Re: [PATCH v3 2/9] igvm: track memory regions

> On 31 Jul 2026, at 3:28 PM, Alexander Graf <[email protected]> wrote:
> 
> 
> On 30.07.26 09:12, Ani Sinha wrote:
>> From: Gerd Hoffmann <[email protected]>
>> 
>> Memory regions added by the current IGVM needs to be tracked so that they can be
>> freed when a new IGVM is loaded.
>> 
>> Reviewed-by: Ani Sinha <[email protected]>
>> Signed-off-by: Gerd Hoffmann <[email protected]>
>> ---
>>  backends/igvm-cfg.c            |  1 +
>>  backends/igvm.c                | 20 ++++++++++++--------
>>  include/system/igvm-internal.h |  6 ++++++
>>  3 files changed, 19 insertions(+), 8 deletions(-)
>> 
>> diff --git a/backends/igvm-cfg.c b/backends/igvm-cfg.c
>> index e1f09855f6..38438a7b1e 100644
>> --- a/backends/igvm-cfg.c
>> +++ b/backends/igvm-cfg.c
>> @@ -65,6 +65,7 @@ static void igvm_complete(UserCreatable *uc, Error **errp)
>>      IgvmCfg *igvm = IGVM_CFG(uc);
>>        igvm->file = qigvm_file_init(igvm->filename, errp);
>> +    QTAILQ_INIT(&igvm->memory_regions);
>>  }
>>    OBJECT_DEFINE_TYPE_WITH_INTERFACES(IgvmCfg, igvm_cfg, IGVM_CFG, OBJECT,
>> diff --git a/backends/igvm.c b/backends/igvm.c
>> index 534032fed8..9e7c90d386 100644
>> --- a/backends/igvm.c
>> +++ b/backends/igvm.c
>> @@ -220,7 +220,7 @@ static void *qigvm_prepare_memory(QIgvm *ctx, uint64_t addr, uint64_t size,
>>                                    int region_identifier, Error **errp)
>>  {
>>      ERRP_GUARD();
>> -    MemoryRegion *igvm_pages = NULL;
>> +    IgvmMemoryRegion *imr = NULL;
>>      Int128 gpa_region_size;
>>      MemoryRegionSection mrs =
>>          memory_region_find(get_system_memory(), addr, size);
>> @@ -254,23 +254,27 @@ static void *qigvm_prepare_memory(QIgvm *ctx, uint64_t addr, uint64_t size,
>>           */
>>          g_autofree char *region_name =
>>              g_strdup_printf("igvm.%X", region_identifier);
>> -        igvm_pages = g_new0(MemoryRegion, 1);
>> +        imr = g_new0(IgvmMemoryRegion, 1);
>> +        imr->mr = g_new0(MemoryRegion, 1);
>>          if (ctx->machine_state->cgs &&
>>              ctx->machine_state->cgs->require_guest_memfd) {
>> -            if (!memory_region_init_ram_guest_memfd(igvm_pages, NULL,
>> +            if (!memory_region_init_ram_guest_memfd(imr->mr, NULL,
> 
> 
> Please make sure to track them with owner set to OBJECT(ctx->machine_state).

This will not work as the owner will have to be of TYPE_DEVICE not of TYPE_MACHINE.

> Without owner, reference counting is disabled and we end up leaking memory regions on cleanup you introduce in patch 3 later.
> 
> 
> Alex