From nobody Mon Mar 2 08:46:22 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; 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; dmarc=pass(p=quarantine dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1772177162; cv=none; d=zohomail.com; s=zohoarc; b=d0a+apSjXmwBop+SyzE4KPZS2w7FeILaAOZIlsQ4hcTizGFIdCE1ZYLWjk4NK1iu6e7idPiTzD66OFX9d2In0YPqq6mRewLnLS9MTF0sHBsSFNqT3FMZtX6uRZ/MD3EUbfJu9kQkaPj6RFmDRgQRKEfCns2M0QDBCp0oMw/Z3s0= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1772177162; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=dqdWfZa9w4qvLo9QVPtCB4DXn7FhhJj33gbvY7/gVO0=; b=CqH0VZ4GeWKMy7ouRoO/GWcdZ3foZ1x12miZZmYwcZWVvG2Wx+uwASmGWMeykVr8AKJGPNg7ky9gr+6frzdxsc49w9QPr4jkWNeePuwp9v0BpZv7Hy4WM3U6YUmsPNQDPm+VbOXF4sWFU1QX6UDefuk7W0T+bS7WbDp8T8xy3oI= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; 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; dmarc=pass header.from= (p=quarantine dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1772177162403650.1008537789803; Thu, 26 Feb 2026 23:26:02 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vvsEL-0005ca-SW; Fri, 27 Feb 2026 02:25:45 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vvsEK-0005bs-Mo for qemu-devel@nongnu.org; Fri, 27 Feb 2026 02:25:44 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vvsEI-0004TY-VK for qemu-devel@nongnu.org; Fri, 27 Feb 2026 02:25:44 -0500 Received: from mail-pj1-f69.google.com (mail-pj1-f69.google.com [209.85.216.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-497-OjCD6sStPJajODjSFFv_ZQ-1; Fri, 27 Feb 2026 02:25:40 -0500 Received: by mail-pj1-f69.google.com with SMTP id 98e67ed59e1d1-35620e2faf0so1166835a91.3 for ; Thu, 26 Feb 2026 23:25:40 -0800 (PST) Received: from rhel9-box.lan ([122.176.129.56]) by smtp.googlemail.com with ESMTPSA id 98e67ed59e1d1-3593ddd7374sm4369743a91.16.2026.02.26.23.25.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 26 Feb 2026 23:25:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1772177142; 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; bh=dqdWfZa9w4qvLo9QVPtCB4DXn7FhhJj33gbvY7/gVO0=; b=JCn9C8A1cqLJme8jZy3rvRfMHfnWSlL/LmYYhsPvBwO73COwWuJ8qOW+qZlIn7MIU+FUoM Ypq4ednIO1SR8t5Mp82w9ZWrIqoT8/sMmPm91k0x7Nc4onWeX8ecadrwWg4Ug0XuKsmqke 9uovRWSa93qDXRgoPFzdmcC+m2fKeJo= X-MC-Unique: OjCD6sStPJajODjSFFv_ZQ-1 X-Mimecast-MFC-AGG-ID: OjCD6sStPJajODjSFFv_ZQ_1772177139 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1772177139; x=1772781939; darn=nongnu.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=dqdWfZa9w4qvLo9QVPtCB4DXn7FhhJj33gbvY7/gVO0=; b=MX5iaNa0ZqZy1EpVLpyVsh/RVtwBQd7PEAWB4nWFh0wYjEPhVxRcpJ+k2874n2L5GT lublDKUKZVMgJcIxt2ZoUeWOYR835CTgKq8P6lRl67CDF1AnH59pAZqY8g6QOZju0Mxl VepGNe0B947Dgs/h3KHlCnlXUhGVcmBECXVy/AsPICQP3dkhARke2rCaGK+IqoDPKXGO 3EklTu/iWyXCTD8ZsyUzw6thCOBCtod1D08uB3hmHgNQ+79P6eBeQqKQnIoh5q6bDcKi UepyguJzylfvBv4RoyyoHWb3uH8h0GoKMvVRhnXBbQg2lduG9zgHsc/aaFsjvkPDyBzx vpFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772177139; x=1772781939; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=dqdWfZa9w4qvLo9QVPtCB4DXn7FhhJj33gbvY7/gVO0=; b=FmPVjeuKFuYmGtYJ16bzsD1pnMgGLYk/bjjFJI5cu+SM0WQ8ep8SmS//i37Jdhc1JU LS6F1VtP26It7olHvfup3mIF3E4q85kibaJxR6SzIb/ewDAtTNvCprLivs/oS2r9gByJ lkWoyjWEd0y5FZn4aIxFhTRW5LtWaGiITqCKpUPFJXdBjicnav2T/mCoILlK59gyhKGg 2rv+edOahBuCy/0SUOsCFJ2H1xv6ltnH1Esjsyn2B2kUAIyscu7XVv+2357X8Pt/TIAf QQHrtA5fJXYOP2bJ9NxfBBaTtX0ekDkI7rVdWQuO/HOTbw3LWaVtcevCmGflHH3Bx14d BxCw== X-Forwarded-Encrypted: i=1; AJvYcCUpo+DleTi+eyNA7zFuHAh2UMUZqbS+K5IBj/bGf0f5lWMyTxB/wLIPGVFgElXSU4nOgx6tRp+1lz4w@nongnu.org X-Gm-Message-State: AOJu0YxgAy/0LenfjeSgs8DtAQI1nLBw1M9Qm5iOmAGL/V3g1qQSkEXY mRBsGzV7AjK1PBqKSnTIJKtiPcLv4W4r1l7KZ8n0FVGu3UcZy4SR5Ijp/eKQp+6iQuP3ml9uM67 9WClN7s0kMSXR/zJknnaWNuiTk1EfFLAC6oskS+3vAAh/q9y/Y+CHLzo5 X-Gm-Gg: ATEYQzwJ394+ArbHO1cZknZU9YtKdNAot/MnvEbFkn/87GCTo0gC1N5R78Fj9SSziEM 007J33s6tgFssEuzeQfdAzXL1S78fvNQdcv1LXDNkUjzXW1LWGFglUJtDqyUGgDW0v/9rkhpryX dK5Z393y3aSUchxdhdNQd95kdkQTkOgXRg+0ZjERlqfQYJ4GBFrr+kgSMCcloEN6GLEzy9j1r93 hS/VbEBOlyIpqzfVdgjyV9pcl9abG0ild2CnE1W/8T2qobIzIhG2Dq6qlVg+vJYYL91u6sAbQeg PckMxyfEKGSHOX551If3G30d/CzMBaxaEBWImtXrLMT+mubVHSBZd/l3bIV+l5S8/ro+MqKbYtC KdfNQCGNkPQmIXh5Uw7/Ej57a8f0XHvMO5XP4537+yeP9kylp0FyrUBg= X-Received: by 2002:a17:90b:1d4f:b0:34a:47d0:9a82 with SMTP id 98e67ed59e1d1-35965cdad17mr1706671a91.23.1772177139152; Thu, 26 Feb 2026 23:25:39 -0800 (PST) X-Received: by 2002:a17:90b:1d4f:b0:34a:47d0:9a82 with SMTP id 98e67ed59e1d1-35965cdad17mr1706651a91.23.1772177138777; Thu, 26 Feb 2026 23:25:38 -0800 (PST) From: Ani Sinha To: Alex Williamson , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Cc: Ani Sinha , pbonzini@redhat.com, ani@anisinha.ca, qemu-devel@nongnu.org Subject: [PATCH v7] hw/vfio: generate new file fd for pseudo device and rebind existing descriptors Date: Fri, 27 Feb 2026 12:54:45 +0530 Message-ID: <20260227072445.406907-1-anisinha@redhat.com> X-Mailer: git-send-email 2.42.0 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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=170.10.129.124; envelope-from=anisinha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -10 X-Spam_score: -1.1 X-Spam_bar: - X-Spam_report: (-1.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.306, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.668, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1772177163507158500 Normally the vfio pseudo device file descriptor lives for the life of the V= M. However, when the kvm VM file descriptor changes, a new file descriptor for the pseudo device needs to be generated against the new kvm VM descript= or. Other existing vfio descriptors needs to be reattached to the new pseudo de= vice descriptor. This change performs the above steps. Tested-by: C=C3=A9dric Le Goater Reviewed-by: C=C3=A9dric Le Goater Signed-off-by: Ani Sinha --- hw/vfio/helpers.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) diff --git a/hw/vfio/helpers.c b/hw/vfio/helpers.c index f68f8165d0..00d42d3b98 100644 --- a/hw/vfio/helpers.c +++ b/hw/vfio/helpers.c @@ -116,6 +116,88 @@ bool vfio_get_info_dma_avail(struct vfio_iommu_type1_i= nfo *info, * we'll re-use it should another vfio device be attached before then. */ int vfio_kvm_device_fd =3D -1; + +/* + * Confidential virtual machines: + * During reset of confidential vms, the kvm vm file descriptor changes. + * In this case, the old vfio kvm file descriptor is + * closed and a new descriptor is created against the new kvm vm file + * descriptor. + */ + +typedef struct VFIODeviceFd { + int fd; + QLIST_ENTRY(VFIODeviceFd) node; +} VFIODeviceFd; + +static QLIST_HEAD(, VFIODeviceFd) vfio_device_fds =3D + QLIST_HEAD_INITIALIZER(vfio_device_fds); + +static void vfio_device_fd_list_add(int fd) +{ + VFIODeviceFd *file_fd; + file_fd =3D g_malloc0(sizeof(*file_fd)); + file_fd->fd =3D fd; + QLIST_INSERT_HEAD(&vfio_device_fds, file_fd, node); +} + +static void vfio_device_fd_list_remove(int fd) +{ + VFIODeviceFd *file_fd, *next; + + QLIST_FOREACH_SAFE(file_fd, &vfio_device_fds, node, next) { + if (file_fd->fd =3D=3D fd) { + QLIST_REMOVE(file_fd, node); + g_free(file_fd); + break; + } + } +} + +static int vfio_device_fd_rebind(NotifierWithReturn *notifier, void *data, + Error **errp) +{ + VFIODeviceFd *file_fd; + struct kvm_device_attr attr =3D { + .group =3D KVM_DEV_VFIO_FILE, + .attr =3D KVM_DEV_VFIO_FILE_ADD, + }; + struct kvm_create_device cd =3D { + .type =3D KVM_DEV_TYPE_VFIO, + }; + + /* we are not interested in pre vmfd change notification */ + if (((VmfdChangeNotifier *)data)->pre) { + return 0; + } + + if (kvm_vm_ioctl(kvm_state, KVM_CREATE_DEVICE, &cd)) { + error_setg_errno(errp, errno, "Failed to create KVM VFIO device"); + return -errno; + } + + if (vfio_kvm_device_fd !=3D -1) { + close(vfio_kvm_device_fd); + } + + vfio_kvm_device_fd =3D cd.fd; + + QLIST_FOREACH(file_fd, &vfio_device_fds, node) { + attr.addr =3D (uint64_t)(unsigned long)&file_fd->fd; + if (ioctl(vfio_kvm_device_fd, KVM_SET_DEVICE_ATTR, &attr)) { + error_setg_errno(errp, errno, + "Failed to add fd %d to KVM VFIO device", + file_fd->fd); + return -errno; + } + } + return 0; +} + +static struct NotifierWithReturn vfio_vmfd_change_notifier =3D { + .notify =3D vfio_device_fd_rebind, +}; + #endif =20 void vfio_kvm_device_close(void) @@ -153,6 +235,11 @@ int vfio_kvm_device_add_fd(int fd, Error **errp) } =20 vfio_kvm_device_fd =3D cd.fd; + /* + * If the vm file descriptor changes, add a notifier so that we can + * re-create the vfio_kvm_device_fd. + */ + kvm_vmfd_add_change_notifier(&vfio_vmfd_change_notifier); } =20 if (ioctl(vfio_kvm_device_fd, KVM_SET_DEVICE_ATTR, &attr)) { @@ -160,6 +247,8 @@ int vfio_kvm_device_add_fd(int fd, Error **errp) fd); return -errno; } + + vfio_device_fd_list_add(fd); #endif return 0; } @@ -183,6 +272,8 @@ int vfio_kvm_device_del_fd(int fd, Error **errp) "Failed to remove fd %d from KVM VFIO device", fd= ); return -errno; } + + vfio_device_fd_list_remove(fd); #endif return 0; } --=20 2.42.0