Virtual command registers are used in the guest only, to prevent
vmexit cost, we cache the capability and store it during initialization.

Signed-off-by: Jacob Pan <jacob.jun....@linux.intel.com>
Reviewed-by: Eric Auger <eric.au...@redhat.com>
Reviewed-by: Lu Baolu <baolu...@linux.intel.com>

---
v7 Reviewed by Eric & Baolu
---

Signed-off-by: Jacob Pan <jacob.jun....@linux.intel.com>
---
 drivers/iommu/dmar.c        | 1 +
 include/linux/intel-iommu.h | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 4d6b7b5b37ee..3b36491c8bbb 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -963,6 +963,7 @@ static int map_iommu(struct intel_iommu *iommu, u64 
phys_addr)
                warn_invalid_dmar(phys_addr, " returns all ones");
                goto unmap;
        }
+       iommu->vccap = dmar_readq(iommu->reg + DMAR_VCCAP_REG);
 
        /* the registers might be more than one page */
        map_size = max_t(int, ecap_max_iotlb_offset(iommu->ecap),
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index f775bb825343..e02a96848586 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -194,6 +194,9 @@
 #define ecap_max_handle_mask(e) ((e >> 20) & 0xf)
 #define ecap_sc_support(e)     ((e >> 7) & 0x1) /* Snooping Control */
 
+/* Virtual command interface capability */
+#define vccap_pasid(v)         ((v & DMA_VCS_PAS)) /* PASID allocation */
+
 /* IOTLB_REG */
 #define DMA_TLB_FLUSH_GRANU_OFFSET  60
 #define DMA_TLB_GLOBAL_FLUSH (((u64)1) << 60)
@@ -287,6 +290,7 @@
 
 /* PRS_REG */
 #define DMA_PRS_PPR    ((u32)1)
+#define DMA_VCS_PAS    ((u64)1)
 
 #define IOMMU_WAIT_OP(iommu, offset, op, cond, sts)                    \
 do {                                                                   \
@@ -562,6 +566,7 @@ struct intel_iommu {
        u64             reg_size; /* size of hw register set */
        u64             cap;
        u64             ecap;
+       u64             vccap;
        u32             gcmd; /* Holds TE, EAFL. Don't need SRTP, SFL, WBF */
        raw_spinlock_t  register_lock; /* protect register handling */
        int             seq_id; /* sequence id of the iommu */
-- 
2.7.4

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