Re: [Qemu-devel] [PATCH] intel_iommu: do address space switching when reset

2018-09-06 Thread Peter Xu
On Thu, Sep 06, 2018 at 07:56:49PM -0600, Alex Williamson wrote: > On Fri, 7 Sep 2018 09:00:31 +0800 > Peter Xu wrote: > > > On Thu, Sep 06, 2018 at 12:41:36PM -0600, Alex Williamson wrote: > > > On Thu, 6 Sep 2018 14:53:12 +0800 > > > Peter Xu wrote: > > > > > > > On Wed, Sep 05, 2018 at 08:

Re: [Qemu-devel] [PATCH] intel_iommu: do address space switching when reset

2018-09-06 Thread Alex Williamson
On Fri, 7 Sep 2018 09:00:31 +0800 Peter Xu wrote: > On Thu, Sep 06, 2018 at 12:41:36PM -0600, Alex Williamson wrote: > > On Thu, 6 Sep 2018 14:53:12 +0800 > > Peter Xu wrote: > > > > > On Wed, Sep 05, 2018 at 08:55:50AM -0600, Alex Williamson wrote: > > > > On Wed, 5 Sep 2018 19:31:58 +080

Re: [Qemu-devel] [PATCH] intel_iommu: do address space switching when reset

2018-09-06 Thread Peter Xu
On Thu, Sep 06, 2018 at 12:41:36PM -0600, Alex Williamson wrote: > On Thu, 6 Sep 2018 14:53:12 +0800 > Peter Xu wrote: > > > On Wed, Sep 05, 2018 at 08:55:50AM -0600, Alex Williamson wrote: > > > On Wed, 5 Sep 2018 19:31:58 +0800 > > > Peter Xu wrote: > > > > > > > We will drop all the mappi

Re: [Qemu-devel] [PATCH] intel_iommu: do address space switching when reset

2018-09-06 Thread Alex Williamson
On Thu, 6 Sep 2018 14:53:12 +0800 Peter Xu wrote: > On Wed, Sep 05, 2018 at 08:55:50AM -0600, Alex Williamson wrote: > > On Wed, 5 Sep 2018 19:31:58 +0800 > > Peter Xu wrote: > > > > > We will drop all the mappings when system reset, however we'll still > > > keep the existing memory layouts

Re: [Qemu-devel] [PATCH] intel_iommu: do address space switching when reset

2018-09-05 Thread Peter Xu
On Wed, Sep 05, 2018 at 08:55:50AM -0600, Alex Williamson wrote: > On Wed, 5 Sep 2018 19:31:58 +0800 > Peter Xu wrote: > > > We will drop all the mappings when system reset, however we'll still > > keep the existing memory layouts. That'll be problematic since if IOMMU > > is enabled in the gue

Re: [Qemu-devel] [PATCH] intel_iommu: do address space switching when reset

2018-09-05 Thread Alex Williamson
On Wed, 5 Sep 2018 19:31:58 +0800 Peter Xu wrote: > We will drop all the mappings when system reset, however we'll still > keep the existing memory layouts. That'll be problematic since if IOMMU > is enabled in the guest and then reboot the guest, SeaBIOS will try to > drive a device that with

[Qemu-devel] [PATCH] intel_iommu: do address space switching when reset

2018-09-05 Thread Peter Xu
We will drop all the mappings when system reset, however we'll still keep the existing memory layouts. That'll be problematic since if IOMMU is enabled in the guest and then reboot the guest, SeaBIOS will try to drive a device that with no page mapped there. What we need to do is to rebuild the G