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Mon, 25 Sep 2023 22:14:28 -0400 Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2023 19:14:25 -0700 Received: from vmmteam.bj.intel.com ([10.240.193.84]) by orsmga003.jf.intel.com with ESMTP; 25 Sep 2023 19:14:22 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1695694467; x=1727230467; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=uKZCmRpqgWSTZeMlHWN0D2p8zG/tAmYsBuyTmvb8Xz4=; b=LATf+MCefbKfcmI37n9DIIHDiMZ4dDwS40HxSXANfsXVMSUTeOf8hztd 3pw4bgpMJli3ZMp4ubWm8+wEl1scrnhqFDXWw8QY+TMsU/lK8tEKFxbhC e3UfbxuirWfnFACvwE9s1LlN52SqOUxiTKfmf9rltwhF+/7GSyjyfKZXF JLRlYWQ+qFVCh/VcxM7mxZtfXp8ohJSYToW2wHhl30Lspd0qlpNr/E5RA o4rCblEwvFHGWBJSeiJKHKLKj39SACl/YEb8CZk/8rwCi56VyjDxkIrTW YsLOZmhtBq1q2VLIBB6ZySbgNgqS8J6SGBI/9Q1Lc09xq8ViUSJg1mFix g==; X-IronPort-AV: E=McAfee;i="6600,9927,10843"; a="412380143" X-IronPort-AV: E=Sophos;i="6.03,176,1694761200"; d="scan'208";a="412380143" X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10843"; a="698283058" X-IronPort-AV: E=Sophos;i="6.03,176,1694761200"; d="scan'208";a="698283058" From: Jing Liu To: qemu-devel@nongnu.org Cc: alex.williamson@redhat.com, clg@redhat.com, pbonzini@redhat.com, kevin.tian@intel.com, reinette.chatre@intel.com, jing2.liu@intel.com, jing2.liu@linux.intel.com Subject: [PATCH v3 4/4] vfio/pci: enable MSI-X in interrupt restoring on dynamic allocation Date: Mon, 25 Sep 2023 22:14:07 -0400 Message-Id: <20230926021407.580305-5-jing2.liu@intel.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20230926021407.580305-1-jing2.liu@intel.com> References: <20230926021407.580305-1-jing2.liu@intel.com> 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=192.55.52.88; envelope-from=jing2.liu@intel.com; helo=mgamail.intel.com X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 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_MED=-2.3, RCVD_IN_MSPIKE_H3=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: 2.1.29 Precedence: list List-Id: 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 @intel.com) X-ZM-MESSAGEID: 1695694518037100003 During migration restoring, vfio_enable_vectors() is called to restore enabling MSI-X interrupts for assigned devices. It sets the range from 0 to nr_vectors to kernel to enable MSI-X and the vectors unmasked in guest. During the MSI-X enabling, all the vectors within the range are allocated according to the VFIO_DEVICE_SET_IRQS ioctl. When dynamic MSI-X allocation is supported, we only want the guest unmasked vectors being allocated and enabled. Use vector 0 with an invalid fd to get MSI-X enabled, after that, all the vectors can be allocated in need. Signed-off-by: Jing Liu Reviewed-by: C=C3=A9dric Le Goater Reviewed-by: Alex Williamson --- Changes since v2: - Apply C=C3=A9dric's Reviewed-by. - Apply Alex's Reviewed-by. Changes since v1: - No change. Changes since RFC v1: - Revise the comments. (Alex) - Call the new helper function in previous patch to enable MSI-X. (Alex) --- hw/vfio/pci.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index bf676a49ae77..8a082af39e77 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -402,6 +402,23 @@ static int vfio_enable_vectors(VFIOPCIDevice *vdev, bo= ol msix) int ret =3D 0, i, argsz; int32_t *fds; =20 + /* + * If dynamic MSI-X allocation is supported, the vectors to be allocat= ed + * and enabled can be scattered. Before kernel enabling MSI-X, setting + * nr_vectors causes all these vectors to be allocated on host. + * + * To keep allocation as needed, use vector 0 with an invalid fd to get + * MSI-X enabled first, then set vectors with a potentially sparse set= of + * eventfds to enable interrupts only when enabled in guest. + */ + if (msix && !vdev->msix->noresize) { + ret =3D vfio_enable_msix_no_vec(vdev); + + if (ret) { + return ret; + } + } + argsz =3D sizeof(*irq_set) + (vdev->nr_vectors * sizeof(*fds)); =20 irq_set =3D g_malloc0(argsz); --=20 2.27.0