msix: fixes for 1.0

Only go over the table when function is masked. This is not really important for qemu.git but helps fix a bug in qemu-kvm.git.

Signed-off-by Michael S. Tsirkin <[email protected]>

---
 hw/msix.c |   21 ++++++++++++++-------
 hw/pci.h  |    2 ++

 2 files changed, 16 insertions(+), 7 deletions(-)

hw/msix.c +0 -0

index b15bafc..63b41b9 100644
@@ -79,6 +79,7 @@ static int msix_add_config(struct PCIDevice *pdev, unsigned short nentries,
     /* Make flags bit writable. */

    pdev->wmask[config_offset + MSIX_CONTROL_OFFSET] |= MSIX_ENABLE_MASK | MSIX_MASKALL_MASK;
+    pdev->msix_function_masked = true;
    return 0;

 }

hw/msix.c +0 -5

@@ -117,16 +118,11 @@ static void msix_clr_pending(PCIDevice *dev, int vector)
     *msix_pending_byte(dev, vector) &= ~msix_pending_mask(vector);
  }
 
-static int msix_function_masked(PCIDevice *dev)
-{
-    return dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] & MSIX_MASKALL_MASK;
-}
-
  static int msix_is_masked(PCIDevice *dev, int vector)
  {

    unsigned offset =
        vector * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL;

-    return msix_function_masked(dev) ||
+    return dev->msix_function_masked ||

          dev->msix_table_page[offset] & PCI_MSIX_ENTRY_CTRL_MASKBIT; }

hw/msix.c +10 -0

@@ -138,24 +134,34 @@ static void msix_handle_mask_update(PCIDevice *dev, int vector)
     }
  }
 
+static void msix_update_function_masked(PCIDevice *dev)
+{
+    dev->msix_function_masked = !msix_enabled(dev) ||
+        (dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] & MSIX_MASKALL_MASK);
+}
+
  /* Handle MSI-X capability config write. */
  void msix_write_config(PCIDevice *dev, uint32_t addr,
                        uint32_t val, int len)
  {
     unsigned enable_pos = dev->msix_cap + MSIX_CONTROL_OFFSET;
     int vector;
+    bool was_masked;
 
     if (!range_covers_byte(addr, len, enable_pos)) {
         return;
     }
 
+    was_masked = dev->msix_function_masked;
+    msix_update_function_masked(dev);
+

hw/msix.c +1 -0

@@ -300,6 +306,7 @@ void msix_load(PCIDevice *dev, QEMUFile *f)
     msix_free_irq_entries(dev);
     qemu_get_buffer(f, dev->msix_table_page, n * PCI_MSIX_ENTRY_SIZE);
     qemu_get_buffer(f, dev->msix_table_page + MSIX_PAGE_PENDING, (n + 7) / 8);
+    msix_update_function_masked(dev);
  }
 
  /* Does device support MSI-X? */

hw/pci.h +2 -1

index 4b2e785..625e717 100644
@@ -178,6 +178,8 @@ struct PCIDevice {
     unsigned *msix_entry_used;
     /* Region including the MSI-X table */
     uint32_t msix_bar_size;
+    /* MSIX function mask set or MSIX disabled */
+    bool msix_function_masked;
     /* Version id needed for VMState */
     int32_t version_id;
 
--

1.7.5.53.gc233e

So I believe my bug is due to the fact the new logic included in this patch requires msix_write_config() to be called to unmask the vectors.
Virtio-pci calls msix_write_config(), but ivshmem does not (nor does
PCIe so I'm not sure if it's also affected).

Based on a git bisect, this patch breaks msi-x interrupt delivery in the ivshmem device.

Quoted 10 lines · Michael S. Tsirkin

Only go over the table when function is masked. This is not really important for qemu.git but helps fix a bug in qemu-kvm.git.

Signed-off-by Michael S. Tsirkin <[email protected]>

---
 hw/msix.c |   21 ++++++++++++++-------
 hw/pci.h  |    2 ++

 2 files changed, 16 insertions(+), 7 deletions(-)

Quoted 10 lines

hw/msix.c +0 -0

index b15bafc..63b41b9 100644
@@ -79,6 +79,7 @@ static int msix_add_config(struct PCIDevice *pdev, unsigned short nentries,
     /* Make flags bit writable. */

    pdev->wmask[config_offset + MSIX_CONTROL_OFFSET] |= MSIX_ENABLE_MASK | MSIX_MASKALL_MASK;
+    pdev->msix_function_masked = true;
    return 0;

iiuc, this masks the msix by default.

Quoted 51 lines

 }

hw/msix.c +0 -5

@@ -117,16 +118,11 @@ static void msix_clr_pending(PCIDevice *dev, int vector)
     *msix_pending_byte(dev, vector) &= ~msix_pending_mask(vector);
  }
 
-static int msix_function_masked(PCIDevice *dev)
-{
-    return dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] & MSIX_MASKALL_MASK;
-}
-
  static int msix_is_masked(PCIDevice *dev, int vector)
  {

    unsigned offset =
        vector * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL;

-    return msix_function_masked(dev) ||
+    return dev->msix_function_masked ||

          dev->msix_table_page[offset] & PCI_MSIX_ENTRY_CTRL_MASKBIT; }

hw/msix.c +10 -0

@@ -138,24 +134,34 @@ static void msix_handle_mask_update(PCIDevice *dev, int vector)
     }
  }
 
+static void msix_update_function_masked(PCIDevice *dev)
+{
+    dev->msix_function_masked = !msix_enabled(dev) ||
+        (dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] & MSIX_MASKALL_MASK);
+}
+
  /* Handle MSI-X capability config write. */
  void msix_write_config(PCIDevice *dev, uint32_t addr,
                        uint32_t val, int len)
  {
     unsigned enable_pos = dev->msix_cap + MSIX_CONTROL_OFFSET;
     int vector;
+    bool was_masked;
 
     if (!range_covers_byte(addr, len, enable_pos)) {
         return;
     }
 
+    was_masked = dev->msix_function_masked;
+    msix_update_function_masked(dev);
+
     if (!msix_enabled(dev)) {
         return;
     }
 
     pci_device_deassert_intx(dev);
 

hw/msix.c static void msix_handle_mask_update(PCIDevice *dev, int vector) · line 166

Quoted 4 lines

hw/msix.c +1 -1

-    if (msix_function_masked(dev)) {
+    if (dev->msix_function_masked == was_masked) {
         return;
     }

So I believe my bug is due to the fact the new logic included in this patch requires msix_write_config() to be called to unmask the vectors.

Virtio-pci calls msix_write_config(), but ivshmem does not (nor does
PCIe so I'm not sure if it's also affected).

I haven't been able to fix the bug yet, but I wanted to make sure I was looking in the correct place. Any help of further explanation of this patch would be greatly appreciated.

Sincerely,
Cam

Quoted 26 lines

hw/msix.c +1 -0

@@ -300,6 +306,7 @@ void msix_load(PCIDevice *dev, QEMUFile *f)
     msix_free_irq_entries(dev);
     qemu_get_buffer(f, dev->msix_table_page, n * PCI_MSIX_ENTRY_SIZE);
     qemu_get_buffer(f, dev->msix_table_page + MSIX_PAGE_PENDING, (n + 7) / 8);
+    msix_update_function_masked(dev);
  }
 
  /* Does device support MSI-X? */

hw/pci.h +2 -1

index 4b2e785..625e717 100644
@@ -178,6 +178,8 @@ struct PCIDevice {
     unsigned *msix_entry_used;
     /* Region including the MSI-X table */
     uint32_t msix_bar_size;
+    /* MSIX function mask set or MSIX disabled */
+    bool msix_function_masked;
     /* Version id needed for VMState */
     int32_t version_id;
 
--

1.7.5.53.gc233e

Based on a git bisect, this patch breaks msi-x interrupt delivery in the ivshmem device.

Quoted 2 lines · Cam Macdonell

Based on a git bisect, this patch breaks msi-x interrupt delivery in the ivshmem device.

I think the following should fix it. Compiled-only - could you pls check? If yes let's apply to the stable branch.

-->

ivshmem: add missing msix calls

ivshmem used msix but didn't call it on either reset or config write paths. This used to partically work since guests don't use all of msi-x configuration fields,
and reset is rarely used, but the patch 'msix: track function masked in pci device state' broke that. Fix by adding appropriate calls.

Signed-off-by Michael S. Tsirkin <[email protected]>

--

hw/ivshmem.c +8 -0

index 242fbea..3680c0f 100644
@@ -505,6 +505,7 @@ static void ivshmem_reset(DeviceState *d)
     IVShmemState *s = DO_UPCAST(IVShmemState, dev.qdev, d);
 
     s->intrstatus = 0;
+    msix_reset(&s->dev);
     return;
 }
 

@@ -610,6 +611,13 @@ static int ivshmem_load(QEMUFile* f, void *opaque, int version_id)
     return 0;
 }
 
+static void ivshmem_write_config(PCIDevice *pci_dev, uint32_t address,
+				 uint32_t val, int len)
+{
+    pci_default_write_config(pci_dev, address, val, len);
+    msix_write_config(pci_dev, address, val, len);
+}
+
 static int pci_ivshmem_init(PCIDevice *dev)
 {
     IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);

Quoted 50 lines · Michael S. Tsirkin

Quoted 2 lines · Cam Macdonell

Based on a git bisect, this patch breaks msi-x interrupt delivery in the ivshmem device.

I think the following should fix it. Compiled-only - could you pls check? If yes let's apply to the stable branch.

-->

ivshmem: add missing msix calls

ivshmem used msix but didn't call it on either reset or config write paths. This used to partically work since guests don't use all of msi-x configuration fields,
and reset is rarely used, but the patch 'msix: track function masked in pci device state' broke that. Fix by adding appropriate calls.

Signed-off-by Michael S. Tsirkin <[email protected]>

--

hw/ivshmem.c +8 -0

index 242fbea..3680c0f 100644
@@ -505,6 +505,7 @@ static void ivshmem_reset(DeviceState *d)
     IVShmemState *s = DO_UPCAST(IVShmemState, dev.qdev, d);
 
     s->intrstatus = 0;
+    msix_reset(&s->dev);
     return;
 }
 

@@ -610,6 +611,13 @@ static int ivshmem_load(QEMUFile* f, void *opaque, int version_id)
     return 0;
 }
 
+static void ivshmem_write_config(PCIDevice *pci_dev, uint32_t address,
+				 uint32_t val, int len)
+{
+    pci_default_write_config(pci_dev, address, val, len);
+    msix_write_config(pci_dev, address, val, len);
+}
+
 static int pci_ivshmem_init(PCIDevice *dev)
 {
     IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);

hw/ivshmem.c static int pci_ivshmem_init(PCIDevice *dev) · line 749

Quoted 8 lines

hw/ivshmem.c +2 -0

@@ -734,6 +742,8 @@ static int pci_ivshmem_init(PCIDevice *dev)
 
     }
 
+    s->dev.config_write = ivshmem_write_config;
+
     return 0;
 }
 

But please fix this for real and merge [1]&[2] (with depending patches) into master. The above is just boilerplate code from device POV.

Jan

[1] http://thread.gmane.org/gmane.comp.emulators.kvm.devel/80240
[2] http://thread.gmane.org/gmane.comp.emulators.kvm.devel/80244

Quoted 2 lines · Cam Macdonell

Based on a git bisect, this patch breaks msi-x interrupt delivery in the ivshmem device.

I think the following should fix it. Compiled-only - could you pls check? If yes let's apply to the stable branch.

-->

ivshmem: add missing msix calls

ivshmem used msix but didn't call it on either reset or config write paths. This used to partically work since guests don't use all of msi-x configuration fields,
and reset is rarely used, but the patch 'msix: track function masked in pci device state' broke that. Fix by adding appropriate calls.

Signed-off-by Michael S. Tsirkin <[email protected]>

--

hw/ivshmem.c +10 -0

index 242fbea..3680c0f 100644
@@ -505,6 +505,7 @@ static void ivshmem_reset(DeviceState *d)
     IVShmemState *s = DO_UPCAST(IVShmemState, dev.qdev, d);
 
     s->intrstatus = 0;
+    msix_reset(&s->dev);
     return;
  }
 

@@ -610,6 +611,13 @@ static int ivshmem_load(QEMUFile* f, void *opaque, int version_id)
     return 0;
  }
 
+static void ivshmem_write_config(PCIDevice *pci_dev, uint32_t address,
+                                uint32_t val, int len)
+{
+    pci_default_write_config(pci_dev, address, val, len);
+    msix_write_config(pci_dev, address, val, len);
+}
+
  static int pci_ivshmem_init(PCIDevice *dev)
  {
     IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);

@@ -734,6 +742,8 @@ static int pci_ivshmem_init(PCIDevice *dev)
 
     }
 
+    s->dev.config_write = ivshmem_write_config;
+
     return 0;
  }
 

Quoted 6 lines · Michael S. Tsirkin

Quoted 2 lines · Cam Macdonell

Based on a git bisect, this patch breaks msi-x interrupt delivery in the ivshmem device.

I think the following should fix it. Compiled-only - could you pls check? If yes let's apply to the stable branch.

Thanks for the patch Michael.

It addresses the need for msix_write_config() to be called, but the addition of the msix_reset() is causing a reset of the vectors after they've been initialized in pci_ivshmem_init(). So, interrupts still aren't delivered with this patch applied as it is.

In particular, a reset occurs after pci_ivshmem_init runs, so the msix_entry_used array is reset to 0s, which causes the interrupt delivery to fail.

If I comment out the msix_reset(), then interrupts are delivered. Would the reset be caused by a bug in the guest driver? or do I need to reconfigure the msix after reset? I'm unclear as to the proper behaviour after a reset.

Thanks,
Cam

Quoted 24 lines · Cam Macdonell

Quoted 6 lines · Michael S. Tsirkin

Quoted 2 lines · Cam Macdonell

Based on a git bisect, this patch breaks msi-x interrupt delivery in the ivshmem device.

I think the following should fix it. Compiled-only - could you pls check? If yes let's apply to the stable branch.

Thanks for the patch Michael.

It addresses the need for msix_write_config() to be called, but the addition of the msix_reset() is causing a reset of the vectors after they've been initialized in pci_ivshmem_init().  So, interrupts still aren't delivered with this patch applied as it is.

In particular, a reset occurs after pci_ivshmem_init runs, so the msix_entry_used array is reset to 0s, which causes the interrupt delivery to fail.

If I comment out the msix_reset(), then interrupts are delivered. Would the reset be caused by a bug in the guest driver?  or do I need to reconfigure the msix after reset?  I'm unclear as to the proper behaviour after a reset.

Quoted 3 lines

Thanks,
Cam

I didn't anticipate this, virtio only configures vectors when msi-x is enabled. For 1.0 it's safest to do the same and just re-enable after reset.

So we'll end up with something like the following - does it help?

Side note: exit(1) is not the best way to handle
errors in the init function. I think you should add error_report, then goto err on failures to init, cleanup what you have set up meanwhile and return an error code.

hw/ivshmem.c +31 -11

index 242fbea..c58f4d3 100644
@@ -500,11 +500,29 @@ static void ivshmem_read(void *opaque, const uint8_t * buf, int flags)
     return;
  }
 
+/* Select the MSI-X vectors used by device.
+ * ivshmem maps events to vectors statically, so
+ * we just enable all vectors on init and after reset. */
+static void ivshmem_use_msix(IVShmemState * s)
+{
+    int i;
+
+    if (!msix_present(&s->dev)) {
+        return;
+    }
+
+    for (i = 0; i < s->vectors; i++) {
+        msix_vector_use(&s->dev, i);
+    }
+}
+
  static void ivshmem_reset(DeviceState *d)
  {
     IVShmemState *s = DO_UPCAST(IVShmemState, dev.qdev, d);
 
     s->intrstatus = 0;
+    msix_reset(&s->dev);
+    ivshmem_use_msix(s);
     return;
  }
 

@@ -535,12 +553,8 @@ static uint64_t ivshmem_get_size(IVShmemState * s) {
     return value;
  }
 
-static void ivshmem_setup_msi(IVShmemState * s) {
-
-    int i;
-
-    /* allocate the MSI-X vectors */
-
+static void ivshmem_setup_msi(IVShmemState * s)
+{
     memory_region_init(&s->msix_bar, "ivshmem-msix", 4096);
     if (!msix_init(&s->dev, s->vectors, &s->msix_bar, 1, 0)) {
         pci_register_bar(&s->dev, 1, PCI_BASE_ADDRESS_SPACE_MEMORY,

@@ -551,13 +565,10 @@ static void ivshmem_setup_msi(IVShmemState * s) {
         exit(1);
     }
 
-    /* 'activate' the vectors */
-    for (i = 0; i < s->vectors; i++) {
-        msix_vector_use(&s->dev, i);
-    }
-
     /* allocate Qemu char devices for receiving interrupts */
     s->eventfd_table = g_malloc0(s->vectors * sizeof(EventfdEntry));
+
+    ivshmem_use_msix(s);
  }
 
  static void ivshmem_save(QEMUFile* f, void *opaque)

@@ -610,6 +621,13 @@ static int ivshmem_load(QEMUFile* f, void *opaque, int version_id)
     return 0;
  }
 
+static void ivshmem_write_config(PCIDevice *pci_dev, uint32_t address,
+                                uint32_t val, int len)
+{
+    pci_default_write_config(pci_dev, address, val, len);
+    msix_write_config(pci_dev, address, val, len);
+}
+
  static int pci_ivshmem_init(PCIDevice *dev)
  {
     IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);

@@ -734,6 +752,8 @@ static int pci_ivshmem_init(PCIDevice *dev)
 
     }
 
+    s->dev.config_write = ivshmem_write_config;
+
     return 0;
  }
 

ivshmem used msix but didn't call it on either reset or config write paths. This used to partically work since guests don't use all of msi-x configuration fields,
and reset is rarely used, but the patch 'msix: track function masked in pci device state' broke that. Fix by adding appropriate calls.

Signed-off-by Michael S. Tsirkin <[email protected]>

Reported-by Cam Macdonell <[email protected]>

Tested-by Cam Macdonell <[email protected]>

---

Please apply the following to both master
and 1.0 stable branch. Thanks!

hw/ivshmem.c +31 -11

index 242fbea..c58f4d3 100644
@@ -500,11 +500,29 @@ static void ivshmem_read(void *opaque, const uint8_t * buf, int flags)
     return;
  }
 
+/* Select the MSI-X vectors used by device.
+ * ivshmem maps events to vectors statically, so
+ * we just enable all vectors on init and after reset. */
+static void ivshmem_use_msix(IVShmemState * s)
+{
+    int i;
+
+    if (!msix_present(&s->dev)) {
+        return;
+    }
+
+    for (i = 0; i < s->vectors; i++) {
+        msix_vector_use(&s->dev, i);
+    }
+}
+
  static void ivshmem_reset(DeviceState *d)
  {
     IVShmemState *s = DO_UPCAST(IVShmemState, dev.qdev, d);
 
     s->intrstatus = 0;
+    msix_reset(&s->dev);
+    ivshmem_use_msix(s);
     return;
  }
 

@@ -535,12 +553,8 @@ static uint64_t ivshmem_get_size(IVShmemState * s) {
     return value;
  }
 
-static void ivshmem_setup_msi(IVShmemState * s) {
-
-    int i;
-
-    /* allocate the MSI-X vectors */
-
+static void ivshmem_setup_msi(IVShmemState * s)
+{
     memory_region_init(&s->msix_bar, "ivshmem-msix", 4096);
     if (!msix_init(&s->dev, s->vectors, &s->msix_bar, 1, 0)) {
         pci_register_bar(&s->dev, 1, PCI_BASE_ADDRESS_SPACE_MEMORY,

@@ -551,13 +565,10 @@ static void ivshmem_setup_msi(IVShmemState * s) {
         exit(1);
     }
 
-    /* 'activate' the vectors */
-    for (i = 0; i < s->vectors; i++) {
-        msix_vector_use(&s->dev, i);
-    }
-
     /* allocate Qemu char devices for receiving interrupts */
     s->eventfd_table = g_malloc0(s->vectors * sizeof(EventfdEntry));
+
+    ivshmem_use_msix(s);
  }
 
  static void ivshmem_save(QEMUFile* f, void *opaque)

@@ -610,6 +621,13 @@ static int ivshmem_load(QEMUFile* f, void *opaque, int version_id)
     return 0;
  }
 
+static void ivshmem_write_config(PCIDevice *pci_dev, uint32_t address,
+                                uint32_t val, int len)
+{
+    pci_default_write_config(pci_dev, address, val, len);
+    msix_write_config(pci_dev, address, val, len);
+}
+
  static int pci_ivshmem_init(PCIDevice *dev)
  {
     IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);

@@ -734,6 +752,8 @@ static int pci_ivshmem_init(PCIDevice *dev)
 
     }
 
+    s->dev.config_write = ivshmem_write_config;
+
     return 0;
  }
 

Can this patch be merged, please?

Quoted 103 lines

ivshmem used msix but didn't call it on either reset or config write paths. This used to partically work since guests don't use all of msi-x configuration fields,
and reset is rarely used, but the patch 'msix: track function masked in pci device state' broke that. Fix by adding appropriate calls.

Signed-off-by Michael S. Tsirkin <[email protected]>

Reported-by Cam Macdonell <[email protected]>

Tested-by Cam Macdonell <[email protected]>

---

Please apply the following to both master
and 1.0 stable branch. Thanks!

hw/ivshmem.c +31 -11

index 242fbea..c58f4d3 100644
@@ -500,11 +500,29 @@ static void ivshmem_read(void *opaque, const uint8_t * buf, int flags)
    return;
 }
 
+/* Select the MSI-X vectors used by device.
+ * ivshmem maps events to vectors statically, so
+ * we just enable all vectors on init and after reset. */
+static void ivshmem_use_msix(IVShmemState * s)
+{
+    int i;
+
+    if (!msix_present(&s->dev)) {
+        return;
+    }
+
+    for (i = 0; i < s->vectors; i++) {
+        msix_vector_use(&s->dev, i);
+    }
+}
+
 static void ivshmem_reset(DeviceState *d)
 {
    IVShmemState *s = DO_UPCAST(IVShmemState, dev.qdev, d);
 
    s->intrstatus = 0;
+    msix_reset(&s->dev);
+    ivshmem_use_msix(s);
    return;
 }
 

@@ -535,12 +553,8 @@ static uint64_t ivshmem_get_size(IVShmemState * s) {
    return value;
 }
 
-static void ivshmem_setup_msi(IVShmemState * s) {
-
-    int i;
-
-    /* allocate the MSI-X vectors */
-
+static void ivshmem_setup_msi(IVShmemState * s)
+{
    memory_region_init(&s->msix_bar, "ivshmem-msix", 4096);
    if (!msix_init(&s->dev, s->vectors, &s->msix_bar, 1, 0)) {
        pci_register_bar(&s->dev, 1, PCI_BASE_ADDRESS_SPACE_MEMORY,

@@ -551,13 +565,10 @@ static void ivshmem_setup_msi(IVShmemState * s) {
        exit(1);
    }
 
-    /* 'activate' the vectors */
-    for (i = 0; i < s->vectors; i++) {
-        msix_vector_use(&s->dev, i);
-    }
-
    /* allocate Qemu char devices for receiving interrupts */
    s->eventfd_table = g_malloc0(s->vectors * sizeof(EventfdEntry));
+
+    ivshmem_use_msix(s);
 }
 
 static void ivshmem_save(QEMUFile* f, void *opaque)

@@ -610,6 +621,13 @@ static int ivshmem_load(QEMUFile* f, void *opaque, int version_id)
    return 0;
 }
 
+static void ivshmem_write_config(PCIDevice *pci_dev, uint32_t address,
+                                uint32_t val, int len)
+{
+    pci_default_write_config(pci_dev, address, val, len);
+    msix_write_config(pci_dev, address, val, len);
+}
+
 static int pci_ivshmem_init(PCIDevice *dev)
 {
    IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);

@@ -734,6 +752,8 @@ static int pci_ivshmem_init(PCIDevice *dev)
 
    }
 
+    s->dev.config_write = ivshmem_write_config;
+
    return 0;
 }
 

From: Jan Kiszka <[email protected]>

This fixes bugs dealing with msi-x mask bits pointed out by Jan Kiszka.

Jan Kiszka (1):
msix: Prevent bogus mask updates on MMIO accesses

Michael S. Tsirkin (2):
msix: track function masked in pci device state
msix: avoid mask updates if mask is unchanged

  hw/msix.c |   48 ++++++++++++++++++++++++++++++++++++------------
  hw/pci.h  |    2 ++
  2 files changed, 38 insertions(+), 12 deletions(-)