From 3fedeb0f9c045c8fb71e4016f28b13df8da32b24 Mon Sep 17 00:00:00 2001 Message-Id: <3fedeb0f9c045c8fb71e4016f28b13df8da32b24.1357660440.git.minovotn@redhat.com> In-Reply-To: References: From: Alex Williamson Date: Mon, 7 Jan 2013 17:14:24 +0100 Subject: [PATCH 4/4] pci-assign: Enable MSIX on device to match guest RH-Author: Alex Williamson Message-id: <20130107170918.32146.20266.stgit@bling.home> Patchwork-id: 45618 O-Subject: [RHEL6.4 qemu-kvm PATCH] pci-assign: Enable MSIX on device to match guest Bugzilla: 886410 RH-Acked-by: Michael S. Tsirkin RH-Acked-by: Don Dutile RH-Acked-by: Amos Kong Bugzilla: bz886410 Brew: http://brewweb.devel.redhat.com/brew/taskinfo?taskID=5243200 Upstream: Posted & Ack'd by MST When a guest enables MSIX on a device we evaluate the MSIX vector table, typically find no unmasked vectors and don't switch the device to MSIX mode. This generally works fine and the device will be switched once the guest enables and therefore unmasks a vector. Unfortunately some drivers enable MSIX, then use interfaces to send commands between VF & PF or PF & firmware that act based on the host state of the device. These therefore may break when MSIX is managed lazily. This change re-enables the previous test used to enable MSIX (see qemu-kvm a6b402c9), which basically guesses whether a vector will be used based on the data field of the vector table. Cc: qemu-stable@nongnu.org Signed-off-by: Alex Williamson Acked-by: Michael S. Tsirkin --- Testing: Tested with igbvf & e1000e devices under RHEL6, FreeBSD9, and Windows guests. The equivalent RHEL patch to the referenced commit is bd93301f. hw/device-assignment.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) Signed-off-by: Michal Novotny --- hw/device-assignment.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/hw/device-assignment.c b/hw/device-assignment.c index b2540a8..589e8d0 100644 --- a/hw/device-assignment.c +++ b/hw/device-assignment.c @@ -1139,6 +1139,19 @@ static bool msix_masked(MSIXTableEntry *entry) return (entry->ctrl & cpu_to_le32(0x1)) != 0; } +/* + * When MSI-X is first enabled the vector table typically has all the + * vectors masked, so we can't use that as the obvious test to figure out + * how many vectors to initially enable. Instead we look at the data field + * because this is what worked for pci-assign for a long time. This makes + * sure the physical MSI-X state tracks the guest's view, which is important + * for some VF/PF and PF/fw communication channels. + */ +static bool msix_skipped(MSIXTableEntry *entry) +{ + return !entry->data; +} + static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev) { AssignedDevice *adev = container_of(pci_dev, AssignedDevice, dev); @@ -1150,7 +1163,7 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev) /* Get the usable entry number for allocating */ for (i = 0; i < adev->msix_max; i++, entry++) { - if (msix_masked(entry)) { + if (msix_skipped(entry)) { continue; } entries_nr++; @@ -1185,7 +1198,7 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev) msix_entry.assigned_dev_id = msix_nr.assigned_dev_id; entry = adev->msix_table; for (i = 0; i < adev->msix_max; i++, entry++) { - if (msix_masked(entry)) { + if (msix_skipped(entry)) { continue; } -- 1.7.11.7