From patchwork Sat Aug 27 13:03:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12957025 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4D810C0502E for ; Sat, 27 Aug 2022 13:04:04 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BAF8810ECA1; Sat, 27 Aug 2022 13:04:00 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1528610EC98 for ; Sat, 27 Aug 2022 13:03:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1661605437; 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=8oYLP+2x7Pkqzzkqq4VihKJhfPzpTwkNdBTIupOYQYo=; b=Nt1yBE9hoIzQTxboGgXLbgY/Ep10UEjBXEMLkmHxSDblxTDC58Yk6oWiMPt5C/wFpq+YIY AeW0P+THSSEVwoIvmUmnIm44DvkMZOiNBj2KhVztu2mMJMi9KqUfiQOIEt59Y3McK4t5nQ xiDVUweolRz1jxsVIkhyyzhda/n7twE= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-628-o9whNxK1N9C0xpAqrQg5Cg-1; Sat, 27 Aug 2022 09:03:56 -0400 X-MC-Unique: o9whNxK1N9C0xpAqrQg5Cg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 67B313802B83; Sat, 27 Aug 2022 13:03:55 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.192.40]) by smtp.corp.redhat.com (Postfix) with ESMTP id E79D6C15BC0; Sat, 27 Aug 2022 13:03:52 +0000 (UTC) From: Vitaly Kuznetsov To: linux-hyperv@vger.kernel.org Subject: [PATCH v3 2/3] Drivers: hv: Always reserve framebuffer region for Gen1 VMs Date: Sat, 27 Aug 2022 15:03:44 +0200 Message-Id: <20220827130345.1320254-3-vkuznets@redhat.com> In-Reply-To: <20220827130345.1320254-1-vkuznets@redhat.com> References: <20220827130345.1320254-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Wei Liu , Stephen Hemminger , linux-pci@vger.kernel.org, Haiyang Zhang , Dexuan Cui , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Michael Kelley , Deepak Rawat , Bjorn Helgaas , "K. Y. Srinivasan" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" vmbus_reserve_fb() tries reserving framebuffer region iff 'screen_info.lfb_base' is set. Gen2 VMs seem to have it set by EFI and/or by the kernel EFI FB driver (or, in some edge cases like kexec, the address where the buffer was moved, see https://lore.kernel.org/all/20201014092429.1415040-1-kasong@redhat.com/) but on Gen1 VM it depends on bootloader behavior. With grub, it depends on 'gfxpayload=' setting but in some cases it is observed to be zero. That being said, relying on 'screen_info.lfb_base' to reserve framebuffer region is risky. For Gen1 VMs, it should always be possible to get the address from the dedicated PCI device instead. Check for legacy PCI video device presence and reserve the whole region for framebuffer on Gen1 VMs. Reviewed-by: Michael Kelley Signed-off-by: Vitaly Kuznetsov --- drivers/hv/vmbus_drv.c | 46 +++++++++++++++++++++++++++++------------- 1 file changed, 32 insertions(+), 14 deletions(-) diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 23c680d1a0f5..536f68e563c6 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include "hyperv_vmbus.h" @@ -2262,26 +2263,43 @@ static int vmbus_acpi_remove(struct acpi_device *device) static void vmbus_reserve_fb(void) { - int size; + resource_size_t start = 0, size; + struct pci_dev *pdev; + + if (efi_enabled(EFI_BOOT)) { + /* Gen2 VM: get FB base from EFI framebuffer */ + start = screen_info.lfb_base; + size = max_t(__u32, screen_info.lfb_size, 0x800000); + } else { + /* Gen1 VM: get FB base from PCI */ + pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT, + PCI_DEVICE_ID_HYPERV_VIDEO, NULL); + if (!pdev) + return; + + if (pdev->resource[0].flags & IORESOURCE_MEM) { + start = pci_resource_start(pdev, 0); + size = pci_resource_len(pdev, 0); + } + + /* + * Release the PCI device so hyperv_drm or hyperv_fb driver can + * grab it later. + */ + pci_dev_put(pdev); + } + + if (!start) + return; + /* * Make a claim for the frame buffer in the resource tree under the * first node, which will be the one below 4GB. The length seems to * be underreported, particularly in a Generation 1 VM. So start out * reserving a larger area and make it smaller until it succeeds. */ - - if (screen_info.lfb_base) { - if (efi_enabled(EFI_BOOT)) - size = max_t(__u32, screen_info.lfb_size, 0x800000); - else - size = max_t(__u32, screen_info.lfb_size, 0x4000000); - - for (; !fb_mmio && (size >= 0x100000); size >>= 1) { - fb_mmio = __request_region(hyperv_mmio, - screen_info.lfb_base, size, - fb_mmio_name, 0); - } - } + for (; !fb_mmio && (size >= 0x100000); size >>= 1) + fb_mmio = __request_region(hyperv_mmio, start, size, fb_mmio_name, 0); } /**