intel-iommu: PASID support

This patch introduce ECAP_PASID via "x-pasid-mode". Based on the
existing support for scalable mode, we need to implement the following
missing parts:

1) tag VTDAddressSpace with PASID and support IOMMU/DMA translation
   with PASID
2) tag IOTLB with PASID
3) PASID cache and its flush
4) PASID based IOTLB invalidation

For simplicity PASID cache is not implemented so we can simply
implement the PASID cache flush as a no and leave it to be implemented
in the future. For PASID based IOTLB invalidation, since we haven't
had L1 stage support, the PASID based IOTLB invalidation is not
implemented yet. For PASID based device IOTLB invalidation, it
requires the support for vhost so we forbid enabling device IOTLB when
PASID is enabled now. Those work could be done in the future.

Note that though PASID based IOMMU translation is ready but no device
can issue PASID DMA right now. In this case, PCI_NO_PASID is used as
PASID to identify the address without PASID. vtd_find_add_as() has
been extended to provision address space with PASID which could be
utilized by the future extension of PCI core to allow device model to
use PASID based DMA translation.

This feature would be useful for:

1) prototyping PASID support for devices like virtio
2) future vPASID work
3) future PRS and vSVA work

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20221028061436.30093-5-jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

2 files changed, 8 insertions, 1 deletions

diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
index e49fff2..46d973e 100644
--- a/include/hw/i386/intel_iommu.h
+++ b/include/hw/i386/intel_iommu.h
@@ -97,11 +97,13 @@ struct VTDPASIDEntry {
 struct VTDAddressSpace {
     PCIBus *bus;
     uint8_t devfn;
+    uint32_t pasid;
     AddressSpace as;
     IOMMUMemoryRegion iommu;
     MemoryRegion root;          /* The root container of the device */
     MemoryRegion nodmar;        /* The alias of shared nodmar MR */
     MemoryRegion iommu_ir;      /* Interrupt region: 0xfeeXXXXX */
+    MemoryRegion iommu_ir_fault; /* Interrupt region for catching fault */
     IntelIOMMUState *iommu_state;
     VTDContextCacheEntry context_cache_entry;
     QLIST_ENTRY(VTDAddressSpace) next;
@@ -113,6 +115,7 @@ struct VTDAddressSpace {
 struct VTDIOTLBEntry {
     uint64_t gfn;
     uint16_t domain_id;
+    uint32_t pasid;
     uint64_t slpte;
     uint64_t mask;
     uint8_t access_flags;
@@ -261,6 +264,7 @@ struct IntelIOMMUState {
     uint8_t aw_bits;                /* Host/IOVA address width (in bits) */
     bool dma_drain;                 /* Whether DMA r/w draining enabled */
     bool dma_translation;           /* Whether DMA translation supported */
+    bool pasid;                     /* Whether to support PASID */
 
     /*
      * Protects IOMMU states in general.  Currently it protects the
@@ -272,6 +276,7 @@ struct IntelIOMMUState {
 /* Find the VTD Address space associated with the given bus pointer,
  * create a new one if none exists
  */
-VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn);
+VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus,
+                                 int devfn, unsigned int pasid);
 
 #endif
diff --git a/include/hw/pci/pci_bus.h b/include/hw/pci/pci_bus.h
index eb94e7e..5653175 100644
--- a/include/hw/pci/pci_bus.h
+++ b/include/hw/pci/pci_bus.h
@@ -28,6 +28,8 @@ enum PCIBusFlags {
     PCI_BUS_CXL                                             = 0x0004,
 };
 
+#define PCI_NO_PASID UINT32_MAX
+
 struct PCIBus {
     BusState qbus;
     enum PCIBusFlags flags;