i386 (MSHV, migration) and Rust changes for 2025-10-09

[PULL 10/35] hw/intc: Generalize APIC helper names from kvm_* to accel_*

Posted by Paolo Bonzini 1 month ago

From: Magnus Kulke <magnuskulke@linux.microsoft.com>

Rename APIC helper functions to use an accel_* prefix instead of kvm_*
to support use by accelerators other than KVM. This is a preparatory
step for integrating MSHV support with common APIC logic.

Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250916164847.77883-5-magnuskulke@linux.microsoft.com
[Remove dead definition of mshv_msi_via_irqfd_enabled. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 include/system/accel-irq.h |  37 +++++++++++++
 include/system/mshv.h      |  17 ++++++
 accel/accel-irq.c          | 106 +++++++++++++++++++++++++++++++++++++
 hw/intc/ioapic.c           |  20 ++++---
 hw/virtio/virtio-pci.c     |  21 ++++----
 accel/meson.build          |   2 +-
 6 files changed, 185 insertions(+), 18 deletions(-)
 create mode 100644 include/system/accel-irq.h
 create mode 100644 accel/accel-irq.c

diff --git a/include/system/accel-irq.h b/include/system/accel-irq.h
new file mode 100644
index 00000000000..671fb7dfdbb
--- /dev/null
+++ b/include/system/accel-irq.h
@@ -0,0 +1,37 @@
+/*
+ * Accelerated irqchip abstraction
+ *
+ * Copyright Microsoft, Corp. 2025
+ *
+ * Authors: Ziqiao Zhou <ziqiaozhou@microsoft.com>
+ *          Magnus Kulke <magnuskulke@microsoft.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef SYSTEM_ACCEL_IRQ_H
+#define SYSTEM_ACCEL_IRQ_H
+#include "hw/pci/msi.h"
+#include "qemu/osdep.h"
+#include "system/kvm.h"
+#include "system/mshv.h"
+
+static inline bool accel_msi_via_irqfd_enabled(void)
+{
+    return mshv_msi_via_irqfd_enabled() || kvm_msi_via_irqfd_enabled();
+}
+
+static inline bool accel_irqchip_is_split(void)
+{
+    return mshv_msi_via_irqfd_enabled() || kvm_irqchip_is_split();
+}
+
+int accel_irqchip_add_msi_route(KVMRouteChange *c, int vector, PCIDevice *dev);
+int accel_irqchip_update_msi_route(int vector, MSIMessage msg, PCIDevice *dev);
+void accel_irqchip_commit_route_changes(KVMRouteChange *c);
+void accel_irqchip_commit_routes(void);
+void accel_irqchip_release_virq(int virq);
+int accel_irqchip_add_irqfd_notifier_gsi(EventNotifier *n, EventNotifier *rn,
+                                         int virq);
+int accel_irqchip_remove_irqfd_notifier_gsi(EventNotifier *n, int virq);
+#endif
diff --git a/include/system/mshv.h b/include/system/mshv.h
index 342f1ef6a98..2a504ed81f2 100644
--- a/include/system/mshv.h
+++ b/include/system/mshv.h
@@ -22,4 +22,21 @@
 #define CONFIG_MSHV_IS_POSSIBLE
 #endif
 
+#ifdef CONFIG_MSHV_IS_POSSIBLE
+extern bool mshv_allowed;
+#define mshv_enabled() (mshv_allowed)
+#else /* CONFIG_MSHV_IS_POSSIBLE */
+#define mshv_enabled() false
+#endif
+#define mshv_msi_via_irqfd_enabled() false
+
+/* interrupt */
+int mshv_irqchip_add_msi_route(int vector, PCIDevice *dev);
+int mshv_irqchip_update_msi_route(int virq, MSIMessage msg, PCIDevice *dev);
+void mshv_irqchip_commit_routes(void);
+void mshv_irqchip_release_virq(int virq);
+int mshv_irqchip_add_irqfd_notifier_gsi(const EventNotifier *n,
+                                        const EventNotifier *rn, int virq);
+int mshv_irqchip_remove_irqfd_notifier_gsi(const EventNotifier *n, int virq);
+
 #endif
diff --git a/accel/accel-irq.c b/accel/accel-irq.c
new file mode 100644
index 00000000000..7f864e35c4e
--- /dev/null
+++ b/accel/accel-irq.c
@@ -0,0 +1,106 @@
+/*
+ * Accelerated irqchip abstraction
+ *
+ * Copyright Microsoft, Corp. 2025
+ *
+ * Authors: Ziqiao Zhou <ziqiaozhou@microsoft.com>
+ *          Magnus Kulke <magnuskulke@microsoft.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "hw/pci/msi.h"
+
+#include "system/kvm.h"
+#include "system/mshv.h"
+#include "system/accel-irq.h"
+
+int accel_irqchip_add_msi_route(KVMRouteChange *c, int vector, PCIDevice *dev)
+{
+#ifdef CONFIG_MSHV_IS_POSSIBLE
+    if (mshv_msi_via_irqfd_enabled()) {
+        return mshv_irqchip_add_msi_route(vector, dev);
+    }
+#endif
+    if (kvm_enabled()) {
+        return kvm_irqchip_add_msi_route(c, vector, dev);
+    }
+    return -ENOSYS;
+}
+
+int accel_irqchip_update_msi_route(int vector, MSIMessage msg, PCIDevice *dev)
+{
+#ifdef CONFIG_MSHV_IS_POSSIBLE
+    if (mshv_msi_via_irqfd_enabled()) {
+        return mshv_irqchip_update_msi_route(vector, msg, dev);
+    }
+#endif
+    if (kvm_enabled()) {
+        return kvm_irqchip_update_msi_route(kvm_state, vector, msg, dev);
+    }
+    return -ENOSYS;
+}
+
+void accel_irqchip_commit_route_changes(KVMRouteChange *c)
+{
+#ifdef CONFIG_MSHV_IS_POSSIBLE
+    if (mshv_msi_via_irqfd_enabled()) {
+        mshv_irqchip_commit_routes();
+    }
+#endif
+    if (kvm_enabled()) {
+        kvm_irqchip_commit_route_changes(c);
+    }
+}
+
+void accel_irqchip_commit_routes(void)
+{
+#ifdef CONFIG_MSHV_IS_POSSIBLE
+    if (mshv_msi_via_irqfd_enabled()) {
+        mshv_irqchip_commit_routes();
+    }
+#endif
+    if (kvm_enabled()) {
+        kvm_irqchip_commit_routes(kvm_state);
+    }
+}
+
+void accel_irqchip_release_virq(int virq)
+{
+#ifdef CONFIG_MSHV_IS_POSSIBLE
+    if (mshv_msi_via_irqfd_enabled()) {
+        mshv_irqchip_release_virq(virq);
+    }
+#endif
+    if (kvm_enabled()) {
+        kvm_irqchip_release_virq(kvm_state, virq);
+    }
+}
+
+int accel_irqchip_add_irqfd_notifier_gsi(EventNotifier *n, EventNotifier *rn,
+                                         int virq)
+{
+#ifdef CONFIG_MSHV_IS_POSSIBLE
+    if (mshv_msi_via_irqfd_enabled()) {
+        return mshv_irqchip_add_irqfd_notifier_gsi(n, rn, virq);
+    }
+#endif
+    if (kvm_enabled()) {
+        return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, rn, virq);
+    }
+    return -ENOSYS;
+}
+
+int accel_irqchip_remove_irqfd_notifier_gsi(EventNotifier *n, int virq)
+{
+#ifdef CONFIG_MSHV_IS_POSSIBLE
+    if (mshv_msi_via_irqfd_enabled()) {
+        return mshv_irqchip_remove_irqfd_notifier_gsi(n, virq);
+    }
+#endif
+    if (kvm_enabled()) {
+        return kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n, virq);
+    }
+    return -ENOSYS;
+}
diff --git a/hw/intc/ioapic.c b/hw/intc/ioapic.c
index 133bef852d1..e431d003117 100644
--- a/hw/intc/ioapic.c
+++ b/hw/intc/ioapic.c
@@ -30,12 +30,18 @@
 #include "hw/intc/ioapic_internal.h"
 #include "hw/pci/msi.h"
 #include "hw/qdev-properties.h"
+#include "system/accel-irq.h"
 #include "system/kvm.h"
 #include "system/system.h"
 #include "hw/i386/apic-msidef.h"
 #include "hw/i386/x86-iommu.h"
 #include "trace.h"
 
+
+#if defined(CONFIG_KVM) || defined(CONFIG_MSHV)
+#define ACCEL_GSI_IRQFD_POSSIBLE
+#endif
+
 #define APIC_DELIVERY_MODE_SHIFT 8
 #define APIC_POLARITY_SHIFT 14
 #define APIC_TRIG_MODE_SHIFT 15
@@ -191,10 +197,10 @@ static void ioapic_set_irq(void *opaque, int vector, int level)
 
 static void ioapic_update_kvm_routes(IOAPICCommonState *s)
 {
-#ifdef CONFIG_KVM
+#ifdef ACCEL_GSI_IRQFD_POSSIBLE
     int i;
 
-    if (kvm_irqchip_is_split()) {
+    if (accel_irqchip_is_split()) {
         for (i = 0; i < IOAPIC_NUM_PINS; i++) {
             MSIMessage msg;
             struct ioapic_entry_info info;
@@ -202,15 +208,15 @@ static void ioapic_update_kvm_routes(IOAPICCommonState *s)
             if (!info.masked) {
                 msg.address = info.addr;
                 msg.data = info.data;
-                kvm_irqchip_update_msi_route(kvm_state, i, msg, NULL);
+                accel_irqchip_update_msi_route(i, msg, NULL);
             }
         }
-        kvm_irqchip_commit_routes(kvm_state);
+        accel_irqchip_commit_routes();
     }
 #endif
 }
 
-#ifdef CONFIG_KVM
+#ifdef ACCEL_KERNEL_GSI_IRQFD_POSSIBLE
 static void ioapic_iec_notifier(void *private, bool global,
                                 uint32_t index, uint32_t mask)
 {
@@ -428,11 +434,11 @@ static const MemoryRegionOps ioapic_io_ops = {
 
 static void ioapic_machine_done_notify(Notifier *notifier, void *data)
 {
-#ifdef CONFIG_KVM
+#ifdef ACCEL_KERNEL_GSI_IRQFD_POSSIBLE
     IOAPICCommonState *s = container_of(notifier, IOAPICCommonState,
                                         machine_done);
 
-    if (kvm_irqchip_is_split()) {
+    if (accel_irqchip_is_split()) {
         X86IOMMUState *iommu = x86_iommu_get_default();
         if (iommu) {
             /* Register this IOAPIC with IOMMU IEC notifier, so that
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 767216d7959..0cdc16217ff 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -34,6 +34,7 @@
 #include "hw/pci/msi.h"
 #include "hw/pci/msix.h"
 #include "hw/loader.h"
+#include "system/accel-irq.h"
 #include "system/kvm.h"
 #include "hw/virtio/virtio-pci.h"
 #include "qemu/range.h"
@@ -825,11 +826,11 @@ static int kvm_virtio_pci_vq_vector_use(VirtIOPCIProxy *proxy,
 
     if (irqfd->users == 0) {
         KVMRouteChange c = kvm_irqchip_begin_route_changes(kvm_state);
-        ret = kvm_irqchip_add_msi_route(&c, vector, &proxy->pci_dev);
+        ret = accel_irqchip_add_msi_route(&c, vector, &proxy->pci_dev);
         if (ret < 0) {
             return ret;
         }
-        kvm_irqchip_commit_route_changes(&c);
+        accel_irqchip_commit_route_changes(&c);
         irqfd->virq = ret;
     }
     irqfd->users++;
@@ -841,7 +842,7 @@ static void kvm_virtio_pci_vq_vector_release(VirtIOPCIProxy *proxy,
 {
     VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
     if (--irqfd->users == 0) {
-        kvm_irqchip_release_virq(kvm_state, irqfd->virq);
+        accel_irqchip_release_virq(irqfd->virq);
     }
 }
 
@@ -850,7 +851,7 @@ static int kvm_virtio_pci_irqfd_use(VirtIOPCIProxy *proxy,
                                  unsigned int vector)
 {
     VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
-    return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL, irqfd->virq);
+    return accel_irqchip_add_irqfd_notifier_gsi(n, NULL, irqfd->virq);
 }
 
 static void kvm_virtio_pci_irqfd_release(VirtIOPCIProxy *proxy,
@@ -860,7 +861,7 @@ static void kvm_virtio_pci_irqfd_release(VirtIOPCIProxy *proxy,
     VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
     int ret;
 
-    ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n, irqfd->virq);
+    ret = accel_irqchip_remove_irqfd_notifier_gsi(n, irqfd->virq);
     assert(ret == 0);
 }
 static int virtio_pci_get_notifier(VirtIOPCIProxy *proxy, int queue_no,
@@ -995,12 +996,12 @@ static int virtio_pci_one_vector_unmask(VirtIOPCIProxy *proxy,
     if (proxy->vector_irqfd) {
         irqfd = &proxy->vector_irqfd[vector];
         if (irqfd->msg.data != msg.data || irqfd->msg.address != msg.address) {
-            ret = kvm_irqchip_update_msi_route(kvm_state, irqfd->virq, msg,
-                                               &proxy->pci_dev);
+            ret = accel_irqchip_update_msi_route(irqfd->virq, msg,
+                                                 &proxy->pci_dev);
             if (ret < 0) {
                 return ret;
             }
-            kvm_irqchip_commit_routes(kvm_state);
+            accel_irqchip_commit_routes();
         }
     }
 
@@ -1229,7 +1230,7 @@ static int virtio_pci_set_guest_notifiers(DeviceState *d, int nvqs, bool assign)
     VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
     int r, n;
     bool with_irqfd = msix_enabled(&proxy->pci_dev) &&
-        kvm_msi_via_irqfd_enabled();
+        accel_msi_via_irqfd_enabled() ;
 
     nvqs = MIN(nvqs, VIRTIO_QUEUE_MAX);
 
@@ -1433,7 +1434,7 @@ static void virtio_pci_set_vector(VirtIODevice *vdev,
                                   uint16_t new_vector)
 {
     bool kvm_irqfd = (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
-        msix_enabled(&proxy->pci_dev) && kvm_msi_via_irqfd_enabled();
+        msix_enabled(&proxy->pci_dev) && accel_msi_via_irqfd_enabled();
 
     if (new_vector == old_vector) {
         return;
diff --git a/accel/meson.build b/accel/meson.build
index 25b0f100b51..6349efe682f 100644
--- a/accel/meson.build
+++ b/accel/meson.build
@@ -1,6 +1,6 @@
 common_ss.add(files('accel-common.c'))
 specific_ss.add(files('accel-target.c'))
-system_ss.add(files('accel-system.c', 'accel-blocker.c', 'accel-qmp.c'))
+system_ss.add(files('accel-system.c', 'accel-blocker.c', 'accel-qmp.c', 'accel-irq.c'))
 user_ss.add(files('accel-user.c'))
 
 subdir('tcg')
-- 
2.51.0

Re: [PULL 10/35] hw/intc: Generalize APIC helper names from kvm_* to accel_*

Posted by Cédric Le Goater 1 week, 4 days ago

Hi,

On 10/9/25 09:50, Paolo Bonzini wrote:
> From: Magnus Kulke <magnuskulke@linux.microsoft.com>
> 
> Rename APIC helper functions to use an accel_* prefix instead of kvm_*
> to support use by accelerators other than KVM. This is a preparatory
> step for integrating MSHV support with common APIC logic.
> 
> Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com>
> Link: https://lore.kernel.org/r/20250916164847.77883-5-magnuskulke@linux.microsoft.com
> [Remove dead definition of mshv_msi_via_irqfd_enabled. - Paolo]
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>   include/system/accel-irq.h |  37 +++++++++++++
>   include/system/mshv.h      |  17 ++++++
>   accel/accel-irq.c          | 106 +++++++++++++++++++++++++++++++++++++
>   hw/intc/ioapic.c           |  20 ++++---
>   hw/virtio/virtio-pci.c     |  21 ++++----
>   accel/meson.build          |   2 +-
>   6 files changed, 185 insertions(+), 18 deletions(-)
>   create mode 100644 include/system/accel-irq.h
>   create mode 100644 accel/accel-irq.c

This change seems to introduce a regression with interrupt remapping
when running a VM configured with an intel-iommu device and an assigned
PCI VF. At boot, Linux complains with :

[   15.416794] __common_interrupt: 2.37 No irq handler for vector
[   15.417266] __common_interrupt: 2.37 No irq handler for vector
[   15.417733] __common_interrupt: 2.37 No irq handler for vector
[   15.418202] __common_interrupt: 2.37 No irq handler for vector
[   15.418670] __common_interrupt: 2.37 No irq handler for vector
[   15.419143] __common_interrupt: 2.37 No irq handler for vector
[   15.419608] __common_interrupt: 2.37 No irq handler for vector
[   15.420094] __common_interrupt: 2.37 No irq handler for vector
[   15.420556] __common_interrupt: 2.37 No irq handler for vector


CC’ingg Zhenzhong, Joao, Clement for awareness and their expertise
in intel-iommu and interrupt remapping.

Thanks,

C.



> 
> diff --git a/include/system/accel-irq.h b/include/system/accel-irq.h
> new file mode 100644
> index 00000000000..671fb7dfdbb
> --- /dev/null
> +++ b/include/system/accel-irq.h
> @@ -0,0 +1,37 @@
> +/*
> + * Accelerated irqchip abstraction
> + *
> + * Copyright Microsoft, Corp. 2025
> + *
> + * Authors: Ziqiao Zhou <ziqiaozhou@microsoft.com>
> + *          Magnus Kulke <magnuskulke@microsoft.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + */
> +
> +#ifndef SYSTEM_ACCEL_IRQ_H
> +#define SYSTEM_ACCEL_IRQ_H
> +#include "hw/pci/msi.h"
> +#include "qemu/osdep.h"
> +#include "system/kvm.h"
> +#include "system/mshv.h"
> +
> +static inline bool accel_msi_via_irqfd_enabled(void)
> +{
> +    return mshv_msi_via_irqfd_enabled() || kvm_msi_via_irqfd_enabled();
> +}
> +
> +static inline bool accel_irqchip_is_split(void)
> +{
> +    return mshv_msi_via_irqfd_enabled() || kvm_irqchip_is_split();
> +}
> +
> +int accel_irqchip_add_msi_route(KVMRouteChange *c, int vector, PCIDevice *dev);
> +int accel_irqchip_update_msi_route(int vector, MSIMessage msg, PCIDevice *dev);
> +void accel_irqchip_commit_route_changes(KVMRouteChange *c);
> +void accel_irqchip_commit_routes(void);
> +void accel_irqchip_release_virq(int virq);
> +int accel_irqchip_add_irqfd_notifier_gsi(EventNotifier *n, EventNotifier *rn,
> +                                         int virq);
> +int accel_irqchip_remove_irqfd_notifier_gsi(EventNotifier *n, int virq);
> +#endif
> diff --git a/include/system/mshv.h b/include/system/mshv.h
> index 342f1ef6a98..2a504ed81f2 100644
> --- a/include/system/mshv.h
> +++ b/include/system/mshv.h
> @@ -22,4 +22,21 @@
>   #define CONFIG_MSHV_IS_POSSIBLE
>   #endif
>   
> +#ifdef CONFIG_MSHV_IS_POSSIBLE
> +extern bool mshv_allowed;
> +#define mshv_enabled() (mshv_allowed)
> +#else /* CONFIG_MSHV_IS_POSSIBLE */
> +#define mshv_enabled() false
> +#endif
> +#define mshv_msi_via_irqfd_enabled() false
> +
> +/* interrupt */
> +int mshv_irqchip_add_msi_route(int vector, PCIDevice *dev);
> +int mshv_irqchip_update_msi_route(int virq, MSIMessage msg, PCIDevice *dev);
> +void mshv_irqchip_commit_routes(void);
> +void mshv_irqchip_release_virq(int virq);
> +int mshv_irqchip_add_irqfd_notifier_gsi(const EventNotifier *n,
> +                                        const EventNotifier *rn, int virq);
> +int mshv_irqchip_remove_irqfd_notifier_gsi(const EventNotifier *n, int virq);
> +
>   #endif
> diff --git a/accel/accel-irq.c b/accel/accel-irq.c
> new file mode 100644
> index 00000000000..7f864e35c4e
> --- /dev/null
> +++ b/accel/accel-irq.c
> @@ -0,0 +1,106 @@
> +/*
> + * Accelerated irqchip abstraction
> + *
> + * Copyright Microsoft, Corp. 2025
> + *
> + * Authors: Ziqiao Zhou <ziqiaozhou@microsoft.com>
> + *          Magnus Kulke <magnuskulke@microsoft.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + */
> +
> +#include "qemu/osdep.h"
> +#include "hw/pci/msi.h"
> +
> +#include "system/kvm.h"
> +#include "system/mshv.h"
> +#include "system/accel-irq.h"
> +
> +int accel_irqchip_add_msi_route(KVMRouteChange *c, int vector, PCIDevice *dev)
> +{
> +#ifdef CONFIG_MSHV_IS_POSSIBLE
> +    if (mshv_msi_via_irqfd_enabled()) {
> +        return mshv_irqchip_add_msi_route(vector, dev);
> +    }
> +#endif
> +    if (kvm_enabled()) {
> +        return kvm_irqchip_add_msi_route(c, vector, dev);
> +    }
> +    return -ENOSYS;
> +}
> +
> +int accel_irqchip_update_msi_route(int vector, MSIMessage msg, PCIDevice *dev)
> +{
> +#ifdef CONFIG_MSHV_IS_POSSIBLE
> +    if (mshv_msi_via_irqfd_enabled()) {
> +        return mshv_irqchip_update_msi_route(vector, msg, dev);
> +    }
> +#endif
> +    if (kvm_enabled()) {
> +        return kvm_irqchip_update_msi_route(kvm_state, vector, msg, dev);
> +    }
> +    return -ENOSYS;
> +}
> +
> +void accel_irqchip_commit_route_changes(KVMRouteChange *c)
> +{
> +#ifdef CONFIG_MSHV_IS_POSSIBLE
> +    if (mshv_msi_via_irqfd_enabled()) {
> +        mshv_irqchip_commit_routes();
> +    }
> +#endif
> +    if (kvm_enabled()) {
> +        kvm_irqchip_commit_route_changes(c);
> +    }
> +}
> +
> +void accel_irqchip_commit_routes(void)
> +{
> +#ifdef CONFIG_MSHV_IS_POSSIBLE
> +    if (mshv_msi_via_irqfd_enabled()) {
> +        mshv_irqchip_commit_routes();
> +    }
> +#endif
> +    if (kvm_enabled()) {
> +        kvm_irqchip_commit_routes(kvm_state);
> +    }
> +}
> +
> +void accel_irqchip_release_virq(int virq)
> +{
> +#ifdef CONFIG_MSHV_IS_POSSIBLE
> +    if (mshv_msi_via_irqfd_enabled()) {
> +        mshv_irqchip_release_virq(virq);
> +    }
> +#endif
> +    if (kvm_enabled()) {
> +        kvm_irqchip_release_virq(kvm_state, virq);
> +    }
> +}
> +
> +int accel_irqchip_add_irqfd_notifier_gsi(EventNotifier *n, EventNotifier *rn,
> +                                         int virq)
> +{
> +#ifdef CONFIG_MSHV_IS_POSSIBLE
> +    if (mshv_msi_via_irqfd_enabled()) {
> +        return mshv_irqchip_add_irqfd_notifier_gsi(n, rn, virq);
> +    }
> +#endif
> +    if (kvm_enabled()) {
> +        return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, rn, virq);
> +    }
> +    return -ENOSYS;
> +}
> +
> +int accel_irqchip_remove_irqfd_notifier_gsi(EventNotifier *n, int virq)
> +{
> +#ifdef CONFIG_MSHV_IS_POSSIBLE
> +    if (mshv_msi_via_irqfd_enabled()) {
> +        return mshv_irqchip_remove_irqfd_notifier_gsi(n, virq);
> +    }
> +#endif
> +    if (kvm_enabled()) {
> +        return kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n, virq);
> +    }
> +    return -ENOSYS;
> +}
> diff --git a/hw/intc/ioapic.c b/hw/intc/ioapic.c
> index 133bef852d1..e431d003117 100644
> --- a/hw/intc/ioapic.c
> +++ b/hw/intc/ioapic.c
> @@ -30,12 +30,18 @@
>   #include "hw/intc/ioapic_internal.h"
>   #include "hw/pci/msi.h"
>   #include "hw/qdev-properties.h"
> +#include "system/accel-irq.h"
>   #include "system/kvm.h"
>   #include "system/system.h"
>   #include "hw/i386/apic-msidef.h"
>   #include "hw/i386/x86-iommu.h"
>   #include "trace.h"
>   
> +
> +#if defined(CONFIG_KVM) || defined(CONFIG_MSHV)
> +#define ACCEL_GSI_IRQFD_POSSIBLE
> +#endif
> +
>   #define APIC_DELIVERY_MODE_SHIFT 8
>   #define APIC_POLARITY_SHIFT 14
>   #define APIC_TRIG_MODE_SHIFT 15
> @@ -191,10 +197,10 @@ static void ioapic_set_irq(void *opaque, int vector, int level)
>   
>   static void ioapic_update_kvm_routes(IOAPICCommonState *s)
>   {
> -#ifdef CONFIG_KVM
> +#ifdef ACCEL_GSI_IRQFD_POSSIBLE
>       int i;
>   
> -    if (kvm_irqchip_is_split()) {
> +    if (accel_irqchip_is_split()) {
>           for (i = 0; i < IOAPIC_NUM_PINS; i++) {
>               MSIMessage msg;
>               struct ioapic_entry_info info;
> @@ -202,15 +208,15 @@ static void ioapic_update_kvm_routes(IOAPICCommonState *s)
>               if (!info.masked) {
>                   msg.address = info.addr;
>                   msg.data = info.data;
> -                kvm_irqchip_update_msi_route(kvm_state, i, msg, NULL);
> +                accel_irqchip_update_msi_route(i, msg, NULL);
>               }
>           }
> -        kvm_irqchip_commit_routes(kvm_state);
> +        accel_irqchip_commit_routes();
>       }
>   #endif
>   }
>   
> -#ifdef CONFIG_KVM
> +#ifdef ACCEL_KERNEL_GSI_IRQFD_POSSIBLE
>   static void ioapic_iec_notifier(void *private, bool global,
>                                   uint32_t index, uint32_t mask)
>   {
> @@ -428,11 +434,11 @@ static const MemoryRegionOps ioapic_io_ops = {
>   
>   static void ioapic_machine_done_notify(Notifier *notifier, void *data)
>   {
> -#ifdef CONFIG_KVM
> +#ifdef ACCEL_KERNEL_GSI_IRQFD_POSSIBLE
>       IOAPICCommonState *s = container_of(notifier, IOAPICCommonState,
>                                           machine_done);
>   
> -    if (kvm_irqchip_is_split()) {
> +    if (accel_irqchip_is_split()) {
>           X86IOMMUState *iommu = x86_iommu_get_default();
>           if (iommu) {
>               /* Register this IOAPIC with IOMMU IEC notifier, so that
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index 767216d7959..0cdc16217ff 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -34,6 +34,7 @@
>   #include "hw/pci/msi.h"
>   #include "hw/pci/msix.h"
>   #include "hw/loader.h"
> +#include "system/accel-irq.h"
>   #include "system/kvm.h"
>   #include "hw/virtio/virtio-pci.h"
>   #include "qemu/range.h"
> @@ -825,11 +826,11 @@ static int kvm_virtio_pci_vq_vector_use(VirtIOPCIProxy *proxy,
>   
>       if (irqfd->users == 0) {
>           KVMRouteChange c = kvm_irqchip_begin_route_changes(kvm_state);
> -        ret = kvm_irqchip_add_msi_route(&c, vector, &proxy->pci_dev);
> +        ret = accel_irqchip_add_msi_route(&c, vector, &proxy->pci_dev);
>           if (ret < 0) {
>               return ret;
>           }
> -        kvm_irqchip_commit_route_changes(&c);
> +        accel_irqchip_commit_route_changes(&c);
>           irqfd->virq = ret;
>       }
>       irqfd->users++;
> @@ -841,7 +842,7 @@ static void kvm_virtio_pci_vq_vector_release(VirtIOPCIProxy *proxy,
>   {
>       VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
>       if (--irqfd->users == 0) {
> -        kvm_irqchip_release_virq(kvm_state, irqfd->virq);
> +        accel_irqchip_release_virq(irqfd->virq);
>       }
>   }
>   
> @@ -850,7 +851,7 @@ static int kvm_virtio_pci_irqfd_use(VirtIOPCIProxy *proxy,
>                                    unsigned int vector)
>   {
>       VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
> -    return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL, irqfd->virq);
> +    return accel_irqchip_add_irqfd_notifier_gsi(n, NULL, irqfd->virq);
>   }
>   
>   static void kvm_virtio_pci_irqfd_release(VirtIOPCIProxy *proxy,
> @@ -860,7 +861,7 @@ static void kvm_virtio_pci_irqfd_release(VirtIOPCIProxy *proxy,
>       VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
>       int ret;
>   
> -    ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n, irqfd->virq);
> +    ret = accel_irqchip_remove_irqfd_notifier_gsi(n, irqfd->virq);
>       assert(ret == 0);
>   }
>   static int virtio_pci_get_notifier(VirtIOPCIProxy *proxy, int queue_no,
> @@ -995,12 +996,12 @@ static int virtio_pci_one_vector_unmask(VirtIOPCIProxy *proxy,
>       if (proxy->vector_irqfd) {
>           irqfd = &proxy->vector_irqfd[vector];
>           if (irqfd->msg.data != msg.data || irqfd->msg.address != msg.address) {
> -            ret = kvm_irqchip_update_msi_route(kvm_state, irqfd->virq, msg,
> -                                               &proxy->pci_dev);
> +            ret = accel_irqchip_update_msi_route(irqfd->virq, msg,
> +                                                 &proxy->pci_dev);
>               if (ret < 0) {
>                   return ret;
>               }
> -            kvm_irqchip_commit_routes(kvm_state);
> +            accel_irqchip_commit_routes();
>           }
>       }
>   
> @@ -1229,7 +1230,7 @@ static int virtio_pci_set_guest_notifiers(DeviceState *d, int nvqs, bool assign)
>       VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
>       int r, n;
>       bool with_irqfd = msix_enabled(&proxy->pci_dev) &&
> -        kvm_msi_via_irqfd_enabled();
> +        accel_msi_via_irqfd_enabled() ;
>   
>       nvqs = MIN(nvqs, VIRTIO_QUEUE_MAX);
>   
> @@ -1433,7 +1434,7 @@ static void virtio_pci_set_vector(VirtIODevice *vdev,
>                                     uint16_t new_vector)
>   {
>       bool kvm_irqfd = (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
> -        msix_enabled(&proxy->pci_dev) && kvm_msi_via_irqfd_enabled();
> +        msix_enabled(&proxy->pci_dev) && accel_msi_via_irqfd_enabled();
>   
>       if (new_vector == old_vector) {
>           return;
> diff --git a/accel/meson.build b/accel/meson.build
> index 25b0f100b51..6349efe682f 100644
> --- a/accel/meson.build
> +++ b/accel/meson.build
> @@ -1,6 +1,6 @@
>   common_ss.add(files('accel-common.c'))
>   specific_ss.add(files('accel-target.c'))
> -system_ss.add(files('accel-system.c', 'accel-blocker.c', 'accel-qmp.c'))
> +system_ss.add(files('accel-system.c', 'accel-blocker.c', 'accel-qmp.c', 'accel-irq.c'))
>   user_ss.add(files('accel-user.c'))
>   
>   subdir('tcg')

Re: [PULL 10/35] hw/intc: Generalize APIC helper names from kvm_* to accel_*

Posted by Magnus Kulke 1 week, 2 days ago

On Mon, Nov 03, 2025 at 10:43:36PM +0100, Cédric Le Goater wrote:
> Hi,
> 
> On 10/9/25 09:50, Paolo Bonzini wrote:
> > From: Magnus Kulke <magnuskulke@linux.microsoft.com>
> > 
> > Rename APIC helper functions to use an accel_* prefix instead of kvm_*
> > to support use by accelerators other than KVM. This is a preparatory
> > step for integrating MSHV support with common APIC logic.
> > 
> > Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com>
> > Link: https://lore.kernel.org/r/20250916164847.77883-5-magnuskulke@linux.microsoft.com
> > [Remove dead definition of mshv_msi_via_irqfd_enabled. - Paolo]
> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> > ---
> >   include/system/accel-irq.h |  37 +++++++++++++
> >   include/system/mshv.h      |  17 ++++++
> >   accel/accel-irq.c          | 106 +++++++++++++++++++++++++++++++++++++
> >   hw/intc/ioapic.c           |  20 ++++---
> >   hw/virtio/virtio-pci.c     |  21 ++++----
> >   accel/meson.build          |   2 +-
> >   6 files changed, 185 insertions(+), 18 deletions(-)
> >   create mode 100644 include/system/accel-irq.h
> >   create mode 100644 accel/accel-irq.c
> 
> This change seems to introduce a regression with interrupt remapping
> when running a VM configured with an intel-iommu device and an assigned
> PCI VF. At boot, Linux complains with :
> 

Thank you for reporting, Cédric. From glancing over it, it looks like a
typo: we check for `ACCEL_KERNEL_GSI_IRQFD_POSSIBLE` instead of
`ACCEL_GSI_IRQFD_POSSIBLE` in ioapic.c. The former doesn't seem to be
defined anywhere.

Can you verify if changing that fixes the issue for you?

s/ACCEL_KERNEL_GSI_IRQFD_POSSIBLE/ACCEL_GSI_IRQFD_POSSIBLE/g

best,

magnus

> [   15.416794] __common_interrupt: 2.37 No irq handler for vector
> [   15.417266] __common_interrupt: 2.37 No irq handler for vector
> [   15.417733] __common_interrupt: 2.37 No irq handler for vector
> [   15.418202] __common_interrupt: 2.37 No irq handler for vector
> [   15.418670] __common_interrupt: 2.37 No irq handler for vector
> [   15.419143] __common_interrupt: 2.37 No irq handler for vector
> [   15.419608] __common_interrupt: 2.37 No irq handler for vector
> [   15.420094] __common_interrupt: 2.37 No irq handler for vector
> [   15.420556] __common_interrupt: 2.37 No irq handler for vector
> 
> 
> CC’ingg Zhenzhong, Joao, Clement for awareness and their expertise
> in intel-iommu and interrupt remapping.
> 
> Thanks,
> 
> C.
> 
> 
> 
> > 
> > diff --git a/include/system/accel-irq.h b/include/system/accel-irq.h
> > new file mode 100644
> > index 00000000000..671fb7dfdbb
> > --- /dev/null
> > +++ b/include/system/accel-irq.h
> > @@ -0,0 +1,37 @@
> > +/*
> > + * Accelerated irqchip abstraction
> > + *
> > + * Copyright Microsoft, Corp. 2025
> > + *
> > + * Authors: Ziqiao Zhou <ziqiaozhou@microsoft.com>
> > + *          Magnus Kulke <magnuskulke@microsoft.com>
> > + *
> > + * SPDX-License-Identifier: GPL-2.0-or-later
> > + */
> > +
> > +#ifndef SYSTEM_ACCEL_IRQ_H
> > +#define SYSTEM_ACCEL_IRQ_H
> > +#include "hw/pci/msi.h"
> > +#include "qemu/osdep.h"
> > +#include "system/kvm.h"
> > +#include "system/mshv.h"
> > +
> > +static inline bool accel_msi_via_irqfd_enabled(void)
> > +{
> > +    return mshv_msi_via_irqfd_enabled() || kvm_msi_via_irqfd_enabled();
> > +}
> > +
> > +static inline bool accel_irqchip_is_split(void)
> > +{
> > +    return mshv_msi_via_irqfd_enabled() || kvm_irqchip_is_split();
> > +}
> > +
> > +int accel_irqchip_add_msi_route(KVMRouteChange *c, int vector, PCIDevice *dev);
> > +int accel_irqchip_update_msi_route(int vector, MSIMessage msg, PCIDevice *dev);
> > +void accel_irqchip_commit_route_changes(KVMRouteChange *c);
> > +void accel_irqchip_commit_routes(void);
> > +void accel_irqchip_release_virq(int virq);
> > +int accel_irqchip_add_irqfd_notifier_gsi(EventNotifier *n, EventNotifier *rn,
> > +                                         int virq);
> > +int accel_irqchip_remove_irqfd_notifier_gsi(EventNotifier *n, int virq);
> > +#endif
> > diff --git a/include/system/mshv.h b/include/system/mshv.h
> > index 342f1ef6a98..2a504ed81f2 100644
> > --- a/include/system/mshv.h
> > +++ b/include/system/mshv.h
> > @@ -22,4 +22,21 @@
> >   #define CONFIG_MSHV_IS_POSSIBLE
> >   #endif
> > +#ifdef CONFIG_MSHV_IS_POSSIBLE
> > +extern bool mshv_allowed;
> > +#define mshv_enabled() (mshv_allowed)
> > +#else /* CONFIG_MSHV_IS_POSSIBLE */
> > +#define mshv_enabled() false
> > +#endif
> > +#define mshv_msi_via_irqfd_enabled() false
> > +
> > +/* interrupt */
> > +int mshv_irqchip_add_msi_route(int vector, PCIDevice *dev);
> > +int mshv_irqchip_update_msi_route(int virq, MSIMessage msg, PCIDevice *dev);
> > +void mshv_irqchip_commit_routes(void);
> > +void mshv_irqchip_release_virq(int virq);
> > +int mshv_irqchip_add_irqfd_notifier_gsi(const EventNotifier *n,
> > +                                        const EventNotifier *rn, int virq);
> > +int mshv_irqchip_remove_irqfd_notifier_gsi(const EventNotifier *n, int virq);
> > +
> >   #endif
> > diff --git a/accel/accel-irq.c b/accel/accel-irq.c
> > new file mode 100644
> > index 00000000000..7f864e35c4e
> > --- /dev/null
> > +++ b/accel/accel-irq.c
> > @@ -0,0 +1,106 @@
> > +/*
> > + * Accelerated irqchip abstraction
> > + *
> > + * Copyright Microsoft, Corp. 2025
> > + *
> > + * Authors: Ziqiao Zhou <ziqiaozhou@microsoft.com>
> > + *          Magnus Kulke <magnuskulke@microsoft.com>
> > + *
> > + * SPDX-License-Identifier: GPL-2.0-or-later
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +#include "hw/pci/msi.h"
> > +
> > +#include "system/kvm.h"
> > +#include "system/mshv.h"
> > +#include "system/accel-irq.h"
> > +
> > +int accel_irqchip_add_msi_route(KVMRouteChange *c, int vector, PCIDevice *dev)
> > +{
> > +#ifdef CONFIG_MSHV_IS_POSSIBLE
> > +    if (mshv_msi_via_irqfd_enabled()) {
> > +        return mshv_irqchip_add_msi_route(vector, dev);
> > +    }
> > +#endif
> > +    if (kvm_enabled()) {
> > +        return kvm_irqchip_add_msi_route(c, vector, dev);
> > +    }
> > +    return -ENOSYS;
> > +}
> > +
> > +int accel_irqchip_update_msi_route(int vector, MSIMessage msg, PCIDevice *dev)
> > +{
> > +#ifdef CONFIG_MSHV_IS_POSSIBLE
> > +    if (mshv_msi_via_irqfd_enabled()) {
> > +        return mshv_irqchip_update_msi_route(vector, msg, dev);
> > +    }
> > +#endif
> > +    if (kvm_enabled()) {
> > +        return kvm_irqchip_update_msi_route(kvm_state, vector, msg, dev);
> > +    }
> > +    return -ENOSYS;
> > +}
> > +
> > +void accel_irqchip_commit_route_changes(KVMRouteChange *c)
> > +{
> > +#ifdef CONFIG_MSHV_IS_POSSIBLE
> > +    if (mshv_msi_via_irqfd_enabled()) {
> > +        mshv_irqchip_commit_routes();
> > +    }
> > +#endif
> > +    if (kvm_enabled()) {
> > +        kvm_irqchip_commit_route_changes(c);
> > +    }
> > +}
> > +
> > +void accel_irqchip_commit_routes(void)
> > +{
> > +#ifdef CONFIG_MSHV_IS_POSSIBLE
> > +    if (mshv_msi_via_irqfd_enabled()) {
> > +        mshv_irqchip_commit_routes();
> > +    }
> > +#endif
> > +    if (kvm_enabled()) {
> > +        kvm_irqchip_commit_routes(kvm_state);
> > +    }
> > +}
> > +
> > +void accel_irqchip_release_virq(int virq)
> > +{
> > +#ifdef CONFIG_MSHV_IS_POSSIBLE
> > +    if (mshv_msi_via_irqfd_enabled()) {
> > +        mshv_irqchip_release_virq(virq);
> > +    }
> > +#endif
> > +    if (kvm_enabled()) {
> > +        kvm_irqchip_release_virq(kvm_state, virq);
> > +    }
> > +}
> > +
> > +int accel_irqchip_add_irqfd_notifier_gsi(EventNotifier *n, EventNotifier *rn,
> > +                                         int virq)
> > +{
> > +#ifdef CONFIG_MSHV_IS_POSSIBLE
> > +    if (mshv_msi_via_irqfd_enabled()) {
> > +        return mshv_irqchip_add_irqfd_notifier_gsi(n, rn, virq);
> > +    }
> > +#endif
> > +    if (kvm_enabled()) {
> > +        return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, rn, virq);
> > +    }
> > +    return -ENOSYS;
> > +}
> > +
> > +int accel_irqchip_remove_irqfd_notifier_gsi(EventNotifier *n, int virq)
> > +{
> > +#ifdef CONFIG_MSHV_IS_POSSIBLE
> > +    if (mshv_msi_via_irqfd_enabled()) {
> > +        return mshv_irqchip_remove_irqfd_notifier_gsi(n, virq);
> > +    }
> > +#endif
> > +    if (kvm_enabled()) {
> > +        return kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n, virq);
> > +    }
> > +    return -ENOSYS;
> > +}
> > diff --git a/hw/intc/ioapic.c b/hw/intc/ioapic.c
> > index 133bef852d1..e431d003117 100644
> > --- a/hw/intc/ioapic.c
> > +++ b/hw/intc/ioapic.c
> > @@ -30,12 +30,18 @@
> >   #include "hw/intc/ioapic_internal.h"
> >   #include "hw/pci/msi.h"
> >   #include "hw/qdev-properties.h"
> > +#include "system/accel-irq.h"
> >   #include "system/kvm.h"
> >   #include "system/system.h"
> >   #include "hw/i386/apic-msidef.h"
> >   #include "hw/i386/x86-iommu.h"
> >   #include "trace.h"
> > +
> > +#if defined(CONFIG_KVM) || defined(CONFIG_MSHV)
> > +#define ACCEL_GSI_IRQFD_POSSIBLE
> > +#endif
> > +
> >   #define APIC_DELIVERY_MODE_SHIFT 8
> >   #define APIC_POLARITY_SHIFT 14
> >   #define APIC_TRIG_MODE_SHIFT 15
> > @@ -191,10 +197,10 @@ static void ioapic_set_irq(void *opaque, int vector, int level)
> >   static void ioapic_update_kvm_routes(IOAPICCommonState *s)
> >   {
> > -#ifdef CONFIG_KVM
> > +#ifdef ACCEL_GSI_IRQFD_POSSIBLE
> >       int i;
> > -    if (kvm_irqchip_is_split()) {
> > +    if (accel_irqchip_is_split()) {
> >           for (i = 0; i < IOAPIC_NUM_PINS; i++) {
> >               MSIMessage msg;
> >               struct ioapic_entry_info info;
> > @@ -202,15 +208,15 @@ static void ioapic_update_kvm_routes(IOAPICCommonState *s)
> >               if (!info.masked) {
> >                   msg.address = info.addr;
> >                   msg.data = info.data;
> > -                kvm_irqchip_update_msi_route(kvm_state, i, msg, NULL);
> > +                accel_irqchip_update_msi_route(i, msg, NULL);
> >               }
> >           }
> > -        kvm_irqchip_commit_routes(kvm_state);
> > +        accel_irqchip_commit_routes();
> >       }
> >   #endif
> >   }
> > -#ifdef CONFIG_KVM
> > +#ifdef ACCEL_KERNEL_GSI_IRQFD_POSSIBLE
> >   static void ioapic_iec_notifier(void *private, bool global,
> >                                   uint32_t index, uint32_t mask)
> >   {
> > @@ -428,11 +434,11 @@ static const MemoryRegionOps ioapic_io_ops = {
> >   static void ioapic_machine_done_notify(Notifier *notifier, void *data)
> >   {
> > -#ifdef CONFIG_KVM
> > +#ifdef ACCEL_KERNEL_GSI_IRQFD_POSSIBLE
> >       IOAPICCommonState *s = container_of(notifier, IOAPICCommonState,
> >                                           machine_done);
> > -    if (kvm_irqchip_is_split()) {
> > +    if (accel_irqchip_is_split()) {
> >           X86IOMMUState *iommu = x86_iommu_get_default();
> >           if (iommu) {
> >               /* Register this IOAPIC with IOMMU IEC notifier, so that
> > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> > index 767216d7959..0cdc16217ff 100644
> > --- a/hw/virtio/virtio-pci.c
> > +++ b/hw/virtio/virtio-pci.c
> > @@ -34,6 +34,7 @@
> >   #include "hw/pci/msi.h"
> >   #include "hw/pci/msix.h"
> >   #include "hw/loader.h"
> > +#include "system/accel-irq.h"
> >   #include "system/kvm.h"
> >   #include "hw/virtio/virtio-pci.h"
> >   #include "qemu/range.h"
> > @@ -825,11 +826,11 @@ static int kvm_virtio_pci_vq_vector_use(VirtIOPCIProxy *proxy,
> >       if (irqfd->users == 0) {
> >           KVMRouteChange c = kvm_irqchip_begin_route_changes(kvm_state);
> > -        ret = kvm_irqchip_add_msi_route(&c, vector, &proxy->pci_dev);
> > +        ret = accel_irqchip_add_msi_route(&c, vector, &proxy->pci_dev);
> >           if (ret < 0) {
> >               return ret;
> >           }
> > -        kvm_irqchip_commit_route_changes(&c);
> > +        accel_irqchip_commit_route_changes(&c);
> >           irqfd->virq = ret;
> >       }
> >       irqfd->users++;
> > @@ -841,7 +842,7 @@ static void kvm_virtio_pci_vq_vector_release(VirtIOPCIProxy *proxy,
> >   {
> >       VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
> >       if (--irqfd->users == 0) {
> > -        kvm_irqchip_release_virq(kvm_state, irqfd->virq);
> > +        accel_irqchip_release_virq(irqfd->virq);
> >       }
> >   }
> > @@ -850,7 +851,7 @@ static int kvm_virtio_pci_irqfd_use(VirtIOPCIProxy *proxy,
> >                                    unsigned int vector)
> >   {
> >       VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
> > -    return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL, irqfd->virq);
> > +    return accel_irqchip_add_irqfd_notifier_gsi(n, NULL, irqfd->virq);
> >   }
> >   static void kvm_virtio_pci_irqfd_release(VirtIOPCIProxy *proxy,
> > @@ -860,7 +861,7 @@ static void kvm_virtio_pci_irqfd_release(VirtIOPCIProxy *proxy,
> >       VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
> >       int ret;
> > -    ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n, irqfd->virq);
> > +    ret = accel_irqchip_remove_irqfd_notifier_gsi(n, irqfd->virq);
> >       assert(ret == 0);
> >   }
> >   static int virtio_pci_get_notifier(VirtIOPCIProxy *proxy, int queue_no,
> > @@ -995,12 +996,12 @@ static int virtio_pci_one_vector_unmask(VirtIOPCIProxy *proxy,
> >       if (proxy->vector_irqfd) {
> >           irqfd = &proxy->vector_irqfd[vector];
> >           if (irqfd->msg.data != msg.data || irqfd->msg.address != msg.address) {
> > -            ret = kvm_irqchip_update_msi_route(kvm_state, irqfd->virq, msg,
> > -                                               &proxy->pci_dev);
> > +            ret = accel_irqchip_update_msi_route(irqfd->virq, msg,
> > +                                                 &proxy->pci_dev);
> >               if (ret < 0) {
> >                   return ret;
> >               }
> > -            kvm_irqchip_commit_routes(kvm_state);
> > +            accel_irqchip_commit_routes();
> >           }
> >       }
> > @@ -1229,7 +1230,7 @@ static int virtio_pci_set_guest_notifiers(DeviceState *d, int nvqs, bool assign)
> >       VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
> >       int r, n;
> >       bool with_irqfd = msix_enabled(&proxy->pci_dev) &&
> > -        kvm_msi_via_irqfd_enabled();
> > +        accel_msi_via_irqfd_enabled() ;
> >       nvqs = MIN(nvqs, VIRTIO_QUEUE_MAX);
> > @@ -1433,7 +1434,7 @@ static void virtio_pci_set_vector(VirtIODevice *vdev,
> >                                     uint16_t new_vector)
> >   {
> >       bool kvm_irqfd = (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
> > -        msix_enabled(&proxy->pci_dev) && kvm_msi_via_irqfd_enabled();
> > +        msix_enabled(&proxy->pci_dev) && accel_msi_via_irqfd_enabled();
> >       if (new_vector == old_vector) {
> >           return;
> > diff --git a/accel/meson.build b/accel/meson.build
> > index 25b0f100b51..6349efe682f 100644
> > --- a/accel/meson.build
> > +++ b/accel/meson.build
> > @@ -1,6 +1,6 @@
> >   common_ss.add(files('accel-common.c'))
> >   specific_ss.add(files('accel-target.c'))
> > -system_ss.add(files('accel-system.c', 'accel-blocker.c', 'accel-qmp.c'))
> > +system_ss.add(files('accel-system.c', 'accel-blocker.c', 'accel-qmp.c', 'accel-irq.c'))
> >   user_ss.add(files('accel-user.c'))
> >   subdir('tcg')

Re: [PULL 10/35] hw/intc: Generalize APIC helper names from kvm_* to accel_*

Posted by Cédric Le Goater 1 week, 1 day ago

On 11/5/25 16:24, Magnus Kulke wrote:
> On Mon, Nov 03, 2025 at 10:43:36PM +0100, Cédric Le Goater wrote:
>> Hi,
>>
>> On 10/9/25 09:50, Paolo Bonzini wrote:
>>> From: Magnus Kulke <magnuskulke@linux.microsoft.com>
>>>
>>> Rename APIC helper functions to use an accel_* prefix instead of kvm_*
>>> to support use by accelerators other than KVM. This is a preparatory
>>> step for integrating MSHV support with common APIC logic.
>>>
>>> Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com>
>>> Link: https://lore.kernel.org/r/20250916164847.77883-5-magnuskulke@linux.microsoft.com
>>> [Remove dead definition of mshv_msi_via_irqfd_enabled. - Paolo]
>>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>>> ---
>>>    include/system/accel-irq.h |  37 +++++++++++++
>>>    include/system/mshv.h      |  17 ++++++
>>>    accel/accel-irq.c          | 106 +++++++++++++++++++++++++++++++++++++
>>>    hw/intc/ioapic.c           |  20 ++++---
>>>    hw/virtio/virtio-pci.c     |  21 ++++----
>>>    accel/meson.build          |   2 +-
>>>    6 files changed, 185 insertions(+), 18 deletions(-)
>>>    create mode 100644 include/system/accel-irq.h
>>>    create mode 100644 accel/accel-irq.c
>>
>> This change seems to introduce a regression with interrupt remapping
>> when running a VM configured with an intel-iommu device and an assigned
>> PCI VF. At boot, Linux complains with :
>>
> 
> Thank you for reporting, Cédric. From glancing over it, it looks like a
> typo: we check for `ACCEL_KERNEL_GSI_IRQFD_POSSIBLE` instead of
> `ACCEL_GSI_IRQFD_POSSIBLE` in ioapic.c. The former doesn't seem to be
> defined anywhere.
> 
> Can you verify if changing that fixes the issue for you?
> 
> s/ACCEL_KERNEL_GSI_IRQFD_POSSIBLE/ACCEL_GSI_IRQFD_POSSIBLE/g

Oh I should have spotted that. Kernel does not hang anymore and messages
are gone. Sending a patch.

Thanks,

C.