memory: address_space_to_flatview needs RCU lock

[Qemu-devel] [PATCH 1/7] openpic_kvm: drop address_space_to_flatview call

Posted by Paolo Bonzini 7 years, 11 months ago

The MemoryListener is registered on address_space_memory, there is
not much to assert.  This currently works because the callback
is invoked only once when the listener is registered, but section->fv
is the _new_ FlatView, not the old one on later calls and that
would break.

This confines address_space_to_flatview to exec.c and memory.c.

Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/intc/openpic_kvm.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/hw/intc/openpic_kvm.c b/hw/intc/openpic_kvm.c
index fa83420254..39a6f369c5 100644
--- a/hw/intc/openpic_kvm.c
+++ b/hw/intc/openpic_kvm.c
@@ -124,10 +124,6 @@ static void kvm_openpic_region_add(MemoryListener *listener,
     uint64_t reg_base;
     int ret;
 
-    if (section->fv != address_space_to_flatview(&address_space_memory)) {
-        abort();
-    }
-
     /* Ignore events on regions that are not us */
     if (section->mr != &opp->mem) {
         return;
-- 
2.14.3

Re: [Qemu-devel] [PATCH 1/7] openpic_kvm: drop address_space_to_flatview call

Posted by David Gibson 7 years, 11 months ago

On Mon, Mar 05, 2018 at 09:36:49AM +0100, Paolo Bonzini wrote:
> The MemoryListener is registered on address_space_memory, there is
> not much to assert.  This currently works because the callback
> is invoked only once when the listener is registered, but section->fv
> is the _new_ FlatView, not the old one on later calls and that
> would break.
> 
> This confines address_space_to_flatview to exec.c and memory.c.
> 
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Acked-by: David Gibson <david@gibson.dropbear.id.au>

Do you want me to take this through my tree?


> ---
>  hw/intc/openpic_kvm.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/hw/intc/openpic_kvm.c b/hw/intc/openpic_kvm.c
> index fa83420254..39a6f369c5 100644
> --- a/hw/intc/openpic_kvm.c
> +++ b/hw/intc/openpic_kvm.c
> @@ -124,10 +124,6 @@ static void kvm_openpic_region_add(MemoryListener *listener,
>      uint64_t reg_base;
>      int ret;
>  
> -    if (section->fv != address_space_to_flatview(&address_space_memory)) {
> -        abort();
> -    }
> -
>      /* Ignore events on regions that are not us */
>      if (section->mr != &opp->mem) {
>          return;

-- 
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

Re: [Qemu-devel] [PATCH 1/7] openpic_kvm: drop address_space_to_flatview call

Posted by Paolo Bonzini 7 years, 11 months ago

On 06/03/2018 01:10, David Gibson wrote:
> On Mon, Mar 05, 2018 at 09:36:49AM +0100, Paolo Bonzini wrote:
>> The MemoryListener is registered on address_space_memory, there is
>> not much to assert.  This currently works because the callback
>> is invoked only once when the listener is registered, but section->fv
>> is the _new_ FlatView, not the old one on later calls and that
>> would break.
>>
>> This confines address_space_to_flatview to exec.c and memory.c.
>>
>> Cc: qemu-stable@nongnu.org
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> 
> Acked-by: David Gibson <david@gibson.dropbear.id.au>
> 
> Do you want me to take this through my tree?

No need since Alexey has already reviewed the rest.  Thanks!

Paolo

> 
> 
>> ---
>>  hw/intc/openpic_kvm.c | 4 ----
>>  1 file changed, 4 deletions(-)
>>
>> diff --git a/hw/intc/openpic_kvm.c b/hw/intc/openpic_kvm.c
>> index fa83420254..39a6f369c5 100644
>> --- a/hw/intc/openpic_kvm.c
>> +++ b/hw/intc/openpic_kvm.c
>> @@ -124,10 +124,6 @@ static void kvm_openpic_region_add(MemoryListener *listener,
>>      uint64_t reg_base;
>>      int ret;
>>  
>> -    if (section->fv != address_space_to_flatview(&address_space_memory)) {
>> -        abort();
>> -    }
>> -
>>      /* Ignore events on regions that are not us */
>>      if (section->mr != &opp->mem) {
>>          return;
>

Re: [Qemu-devel] [PATCH 1/7] openpic_kvm: drop address_space_to_flatview call

Posted by Alexey Kardashevskiy 7 years, 11 months ago

On 05/03/18 19:36, Paolo Bonzini wrote:
> The MemoryListener is registered on address_space_memory, there is
> not much to assert.  This currently works because the callback
> is invoked only once when the listener is registered, but section->fv
> is the _new_ FlatView, not the old one on later calls and that
> would break.
> 
> This confines address_space_to_flatview to exec.c and memory.c.
> 
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>

> ---
>  hw/intc/openpic_kvm.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/hw/intc/openpic_kvm.c b/hw/intc/openpic_kvm.c
> index fa83420254..39a6f369c5 100644
> --- a/hw/intc/openpic_kvm.c
> +++ b/hw/intc/openpic_kvm.c
> @@ -124,10 +124,6 @@ static void kvm_openpic_region_add(MemoryListener *listener,
>      uint64_t reg_base;
>      int ret;
>  
> -    if (section->fv != address_space_to_flatview(&address_space_memory)) {
> -        abort();
> -    }
> -
>      /* Ignore events on regions that are not us */
>      if (section->mr != &opp->mem) {
>          return;
> 


-- 
Alexey