On 29.09.20 14:41, Marek Marczykowski-Górecki wrote:
On Tue, Sep 29, 2020 at 03:27:43PM +0300, Denis Efremov wrote:
Hi,
On 9/28/20 12:36 PM, Marek Marczykowski-Górecki wrote:
On Mon, Sep 28, 2020 at 07:02:19AM +0200, Jürgen Groß wrote:
On 27.09.20 13:14, Marek Marczykowski-Górecki wrote:
Hi all,
I get kernel panic on 'floppy' module load. If I blacklist the module,
then everything works.
The issue happens in Xen HVM, other virtualization modes (PV, PVH) works
fine. PV dom0 works too. I haven't tried bare metal, but I assume it
works fine too.
Could you please try bare metal?
I don't have any hw with floppy controller at hand...
Booting on what I have, it works, loading floppy just says -ENODEV.
I saw that the issue was bisected [1] to commit
c330fb1ddc0a ("XEN uses irqdesc::irq_data_common::handler_data to store a
per interrupt XEN data pointer which contains XEN specific information.")
I have hardware, but I've never worked with Xen. It will take me some time
to set it up and reproduce the problem. I think I will do it in a week.
Can you try to boot 4.19.143 (or any other including that commit)
directly on the hardware and make sure floppy module is loaded? We do
know it's broken in Xen HVM, it would be interested to see if it works
without Xen. Even better if you could use the same kernel config:
https://gist.github.com/marmarek/1e6a359c9a99af3ed8fc16af0f36d8a6
I think it is not directly related to floppy, but a more general problem
for HVM guests.
I'm suspecting an issue with legacy IRQs. Could you please try the
attached patch?
Juergen
>From 35b71ae9cc69cdd151cc3a4d587f67eb8d86007d Mon Sep 17 00:00:00 2001
From: Juergen Gross <jgross@xxxxxxxx>
Date: Tue, 29 Sep 2020 15:47:21 +0200
Subject: [PATCH] xen/events: don't use chip_data for legacy IRQs
Storing Xen specific data via chip_data is fine, as long as this isn't
done for a legacy IRQ.
Use a local array for this purpose in case of legacy IRQs.
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
drivers/xen/events/events_base.c | 29 +++++++++++++++++++++--------
1 file changed, 21 insertions(+), 8 deletions(-)
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 90b8f56fbadb..6f02c18fa65c 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -92,6 +92,8 @@ static bool (*pirq_needs_eoi)(unsigned irq);
/* Xen will never allocate port zero for any purpose. */
#define VALID_EVTCHN(chn) ((chn) != 0)
+static struct irq_info *legacy_info_ptrs[NR_IRQS_LEGACY];
+
static struct irq_chip xen_dynamic_chip;
static struct irq_chip xen_percpu_chip;
static struct irq_chip xen_pirq_chip;
@@ -156,7 +158,18 @@ int get_evtchn_to_irq(evtchn_port_t evtchn)
/* Get info for IRQ */
struct irq_info *info_for_irq(unsigned irq)
{
- return irq_get_chip_data(irq);
+ if (irq < nr_legacy_irqs())
+ return legacy_info_ptrs[irq];
+ else
+ return irq_get_chip_data(irq);
+}
+
+static void set_info_for_irq(unsigned int irq, struct irq_info *info)
+{
+ if (irq < nr_legacy_irqs())
+ legacy_info_ptrs[irq] = info;
+ else
+ irq_set_chip_data(irq, info);
}
/* Constructors for packed IRQ information. */
@@ -377,7 +390,7 @@ static void xen_irq_init(unsigned irq)
info->type = IRQT_UNBOUND;
info->refcnt = -1;
- irq_set_chip_data(irq, info);
+ set_info_for_irq(irq, info);
list_add_tail(&info->list, &xen_irq_list_head);
}
@@ -426,14 +439,14 @@ static int __must_check xen_allocate_irq_gsi(unsigned gsi)
static void xen_free_irq(unsigned irq)
{
- struct irq_info *info = irq_get_chip_data(irq);
+ struct irq_info *info = info_for_irq(irq);
if (WARN_ON(!info))
return;
list_del(&info->list);
- irq_set_chip_data(irq, NULL);
+ set_info_for_irq(irq, NULL);
WARN_ON(info->refcnt > 0);
@@ -603,7 +616,7 @@ EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
static void __unbind_from_irq(unsigned int irq)
{
evtchn_port_t evtchn = evtchn_from_irq(irq);
- struct irq_info *info = irq_get_chip_data(irq);
+ struct irq_info *info = info_for_irq(irq);
if (info->refcnt > 0) {
info->refcnt--;
@@ -1108,7 +1121,7 @@ int bind_ipi_to_irqhandler(enum ipi_vector ipi,
void unbind_from_irqhandler(unsigned int irq, void *dev_id)
{
- struct irq_info *info = irq_get_chip_data(irq);
+ struct irq_info *info = info_for_irq(irq);
if (WARN_ON(!info))
return;
@@ -1142,7 +1155,7 @@ int evtchn_make_refcounted(evtchn_port_t evtchn)
if (irq == -1)
return -ENOENT;
- info = irq_get_chip_data(irq);
+ info = info_for_irq(irq);
if (!info)
return -ENOENT;
@@ -1170,7 +1183,7 @@ int evtchn_get(evtchn_port_t evtchn)
if (irq == -1)
goto done;
- info = irq_get_chip_data(irq);
+ info = info_for_irq(irq);
if (!info)
goto done;
--
2.26.2
