Re: [PATCH v2 39/39] xen/riscv: introduce IMSIC h/w interrupt file attaching to vcpu

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

On 9/21/26 2:32 PM, Jan Beulich wrote:
> On 27.08.2026 17:21, Oleksii Kurochko wrote:
> > Introduce imsic_vsfile_attach() to initialize the AIA-related state needed
> > for a vCPU to have a working guest interrupt file.
> >
> > A guest (VS) interrupt file must be mapped to one of a pCPU's
> > hardware interrupt files (if they exist), so the pCPU a vCPU will actually
> > run on needs to be known first. arch_vcpu_create() is therefore not a
> > suitable place to call vcpu_aia_init(), since the pCPU assigned to a
> > vCPU can still change before it is first scheduled. To avoid
> > reassigning the VS interrupt file id and remapping it to a different
> > pCPU's hardware interrupt file, imsic_vsfile_attach() is called from a
> > later point in the scheduling path (e.g. continue_new_vcpu()).
> Hmm, why does first-time handling need to be this different from the
> handling of a vCPU moving across pCPU-s? The sole difference should be
> "no state to load" vs "load state that was saved on the old pCPU".
Generally I think it could be the same but not all the steps done in 
migration functions aren't needed for new vCPU (despite of the fact they 
aren't harmful). For new vCPU it seems to me it is enough only to attach 
h/w interrupt file to vCPU.
~ Oleksii