* [PATCH v2 1/2] tools/libxl: Skip invalid IRQs
2025-04-18 21:05 [PATCH v2 0/2] libxl: Skip invalid IRQs Jason Andryuk
@ 2025-04-18 21:05 ` Jason Andryuk
2025-04-23 14:51 ` Anthony PERARD
2025-04-18 21:05 ` [PATCH v2 2/2] tools/libxl: Switch irq to unsigned int Jason Andryuk
1 sibling, 1 reply; 5+ messages in thread
From: Jason Andryuk @ 2025-04-18 21:05 UTC (permalink / raw)
To: xen-devel; +Cc: Jason Andryuk, Anthony PERARD, Juergen Gross
A PCI device's irq field is an 8-bit number. A value of 0xff indicates
that the device IRQ is not connected. Additionally, the Linux ACPI code
can convert these 0xff values to IRQ_NOTCONNECTED(0x80000000) because
"0x80000000 is guaranteed to be outside the available range of
interrupts and easy to distinguish from other possible incorrect
values." When the hypercall to assign that IRQ fails, device
passthrough as a whole fails.
Add checking for a valid IRQ and skip the IRQ handling for PCI devices
outside that range. This allows for passthrough of devices without
legacy IRQs.
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
---
v2:
Remove () from around fscanf()
---
tools/libs/light/libxl_pci.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/tools/libs/light/libxl_pci.c b/tools/libs/light/libxl_pci.c
index 1647fd6f47..6ddcdef6ad 100644
--- a/tools/libs/light/libxl_pci.c
+++ b/tools/libs/light/libxl_pci.c
@@ -26,6 +26,9 @@
#define PCI_BDF_XSPATH "%04x-%02x-%02x-%01x"
#define PCI_PT_QDEV_ID "pci-pt-%02x_%02x.%01x"
+/* PCI Interrupt Line is an 8-bit value, 0xff means disconnected. */
+#define PCI_IRQ_LINE_LIMIT 0xff
+
static unsigned int pci_encode_bdf(libxl_device_pci *pci)
{
unsigned int value;
@@ -1495,7 +1498,7 @@ static void pci_add_dm_done(libxl__egc *egc,
LOGED(ERROR, domainid, "Couldn't open %s", sysfs_path);
goto out_no_irq;
}
- if ((fscanf(f, "%u", &irq) == 1) && irq) {
+ if (fscanf(f, "%u", &irq) == 1 && irq > 0 && irq < PCI_IRQ_LINE_LIMIT) {
r = xc_physdev_map_pirq(ctx->xch, domid, irq, &irq);
if (r < 0) {
LOGED(ERROR, domainid, "xc_physdev_map_pirq irq=%d (error=%d)",
@@ -2257,7 +2260,7 @@ skip_bar:
goto skip_legacy_irq;
}
- if ((fscanf(f, "%u", &irq) == 1) && irq) {
+ if (fscanf(f, "%u", &irq) == 1 && irq > 0 && irq < PCI_IRQ_LINE_LIMIT) {
rc = xc_physdev_unmap_pirq(ctx->xch, domid, irq);
if (rc < 0) {
/*
--
2.49.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v2 2/2] tools/libxl: Switch irq to unsigned int
2025-04-18 21:05 [PATCH v2 0/2] libxl: Skip invalid IRQs Jason Andryuk
2025-04-18 21:05 ` [PATCH v2 1/2] tools/libxl: " Jason Andryuk
@ 2025-04-18 21:05 ` Jason Andryuk
2025-04-23 14:59 ` Anthony PERARD
1 sibling, 1 reply; 5+ messages in thread
From: Jason Andryuk @ 2025-04-18 21:05 UTC (permalink / raw)
To: xen-devel; +Cc: Jason Andryuk, Anthony PERARD, Juergen Gross
The PCI device irq is read with fscanf(%u). Switch the irq variable to
unsigned int to match.
Linux driver/pci/pci-sysfs.c:irq_show() uses %u to print the value.
However, unsigned int irq doesn't compile because of:
error: pointer targets in passing argument 4 of 'xc_physdev_map_pirq' differ in signedness [-Werror=pointer-sign]
Add int pirq to provide the desired type instead of re-using irq.
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
---
v2:
New
---
tools/libs/light/libxl_pci.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/tools/libs/light/libxl_pci.c b/tools/libs/light/libxl_pci.c
index 6ddcdef6ad..a8460fb3ec 100644
--- a/tools/libs/light/libxl_pci.c
+++ b/tools/libs/light/libxl_pci.c
@@ -1420,8 +1420,8 @@ static void pci_add_dm_done(libxl__egc *egc,
char *sysfs_path;
FILE *f;
unsigned long long start, end, flags, size;
- int irq, i;
- int r;
+ unsigned int irq;
+ int i, r;
uint32_t flag = XEN_DOMCTL_DEV_RDM_RELAXED;
uint32_t domainid = domid;
bool isstubdom = libxl_is_stubdom(ctx, domid, &domainid);
@@ -1499,7 +1499,9 @@ static void pci_add_dm_done(libxl__egc *egc,
goto out_no_irq;
}
if (fscanf(f, "%u", &irq) == 1 && irq > 0 && irq < PCI_IRQ_LINE_LIMIT) {
- r = xc_physdev_map_pirq(ctx->xch, domid, irq, &irq);
+ int pirq = irq;
+
+ r = xc_physdev_map_pirq(ctx->xch, domid, irq, &pirq);
if (r < 0) {
LOGED(ERROR, domainid, "xc_physdev_map_pirq irq=%d (error=%d)",
irq, r);
@@ -1507,10 +1509,10 @@ static void pci_add_dm_done(libxl__egc *egc,
rc = ERROR_FAIL;
goto out;
}
- r = xc_domain_irq_permission(ctx->xch, domid, irq, 1);
+ r = xc_domain_irq_permission(ctx->xch, domid, pirq, 1);
if (r < 0) {
LOGED(ERROR, domainid,
- "xc_domain_irq_permission irq=%d (error=%d)", irq, r);
+ "xc_domain_irq_permission irq=%d (error=%d)", pirq, r);
fclose(f);
rc = ERROR_FAIL;
goto out;
@@ -2182,8 +2184,8 @@ static void pci_remove_detached(libxl__egc *egc,
{
STATE_AO_GC(prs->aodev->ao);
libxl_ctx *ctx = libxl__gc_owner(gc);
- unsigned int start = 0, end = 0, flags = 0, size = 0;
- int irq = 0, i, stubdomid = 0;
+ unsigned int start = 0, end = 0, flags = 0, size = 0, irq = 0;
+ int i, stubdomid = 0;
const char *sysfs_path;
FILE *f;
uint32_t domainid = prs->domid;
--
2.49.0
^ permalink raw reply related [flat|nested] 5+ messages in thread