.24.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.371, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, Laurent Vivier , Thomas Huth , "Michael S. Tsirkin" , Stefan Hajnoczi , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Paolo Bonzini Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" Memory regions must be mmap(MAP_SHARED) so that modifications made by the vhost device backend process are visible to QEMU and vice versa. Use the new memory_region_is_mapped_shared() function to check this and print a warning if guest RAM is not shared: qemu-system-x86_64: -device vhost-user-fs-pci,chardev=3Dchar0,tag=3Dmyfs:= warning: Found vhost-user memory region without MAP_SHARED (did you forget= -object memory-*,share=3Don?) qemu-system-x86_64: Failed to read from slave. This warning makes it clear that memory needs to be configured with share=3Don. Without this patch the vhost device is initialized and the device fails with vague error messages caused by inconsistent memory views. The warning should make it easier to troubleshoot QEMU command-lines that lack share=3Don memory. I couldn't figure out how to make this a vhost_dev_init() error, because memory regions aren't necessarily final when it is called. Also, hotplug can add memory regions without MAP_SHARED in the future, so we still need to warn about that. Reported-by: Kevin Wolf Reviewed-by: Marc-Andr=C3=A9 Lureau Signed-off-by: Stefan Hajnoczi --- hw/virtio/vhost-user.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index ee57abe045..42976e6b30 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -2287,11 +2287,23 @@ vhost_user_crypto_close_session(struct vhost_dev *d= ev, uint64_t session_id) static bool vhost_user_mem_section_filter(struct vhost_dev *dev, MemoryRegionSection *section) { - bool result; + /* An fd is required so we can pass it to the device backend process */ + if (memory_region_get_fd(section->mr) < 0) { + return false; + } =20 - result =3D memory_region_get_fd(section->mr) >=3D 0; - - return result; + /* + * It must be mmap(MAP_SHARED) so memory stores from the device backend + * process are visible to us and vice versa. + */ + if (!memory_region_is_mapped_shared(section->mr)) { + static bool warned; + warn_report_once_cond(&warned, "Found vhost-user memory region " + "without MAP_SHARED (did you forget -object " + "memory-*,share=3Don?)"); + return false; + } + return true; } =20 static int vhost_user_get_inflight_fd(struct vhost_dev *dev, --=20 2.31.1