diff options
| author | Lu Baolu <baolu.lu@linux.intel.com> | 2019-03-20 09:58:33 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-20 09:15:03 +0200 |
| commit | 486d82206c3bfd21f9ea4a3b6bca8ca7c9060285 (patch) | |
| tree | 41c6bbc56c20297174dc876e9cd22ec18b3ef179 | |
| parent | 19525f7b031f1018a74ed3760b81a4f0f3940fa3 (diff) | |
iommu/vt-d: Check capability before disabling protected memory
[ Upstream commit 5bb71fc790a88d063507dc5d445ab8b14e845591 ]
The spec states in 10.4.16 that the Protected Memory Enable
Register should be treated as read-only for implementations
not supporting protected memory regions (PLMR and PHMR fields
reported as Clear in the Capability register).
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: mark gross <mgross@intel.com>
Suggested-by: Ashok Raj <ashok.raj@intel.com>
Fixes: f8bab73515ca5 ("intel-iommu: PMEN support")
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/iommu/intel-iommu.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 802ba7b16e09..fe935293fa7b 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1646,6 +1646,9 @@ static void iommu_disable_protect_mem_regions(struct intel_iommu *iommu) u32 pmen; unsigned long flags; + if (!cap_plmr(iommu->cap) && !cap_phmr(iommu->cap)) + return; + raw_spin_lock_irqsave(&iommu->register_lock, flags); pmen = readl(iommu->reg + DMAR_PMEN_REG); pmen &= ~DMA_PMEN_EPM; |