[PATCH v1 07/22] intel_iommu: add set/unset_iommu_context callback

Liu Yi L
2020-03-22T12:30:48Z

This patch adds set/unset_iommu_context() impelementation in Intel
vIOMMU. For Intel platform, pass-through modules (e.g. VFIO) could
set HostIOMMUContext to Intel vIOMMU emulator.

Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Yi Sun <yi.y.sun@linux.intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
---
hw/i386/intel_iommu.c | 70 +++++++++++++++++++++++++++++++++++++++----
include/hw/i386/intel_iommu.h | 17 +++++++++--
2 files changed, 80 insertions(+), 7 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 4b22910..8d9204f 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -3354,23 +3354,35 @@ static const MemoryRegionOps vtd_mem_ir_ops = {
},
};

-VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
+/**
+ * Fetch a VTDBus instance for given PCIBus. If no existing instance,
+ * allocate one.
+ */
+static VTDBus *vtd_find_add_bus(IntelIOMMUState *s, PCIBus *bus)
{
uintptr_t key = (uintptr_t)bus;
VTDBus *vtd_bus = g_hash_table_lookup(s->vtd_as_by_busptr, &key);
- VTDAddressSpace *vtd_dev_as;
- char name[128];

if (!vtd_bus) {
uintptr_t *new_key = g_malloc(sizeof(*new_key));
*new_key = (uintptr_t)bus;
/* No corresponding free() */
- vtd_bus = g_malloc0(sizeof(VTDBus) + sizeof(VTDAddressSpace *) * \
- PCI_DEVFN_MAX);
+ vtd_bus = g_malloc0(sizeof(VTDBus) + PCI_DEVFN_MAX * \
+ (sizeof(VTDAddressSpace *) + \
+ sizeof(VTDHostIOMMUContext *)));
vtd_bus->bus = bus;
g_hash_table_insert(s->vtd_as_by_busptr, new_key, vtd_bus);
}
+ return vtd_bus;
+}
+
+VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
+{
+ VTDBus *vtd_bus;
+ VTDAddressSpace *vtd_dev_as;
+ char name[128];

+ vtd_bus = vtd_find_add_bus(s, bus);
vtd_dev_as = vtd_bus->dev_as[devfn];

if (!vtd_dev_as) {
@@ -3436,6 +3448,52 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
return vtd_dev_as;
}

+static int vtd_dev_set_iommu_context(PCIBus *bus, void *opaque,
+ int devfn,
+ HostIOMMUContext *host_icx)
+{
+ IntelIOMMUState *s = opaque;
+ VTDBus *vtd_bus;
+ VTDHostIOMMUContext *vtd_dev_icx;
+
+ assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
+
+ vtd_bus = vtd_find_add_bus(s, bus);
+
+ vtd_iommu_lock(s);
+ vtd_dev_icx = vtd_bus->dev_icx[devfn];
+
+ if (!vtd_dev_icx) {
+ vtd_bus->dev_icx[devfn] = vtd_dev_icx =
+ g_malloc0(sizeof(VTDHostIOMMUContext));
+ vtd_dev_icx->vtd_bus = vtd_bus;
+ vtd_dev_icx->devfn = (uint8_t)devfn;
+ vtd_dev_icx->iommu_state = s;
+ vtd_dev_icx->host_icx = host_icx;
+ }
+ vtd_iommu_unlock(s);
+
+ return 0;
+}
+
+static void vtd_dev_unset_iommu_context(PCIBus *bus, void *opaque, int devfn)
+{
+ IntelIOMMUState *s = opaque;
+ VTDBus *vtd_bus;
+ VTDHostIOMMUContext *vtd_dev_icx;
+
+ assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
+
+ vtd_bus = vtd_find_add_bus(s, bus);
+
+ vtd_iommu_lock(s);
+
+ vtd_dev_icx = vtd_bus->dev_icx[devfn];
+ g_free(vtd_dev_icx);
+
+ vtd_iommu_unlock(s);
+}
+
static uint64_t get_naturally_aligned_size(uint64_t start,
uint64_t size, int gaw)
{
@@ -3731,6 +3789,8 @@ static AddressSpace *vtd_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)

static PCIIOMMUOps vtd_iommu_ops = {
.get_address_space = vtd_host_dma_iommu,
+ .set_iommu_context = vtd_dev_set_iommu_context,
+ .unset_iommu_context = vtd_dev_unset_iommu_context,
};

static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
index 3870052..9b4fc0a 100644
--- a/include/hw/i386/intel_iommu.h
+++ b/include/hw/i386/intel_iommu.h
@@ -64,6 +64,7 @@ typedef union VTD_IR_TableEntry VTD_IR_TableEntry;
typedef union VTD_IR_MSIAddress VTD_IR_MSIAddress;
typedef struct VTDPASIDDirEntry VTDPASIDDirEntry;
typedef struct VTDPASIDEntry VTDPASIDEntry;
+typedef struct VTDHostIOMMUContext VTDHostIOMMUContext;

/* Context-Entry */
struct VTDContextEntry {
@@ -112,10 +113,20 @@ struct VTDAddressSpace {
IOVATree *iova_tree; /* Traces mapped IOVA ranges */
};

+struct VTDHostIOMMUContext {
+ VTDBus *vtd_bus;
+ uint8_t devfn;
+ HostIOMMUContext *host_icx;
+ IntelIOMMUState *iommu_state;
+};
+
struct VTDBus {
- PCIBus* bus; /* A reference to the bus to provide translation for */
+ /* A reference to the bus to provide translation for */
+ PCIBus *bus;
/* A table of VTDAddressSpace objects indexed by devfn */
- VTDAddressSpace *dev_as[];
+ VTDAddressSpace *dev_as[PCI_DEVFN_MAX];
+ /* A table of VTDHostIOMMUContext objects indexed by devfn */
+ VTDHostIOMMUContext *dev_icx[PCI_DEVFN_MAX];
};

struct VTDIOTLBEntry {
@@ -271,6 +282,8 @@ struct IntelIOMMUState {
/*
* Protects IOMMU states in general. Currently it protects the
* per-IOMMU IOTLB cache, and context entry cache in VTDAddressSpace.
+ * Protect the update/usage of HostIOMMUContext pointer cached in
+ * VTDBus->dev_icx array as array elements may be updated by hotplug
*/
QemuMutex iommu_lock;
};
--
2.7.4