Attachment 888273 Details for Bug 1027565 – proposed patch for the *separate* USB problem (downstream only)

[patch] proposed patch for the *separate* USB problem (downstream only)

0001-uhci-UNfix-irq-routing-for-RHEL-6-machtypes-RHEL-onl.patch (text/plain), 5.15 KB, created by Laszlo Ersek on 2014-04-21 21:58:08 UTC

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Creator: Laszlo Ersek

Created: 2014-04-21 21:58:08 UTC

Size: 5.15 KB

patch

obsolete

>From 869eff10c5daf4d1ebd917f27d4a822d2234f7c2 Mon Sep 17 00:00:00 2001
>From: Laszlo Ersek <lersek@redhat.com>
>Date: Mon, 21 Apr 2014 21:19:23 +0200
>Subject: [RHEL-7.0 0day qemu-kvm PATCH] uhci: UNfix irq routing for RHEL-6
> machtypes (RHEL only)
>
>Refer to the following upstream commit, present in v1.2.0 and RHEL-7:
>
>    commit 973002c11460efd3c17fe61a76711a103e30e1f9
>    Author: Gerd Hoffmann <kraxel@redhat.com>
>    Date:   Fri May 25 12:53:47 2012 +0200
>
>        uhci: fix irq routing
>
>        The multifunction ich9 ehci controller with uhci companions uses a
>        different interrupt pin for each function.  The three uhci devices
>        get pins A, B and C, whereas ehci uses pin D.  This way the guest
>        can assign different IRQ lines to each controller.
>
>        Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
>
>This is a performance optimization so that IRQ sharing can be avoided in
>the guest.
>
>Contrarily, the RHEL-6 emulator exclusively assigns pin D to each of the
>three devices (see "hw/usb-uhci.c" there):
>- usb_uhci_ich9_1_initfn()
>- usb_uhci_ich9_2_initfn()
>- usb_uhci_ich9_3_initfn()
>
>These init functions call usb_uhci_common_initfn(), which in turn assigns:
>
>    pci_conf[0x3d] = 4; // interrupt pin 3
>
>This mismatch breaks migration for rhel6.x.0 machine types from the
>RHEL-6.5 emulator to the RHEL-7.0 one.
>
>For example, considering the uhci1 controller, the guest kernel, started
>on the RHEL-6.5 source host, will see pin D advertised, and (according to
>the PCI interrupt routing table provided by SeaBIOS) will route it to IRQ
>11:
>
>  dmesg:
>
>    uhci_hcd 0000:00:11.0: PCI INT D -> Link[LNKD] -> GSI 11 (level, high)
>    -> IRQ 11
>
>  /proc/interrupts:
>
>     10: ... IO-APIC-fasteoi   virtio0
>     11: ... IO-APIC-fasteoi   uhci_hcd:usb1
>
>When the same guest kernel, using the same rhel6.5.0 machine type, is
>started fresh on the RHEL-7.0 target host, pin A is advertised instead
>(and routed to a different IRQ, based on the same table from SeaBIOS):
>
>  dmesg:
>
>    uhci_hcd 0000:00:11.0: PCI INT A -> Link[LNKA] -> GSI 10 (level, high)
>    -> IRQ 10
>
>  /proc/interrupts:
>
>     10: ... IO-APIC-fasteoi   uhci_hcd:usb1, virtio0
>
>This is no problem as long as we don't migrate.
>
>When we migrate the rhel6.x.0 machtype guest from the RHEL-6.5 host to the
>RHEL-7.0 host, the guest kernel (having booted on the source host) will
>expect the interrupts for the UHCI device on pin D / IRQ 11. However, the
>target host will inject the interrupts on pin A / IRQ 10. No handler in
>the guest kernel will claim such IRQ 10 instances (examples are: HDA or
>virtio-balloon), hence IRQ 10 will be disabled.
>
>We can fix this in at least two ways:
>(1) Drop the persistent "UHCIState.irq_pin" field, and simply use the pin
>    identifier that is stored in PCI config space (at offset 0x3d).
>(2) Introduce yet another RHEL-6 compatibility knob that selects pin D for
>    all three ICH9-UHCI controllers.
>
>Since PCI config space could be accessible to the guest, and we'd use the
>setting as a subscript into the s->dev.irq[] array in uhci_update_irq(),
>it seems safer to go with (2).
>
>Signed-off-by: Laszlo Ersek <lersek@redhat.com>
>---
> include/hw/usb.h  |  4 ++++
> hw/i386/pc_piix.c |  1 +
> hw/usb/hcd-uhci.c | 13 ++++++++++++-
> 3 files changed, 17 insertions(+), 1 deletion(-)
>
>diff --git a/include/hw/usb.h b/include/hw/usb.h
>index b111be0..5668701 100644
>--- a/include/hw/usb.h
>+++ b/include/hw/usb.h
>@@ -578,4 +578,8 @@ int usb_get_quirks(uint16_t vendor_id, uint16_t product_id,
>                    uint8_t interface_class, uint8_t interface_subclass,
>                    uint8_t interface_protocol);
> 
>+
>+/* hcd-uhci.c -- RHEL-6 machine type compatibility */
>+extern bool ich9_uhci123_irqpin_override;
>+
> #endif
>diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
>index fea98b6..67d51da 100644
>--- a/hw/i386/pc_piix.c
>+++ b/hw/i386/pc_piix.c
>@@ -955,6 +955,7 @@ static void pc_compat_rhel650(QEMUMachineInitArgs *args)
>     has_acpi_build = false;
>     gigabyte_align = false;
>     shadow_bios_after_incoming = true;
>+    ich9_uhci123_irqpin_override = true;
> }
> 
> static void pc_init_rhel650(QEMUMachineInitArgs *args)
>diff --git a/hw/usb/hcd-uhci.c b/hw/usb/hcd-uhci.c
>index 4fc3410..3380107 100644
>--- a/hw/usb/hcd-uhci.c
>+++ b/hw/usb/hcd-uhci.c
>@@ -187,6 +187,8 @@ typedef struct UHCI_QH {
>     uint32_t el_link;
> } UHCI_QH;
> 
>+bool ich9_uhci123_irqpin_override;
>+
> static void uhci_async_cancel(UHCIAsync *async);
> static void uhci_queue_fill(UHCIQueue *q, UHCI_TD *td);
> 
>@@ -1232,7 +1234,16 @@ static int usb_uhci_common_initfn(PCIDevice *dev)
>     /* TODO: reset value should be 0. */
>     pci_conf[USB_SBRN] = USB_RELEASE_1; // release number
> 
>-    s->irq_pin = u->info.irq_pin;
>+    if (ich9_uhci123_irqpin_override &&
>+        u->info.vendor_id == PCI_VENDOR_ID_INTEL &&
>+        (u->info.device_id == PCI_DEVICE_ID_INTEL_82801I_UHCI1 ||
>+         u->info.device_id == PCI_DEVICE_ID_INTEL_82801I_UHCI2 ||
>+         u->info.device_id == PCI_DEVICE_ID_INTEL_82801I_UHCI3)) {
>+        fprintf(stderr, "RHEL-6 compat: %s: irq_pin = 3\n", u->info.name);
>+        s->irq_pin = 3;
>+    } else {
>+        s->irq_pin = u->info.irq_pin;
>+    }
>     pci_config_set_interrupt_pin(pci_conf, s->irq_pin + 1);
> 
>     if (s->masterbus) {
>-- 
>1.8.3.1
>

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Attachments on bug 1027565: 885244 | 885245 | 885252 | 885649 | 885650 | 885795 | 885838 | 886494 | 886593 | 886840 | 886841 | 886964 | 888022 | 888273