From patchwork Thu Aug 25 09:00:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12954399 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B097C64990 for ; Thu, 25 Aug 2022 09:00:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236753AbiHYJAk (ORCPT ); Thu, 25 Aug 2022 05:00:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49366 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233777AbiHYJAi (ORCPT ); Thu, 25 Aug 2022 05:00:38 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D39EBF43 for ; Thu, 25 Aug 2022 02:00:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1661418036; 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=23P3Co+/Djz33H05V6CMmPYXP2reF7URWbDmqqAYxBY=; b=dsXWoL5EUkaYKiryxWUYJBVGs6frl7QbZWy+aM3v4WJxqTUcNZH3/2yYTLNggK0t5aL2Ch Ag68kAA7V7FKJ9svn7eFLJkHEH0VdJngOrFSV0T560C2waCPChFYC3WmAlneh41qum/kNy rf+7VLaMhAyeSgaBK5ibqzRD15FDCdU= 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-589-AtI0Dh6tPtakz3ZlsfTqMg-1; Thu, 25 Aug 2022 05:00:33 -0400 X-MC-Unique: AtI0Dh6tPtakz3ZlsfTqMg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id DD0773C0F37A; Thu, 25 Aug 2022 09:00:32 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.194.159]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4826440B40C8; Thu, 25 Aug 2022 09:00:30 +0000 (UTC) From: Vitaly Kuznetsov To: linux-hyperv@vger.kernel.org Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-pci@vger.kernel.org, Bjorn Helgaas , Wei Liu , Deepak Rawat , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Dexuan Cui , Michael Kelley Subject: [PATCH v2 2/3] Drivers: hv: Always reserve framebuffer region for Gen1 VMs Date: Thu, 25 Aug 2022 11:00:23 +0200 Message-Id: <20220825090024.1007883-3-vkuznets@redhat.com> In-Reply-To: <20220825090024.1007883-1-vkuznets@redhat.com> References: <20220825090024.1007883-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org vmbus_reserve_fb() tries reserving framebuffer region iff 'screen_info.lfb_base' is set. Gen2 VMs seem to have it set by EFI fb (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. Relying on 'screen_info.lfb_base' to reserve framebuffer region is risky. Instead, it is possible to get the address from the dedicated PCI device which is always present. Check for legacy PCI video device presence and reserve the whole region for framebuffer on Gen1 VMs. Signed-off-by: Vitaly Kuznetsov Reviewed-by: Michael Kelley --- 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); } /**