Re: [PATCH v1 07/17] xen/riscv: introduce vCPU AIA initialization

On 8/13/26 11:47 AM, Jan Beulich wrote:
> On 13.08.2026 11:24, Baptiste Le Duc wrote:
>>> --- a/xen/arch/riscv/aia.c
>>> +++ b/xen/arch/riscv/aia.c
>>> @@ -14,6 +14,7 @@
>>>   #include <asm/cpufeature.h>
>>>   #include <asm/csr.h>
>>>   #include <asm/current.h>
>>> +#include <asm/imsic.h>
>>>   
>>>   struct vgein_ctrl {
>>>       unsigned long bmp;
>>> @@ -36,6 +37,35 @@ bool aia_usable(void)
>>>       return _aia_usable;
>>>   }
>>>   
>>> +void vcpu_aia_init(struct vcpu *v)
>>> +{
>>> +    unsigned int new_vsfile_id;
>>> +    int rc;
>>> +
>>> +    if ( !aia_usable() )
>>> +        return;
>>> +
>>> +    new_vsfile_id = vgein_assign(v);
>>> +
>>> +    /*
>>> +     * vgein_assign() returns 0 when no free h/w guest interrupt file is
>>> +     * available (including GEILEN == 0); imsic_map_guest_file() maps nothing
>>> +     * in that case.
>>> +     */
>>> +    rc = imsic_map_guest_file(v, new_vsfile_id);
>>> +    if ( rc )
>>> +    {
>>> +        /* Can't continue w/o correctly mapped IMSIC interrupt file */
>>> +        domain_crash(v->domain);
>>
>> The vgein id assigned a few lines up is not released here. The domain is dying
>> anyway, but the guest interrupt file stays marked in use on that pCPU forever,
>> since nothing else ever calls vgein_release(). A vgein_release(v,
>> new_vsfile_id) before the domain_crash() would fix it.
> 
> Instead of (or in addition to) doing that here, wouldn't releasing better be part
> of the normal cleanup path? Whether "instead of" or "in addition to" depends on
> the implications of deferring the release. But to guarantee no leak, domain
> cleanup will want to either do the release, or have an explicit check that is was
> done.

I think vgein_release() should be here, as when the IMSIC software 
interrupt file is supported, it will mean that domain_crash() can 
generally be dropped (there is no need to call imsic_map_guest_file() 
for s/w IMSIC interrupt file) and the vCPU can use the software 
interrupt file instead of killing the domain.

~ Oleksii