On Mon, Jan 16, 2017 at 04:01:00PM +0800, Jason Wang wrote:
On 2017年01月16日 15:50, Peter Xu wrote:
On Mon, Jan 16, 2017 at 02:20:31PM +0800, Jason Wang wrote:
[...]
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index fd75112..2596f11 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -1343,9 +1343,49 @@ static void vtd_handle_gcmd_sirtp(IntelIOMMUState *s)
vtd_set_clear_mask_long(s, DMAR_GSTS_REG, 0, VTD_GSTS_IRTPS);
}
+static void vtd_switch_address_space(VTDAddressSpace *as, bool iommu_enabled)
Looks like you can check s->dmar_enabled here?
Yes, we need to check old state in case we don't need a switch at all.
Actually I checked it...
I mean is there a chance that iommu_enabled( better name should be
dmar_enabled) is not equal to s->dmar_enabled? Looks not.
vtd_handle_gcmd_te() did:
...
if (en) {
s->dmar_enabled = true;
/* Ok - report back to driver */
vtd_set_clear_mask_long(s, DMAR_GSTS_REG, 0, VTD_GSTS_TES);
} else {
s->dmar_enabled = false;
...
You can vtd_switch_address_space_all(s, en) after this which will call this
function. And another caller like you've pointed out has already call this
through s->dmar_enabled. So en here is always s->dmar_enalbed?
Hmm, yes...
(I would still prefer keeping this parameter for readablility.
Though, I prefer your suggestion to rename it to dmar_enabled)
-- peterx