| Message ID | 20190722154552.73458-1-roger.pau@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | x86/iommu: add comment regarding setting of need_sync | expand |
On 22.07.2019 17:45, Roger Pau Monne wrote: > Clarify why relaxed hardware domains don't need iommu page-table > syncing. > > Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Acked-by: Jan Beulich <jbeulich@suse.com>
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c index 79ec6719f5..f8c3bf53bd 100644 --- a/xen/drivers/passthrough/iommu.c +++ b/xen/drivers/passthrough/iommu.c @@ -185,6 +185,10 @@ void __hwdom_init iommu_hwdom_init(struct domain *d) register_keyhandler('o', &iommu_dump_p2m_table, "dump iommu p2m table", 0); hd->status = IOMMU_STATUS_initializing; + /* + * NB: relaxed hw domains don't need sync because all ram is already + * mapped in the iommu page tables. + */ hd->need_sync = iommu_hwdom_strict && !iommu_use_hap_pt(d); if ( need_iommu_pt_sync(d) ) {
Clarify why relaxed hardware domains don't need iommu page-table syncing. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> --- Cc: Jan Beulich <jbeulich@suse.com> --- xen/drivers/passthrough/iommu.c | 4 ++++ 1 file changed, 4 insertions(+)