| Message ID | 20231019104551.27870-1-roger.pau@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [for-4.18] iommu: fix quarantine mode command line documentation | expand |
On 19.10.2023 12:45, Roger Pau Monne wrote: > With the addition of per-device quarantine page tables the sink page is now > exclusive for each device, and thus writable. Update the documentation to > reflect the current implementation. > > Fixes: 14dd241aad8a ('IOMMU/x86: use per-device page tables for quarantining') > Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
Hi Jan, Roger, > On Oct 19, 2023, at 18:50, Jan Beulich <jbeulich@suse.com> wrote: > > On 19.10.2023 12:45, Roger Pau Monne wrote: >> With the addition of per-device quarantine page tables the sink page is now >> exclusive for each device, and thus writable. Update the documentation to >> reflect the current implementation. >> >> Fixes: 14dd241aad8a ('IOMMU/x86: use per-device page tables for quarantining') >> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> > > Reviewed-by: Jan Beulich <jbeulich@suse.com> Release-acked-by: Henry Wang <Henry.Wang@arm.com> Kind regards, Henry
diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line.pandoc index 604650aaeeef..9121d8a29404 100644 --- a/docs/misc/xen-command-line.pandoc +++ b/docs/misc/xen-command-line.pandoc @@ -1520,15 +1520,14 @@ boolean (e.g. `iommu=no`) can override this and leave the IOMMUs disabled. should be enabled. Quarantining can be done in two ways: In its basic form, all in-flight DMA will simply be forced to encounter IOMMU faults. Since there are systems where doing so can cause host lockup, - an alternative form is available where writes to memory will be made - fault, but reads will be directed to a scratch page. The implication - here is that such reads will go unnoticed, i.e. an admin may not - become aware of the underlying problem. + an alternative form is available where accesses to memory will be directed + to a scratch page. The implication here is that such accesses will go + unnoticed, i.e. an admin may not become aware of the underlying problem. Therefore, if this option is set to true (the default), Xen always quarantines such devices; they must be explicitly assigned back to Dom0 before they can be used there again. If set to "scratch-page", still - active DMA reads will additionally be directed to a "scratch" page. If + active DMA operations will additionally be directed to a "scratch" page. If set to false, Xen will only quarantine devices the toolstack has arranged for getting quarantined, and only in the "basic" form.
With the addition of per-device quarantine page tables the sink page is now exclusive for each device, and thus writable. Update the documentation to reflect the current implementation. Fixes: 14dd241aad8a ('IOMMU/x86: use per-device page tables for quarantining') Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> --- docs/misc/xen-command-line.pandoc | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)