From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34100) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W36fY-0002q3-Ru for qemu-devel@nongnu.org; Tue, 14 Jan 2014 11:16:54 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1W36fS-0001Dj-TB for qemu-devel@nongnu.org; Tue, 14 Jan 2014 11:16:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:26753) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W36fS-0001De-Jb for qemu-devel@nongnu.org; Tue, 14 Jan 2014 11:16:42 -0500 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s0EGGfk6025750 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 14 Jan 2014 11:16:41 -0500 From: Bandan Das Date: Tue, 14 Jan 2014 21:45:44 +0530 Message-Id: <1389716144-31076-3-git-send-email-bsd@redhat.com> In-Reply-To: <1389716144-31076-1-git-send-email-bsd@redhat.com> References: <1389716144-31076-1-git-send-email-bsd@redhat.com> Subject: [Qemu-devel] [PATCH 2/2] vfio: Do not reattempt a failed rom read List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: alex.williamson@redhat.com During lazy rom loading, if rom read fails, and the guest attempts a read again, vfio_rom_read will again attempt it. Add a boolean to prevent this. There could be a case where a failed rom read might succeed the next time because of a device reset or such, but it's best to exclude unpredictable behavior Signed-off-by: Bandan Das --- hw/misc/vfio.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c index e5b2826..c500067 100644 --- a/hw/misc/vfio.c +++ b/hw/misc/vfio.c @@ -191,6 +191,7 @@ typedef struct VFIODevice { bool has_flr; bool has_pm_reset; bool needs_reset; + bool rom_read_failed; } VFIODevice; typedef struct VFIOGroup { @@ -1125,6 +1126,7 @@ static void vfio_pci_load_rom(VFIODevice *vdev) vdev->rom_offset = reg_info.offset; if (!vdev->rom_size) { + vdev->rom_read_failed = true; error_report_once("vfio-pci: Cannot read device rom at " "%04x:%02x:%02x.%x\n", vdev->host.domain, vdev->host.bus, vdev->host.slot, @@ -1161,7 +1163,7 @@ static uint64_t vfio_rom_read(void *opaque, hwaddr addr, unsigned size) uint64_t val = ((uint64_t)1 << (size * 8)) - 1; /* Load the ROM lazily when the guest tries to read it */ - if (unlikely(!vdev->rom)) { + if (unlikely(!vdev->rom_read_failed && !vdev->rom)) { vfio_pci_load_rom(vdev); } @@ -1230,6 +1232,7 @@ static void vfio_pci_size_rom(VFIODevice *vdev) PCI_BASE_ADDRESS_SPACE_MEMORY, &vdev->pdev.rom); vdev->pdev.has_rom = true; + vdev->rom_read_failed = false; } static void vfio_vga_write(void *opaque, hwaddr addr, -- 1.8.3.1