[Qemu-devel] [PATCH] spapr: fix migration to pseries machine < 2.8

[Qemu-devel] [PATCH] spapr: fix migration to pseries machine < 2.8

[Laurent Vivier]

since commit 5c4537bd ("spapr: Fix 2.7<->2.8 migration of PCI host bridge"),
some migration fields are forged from the new ones in spapr_pci_pre_save().

It works well, except when the number of MSI devices is 0,
because in this case the function exits immediately.

This fix moves the migration code before the exit code.

The problem can be reproduced with these commands:

source qemu-2.9:

    qemu-system-ppc64 -monitor stdio -M pseries-2.6 -nodefaults -S

destination qemu-2.6:

    qemu-system-ppc64 -monitor stdio -M pseries-2.6 -nodefaults \
                      -incoming tcp:0:4444

on the source:

    migrate tcp:localhost:4444

Destination fails with the following error:

    qemu-system-ppc64: error while loading state for
                       instance 0x0 of device 'spapr_pci'
    qemu-system-ppc64: load of migration failed: Invalid argument

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 hw/ppc/spapr_pci.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index 0b447f2..bd30b4f 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -1873,20 +1873,6 @@ static void spapr_pci_pre_save(void *opaque)
     gpointer key, value;
     int i;
 
-    g_free(sphb->msi_devs);
-    sphb->msi_devs = NULL;
-    sphb->msi_devs_num = g_hash_table_size(sphb->msi);
-    if (!sphb->msi_devs_num) {
-        return;
-    }
-    sphb->msi_devs = g_malloc(sphb->msi_devs_num * sizeof(spapr_pci_msi_mig));
-
-    g_hash_table_iter_init(&iter, sphb->msi);
-    for (i = 0; g_hash_table_iter_next(&iter, &key, &value); ++i) {
-        sphb->msi_devs[i].key = *(uint32_t *) key;
-        sphb->msi_devs[i].value = *(spapr_pci_msi *) value;
-    }
-
     if (sphb->pre_2_8_migration) {
         sphb->mig_liobn = sphb->dma_liobn[0];
         sphb->mig_mem_win_addr = sphb->mem_win_addr;
@@ -1900,6 +1886,20 @@ static void spapr_pci_pre_save(void *opaque)
             sphb->mig_mem_win_size += sphb->mem64_win_size;
         }
     }
+
+    g_free(sphb->msi_devs);
+    sphb->msi_devs = NULL;
+    sphb->msi_devs_num = g_hash_table_size(sphb->msi);
+    if (!sphb->msi_devs_num) {
+        return;
+    }
+    sphb->msi_devs = g_malloc(sphb->msi_devs_num * sizeof(spapr_pci_msi_mig));
+
+    g_hash_table_iter_init(&iter, sphb->msi);
+    for (i = 0; g_hash_table_iter_next(&iter, &key, &value); ++i) {
+        sphb->msi_devs[i].key = *(uint32_t *) key;
+        sphb->msi_devs[i].value = *(spapr_pci_msi *) value;
+    }
 }
 
 static int spapr_pci_post_load(void *opaque, int version_id)
-- 
2.9.4

Re: [Qemu-devel] [Qemu-ppc] [PATCH] spapr: fix migration to pseries machine < 2.8

[Greg Kurz]

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On Wed, 28 Jun 2017 16:09:19 +0200
Laurent Vivier <lvivier@redhat.com> wrote:

> since commit 5c4537bd ("spapr: Fix 2.7<->2.8 migration of PCI host bridge"),
> some migration fields are forged from the new ones in spapr_pci_pre_save().
> 
> It works well, except when the number of MSI devices is 0,
> because in this case the function exits immediately.
> 
> This fix moves the migration code before the exit code.
> 
> The problem can be reproduced with these commands:
> 
> source qemu-2.9:
> 
>     qemu-system-ppc64 -monitor stdio -M pseries-2.6 -nodefaults -S
> 
> destination qemu-2.6:
> 
>     qemu-system-ppc64 -monitor stdio -M pseries-2.6 -nodefaults \
>                       -incoming tcp:0:4444
> 
> on the source:
> 
>     migrate tcp:localhost:4444
> 
> Destination fails with the following error:
> 
>     qemu-system-ppc64: error while loading state for
>                        instance 0x0 of device 'spapr_pci'
>     qemu-system-ppc64: load of migration failed: Invalid argument
> 
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> ---

Maybe Cc: qemu-stable ?

Reviewed-by: Greg Kurz <groug@kaod.org>

>  hw/ppc/spapr_pci.c | 28 ++++++++++++++--------------
>  1 file changed, 14 insertions(+), 14 deletions(-)
> 
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 0b447f2..bd30b4f 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -1873,20 +1873,6 @@ static void spapr_pci_pre_save(void *opaque)
>      gpointer key, value;
>      int i;
>  
> -    g_free(sphb->msi_devs);
> -    sphb->msi_devs = NULL;
> -    sphb->msi_devs_num = g_hash_table_size(sphb->msi);
> -    if (!sphb->msi_devs_num) {
> -        return;
> -    }
> -    sphb->msi_devs = g_malloc(sphb->msi_devs_num * sizeof(spapr_pci_msi_mig));
> -
> -    g_hash_table_iter_init(&iter, sphb->msi);
> -    for (i = 0; g_hash_table_iter_next(&iter, &key, &value); ++i) {
> -        sphb->msi_devs[i].key = *(uint32_t *) key;
> -        sphb->msi_devs[i].value = *(spapr_pci_msi *) value;
> -    }
> -
>      if (sphb->pre_2_8_migration) {
>          sphb->mig_liobn = sphb->dma_liobn[0];
>          sphb->mig_mem_win_addr = sphb->mem_win_addr;
> @@ -1900,6 +1886,20 @@ static void spapr_pci_pre_save(void *opaque)
>              sphb->mig_mem_win_size += sphb->mem64_win_size;
>          }
>      }
> +
> +    g_free(sphb->msi_devs);
> +    sphb->msi_devs = NULL;
> +    sphb->msi_devs_num = g_hash_table_size(sphb->msi);
> +    if (!sphb->msi_devs_num) {
> +        return;
> +    }
> +    sphb->msi_devs = g_malloc(sphb->msi_devs_num * sizeof(spapr_pci_msi_mig));
> +
> +    g_hash_table_iter_init(&iter, sphb->msi);
> +    for (i = 0; g_hash_table_iter_next(&iter, &key, &value); ++i) {
> +        sphb->msi_devs[i].key = *(uint32_t *) key;
> +        sphb->msi_devs[i].value = *(spapr_pci_msi *) value;
> +    }
>  }
>  
>  static int spapr_pci_post_load(void *opaque, int version_id)


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Re: [Qemu-devel] [PATCH] spapr: fix migration to pseries machine < 2.8

[David Gibson]

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On Wed, Jun 28, 2017 at 04:09:19PM +0200, Laurent Vivier wrote:
1;4602;0c> since commit 5c4537bd ("spapr: Fix 2.7<->2.8 migration of PCI host bridge"),
> some migration fields are forged from the new ones in spapr_pci_pre_save().
> 
> It works well, except when the number of MSI devices is 0,
> because in this case the function exits immediately.
> 
> This fix moves the migration code before the exit code.
> 
> The problem can be reproduced with these commands:
> 
> source qemu-2.9:
> 
>     qemu-system-ppc64 -monitor stdio -M pseries-2.6 -nodefaults -S
> 
> destination qemu-2.6:
> 
>     qemu-system-ppc64 -monitor stdio -M pseries-2.6 -nodefaults \
>                       -incoming tcp:0:4444
> 
> on the source:
> 
>     migrate tcp:localhost:4444
> 
> Destination fails with the following error:
> 
>     qemu-system-ppc64: error while loading state for
>                        instance 0x0 of device 'spapr_pci'
>     qemu-system-ppc64: load of migration failed: Invalid argument
> 
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>

Applied to ppc-for-2.10.

> ---
>  hw/ppc/spapr_pci.c | 28 ++++++++++++++--------------
>  1 file changed, 14 insertions(+), 14 deletions(-)
> 
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 0b447f2..bd30b4f 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -1873,20 +1873,6 @@ static void spapr_pci_pre_save(void *opaque)
>      gpointer key, value;
>      int i;
>  
> -    g_free(sphb->msi_devs);
> -    sphb->msi_devs = NULL;
> -    sphb->msi_devs_num = g_hash_table_size(sphb->msi);
> -    if (!sphb->msi_devs_num) {
> -        return;
> -    }
> -    sphb->msi_devs = g_malloc(sphb->msi_devs_num * sizeof(spapr_pci_msi_mig));
> -
> -    g_hash_table_iter_init(&iter, sphb->msi);
> -    for (i = 0; g_hash_table_iter_next(&iter, &key, &value); ++i) {
> -        sphb->msi_devs[i].key = *(uint32_t *) key;
> -        sphb->msi_devs[i].value = *(spapr_pci_msi *) value;
> -    }
> -
>      if (sphb->pre_2_8_migration) {
>          sphb->mig_liobn = sphb->dma_liobn[0];
>          sphb->mig_mem_win_addr = sphb->mem_win_addr;
> @@ -1900,6 +1886,20 @@ static void spapr_pci_pre_save(void *opaque)
>              sphb->mig_mem_win_size += sphb->mem64_win_size;
>          }
>      }
> +
> +    g_free(sphb->msi_devs);
> +    sphb->msi_devs = NULL;
> +    sphb->msi_devs_num = g_hash_table_size(sphb->msi);
> +    if (!sphb->msi_devs_num) {
> +        return;
> +    }
> +    sphb->msi_devs = g_malloc(sphb->msi_devs_num * sizeof(spapr_pci_msi_mig));
> +
> +    g_hash_table_iter_init(&iter, sphb->msi);
> +    for (i = 0; g_hash_table_iter_next(&iter, &key, &value); ++i) {
> +        sphb->msi_devs[i].key = *(uint32_t *) key;
> +        sphb->msi_devs[i].value = *(spapr_pci_msi *) value;
> +    }
>  }
>  
>  static int spapr_pci_post_load(void *opaque, int version_id)

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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