[Xen-changelog] [xen staging] x86/vtd: Don't include control register state in the table pointers

[patchbot@xxxxxxx]

commit a9a05aeee10a5a3763a41305a9f38112dd1fcc82
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Tue Nov 27 17:21:17 2018 +0000
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Tue Mar 12 13:57:13 2019 +0000

    x86/vtd: Don't include control register state in the table pointers
    
    iremap_maddr and qinval_maddr point to the base of a block of contiguous 
RAM,
    allocated by the driver, holding the Interrupt Remapping table, and the 
Queued
    Invalidation ring.
    
    Despite their name, they are actually the values of the hardware register,
    including control metadata in the lower 12 bits.  While uses of these fields
    do appear to correctly shift out the metadata, this is very subtle behaviour
    and confusing to follow.
    
    Nothing uses the metadata, so make the fields actually point at the base of
    the relevant tables.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Kevin Tian <kevin.tian@xxxxxxxxx>
---
 xen/drivers/passthrough/vtd/intremap.c | 13 +++++++------
 xen/drivers/passthrough/vtd/qinval.c   |  8 ++++----
 xen/drivers/passthrough/vtd/utils.c    |  5 +++--
 3 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/xen/drivers/passthrough/vtd/intremap.c 
b/xen/drivers/passthrough/vtd/intremap.c
index 838268d772..1d19856091 100644
--- a/xen/drivers/passthrough/vtd/intremap.c
+++ b/xen/drivers/passthrough/vtd/intremap.c
@@ -802,14 +802,15 @@ int enable_intremap(struct iommu *iommu, int eim)
         ir_ctrl->iremap_num = 0;
     }
 
-    /* set extended interrupt mode bit */
-    ir_ctrl->iremap_maddr |= eim ? IRTA_EIME : 0;
-
     spin_lock_irqsave(&iommu->register_lock, flags);
 
-    /* set size of the interrupt remapping table */
-    ir_ctrl->iremap_maddr |= IRTA_REG_TABLE_SIZE;
-    dmar_writeq(iommu->reg, DMAR_IRTA_REG, ir_ctrl->iremap_maddr);
+    /*
+     * Set size of the interrupt remapping table and optionally Extended
+     * Interrupt Mode.
+     */
+    dmar_writeq(iommu->reg, DMAR_IRTA_REG,
+                ir_ctrl->iremap_maddr | IRTA_REG_TABLE_SIZE |
+                (eim ? IRTA_EIME : 0));
 
     /* set SIRTP */
     gcmd = dmar_readl(iommu->reg, DMAR_GSTS_REG);
diff --git a/xen/drivers/passthrough/vtd/qinval.c 
b/xen/drivers/passthrough/vtd/qinval.c
index e95dc54a8d..01447cf9a8 100644
--- a/xen/drivers/passthrough/vtd/qinval.c
+++ b/xen/drivers/passthrough/vtd/qinval.c
@@ -428,6 +428,8 @@ int enable_qinval(struct iommu *iommu)
     flush->context = flush_context_qi;
     flush->iotlb = flush_iotlb_qi;
 
+    spin_lock_irqsave(&iommu->register_lock, flags);
+
     /* Setup Invalidation Queue Address(IQA) register with the
      * address of the page we just allocated.  QS field at
      * bits[2:0] to indicate size of queue is one 4KB page.
@@ -435,10 +437,8 @@ int enable_qinval(struct iommu *iommu)
      * registers are automatically reset to 0 with write
      * to IQA register.
      */
-    qi_ctrl->qinval_maddr |= QINVAL_PAGE_ORDER;
-
-    spin_lock_irqsave(&iommu->register_lock, flags);
-    dmar_writeq(iommu->reg, DMAR_IQA_REG, qi_ctrl->qinval_maddr);
+    dmar_writeq(iommu->reg, DMAR_IQA_REG,
+                qi_ctrl->qinval_maddr | QINVAL_PAGE_ORDER);
 
     dmar_writeq(iommu->reg, DMAR_IQT_REG, 0);
 
diff --git a/xen/drivers/passthrough/vtd/utils.c 
b/xen/drivers/passthrough/vtd/utils.c
index 85e0f41d85..94a6e4eec9 100644
--- a/xen/drivers/passthrough/vtd/utils.c
+++ b/xen/drivers/passthrough/vtd/utils.c
@@ -204,8 +204,9 @@ void vtd_dump_iommu_info(unsigned char key)
         if ( status & DMA_GSTS_IRES )
         {
             /* Dump interrupt remapping table. */
-            u64 iremap_maddr = dmar_readq(iommu->reg, DMAR_IRTA_REG);
-            int nr_entry = 1 << ((iremap_maddr & 0xF) + 1);
+            uint64_t irta = dmar_readq(iommu->reg, DMAR_IRTA_REG);
+            uint64_t iremap_maddr = irta & PAGE_MASK;
+            unsigned int nr_entry = 1 << ((irta & 0xF) + 1);
             struct iremap_entry *iremap_entries = NULL;
             int print_cnt = 0;
 
--
generated by git-patchbot for /home/xen/git/xen.git#staging

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