[RFC PATCH V2 18/26] X86/vvtd: Enable Interrupt Remapping through GCMD

[Lan Tianyu <tianyu.lan@intel.com>]

From: Chao Gao <chao.gao@intel.com>

Software writes this field to enable/disable interrupt reampping. This patch
emulate IRES field of GCMD.

Signed-off-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
---
 xen/arch/x86/hvm/vvtd.c             | 26 ++++++++++++++++++++++++++
 xen/drivers/passthrough/vtd/iommu.h |  3 ++-
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/hvm/vvtd.c b/xen/arch/x86/hvm/vvtd.c
index be3acd5..10b0cd0 100644
--- a/xen/arch/x86/hvm/vvtd.c
+++ b/xen/arch/x86/hvm/vvtd.c
@@ -278,6 +278,24 @@ static int vvtd_handle_gcmd_qie(struct vvtd *vvtd, uint32_t val)
     return X86EMUL_OKAY;
 }
 
+static int vvtd_handle_gcmd_ire(struct vvtd *vvtd, uint32_t val)
+{
+    VVTD_DEBUG(VVTD_DBG_RW, "Enable Interrupt Remapping.");
+
+    if ( val & DMA_GCMD_IRE )
+    {
+        vvtd->status |= VIOMMU_STATUS_IRQ_REMAPPING_ENABLED;
+        __vvtd_set_bit(vvtd, DMAR_GSTS_REG, DMA_GSTS_IRES_BIT);
+    }
+    else
+    {
+        vvtd->status |= ~VIOMMU_STATUS_IRQ_REMAPPING_ENABLED;
+        __vvtd_clear_bit(vvtd, DMAR_GSTS_REG, DMA_GSTS_IRES_BIT);
+    }
+
+    return X86EMUL_OKAY;
+}
+
 static int vvtd_handle_gcmd_sirtp(struct vvtd *vvtd, uint32_t val)
 {
     uint64_t irta;
@@ -285,6 +303,10 @@ static int vvtd_handle_gcmd_sirtp(struct vvtd *vvtd, uint32_t val)
     if ( !(val & DMA_GCMD_SIRTP) )
         return X86EMUL_OKAY;
 
+    if ( vvtd_irq_remapping_enabled(vvtd) )
+        VVTD_DEBUG(VVTD_DBG_RW, "Update Interrupt Remapping Table when "
+                   "active." );
+
     vvtd_get_reg_quad(vvtd, DMAR_IRTA_REG, irta);
     vvtd->irt = DMA_IRTA_ADDR(irta) >> PAGE_SHIFT;
     vvtd->irt_max_entry = DMA_IRTA_SIZE(irta);
@@ -311,6 +333,10 @@ static int vvtd_write_gcmd(struct vvtd *vvtd, uint32_t val)
         vvtd_handle_gcmd_sirtp(vvtd, val);
     if ( changed & DMA_GCMD_QIE )
         vvtd_handle_gcmd_qie(vvtd, val);
+    if ( changed & DMA_GCMD_IRE )
+        vvtd_handle_gcmd_ire(vvtd, val);
+    if ( changed & ~(DMA_GCMD_QIE | DMA_GCMD_SIRTP | DMA_GCMD_IRE) )
+        gdprintk(XENLOG_INFO, "Only QIE,SIRTP,IRE in GCMD_REG are handled.\n");
 
     return X86EMUL_OKAY;
 }
diff --git a/xen/drivers/passthrough/vtd/iommu.h b/xen/drivers/passthrough/vtd/iommu.h
index 2d60df6..03361c0 100644
--- a/xen/drivers/passthrough/vtd/iommu.h
+++ b/xen/drivers/passthrough/vtd/iommu.h
@@ -195,7 +195,8 @@
 #define DMA_GSTS_WBFS   (((u64)1) << 27)
 #define DMA_GSTS_QIES_BIT       26
 #define DMA_GSTS_QIES           (((u64)1) << DMA_GSTS_QIES_BIT)
-#define DMA_GSTS_IRES   (((u64)1) <<25)
+#define DMA_GSTS_IRES_BIT       25
+#define DMA_GSTS_IRES   (((u64)1) << DMA_GSTS_IRES_BIT)
 #define DMA_GSTS_SIRTPS_BIT     24
 #define DMA_GSTS_SIRTPS (((u64)1) << DMA_GSTS_SIRTPS_BIT)
 #define DMA_GSTS_CFIS   (((u64)1) <<23)
-- 
1.8.3.1


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