Re: [PATCH for-4.15] xen/vgic: Implement write to ISPENDR in vGICv{2, 3}

2021-02-25 Thread Stefano Stabellini
On Thu, 25 Feb 2021, Julien Grall wrote: > On 22/02/2021 13:45, Bertrand Marquis wrote: > > Hi Julien, > > > > > On 20 Feb 2021, at 14:04, Julien Grall wrote: > > > > > > From: Julien Grall > > > > > > Currently, Xen will send a data abort to a guest trying to write to the > > > ISPENDR. > > >

Re: [PATCH for-4.15] xen/vgic: Implement write to ISPENDR in vGICv{2, 3}

2021-02-25 Thread Julien Grall
On 22/02/2021 13:45, Bertrand Marquis wrote: Hi Julien, On 20 Feb 2021, at 14:04, Julien Grall wrote: From: Julien Grall Currently, Xen will send a data abort to a guest trying to write to the ISPENDR. Unfortunately, recent version of Linux (at least 5.9+) will start writing to the regi

Re: [PATCH for-4.15] xen/vgic: Implement write to ISPENDR in vGICv{2, 3}

2021-02-23 Thread Stefano Stabellini
On Tue, 23 Feb 2021, Julien Grall wrote: > Hi Stefano, > > On 23/02/2021 01:24, Stefano Stabellini wrote: > > On Mon, 22 Feb 2021, Bertrand Marquis wrote: > > > > On 20 Feb 2021, at 14:04, Julien Grall wrote: > > The consequence of this patch is that a guest can cause vcpu_unblock(v), > > hence v

Re: [PATCH for-4.15] xen/vgic: Implement write to ISPENDR in vGICv{2, 3}

2021-02-23 Thread Julien Grall
Hi Stefano, On 23/02/2021 01:24, Stefano Stabellini wrote: On Mon, 22 Feb 2021, Bertrand Marquis wrote: On 20 Feb 2021, at 14:04, Julien Grall wrote: The consequence of this patch is that a guest can cause vcpu_unblock(v), hence vcpu_wake(v), to be called for its own vcpu, which basically alw

Re: [PATCH for-4.15] xen/vgic: Implement write to ISPENDR in vGICv{2, 3}

2021-02-22 Thread Stefano Stabellini
On Mon, 22 Feb 2021, Bertrand Marquis wrote: > Hi Julien, > > > On 20 Feb 2021, at 14:04, Julien Grall wrote: > > > > From: Julien Grall > > > > Currently, Xen will send a data abort to a guest trying to write to the > > ISPENDR. > > > > Unfortunately, recent version of Linux (at least 5.9+)

Re: [PATCH for-4.15] xen/vgic: Implement write to ISPENDR in vGICv{2, 3}

2021-02-22 Thread Bertrand Marquis
Hi Julien, > On 20 Feb 2021, at 14:04, Julien Grall wrote: > > From: Julien Grall > > Currently, Xen will send a data abort to a guest trying to write to the > ISPENDR. > > Unfortunately, recent version of Linux (at least 5.9+) will start > writing to the register if the interrupt needs to be

Re: [PATCH for-4.15] xen/vgic: Implement write to ISPENDR in vGICv{2, 3}

2021-02-22 Thread Ian Jackson
Julien Grall writes ("[PATCH for-4.15] xen/vgic: Implement write to ISPENDR in vGICv{2, 3}"): > From: Julien Grall > > Currently, Xen will send a data abort to a guest trying to write to the > ISPENDR. > > Unfortunately, recent version of Linux (at least 5.9+)

[PATCH for-4.15] xen/vgic: Implement write to ISPENDR in vGICv{2, 3}

2021-02-20 Thread Julien Grall
From: Julien Grall Currently, Xen will send a data abort to a guest trying to write to the ISPENDR. Unfortunately, recent version of Linux (at least 5.9+) will start writing to the register if the interrupt needs to be re-triggered (see the callback irq_retrigger). This can happen when a driver